口腔癌の重複癌発生に関する臨床的検討

Abstract

A cohort survey of the occurrence of multiple primary cancers was carried out in patients with oral cancer (n=310) at Tokyo Metropolitan Komagome Hospital. The subjects consisted of 203 males and 107 females.The incidence of multiple primary cancers over the course of 20 years (1976 to 1996) was 18.4%(n=57).Among 57 multiple primary cancers, 44 primary oral cancers, (77.2%) occurred in the oral cavity, and the specific sites were the tongue (19), gingiva (10), buccal mucosa (7), floor of the mouth (5), soft palate (2), and lip (1).Multiple primary cancers occurred frequently in the esophagus (12), stomach (8), lung (6), hypopharynx (2) in males and in the uterus (3) in females.In esophageal cancer, the O/E ratio of male patients was significantly higher, than that in females, differing by a factor of 39.61 times.In males, primary occurrence in elderly patients was associated with a short period until the occurrence of a second cancer, The development of a second cancer reguired a longer period in younger patients than in older patients, i. e., 4.5 years for 40 years old, 3.3 years for 50 years old, 2.5 years for 60 years old, 1.9 years for 70 years old, and 1.7 years for 80 years old.