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Skin Cancers

While not all cases of non-melanoma skin cancer (NMSC) are reported, it is the most commonly diagnosed form of Cancer in Canada

Educational Video Playlist Regarding the Types of NMSC in English and French

Webinar: Melanoma and non-Melanoma Skin Cancers with Dermatologist Dr. Tom Salopek

The two most commonly diagnosed types of NMSC are Basal Cell Carcinoma (BCC) and Squamous Cell Carcinoma (SCC). Merkel Cell Carcinoma (MCC) is a rare form of NMSC.

Learn more about each skin cancer type below .

Basal Cell Carcinoma

Basal Cell Carcinoma (BCC)

Basal Cell Carcinoma represents approximately 80% of all cases of non-melanoma skin cancer (NMSC), and predominantly affects the Caucasian and older population. BCC originates in the basal layer of the epidermis, with studies so far suggesting origins primarily being from stem cells (Peterson SC, et al. Cell stem cell 16.4 (2015): 400-412). Basal cell carcinoma (BCC) is the most common form of skin cancer in Canada and generally arises from cumulative lifetime ultraviolet (UV) exposure and damage to the skin, and as such is often found on areas of the skin most exposed to sunlight.

BCC can develop anywhere, though it is most commonly found in sun-exposed areas. It is possible to have more than one BCC. It is rare, but possible, for BCC to spread, or metastasize – it is estimated that ~1% of BCCs can be classified as advanced BCC (Mohan SV & Chang ALS. Curr Derm Rep 2014;3:40–5).

Appearance

Many BCCs are small, elevated bumps or skin sores, red, pink, or pearly white in color. Some may crust, itch, or bleed and are often mistaken for “pimples” that have been present for several weeks and aren’t healing.

BCCs may appear as:

An open sore that bleeds, oozes, or crusts and remains open for several weeks
A red, raised patch or irritated area that may crust or itch but generally doesn’t hurt
A shiny pink, red, pearly white, or translucent bump
A pink growth with a raised border and crusted central indentation.
A scar-like, white, yellow, or waxy area, often with a poorly defined edge
A darker-colored (pigmented), pearly, translucent skin growth (more common in skin of color than in light skin)
An ulcerated lesion, which means a portion of the skin that covers the growth is not healing

The top layer of skin, the epidermis, is predominantly composed of basal cells, squamous cells, and melanocytes. Basal cells are small and round and have a critical role in maintaining the skin tissue; they are located at the bottom portion of the epidermis and are often referred to as “basement cells” for their foundational position and function. Basal cells are constantly replicating to produce new skin cells which push to the skin’s surface to renew the skin layer as dying cells shed off. This process is essential for skin maintenance, damage repair and wound healing. When basal cells grow out of control and become cancerous, they develop into BCC. This type of skin cancer generally grows relatively slowly and is usually very treatable when addressed early on. Prompt diagnosis and removal can prevent expansion as well as skin disfigurement. Although it is rare for BCC to spread outside of the skin, it is possible and thus prompt attention is always warranted.

Sources: AIM at Skin Cancer, "Basal Cell Carcinoma." [link: https://aimatskincancer.org/basal-cell-carcinoma/]

AIM at Skin Cancer, "BCC Images." [link: https://aimatskincancer.org/basal-cell-carcinoma/basal-cell-carcinoma-images/]

Mohan SV, Chang AL. Advanced Basal Cell Carcinoma: Epidemiology and Therapeutic Innovations. Curr Dermatol Rep. 2014 Feb 9;3(1):40-45. doi: 10.1007/s13671-014-0069-y. PMID: 24587976; PMCID: PMC3931971.

Peterson SC, Eberl M, Vagnozzi AN, Belkadi A, Veniaminova NA, Verhaegen ME, Bichakjian CK, Ward NL, Dlugosz AA, Wong SY. Basal cell carcinoma preferentially arises from stem cells within hair follicle and mechanosensory niches. Cell Stem Cell. 2015 Apr 2;16(4):400-12. doi: 10.1016/j.stem.2015.02.006. PMID: 25842978; PMCID: PMC4387376.

Unlike many types of cancers with a numerical staging system, basal cell carcinoma (BCC) follows a unique categorization based on the chance that cancer might return, also referred to as its risk for recurrence. This unique staging system puts most BCCs into one of two groups: low risk or high risk. Treatment options are then based on each category to prevent recurrence. A third category, Advanced BCC, describes tumours that require more complicated treatment procedures rather than a standard surgical removal to eradicate the disease. Advanced BCCs have spread beyond the immediate area and may require additional measures, including imaging, to determine the extent of the cancer.

