RISK OF 2ND MALIGNANT NEOPLASMS AMONG LONG-TERM SURVIVORS OF TESTICULAR CANCER

Background: We have quantified the site-specific risk of second malign ant neoplasms among nearly 29 000 survivors (greater than or equal to 1 year) of testicular cancer, taking into account the histologic type of initial cancer and the primary therapy used to treat it, Methods: T he study cohort consisted of 28 843 men identified within 16 populatio n-based tumor registries in North America and Europe; over 3300 men ha d survived more than 20 years, New invasive cancers were identified th rough a search of registry files, Results: Second cancers were reporte d in 1406 men (observed-to-expected ratio [O/E] = 1.43; 95% confidence interval 1.36-1.51), with statistically significant excesses noted fo r acute lymphoblastic leukemia (O/E = 5.20), acute nonlymphocytic leuk emia (O/E = 3.07), melanoma (O/E = 1.69), non-Hodgkin's lymphoma (O/E = 1.88), and cancers of the stomach (O/E 1.95), colon (O/E = 1.27), re ctum (O/E = 1.41), pancreas (O/E = 2.21), prostate (O/E = 1.26), kidne y (O/E = 1.50), bladder (O/E = 2.02), thyroid (O/E = 2.92), and connec tive tissue (O/E = 3.16), Overall risk was similar after seminomas (O/ E 1.42) or nonseminomatous tumors (O/E = 1.50), Risk of solid tumors i ncreased with time since the diagnosis of testicular cancer, yielding an O/E = 1.54 (O = 369) among 20-year survivors (two-sided P for trend = .00002), Secondary leukemia was associated with both radiotherapy a nd chemotherapy, whereas excess cancers of the stomach, bladder, and, possibly, pancreas were associated mainly with radiotherapy, Conclusio ns: Men with testicular cancer continue to be at significantly elevate d risk of second malignant neoplasms for more than two decades followi ng initial diagnosis, Patterns of excess second cancers suggest that m any factors may be involved, although the precise roles of treatment, natural history, diagnostic surveillance, and other influences are yet to be clarified.