[A statistical analysis of multiple primary malignant tumors].

The authors analyzed 32 patients with multiple primary malignant tumors treated in the Department of Otolaryngology, Mie Univ. from 1965 to 1984 and reviewed the literature. Of 1149 malignant head and neck tumors in our clinic in the same period, 32 cases (2.79%) were multiple primary malignant tumors. In this series, quadruple and triple malignancies were found in one case each and double ones in the others. The average age of these 32 patients was 67.5 years for the men and 52.7 for the women. The male: female ratio was 4.3:1. The average interval between the first and second tumor was 35 months, and in 17 cases (56.7%), they were synchronous. Laryngeal cancers were the most frequent double-primary lesions and cancers in the head and neck were most commonly associated with stomach cancers in this study.