Resident Editor: John Landefeld, M.D.
Faculty Editor: Ryan Arakaki, M.D.
Background
- Non-melanoma skin cancer (NMSC) is the most common cancer in humans
- 75% of NMSCs are basal cell carcinomas; 25% of NMSC’s are squamous cell carcinomas
- Melanoma incidence has risen from 1/100,000 to 15/100,000 over the last 40 years
Table 6: Skin Malignancies
|
Type |
Description |
Management |
|
Actinic keratosis |
- 1-2% progression per year to SCC if untreated - Ill-defined, erythematous, scaly papule or plaque in sun-exposed areas - Often better palpated than seen - May itch or hurt
|
Individual lesions - Cryotherapy
Field treatment for multiple lesions - Imiquimod 5% cream BIW x16 weeks - 5-FU 5% cream BID x2-4 weeks - Photodynamic therapy (performed in the office, takes only one day, longer recovery time) |
|
Squamous cell carcinoma |
- Erythematous, scaly, indurated papule, plaque, or nodule. - People describe nonhealing lesion that bleeds with minimal trauma - Confirm diagnosis with biopsy before treatment - In all-comers, 5% risk of metastases at the time of diagnosis - In people with darker skin, 20-40% of metastases at the time of diagnosis
|
SCC In Situ: - ED&C - Simple excision - Can consider imiquimod or 5-FU if the patient does not wish to have surgery
SCC: - Simple excision - Mohs micrographic surgery
|
|
Basal cell carcinoma |
- Pearly papule or nodule with rolled borders and arborizing telangiectasias under dermoscopy - Central, non-healing ulceration and/or pigment may be present
4 different pathologic subtypes: - Nodular - Infiltrative/Morpheaform - Superficial - Micronodular
|
Superficial BCC - Electrodessication and curettage (ED&C) - Imiquimod 5% cream M-F daily x6 weeks - 5-fluorouracil 5% cream BID x3-12 weeks
Nodular, infiltrative, micronodular - Options are ED&C (nodular only), simple excision, or Mohs micrographic surgery (especially for high risk) - Choice of treatment will depend on size, depth, subtype, and anatomic site - After treatment, will usually follow with derm q6-12 months for 2 years, then PCP |
|
Melanoma
|
- Increasing incidence (2.2% lifetime risk), and accounts for 1% of cancer deaths - Requisite full-body exam to check all of the patient’s lesions as well as to get a sense of their baseline nevi - Look for “ugly duckling” that is different from the patient’s baseline nevi - Can using “ABCDE” scoring to help decide on biopsy: - Asymmetry - Borders irregular - Color (multi-colored) - Diameter >6mm - Evolution - When in doubt, refer to derm |
- Biopsy (performed by derm) should contain the entire lesion so that pathologist can accurately stage it (i.e. punch or excisional preferred, shave ok if lesion small and superficial) - Excision and potential sentinel lymph node biopsy if tumor stage Ib or higher - Refer to dermatologist or melanoma clinic for evaluation and management |
Safe Sun Guidelines
- Minimize sun exposure during the peak ultraviolet-B (UV-B) 10 a.m. to 4 p.m.
- Apply sunscreen with UVA (not measured by SPF) and UVB protection (broad-spectrum means both UVA and UVB protection) of at least 30. Zinc or titanium-containing products are preferred. Also, remember UVA goes through windows (especially important for patients with photosensitive connective tissue diseases).
- Persons should wear wide-brimmed hats, sunglasses, and protective clothing (e.g., tightly woven fabrics and long-sleeved shirts) when sun exposure cannot be avoided. Physical protection is stronger than sunscreen and preferable when an option.
- Avoid deliberate sun tanning and use of tanning parlors. Tanning parlors are classified as Group 1 carcinogens by the WHO, a classification that includes cigarettes and plutonium.
References
Bolognia, J et al. Dermatology. 3rd Edition. 2011. Elsevier Ltd.