Stomach cancer risk following radiotherapy for testicular cancer.

4536 Background: Testicular cancer (TC) is a highly curable malignancy occurring most commonly among men aged 15-34 years. Survivors are at increased risk for adverse late effects of therapy. Previous studies have reported more than 4-fold risks of stomach cancer after TC, although the potential role of radiotherapy and chemotherapy for TC in these associations is unclear. Methods: We evaluated stomach cancer risk in an international cohort of 23,982 men diagnosed with TC during 1959-1987. Using detailed radiotherapy records, doses to the stomach tumor location were estimated for 92 stomach cancer patients and 180 individually matched controls. Chemotherapy drugs and doses also were recorded. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression. Results: Fifty-seven percent of patients with stomach cancer were diagnosed with TC before age 40 years, 65% had seminoma, 95% had stage I or II disease, and 37% were diagnosed with stomach cancer ≥20 y...