Low-Risk Basal Cell Carcinoma

This type of BCC is based on a lower relative risk of recurrence. These low-risk tumours are usually located on the trunk of the body or extremities and are less than two centimetres (cm) in size. The borders of low-risk BCC have well-defined edges. Patients diagnosed with low-risk BCC are not immunosuppressed and have not experienced prior medical radiation therapy in the area. The pathology report may often describe this type of BCC as nodular or superficial.

High-Risk Basal Cell Carcinoma

High-risk BCC has a higher relative risk of recurrence or returning. All recurrent tumors are automatically labeled high-risk. If a BCC is located on the trunk or extremities, high-risk indicates that the size is greater than two cm in those specific regions. Alternatively, a high-risk BCC could be any size when it is located on the head, neck, or feet, or in the pretibial (shin) or anogenital (anus and genital) areas. In addition, the borders of high-risk BCC are poorly defined. Patients diagnosed with high-risk BCC may be immunosuppressed or have experienced prior medical radiation therapy to the area. The pathology report will often describe this type of BCC as having an aggressive growth pattern. Pathological reporting may also describe these high-risk BCCs as micronodular, infiltrative, sclerosing, or morpheaform (desmoplastic).

Advanced Basal Cell Carcinoma

Advanced BCC is less common (less than 10% of cases), represents extensive disease, such as bone involvement, perineural invasion, or deep soft tissue involvement, and requires more treatment methods to control, such as a combination of surgery, radiation, chemotherapy, and/or immunotherapy. It has spread around the area, to lymph nodes, or to a distant location in the body. Imaging techniques such as a magnetic resonance imaging (MRI) or computed tomography (CT) scan will indicate the extent of disease spread. These tumors have invasive growth, are relatively larger, and are sometimes located in hard-to-treat areas.

BCC can be classified into indolent or aggressive subtypes.

Sources: AIM at Skin Cancer, "How BCC is Staged." [link: https://aimatskincancer.org/basal-cell-carcinoma/bcc-staging-a-practical-description/]

Marzuka AG & Book SE. "Basal Cell Carcinoma: Pathogenesis, Epidemiology, Clinical Features, Diagnosis, Histopathology, and Management." The Yale journal of biology and medicine 88.2 (2015): 167-179.

The ultimate goal of treating basal cell carcinoma (BCC) is to completely remove the tumor with minimal impact on the surrounding area. Surgical techniques that remove BCCs are the most effective method of achieving cure. The most significant concerns with surgical treatment include tissue destruction and potential skin disfiguration that may result from removing the cancer along with healthy tissue on the edges of the cancer. You will have a customized treatment plan depending on your tumour’s location and classification.

Generally, BCCs have an extremely low rate of metastasis, less than 0.1%, and excellent prognosis. For example, the 5-year survival rate for most localized BCCs is close to 100%. Your healthcare provider will plan an appropriate treatment strategy after receiving the pathology report with details about your BCC.

Treatment Options for Basal Cell Carcinoma

Below are descriptions of treatments approved and available for BCC. It is important to note that not all of the treatment options described will apply to every situation. Your healthcare provider will determine which treatments apply to your BCC.

Curettage and Electrodesiccation: For curettage, the clinician scrapes the cancer from the skin with a sharp, looped tool called a curette, then immediately cauterizes the site. Electrodessication, the second step, prevents bleeding at the site without using sutures and burns off residual cancer cells. The wounded site will then be covered with gauze and heals with time. This procedure is a technique effective for low-risk SCSC. Areas with hair growth are unsuitable for this technique due to the potential for inadequate tumor removal and the subsequent risk of spreading.

Shave Excision: In this technique, the epidermal or dermal lesion is removed by sharp horizontal slicing of the skin. The area is numbed with local anesthesia before removing the lesion with a scalpel or electrosurgical loop. Shave excision is recommended for low-risk BCCs detected on the trunk or other extremities. Layers of fat, subcutaneous tissue and deeper tissue are not removed in this technique. It is not suitable for pigmented tumours, cysts, or deep areas of concern. It may also leave a noticeable white scar. After removing the tissue, the sample is sent to a laboratory for examination, where it will be assessed to make sure all the cancer has been removed along the margins of the tumour. On your pathology report, the terms negative, clean, not involved, or clear margins indicate that the tumour has been adequately removed, and is surrounded by normal tissue. If the areas around the tumour do not show healthy cells, you may need to have further excision during another appointment to obtain clear margins.

Mohs Micrographic Surgery: Mohs surgery is the preferred treatment option for people with SCSC because it allows clinicians to achieve a complete removal of all cancer cells observed. Mohs improves the outcomes of removing all of the tumor cells present because the process requires a continuous reexamination of the tissue. Although it is a superior technique, it requires a certified specialist, and it is not appropriate in all cases. Mohs surgery involves removing thin layers of skin one layer at a time and examining each layer under a microscope to determine if any cancer remains. Mohs incorporates a process by which the surgically removed tissue is carefully mapped, color-coded, and microscopically examined. Mapping allows the surgeon to pinpoint the location of the cells on the image back to the skin site. The mapped tissue edges and undersurface are then examined under a microscope to determine whether these areas contain normal or cancer cells. If cancer cells appear, the map specifies the region requiring additional tissue removal. Mohs surgery is complete once the tissue edges and undersurface are absent of cancer cells. Potential side effects from surgery include bleeding, adverse reactions to medications, or difficulty closing the wound, sensory nerve damage, lymphedema, and disfigurement.

