Roles of Radiation Dose and Chemotherapy in the Etiology of Stomach Cancer as a Second Malignancy

Purpose To evaluate the roles of radiation dose, chemotherapy, and other factors in the etiology of stomach cancer in long-term survivors of testicular cancer or Hodgkin lymphoma. Methods and Materials We conducted a cohort study in 5,142 survivors of testicular cancer or Hodgkin lymphoma treated in the Netherlands between 1965 and 1995. In a nested case–control study, detailed information on treatment, smoking, gastrointestinal diseases, and family history was collected for 42 patients with stomach cancer and 126 matched controls. For each subject, the mean radiation dose to the stomach was estimated. Relative risks (RRs) of stomach cancer and the radiation-related excess relative risk (ERR) per gray were calculated by conditional logistic regression analysis. Results The risk of stomach cancer was 3.4-fold increased compared with the general population. The risk increased with increasing mean stomach dose ( p for trend,