By Milan J. Anadkat, MD
Director, Residency Program
Associate Professor
Washington University School of Medicine
Division of Dermatology
September, 2016
The need for immunosuppressive therapy following lung transplantation is currently universal. The individual drugs utilized may vary, along with their dosages, as no clear consensus exists on the optimal regimen. Regardless, a few consistent risks are seen and accepted by lung transplant recipients as a result of chronic immunosuppression, including the risk for infection and the risk for cancer.
The development of skin cancer is known to occur at higher frequencies in solid organ transplant recipients due to immunosuppression. Heart and lung transplant patients typically require greater immunosuppression, thereby further increasing their risk. The most common skin cancer seen in transplant recipients is called a squamous cell carcinoma (SCC), which occurs at least 65 times more commonly than the general population. Transplant patients also develop other skin cancers at higher rates than normal, including basal cell carcinoma, melanoma, Merkel cell carcinoma, and Kaposi’s sarcoma.
The overall risk for skin cancer development is related to the type of immunosuppression utilized, the overall dosage, and the number of years receiving immunosuppression. This risk increases with each subsequent year following transplant. The drugs cyclosporine, azathioprine, and tacrolimus are most notable in their ability to increase the risk for skin cancer development. A newer agent, rapamycin, is utilized less often but has shown to actually decrease the risk skin cancer development.
Skin cancers have the ability to grow, invade, and destroy tissue. In rare cases, skin cancer can metastasize. Metastasis is more likely when skin cancers involve the mucosa (lip, mouth, etc). Metastasis is also more likely to occur in solid organ transplant patients compared to the general population. SCCs that occur in transplant patients often behave differently than SCCs that occur in the general population, even though they do not always look different.
There are certain characteristics of SCCs that occur in transplant patients, however, that should be considered. They tend to grow quickly and are often painful. Younger patients are affected more often when immunosuppressed. Treatment can be difficult as many patients develop multiple SCCs on the skin. The risk for recurrence of SCC after therapy is also much higher, as is the potential for metastasis (as stated earlier).
The best therapy is often via prevention. Patients must be exceptionally diligent about performing self-examinations monthly and getting routine skin examinations (minimum once per year). New bumps or growths that are rapidly changing, bleeding, or painful require prompt attention by a dermatologist.
The value of sun protection also cannot be over emphasized. Patients should be diligent to minimize prolonged UV exposure. Simple measures can be performed; such as seeking shade and avoid sun exposure when the sun is most intense, between 10 AM and 4 PM in temperate zones. This is true even on cloudy days, since UV light (unlike visible light) passes through clouds. Remember that UV light also passes through most side windows in cars; consider getting a UV filter!
Clothing is the best form of sunprotection and should be encouraged. Hats, sunglasses, sleeves, and pants are always better than sunscreens. Certain clothing, with Ultraviolet Protection Factor (UPF), are especially helpful in protecting from UV exposure. Cover what you can! Uncovered portions of the body should be protected with sunscreens daily with at least SPF30, and should be broad spectrum (blocking both UVA and UVB radiation). Reapplication of sunscreen is essentially, generally recommended every 2 hours of continuous sun exposure.
Skin cancers are a serious risk for transplant patients, and should be taken seriously by patients and doctors alike. With proper sunprotective measures and diligent examinations, however, modern medicine is plenty capable of preventing and treating these skin cancers.