Radiation Therapy: Radiation involves concentrating a beam of energy on the tumour. The intense radiation will cause massive damage inside the cancer cells, which will lead to their death. This type of therapy is administered by a radiation specialist at a hospital or treatment centre and may last six or more weeks. Radiation therapy schedules vary among patients, and treatment could occur daily or two to four treatments per week, depending on each case. Caution is warranted when using this treatment because it increases the risk of developing secondary skin cancer within the radiation field. Side effects include poor cosmetic consequences, such as skin pigmentation changes, widening of blood vessels, non-healing ulcers, tissue death, and scarring. If positive margins with tumour cells are detected following surgery, radiation therapy may be recommended as “adjuvant” therapy (meaning an additional or supplement) because it improves the outcome of treatment. A radiation oncologist will determine appropriate options for radiation therapy in each case.

Cryotherapy: This technique removes a BCC by spraying or holding it in contact with liquid nitrogen, a freezing liquid, for 30-60 seconds. The process may be repeated after a pause for thawing. Liquid nitrogen is -320 °F, which is sufficiently cold to damage normal human tissue. With this technique, it is used to freeze and kill the tumour. This rapid technique can be used instead of surgery to remove small BCCs. Patients with small, low-risk, or superficial BCCs may be eligible for cryotherapy.

Photodynamic Therapy: In the first part of this technique, a medication that will later sensitize the cancer cells to light is prescribed. Examples of this medicine include 5-aminolevulinic acid and porfimer sodium. It takes a day or two for the cancer cells to absorb the light-sensitizing medicine. Then, a light with a specific wavelength of energy is focused at the BCC. This process creates toxic free oxygen radicals inside the cancer cells, which kills them. Superficial tumours (those that are small and/or not deep) may be ideal for this therapy. Light cannot completely penetrate deep or large tumours, which makes photodynamic therapy inappropriate for high-risk or advanced BCCs.

Topical Medications Applied to the Skin

In patients with low-risk BCC or superficial BCC or when a patient has numerous BCCs within a specific region, two medications can be used on the skin: 5-fluorouracil and imiquimod. These topical medications are also alternative options for patients who cannot have surgery or radiation therapy.

Topical 5-fluorouracil is a non-invasive and non-disfiguring method of killing the skin cancer cells. The topical solution is absorbed by the cancer cells, which mistake 5-fluorouracil for a metabolite they require to assemble DNA. The cancer cells cannot use 5-fluorouracil to make DNA, and will die due to missing this critical component. It also prevents the cell from manufacturing required DNA components.
Imiquimod is a drug that activates the immune system. For BCC it is prescribed as a topical cream. By generating an immune system reaction at skin sites where it is applied externally, imiquimod results in the death of cancer cells. Application may be several times per week for up to six weeks, depending on the case. Some applications of imiquimod may last longer. Side effects may include a rash, burning, or pain at the application site.

Medications for Advanced Basal Cell Carcinoma

Three medications are approved for specific cases of advanced BCC when locally advanced, nodal, and/or metastatic. Two medicines, vismodegib (Erivedge) and sonidegib (Odomzo), come in pill form and are targeted inhibitors of BCC growth. These drugs are sometimes referred to as hedgehog inhibitors. Another medication, cemiplimab (Libtayo), is administered through an intravenous infusion designed to activate the immune system.

