Second neoplasms in patients with merkel cell carcinoma

BACKGROUND, Merkel cell carcinoma (MCC) has been associated with a high inc idence of other skin tumors and hematological malignancies. The purpose of this study was to analyze data from the Israel Cancer Registry regarding th e incidence of second neoplasms in patients with MCC and their impact on su rvival. METHODS. Sixty-seven patients in whom MCC was diagnosed between 1983 and 19 99 were included. Data were collected on age, gender and ethnic origin, dat es of diagnosis of MCC and any other neoplasm, and date and cause of death, if applicable. Comparison of MCC-specific survival, estimated by the Kapla n-Meier product limit method, between patients with no other neoplasm and t hose with second primary tumors was performed by log rank test. Age-specifi c standardized incidence ratio (SIR) was calculated using 5751 age- and eth nic-matched malignant melanoma patients as a control group. RESULTS. Seventeen patients (25%) had a second neoplasm before, concomitant with, or after the diagnosis of MCC; 2 of them also had a third primary tu mor. The SIR was 2.8 (95% CI; range, 1.38-4.22), significantly higher than the control group. Almost half the tumors were squamous cell carcinomas, ei ther skin or head and neck, and most of the remainder were hematological ma lignancies or breast and ovarian adenocarcinomas. On univariate analysis, t he presence of another neoplasm, regardless of its chronology, was associat ed with higher MCC-specific mortality (65% vs. 40% for patients with MCC on ly; P = 0.022). Analysis of only those patients in whom a second neoplasm d eveloped during follow-up after treatment for MCC yielded an estimated actu arial risk of developing a second primary of 2.1% for each year of observat ion. CONCLUSIONS, There is a high incidence of second neoplasms, including noncu taneous solid tumors, in patients with MCC. The presence of these neoplasms , whether they appear before, after, or simultaneously with MCC, is associa ted with a higher MCC-specific mortality. (C) 2001 American Cancer Society.