I stumbled across this review article (first full reference below) earlier this week.
Skin cancer is the most common form of cancer in the United States. Most skin cancers form in older people on parts of the body exposed to the sun or in people who have weakened immune systems (such as inflammatory bowel disease patients on immunosuppressive therapy).
According to the National Cancer Institute (NCI), in there were more than one million new cases of nonmelanoma skin cancers (NMSC) in the United States in 2010. There were less than 1,000 NMSC deaths during the same time.
NMSC includes squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). Both occur more frequently on sunlight-exposed areas such as the head and neck. BCC is far more common than SCC and accounts for approximately 75% of all NMSC.
The causes of NMSC in the general public are multifactorial, including both environmental and host factors. Known environmental risk factors for NMSC include sun exposure (ultraviolet [UV] light), ionizing radiation, cigarette smoking, and certain chemical exposures such as arsenic. Host risk factors include human papilloma virus infection, genetic susceptibilities, skin type, and immunosuppression.
That last risk factor mentioned – immunosuppression—is one IBD patients have in common with solid organ transplant patients (kidneys, livers, lungs, face, hands). Note the third reference below. The results summary of that article
Two hundred patients developed a first NMSC after a median follow-up of 6.8 years after transplantation. The 3-year risk of the primary NMSC was 2.1%. Of the 200 patients with a primary NMSC, 91 (45.5%) had a second NMSC after a median follow-up after the first NMSC of 1.4 years (range, 3 months to 10 years). The 3-year risk of a second NMSC was 32.2%, and it was 49 times higher than that in patients with no previous NMSC. In a Cox proportional hazards regression model, age older than 50 years at the time of transplantation and male sex were significantly related to the first NMSC. Occurrence of the subsequent NMSC was not related to any risk factor considered, including sex, age at transplantation, type of transplanted organ, type of immunosuppressive therapy, histologic type of the first NMSC, and time since diagnosis of the first NMSC. Histologic type of the first NMSC strongly predicted the type of the subsequent NMSC
Attention is now being paid to other patients (ie IBD, rheumatoid arthritis) on immunosuppression and their increased risk of NMSC.
Millie D. Long, MD and colleagues (first reference) note that no IBD-specific, evidence-based guidelines for NMSC prevention exist. The current recommendations for prevention of skin cancer for the general population include sun avoidance and sun protection strategies include protective clothing, hats, sunglasses, and sunscreens. Sun avoidance should include tanning bed avoidance.
Any skin lesion suspicious for malignancy in a patient with IBD on immunosuppression should be evaluated by a trained dermatologist. Among solid-organ transplant recipients, annual skin examination is recommended by various transplant organizations.
Long and colleagues note “There are no guidelines for skin cancer screening in patients with IBD, as it is unclear whether the risk–benefit ratio of skin cancer screening in IBD patients correlates with that of the general population, or more closely with that of the solid-organ transplant population. Consideration could be given in the future to skin cancer screening programs for patients with IBD on immunosuppression.”
1. Nonmelanoma skin cancer in inflammatory bowel disease: A review; Millie D. Long, Michael D. Kappelman and Clare A. Pipkin; Inflammatory Bowel Diseases Volume 17, Issue 6, pages 1423–1427, June 2011; Article first published online: 25 OCT 2010 | DOI: 10.1002/ibd.21484
2. National Cancer Institute; Skin Cancer
3. Incidence and Clinical Predictors of a Subsequent Nonmelanoma Skin Cancer in Solid Organ Transplant Recipients With a First Nonmelanoma Skin Cancer: A Multicenter Cohort Study; Gianpaolo Tessari; Luigi Naldi; Luigino Boschiero; Francesco Nacchia; Francesca Fior; Alberto Forni; Carlo Rugiu; Giuseppe Faggian; Fabrizia Sassi; Eliana Gotti; Roberto Fiocchi; Giorgio Talamini; Giampiero Girolomoni; Arch Dermatol. 2010;146(3):294-299