Vismodegib (Erivedge) capsules are oral medications indicated for treating adults with metastatic BCC, or locally advanced BCC that has recurred following surgery, or adults who are not candidates for surgery and who are not candidates for radiation. This drug stops growth in BCC cells. The most common side effects reported by people taking this medication are constipation, decreased appetite, diarrhea, distortion of taste, fatigue, hair loss, joint stiffness, muscle spasms, nausea, vomiting, and weight loss. Severe birth defects or embryonic death are a warning that accompanies this medication; Vismodegib cannot be used while pregnant or lactating, and all measures to prevent pregnancy must be strictly followed.
Sonidegib (Odomzo) capsules are oral medications indicated for treating adult patients with locally advanced BCC that has recurred following surgery or radiation therapy or those who are not candidates for surgery or radiation therapy. This drug is a targeted medication that stops growth in BCC cells. The most common side effects reported by individuals taking this medication are abdominal pain, decreased appetite, decreased weight, diarrhea, distortion of taste, fatigue, hair loss, headaches, itching, muscle pain, muscle spasms, nausea, and vomiting; severe birth defects or embryonic death are a warning that accompanies this medication. It cannot be used while pregnant or lactating, and all measures to prevent pregnancy must be strictly followed.
Cemiplimab (Libtayo) is an intravenous medication indicated for the treatment of patients with locally advanced BCC or metastatic BCC who have been previously treated with vismodegib or sonidegib, or patients for whom those drugs were not appropriate. Cemiplimab is a drug designed to generate an immune system reaction to the tumour cells. For certain patients with advanced BCC, it may be the recommended treatment option. If this medication is taken alone, the most common side effects include rash, itching, diarrhea, fatigue, muscle/joint pain, and/or gland dysfunction; warnings that accompany this medication include the possibility of severe, potentially life-threatening inflammatory reactions, a reaction during the infusion, and embryo toxicity. Cemiplimab cannot be used while pregnant or lactating, and all measures to prevent pregnancy must be strictly followed.

Clinical Trials

Depending on your SCSC type, a clinical trial may open for enrollment and appropriate to consider. Clinical trials are experimental research studies that test a new approach or therapy under the guidance of clinicians and a medical review board. These trials are entirely optional for patients. If current and approved treatments are not effectively treating your cancer, clinical trial options may be worthwhile to investigate.

Sources: AIM at Skin Cancer, "How BCC is Treated." [link: https://aimatskincancer.org/basal-cell-carcinoma/bcc-treating-treatment-options/]

AIM at Skin Cancer, "Side Effects of Treatment - BCC." [link: https://aimatskincancer.org/basal-cell-carcinoma/side-effects-of-treatment-bcc/]

The following lifestyle and occupational hazards have been recognized as risk factors for Basal Cell Carcinoma:

Excessive and unprotected exposure to ultraviolet (UV) radiation from outdoor sunshine or indoor tanning lamps
A history of skin burns, trauma, or chronic inflammation
Immunocompromised people or those who have undergone organ transplants
People with lighter-coloured skin who burn and freckle more easily (though people with all complexions are vulnerable to skin cancer
Rare genetic mutations (albinism, xeroderma pigmentosum)
Exposure to carcinogenic agents such as arsenic, coal tar, and others that increase sensitivity to the sun

Diagnosis Procedure

If you or your health care provider suspects you have squamous cell skin cancer (SCSC), you will often be referred to a dermatologist, who will likely take a medical history, perform a physical examination, examine any areas of concern, and decide whether a skin biopsy is warranted. A biopsy is the excision of a small amount of tissue from the lesion for pathology; the area will be numbed to prevent pain.

If a diagnosis of SCSC is made, a complete head-to-toe skin examination to look for other suspicious spots is usually recommended in order to find and remove other lesions. Additional biopsies might be necessary. For SCSC, precancerous lesions include actinic keratoses. People who are diagnosed with SCSC also have a high risk of having additional skin cancers at different skin sites, such as melanoma and/or basal cell carcinoma.

Sources: AIM at Skin Cancer. "BCC Risk Factors." [link: https://aimatskincancer.org/basal-cell-carcinoma/bcc-risk-factors/]

AIM at Skin Cancer, "How BCC is Diagnosed." [link: https://aimatskincancer.org/basal-cell-carcinoma/bccdiagnosed/]

Additional Resources

Immunotherapy

Immunotherapy is a drug treatment that uses the immune system to fight cancer. It may be administered to patients intravenously in the Chemotherapy Unit of the hospital, but it is not the same as chemotherapy.

A number of cancer immunotherapies have been developed using different strategies to help boost immune response. Some immunotherapies help your immune system attack the cancer directly and some help to enhance your body’s immune response to fight the cancer. For example, some cancers trick the immune system by switching off certain pathways so that cancer cells are no longer recognized, allowing them to continue to grow. One type of immunotherapy helps fight cancer by switching on the pathways that the cancer cells have switched off, so that the immune system begins to recognize and attack the cancer. This is only one approach to cancer immunotherapy.

There are different immunotherapies available in Canada to treat skin melanoma. In general, all treatment options can cause serious side effects, sometimes even fatal. That’s why it is always important to carefully weigh the benefits of any cancer treatment against the possible risks. You should discuss possible side effects with your doctor before starting treatment.

Helen's Story

Basal cell carcinoma, in general, is the most common form of skin cancer in the world,” says Dr. Vanessa Bernstein, BC Cancer Agency. “One in eight Canadians will develop it during their lifetime. But the majority of the cases of basal cell cancer won’t be locally advanced or metastatic. These 99 per cent of basal cell cancers will be treated with local options like surgery or radiation, and they’ll be cured most of the time by that. Helen’s is an unusual case because her advanced basal cell cancer is quite a rare form of what’s usually a slow-growing, common skin cancer. It came back after radiation and it kept recurring after treatment, which is when we knew we were in trouble.”

