KEY BISCAYNE, FLA. — With the growing number of organ transplant recipients living longer, it has become increasingly important to treat and counsel these patients about their significantly higher risk of skin cancers, according to a presentation at the annual meeting of the Noah Worcester Dermatological Society.
Mucocutaneous lesions are the most common cancer type among organ transplant patients. The risk may be highest for squamous cell carcinoma, but it is also elevated for rare cancer types. In addition, skin cancers tend to be more aggressive and carry a worse prognosis for organ recipients.
Greater patient education is warranted. The International Transplant Skin Cancer Collaborative (www.itscc.org
There are more than 150,000 living organ transplant recipients. It is likely that 70% of these patients will eventually develop skin cancer, according to Marc D. Brown, M.D., professor of dermatology, University of Rochester (N.Y.).
An estimated 37% of tumors are mucocutaneous. Patients also develop lymphoma (17%), lung cancer (6%), and Kaposi's sarcoma, uterine, and colorectal cancers (4% each). Skin cancer can include squamous cell carcinoma, basal cell carcinoma, melanoma, sarcoma, Merkel cell carcinoma, angiosarcoma, verrucous carcinoma, atypical fibroxanthoma, and leiomyosarcoma.
There is a 65-fold increased incidence of cutaneous squamous cell carcinoma in organ transplant recipients, compared with the general population in Norway (J. Am. Acad. Dermatol. 1999;40:177–86). Researchers are less certain about melanoma incidence. The Norwegian study of 2,561 kidney and heart recipients found three times increased risk of melanoma, but another study of 5,356 patients in Sweden found no increased risk (Br. J. Dermatol. 2000;143:513–9).
Not only are skin cancers more common in organ transplant recipients, they also tend to progress more rapidly. Multiple lesions are more likely. Recurrence and metastasis rates are higher as well.
Incidence of skin cancer increases with the duration of long-term immunosuppression. Other contributing factors are exposure to UV radiation, genetic risk, and infection with human papilloma virus.
The risk of skin cancer might vary by the type of organ transplanted, according to some researchers. For example, squamous cell carcinoma may be two to three times more likely in cardiac vs. renal transplant recipients. In addition, there may be a lower risk of skin cancer after a liver is transplanted, compared with other organs, but additional research is needed, Dr. Brown pointed out.
The International Transplant Skin Cancer Collaborative suggests a full body exam at least annually, with particular attention to previous sites of nonmetastatic skin cancer. In addition, treat actinic keratoses aggressively and lower the threshold for considering a skin biopsy in these patients, the group suggests.
“You can never be faulted for following these high-risk patients too closely,” Dr. Brown said.
The collaborative promotes increased patient education on sun exposure and skin and lymph node self-examination. A telephone survey of 200 organ transplant recipients found 88% were unaware of their increased risk for skin cancer (Dermatol. Surg. 2004;30:610–15). A total of 35% reported regular sunscreen usage in the survey, but 35% also reported getting a sunburn the previous summer.
A separate survey of 122 renal transplant recipients found 41% could not recall skin cancer education (J. Am. Acad. Dermatol. 1999;40:697–701). Although 27% reported seeing a dermatologist after transplantation, only 14% had regular follow-up.
These skin lesions emerged on the back of a patient's head next to a scar left after surgery to remove a previous cancer. Courtesy Dr. Marc D. Brown
A Typical, Challenging Case
A 68-year-old white male with Fitzpatrick type III skin had a bilateral lung transplant in 1993. Four years later, he developed squamous cell carcinoma, primarily in situ. The lesions progressed, and he was diagnosed with squamous cell carcinoma on his vertex and parietal scalp areas in 1998. The lesions were present against a background of multiple actinic keratoses, and were removed by electrodesiccation and curettage.
In mid-2000, the patient had two-stage Mohs' surgery for the vertex squamous cell carcinoma.
Two months later, he presented with “poorly differentiated squamous cell carcinoma without a connection to the epidermis,” said Dr. Brown.
The patient had radiation therapy after developing eight metastases within 1 month. In September of 2000, he developed additional metastases within the radiation site. Clinicians reduced his immunosuppressive drugs by 50%, and the patient developed more than 30 metastatic nodules. The patient then had multiple excisions and radiation therapy with capecitabine (Xeloda) for sensitization. The patient never developed adenopathy. CT scans of his chest were negative. In March 2002, he began a trial of intralesional methotrexate every 2 weeks with excellent resolution, Dr. Brown reported. The patient died in July 2002.