Risk of Second Malignant Neoplasms Among Long-term Survivors of Testicular Cancer

Reviewers: Leonard A. Farber, M.D. and John Chang, M.D.
Source: Journal of the National Cancer Institute 1997; 89:1429-39

Testicular cancer has been treated with a variety of modalities including radiotherapy and chemotherapy, with a 5-year relative survival rate of greater than 90%. Men with testicular cancer are generally in their third or fourth decade of life at diagnosis, and few studies have quantified the long-term risks of second malignant neoplasms among long-term survivors. Previous studies have shown that men with testicular cancer may be at an increased risk for developing secondary cancers of the lung, gastrointestinal tract, and other urogenital sites, as well as leukemia and sarcoma.

This study was a cohort of 28,843 1-year survivors identifiedwithin 16 population-based tumor registries in North America andEurope. There were over 3300 survivors out more than 20 years. Theauthors quantified this data with regard to site-specific risk ofsecond malignant neoplasms, taking into account the histologic typeof initial cancer and the primary treatment involved. Mean follow-upwas 10.2 years.

Results of the study showed secondary cancers reported in 1406men. There was a statistically significant excess seen for acutelymphoblastic leukemia, acute nonlymphoctic leukemia, melanoma,non-Hodgkin's lymphoma (NHL), and cancers of the stomach, colon,rectum, pancreas, prostate, kidney, bladder, thyroid, and connectivetissue. The overall risk was similar for seminomas andnonseminomatous tumors. Secondary leukemia was associated with bothradiotherapy and chemotherapy. Excess cancers of the stomach andbladder were associated mainly with radiotherapy. The actuarialrisks of developing any second cancer, excluding that of thecontralateral testis after diagnosis of testicular cancer were 15.7%at 25 years and 22.6% at 30 years. Increased risks of secondmalignant neoplasms appeared within two decades after testicular cancer diagnosis for leukemia, however, afterwards, the risksdecreased to expectation. For solid tumors of the stomach, bladder,pancreas, and colon, there was an increasing risk over time. Therewere no discernible trends observed for connective tissue and thyroidtumors, malignant melanoma, or NHL.

The authors concluded that survivors of testicular cancer continueto be at significantly elevated risk for developing second malignantneoplasms for more than two decades from the time of initialdiagnosis. They stress the importance in monitoring the carcinogenicpotential of throughout the life of the patient, and to continue todevelop approaches which will decrease or prevent second cancers.