Read the Full Story

Squamous Cell Carcinoma (SCC)

Squamous cell carcinoma (SCC), which begins in the keratinocyte cells, is the second most common skin cancer. This type of skin cancer generally grows slowly and occurs most often burn or wound sites, or on sun-exposed skin, such as the back of the hands, ears, and scalp. It often looks like a sore that is not healing or an enlarging red, scaly patch of skin. Many SCSCs appear as wounds that never heal. They usually grow relatively slowly and may look red, scaly, crater-like, ulcerated, or bumpy. Some are crusty or itchy and may bleed.

The top layer of skin, the epidermis, is predominantly composed of basal cells, squamous cells, and melanocytes. Squamous cells are thin, flat skin cells found in the upper section of the epidermis and appear at the skin’s surface. As part of normal skin maintenance, squamous cells are constantly shed as new cells replace older ones.

SCC is capable of spreading from the surface to deeper layers of skin, lymph nodes or organs. The annual incidence of metastasis of CSCC is approximately 4%. (Burton et al. Am J Clin Dermatol. 2016;17:491-508.)

There are two subtypes of SCC, Adenoid SCC and Desmoplastic SCC, which may have a higher chance of recurrence. Both subtypes often occur on the head or neck, and Adenoid SCC appears as a nude, brown, pink or red nodule.

You might be familiar with the term cutaneous squamous cell carcinoma; this is another way of describing squamous cell skin cancer.

Sources: Canadian Cancer Society, “Squamous Cell Carcinoma.“ [link: http://www.cancer.ca/en/cancer-information/cancer-type/skin-non-melanoma/non-melanoma-skin-cancer/types-of-non-melanoma/?region=on]

AIM at Skin Cancer. "Squamous Cell Skin Cancer." [link: https://aimatskincancer.org/squamous-cell-skin-cancer/]

What Patients Need to Know

Dr. David Zloty, Dermatologist and Clinical Professor at UBC, reviews the latest news, clinical data and other updates as they relate to the treatment of cutaneous squamous cell carcinoma (cSCC), a common and sometimes metastatic skin cancer. Dr. Zloty provides an update on skin cancer statistics in Canada, an overview of the disease features, staging and prognostication, surgery and treatment options including immuno-oncology for cSCC, and the impact of all of this to patients.

Read the NCCN Guidelines for Patients®: Squamous Cell Skin Cancer

Presents information in an easy-to-learn format
Created for people with cancer and those who support them
Step-by-step guides to the cancer care options likely to have the best results
Based on treatment guidelines used by health care providers worldwide
Designed to help you discuss cancer treatment with your doctors

Learn more about the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) here

First Biologic Treatment for Deadly Type of Skin Cancer Gets Strong Positive Recommendation to be Covered by Provincial Health Care

Save Your Skin Foundation Applauds the pan-Canadian Oncology Drug Review recommendation for Provincial Reimbursement of Libtayo™ for the treatment of Advanced Cutaneous Squamous Cell Carcinoma (cSCC)

“As skin cancer prevalence continues to grow in Canada, patients and their loved ones need options for treatment of this potentially deadly disease,” says Kathy Barnard, skin cancer survivor and founder of Save Your Skin Foundation. “Squamous cell carcinoma is not ‘JUST’ skin cancer – it is a wake-up call to all Canadians to be vigilant about the risks of skin cancer and the serious nature of its membership to the most common type of cancer.”

Save Your Skin Foundation Applauds Health Canada’s Notice of Compliance for Libtayo™ for the Treatment of Advanced Cutaneous Squamous Cell Carcinoma (CSCC)

CSCC is the second most common form of skin cancer accounting for approximately one- fifth of all skin cancer cases in Canada. When CSCC invades deeper layers of the skin or adjacent tissues, it is categorized as locally advanced. Once it spreads to other distant parts of the body, it is considered metastatic. Prior to today’s announcement, in 2018 Libtayo™ received FDA approval under Priority Review and was granted Breakthrough Therapy Designation status for advanced CSCC which was created to expedite the development and review of drugs that have the potential for substantial improvement in the treatment of serious or life-threatening conditions.

