Twenty-eight-year incidence and characteristics of post-transplant skin cancers: Comparative analysis of past and recent 10-year experience.

Because primary skin cancers in organ transplant recipients are rare, little is known about the characteristics and risk factors for skin cancers in organ transplant recipients. We searched the Asan Medical Center database of 13 469 organ transplant recipients for cases of all skin cancers from January 1990 to December 2018. Characteristics of and risk factors for skin cancers were analyzed and compared according to the period of transplantation. Of the identified 113 patients with skin cancers, squamous cell carcinoma was the most common cancer followed by basal cell carcinoma and Kaposi sarcoma. The cumulative incidence of skin cancers at 28 years was 5.3%. Over the 10-year period from January 2009 to December 2018, the standardized incidence ratio for premalignant in situ skin lesions increased, whereas the standardized incidence ratio for skin cancers decreased. Age at transplantation and treatment with more than two immunosuppressive agents were risk factors for the development of new skin cancers in organ transplant recipients. Over the most recent 10-year period, post-transplant skin cancers have been found earlier and diversified compared with in the previous period.