Malignant melanoma in solid transplant recipients: collection of database cases and comparison with surveillance, epidemiology, and end results data for outcome analysis

Abstract

Objective: To determine malignant melanoma cause-specific and overall survival among patients with melanoma diagnosed after organ transplantation compared with a national sample with malignant melanoma.

Design: Retrospective review.

Setting: Mayo Clinic sites.

Patients: Immunosuppressed organ transplant recipients with malignant melanoma identified from surgical and medical databases at Mayo Clinic (1978-2007), the Organ Procurement and Transplantation Network/United Network for Organ Sharing database (1999-2006), and the Israel Penn International Transplant Tumor Registry (1967-2007).

Main outcome measures: Prognostic analyses by Breslow thickness and Clark level of overall and melanoma cause-specific survival. Expected survival rates were estimated by applying the age-, sex-, and calendar year-specific survival rates of patients with malignant melanoma cases reported in the Surveillance, Epidemiology, and End Results Program to the study cohort.

Results: Malignant melanoma was diagnosed in 638 patients (724 cases) after transplantation. Breslow thickness was available for 123 patients; Clark level, for 175. Three-year overall survival rates for patients stratified by Breslow thickness (≤ 0.75, 0.76-1.50, 1.51-3.00, and >3.00 mm) were 88.2%, 80.8%, 51.2%, and 55.3%, respectively, and 3-year cause-specific survival rates (95% confidence intervals) were 97.8% (93.7%-100%), 89.4% (76.5%-100%), 73.2% (53.2%-100%), and 73.9% (56.4%-96.6%), respectively. Three-year cause-specific survival rates (95% confidence intervals) for patients stratified by Clark level (I-IV) were 100%, 97.4% (92.4%-100%), 82.8% (65.3%-100%), and 65.8% (51.8%-83.7%), respectively. For patients with Breslow thickness of 1.51 to 3.00 mm and Clark level III or IV, the cause-specific survival rate in the study sample was significantly different from the expected estimates for patients with the same Breslow thickness or Clark level.

Conclusions: Compared with the expected survival rates derived from malignant melanoma cases reported in the Surveillance, Epidemiology, and End Results Program, immunosuppressed organ transplant recipients with thicker melanomas (ie, with a Clark level of III or IV or a Breslow thickness of 1.51 to 3.00 mm) had a significantly poorer malignant melanoma cause-specific survival rate. The overall survival rate was worse among patients with a prior history of transplantation, regardless of Breslow thickness or Clark level.