The following lifestyle and occupational hazards have been recognized as risk factors for Squamous Cell Carcinoma:

Excessive and unprotected exposure to ultraviolet (UV) radiation from outdoor sunshine or indoor tanning lamps
A history of skin burns, trauma, or chronic inflammation
Immunocompromised people or those who have undergone organ transplants
People with lighter-coloured skin who burn and freckle more easily (though people with all complexions are vulnerable to skin cancer
Rare genetic mutations (recessive dystrophic epidermolysis bullosa, xeroderma pigmentosum)
Exposure to carcinogenic agents such as arsenic, azathioprine, coal tar, cyclosporine, mineral and shale oils, soot, X-ray and gamma radiations

Diagnosis Procedure

Sources: AIM at Skin Cancer. "SCC Risk Factors." [link: https://aimatskincancer.org/squamous-cell-skin-cancer/scsc-risk-factors/]

AIM at Skin Cancer, "How SCC is Diagnosed." [link: https://aimatskincancer.org/squamous-cell-skin-cancer/how-scc-is-diagnosed/]

SCC Staging

Unlike many types of cancers with a numerical staging system, squamous cell skin cancer (SCSC) more often follows a unique categorization based on the risk assessment of the primary tumor. This unique staging system puts most SCSCs into one of two groups: Low-Risk and High-Risk. Tumor location and size are the basis for this categorization.

Local, Low-Risk Squamous Cell Skin Cancer: SCSCs that are categorized as low-risk are more likely to develop on the trunk and extremities and are less than two centimetres (cm) in size and two millimetres (mm) in depth. These small tumours are unlikely to return or become metastatic. They have well-defined edges and are not invasive.

Local, High-Risk Squamous Cell Skin Cancer: The group of SCSCs categorized as high-risk have an elevated risk of local recurrence and have a poorer prognosis. High-risk SCSCs have poorly defined edges and grow rapidly. High-risk SCSCs will often appear on the head and neck area, including the ears and lips. Besides the head and neck, SCSCs that develop on the hands and feet, or the pretibial (shin), and anogenital (anus and genital) areas are also at greater risk of local recurrence and nodal metastasis, independent of size. Any tumours that have returned are defined as high risk. Tumors that have invaded deeply into the skin dermis or subcutaneous fat at a depth of greater than two mm are also considered high risk.

Regional or Metastatic Squamous Cell Skin Cancer: In rare cases, the SCSC can develop beyond the local, primary site on the skin. It may have spread in the area (regional) to lymph nodes or distant sites (metastasis). Among SCSC tumours less than or equal to two millimetres (mm) in thickness, the rate of metastasis is usually 0%. For SCSC tumours greater than two mm and up to six mm in thickness, the rate of metastasis is about 4%, and for tumours thicker than six mm, the rate is about 16%.

AIM at Skin Cancer: "SCSC Staging." [link: https://aimatskincancer.org/squamous-cell-skin-cancer/scsc-staging/]

Treatment for SCC

The goals of treating squamous cell skin cancer (SCSC) are to remove the tumour, preserve function, and prevent skin damage. Most people diagnosed with SCSC can be cured by surgically excising or removing the tumour(s). Below are descriptions of approved and available treatments for SCSC. It is important to note that not all of the treatment options described will apply to every situation. Your healthcare providers will determine which treatments apply to your SCSC.

Shave Excision or Standard Surgical Excision: With these techniques, the clinician removes the suspicious skin lesion. The difference between the names includes the amount of tissue removed, whether stitches are necessary for the wound, and whether a noticeable scar will develop. A shave excision is superficial or closer to the skin’s surface and usually applies to tiny, low-risk lesions. A standard surgical excision removes more tissue, may need stitching, and produces a noticeable scar. Standard excision is recommended as the primary treatment for low-risk SCSCs. After removing the tissue, the sample is sent to a laboratory for examination, where it will be assessed to make sure all the cancer has been removed along the margins of the tumour. On your pathology report, the terms negative, clean, not involved, or clear margins indicate that the tumour is surrounded by normal tissue and has been adequately removed. If the areas around the tumour do not show healthy cells, you may need to have further excision during another appointment to obtain clear margins. Other techniques may be recommended if positive margins are observed. In some cases, reconstruction, tissue repair, or skin grafting are undertaken after clear margins are achieved.

Precancer Treatments Applied to the Skin

In patients with SCSC precancers, called actinic keratoses, there are many options for topical therapy. These include the options below:

5-fluorouracil is a traditional chemotherapy but is supplied in more than one formulation, depending on the type of cancer for which it is needed. For skin cancer, it can be applied as a topical cream directly to the skin twice daily to destroy actinic keratoses.
5-fluorouracil/calcipotriol (calcipotriene) is a topical ointment mixture of 5-fluorouracil cream and calcipotriene. Calcipotriol is a derivative of vitamin D and is reported to enhance the immune system.
Imiquimod is a drug that activates and amplifies the immune system. It is prescribed as a topical cream for actinic keratoses.
Tirbanibulin is a topical solution to treat actinic keratosis on the face and scalp. The goal is to prevent these lesions from developing into invasive SCSC.
Diclofenac is a non-steroidal anti-inflammatory agent that has been long-established and used to reduce pain and inflammation.
Chemical peel with trichloroacetic acid may be appropriate for people with extensive actinic keratoses on their face and scalp. This treatment should be performed by a professional and will cause the top layer of skin to come off.
Photodynamic therapy combines medicine with light to kill the tumour cells. Superficial tumours (those that are small and/or not deep) are ideal for this therapy. Light cannot completely penetrate deep or large tumours.

