Risk of second primary cancers, other than melanoma, in an Italian population-based cohort of cutaneous malignant melanoma patients.

A population-based study has been carried out in central Italy to investigate the risk of further non-melanoma primary cancers in a cohort of cutaneous malignant melanoma (CMM) patients. We considered 1835 invasive CMM cases (93.4% histologically verified) diagnosed between 1985 and 1999 by the Tuscany Cancer Registry, central Italy (1 200000 inhabitants) and actively followed up to the end of 1999 for vital status and for the occurrence of a second primary. Only cases diagnosed after 2 months (metachronous) from CMM diagnosis were considered. During 7758 person-years of observation, 94 cancers were observed (93.6% histologically verified) versus 73.8 expected, corresponding to a standardized incidence ratio (SIR) of 1.27 (95% confidence interval (CI) 1.03-1.56). The risk was similarly increased in both sexes, males SIR=1.31 and females SIR=1.23, and it was statistically significant among subjects younger than 60 years (SIR=1.76) but not among those of 60 years and older (SIR=1.14). Significant increased risks were observed for non-melanoma skin cancers (SIR=3.26) and non-Hodgkin's lymphoma (SIR=2.74). Physicians should be aware of the higher risk for non-Hodgkin's lymphoma and clinical follow-up should include lymph node palpation. However, the risk for extranodal lymphomas should also be kept in mind.