Types of Non-Melanoma Skin Cancer
There are several types, including:
About Non-Melanoma Skin Cancers
Basal Cell Carcinoma
Basal cell carcinoma (BCC), the most common type of skin cancer, begins in the basal cells in the deepest layer of skin. 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)
Watch our informative video about basal cell carcinoma here. For additional information please visit www.talkbcc.ca
There are several subtypes of BCC:
- The most common subtype of BCC is nodular BCC, which often appears as a raised lesion with blood vessels on top. It usually appears on the face.
- The second most common subtype is superficial BCC, which takes the form of a red, scaly patch. It often develops on the torso and limbs.
- In the deeper layers of skin, infiltrative BCC can occur. Infiltrative BBC often occurs in the neck and head regions, and takes the appearance of scar tissue.
- Morpheaform or sclerosing BCC usually occurs in the neck and head regions, and takes the appearance of a flat, firm lesion lacking a defined border.
Source: Canadian Cancer Society, “Basal Cell Carcinoma“
Squamous Cell Carcinoma
Squamous cell carcinoma (SCC), which begins in the keratinocyte cells, is the second most common skin cancer. While SCC usually develops in areas that have been exposed to the sun, it can also manifest in burn or wound sites.
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.)
For more information please visit our page: About Squamous Cell Carcinoma
Merkel Cell Carcinoma
Merkel Cell Carcinoma (MCC) is a rare non-melanoma skin cancer. It develops 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 hormones production. MCC generally spreads quickly, and develops in areas often exposed to the sun (head, neck, arms, and legs). MCC is sometimes referred to as neuroendocrine skin cancer or trabecular carcinoma.
For more information please visit our new page: About Merkel Cell Carcinoma
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.
Watch our informative video about actinic keratosis here.
Risk Factors:
The following risk factors may increase a person’s chance of developing actinic keratosis:
- Overexposure to ultraviolet B (UVB) radiation from the sun
- Increased age
- Fair skin
- Weakened immune system
- Previous PUVA (psoralen + UVA) therapy
Signs and Symptoms:
Actinic keratosis is most often seen on skin that is frequently exposed to the sun, such as the face, the backs of hands or a balding scalp. The signs and symptoms of actinic keratosis may include:
- Small, rough patches that may be pink-red or flesh coloured
- An initially flat surface that becomes slightly raised and wart-like
Diagnosis:
Actinic keratosis is diagnosed during an examination of the growth. If it does not go away with treatment or shows signs of developing into SCC, a skin biopsy will be done.
Treatment:
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.
Risk Factors:
The following risk factors may increase a person’s chance of developing Bowen’s disease:
- Overexposure to ultraviolet B (UVB) radiation from the sun
- Increased age
- Previous radiation therapy
- Weakened immune system
- Infection with human papillomavirus (HPV) is associated with Bowen’s disease of the anal and genital skin
- Arsenic exposure
Signs and Symptoms:
Bowen’s disease is most often seen on the legs, backs of hands, fingers or face. The signs and symptoms of Bowen’s disease may include:
- A reddish scaly patch, which is sometimes crusted – may be a single patch or multiple areas
- A windblown appearance of the skin
- Larger, redder and scalier patches than actinic keratoses
Diagnosis:
If the signs and symptoms of Bowen’s disease are present, or if the doctor suspects Bowen’s disease, a biopsy will be done to make a diagnosis. The type of biopsy may be:
- Shave biopsy
- Punch biopsy
Treatment:
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 TO MELANOMA AND NON-MELANOMA SKIN CANCERS
The following may contribute to the development of melanoma and non-melanoma skin cancers.
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.
- 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
EARLY DETECTION IS KEY
You should examine your skin at least monthly. 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.
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.
Canadian Dermatology Association, patient handout “Melanoma Skin Cancer: Know the Signs, Save a Life” 2009.
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 millimeters 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.
For more information about immunotherapy for non-melanoma skin cancers (NMSC): The biology of non-melanoma skin cancers and their strong immunogenicity makes these tumors good candidates for novel and emerging immunotherapeutic agents.
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.
monthly self-exams are key to early detection
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.