Medications for Regional and Metastatic Squamous Cell Skin Cancer

The two most commonly given treatments that are approved and available for regional and metastatic SCSC are cemiplimab (Libtayo) and pembrolizumab (Keytruda). Both are systemic therapies (those that spread throughout the body to treat cancer) and may be combined with other types of therapy.

Cemiplimab (Libtayo) is an intravenous medication indicated for the treatment of patients with SCSC that has spread regionally or metastatic SCSC who are not candidates for curative surgery or curative radiation. Cemiplimab is a drug designed to generate an immune system reaction to the tumour cells. This drug is also approved for basal cell carcinoma and some non-small cell lung cancers. The most common side effects include rash, itching, diarrhea, fatigue, muscle/joint pain, and/or gland dysfunction. Warnings that accompany this medication include the possibility of severe, potentially life threatening inflammatory reactions, a reaction during the infusion, and embryo toxicity.
Pembrolizumab (Keytruda) is an intravenous medication approved for the treatment of patients with recurrent or metastatic SCSC or locally advanced SCSC that is not curable by surgery or radiation. The side effects of this drug are usually similar to mild allergic reactions and inflammation because of the immune system stimulation and may include skin rash, intestinal issues, organ problems, and reactions on infusion. Usually, these are mild but could result in the discontinuation of the drug.

Clinical Trials

Sources: AIM at Skin Cancer, "How SCSC is Treated." [link: https://aimatskincancer.org/squamous-cell-skin-cancer/treatment-options/]

AIM at Skin Cancer, "Side Effects of Treatment - SCSC." [link: https://aimatskincancer.org/squamous-cell-skin-cancer/side-effects-of-treatment-scsc/]

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Gary's Journey

Last year, Garry Hanwell was saying goodbye to his family in preparation for a medically-assisted death, the last resort in his relentless battle with cutaneous squamous cell carcinoma (cSCC), an aggressive and common form of skin cancer. Today, he’s planting a new garden and celebrating 70 years of marriage.

Read the Full Story

Merkel Cell Carcinoma (MCC)

Merkel Cell Carcinoma (MCC) is a rare non-melanoma skin cancer. It can develop in the merkel cells, which are found in the deepest areas of the epidermis and hair follicles. Merkel cells are related to nerve function and production of hormones. MCC generally spreads quickly, and develops in areas often exposed to the sun (head, neck, arms, and legs), but can occur anywhere on the body. Once the cancer starts to metastasize, or spread, to other parts of the body, it becomes metastatic MCC. MCC is sometimes referred to as neuroendocrine skin cancer or trabecular carcinoma.

MCC generally manifests in a non-painful, firm, raised bump on the skin, which may be red or purple in colour. As MCC spreads more bumps may appear nearby, and swelling may occur in the lymph nodes.

Source: Canadian Cancer Society, “Merkel Cell Carcinoma“

Watch our informative video about merkel cell carcinoma:

Download our Net Cancer Fact Sheet

Merkel Cell Carcinoma: From Diagnosis to Treatment

Hear Dr. Marco Iafolla, Medical Oncologist at William Osler Health System, review the latest news, clinical data and other updates as they relate to the treatment of merkel cell carcinoma (MCC). Dr. Iafolla provides an update on the science behind primary and metastatic MCC diagnosis, an overview of the disease features, staging and prognostication, surgery and treatment options including immuno-oncology for MCC, and the impact of all of this to patients.

New study provides a better understanding of Merkel cell carcinoma

A team of researchers at the H. Lee Moffitt Cancer Center and Research Institute are starting to learn more about how Merkel cell carcinoma (MCC) develops.

PRECANCEROUS CONDITIONS: ACTINIC KERATOSIS AND BOWEN’S DISEASE

Precancerous conditions of the skin have the potential to develop into non-melanoma skin cancer. The most common precancerous conditions of the skin are Actinic Keratosis and Bowen’s disease.

Actinic Keratosis

Actinic keratosis is also called solar keratosis, and is often found on sun-exposed areas of the skin in people middle-aged or older. A person with one actinic keratosis will often develop more. The number of actinic keratoses often increases with age. The presence of an actinic keratosis indicates that a person’s skin has suffered sun damage.

Actinic keratoses are considered slow growing. They often go away on their own, but may return. Approximately 1% of actinic keratoses develop into squamous cell carcinoma (SCC) if left untreated. Treatment is required because it is difficult to tell which keratoses will develop into cancer.

Treatment options for actinic keratosis depend on the number and location of keratoses.

