COLON TUMORS OCCURRING AFTER INTERFERON TREATMENT FOR RENAL CANCER

Abstract

Three cases of colon tumors occurring after treatment of renal cancer with interferon are reported. Patient 1, a 68-year-old woman, was found to have sigmoid colon cancer due to chronic anemia at the fourth year after receiving injections of interferon for 6 years following a nephrectomy for renal cancer. She underwent a sigmoid colectomy and histopathologic study revealed moderately differrentiated adenocarcinoma. Patient 2, a 68-year-old man, was found to have tumors in the ascending and transverse colons on colonoscopy after injections of interferon for 3 years 6 month following a nephrectomy for renal cancer. He underwent a hemicolectomy and histopathological examination showed well differrentiated and moderately differrentiated adenocarcinomas. Patient 3, a 54-year-old man, developed bloody stool when interferon had been administered for 2 years after a nephrectomy for renal cancer. Colonoscopy showed four tumors in the sigmoid colon and the tumors were removed by electrocautery. Colonic adenomas were observed histopathologically.
In addition to these three case reports, the development of secondary tumors after interferon therapy is discussed with reference to the literature.