The treatment may include one or a combination of the following:

Topical chemotherapy
- 5-fluorouracil (5-FU, Efudex)
- Ingenol mebutate (Picato)
Topical biological therapy
- Imiquimod (Aldara or Zyclara)
Cryosurgery
- Often used on single spots
- May also be used for many small, raised spots
Surgery
- Simple surgical excision
- Curettage and electrodesiccation
  - May be used on many large spots
Chemical peeling
Laser surgery
Photodynamic therapy

Information obtained from the Canadian Cancer Society.

Bowen’s Disease

Bowen’s disease is an early form of squamous cell carcinoma (SCC). It may be called squamous cell carcinoma in situ. Bowen’s disease involves cancer cells in the epidermis or outermost layer of the skin. Although it can’t spread to the lymph nodes, Bowen’s disease can spread into the deeper layers of the skin if left untreated. When it spreads, it becomes an invasive SCC that then has the potential to spread into the lymph system.

Treatment options for Bowen’s disease depend on the number and location of spots.

The treatment may be one or a combination of the following:

Surgery
- Simple surgical excision
- Curettage and electrodesiccation
Topical chemotherapy
- 5-fluorouracil (5-FU, Efudex)
Topical biological therapy
- Imiquimod (Aldara or Zyclara)
Cryosurgery
Photodynamic therapy

Information obtained from the Canadian Cancer Society.

Contributing Factors

Contributing Factors to Melanoma and Non-Melanoma Skin Cancers

The following may contribute to the development of melanoma and non-melanoma skin cancers:

Unprotected and/or excessive exposure to ultraviolet (UV) radiation
A fair complexion
The tendency to freckle
Occupational exposures to coal tar, pitch, creosote, arsenic compounds, or radium
Some medications, such as immunosuppressants
Family history of skin cancers
Multiple or atypical moles
Severe sunburns, especially as a child

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Early detection is key.

You should examine your skin at least once a month. Make sure you check the back of your body, in your hair, and between your toes. Use a mirror or have someone check for you. Look for changes in moles, any new growths, sores that do not heal, and abnormal areas of skin.

If you have any concerns about your skin and possible skin cancer, contact your physician immediately. More information about the diagnosis process can be found here.

Steps of a Skin Cancer Self-Exam

Using a mirror in a well lit room, check the front of your body -face, neck, shoulders, arms, chest, abdomen, thighs and lower legs.
Turn sideways, raise your arms and look carefully at the right and left sides of your body, including the underarm area.
With a hand-held mirror, check your upper back, neck and scalp. Next, examine your lower back, buttocks, backs of thighs and calves.
Examine your forearms, palms, back of the hands, fingernails and in between each finger.
Finally, check your feet – the tops, soles, toenails, toes and spaces in between.

When checking your own skin or that of your loved ones, keep in mind the “ABCDE’s of skin checks.”

A – Asymmetry. The shape of one half does not match the other half.

B – Border that is irregular. The edges are often ragged, notched, or blurred in outline. The pigment may spread into the surrounding skin.

C – Colour that is uneven. Shades of black, brown, and tan may be present. Areas of white, grey, red, pink, or blue may also be seen.

D – Diameter. There is a change in size, usually an increase. Melanomas can be tiny, but most are larger than 6 mm wide (about 1/4″ wide).

E – Evolving. The mole has changed over the past few weeks or months.

F – Firm. Is the mole harder than the surrounding skin?

G – Growing. Is the mole gradually getting larger?

Contact your doctor right away if you notice any abnormalities. Your doctor may also recommend that you examine your lymph nodes every month.For full instructions on conducting skin self-exams, please CLICK HERE.

NOTE: The information on the Save Your Skin website is not intended to replace the medical advice of a doctor or healthcare provider. While we make every effort to ensure that the information on our site is as current as possible, please note that information and statistics are subject to change as new research and studies are published.

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Making awareness and education available is crucial. Since 2006, the Foundation has worked to raise awareness of melanoma and non-melanoma skin cancers focusing on education, prevention and the need for improved patient care.

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Skin Cancers

While not all cases of non-melanoma skin cancer (NMSC) are reported, it is the most commonly diagnosed form of Cancer in Canada

Basal Cell Carcinoma

Additional Resources

Immunotherapy

Helen's Story

Squamous Cell Carcinoma (SCC)

Gary's Journey

Merkel Cell Carcinoma (MCC)

PRECANCEROUS CONDITIONS: ACTINIC KERATOSIS AND BOWEN’S DISEASE

Actinic Keratosis

Bowen’s Disease

Contributing Factors to Melanoma and Non-Melanoma Skin Cancers

Steps of a Skin Cancer Self-Exam

When checking your own skin or that of your loved ones, keep in mind the “ABCDE’s of skin checks.”

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