[Clinical investigation of familial clustering of cancer].

Five cancer-prone families, i.e., a colorectal cancer family, a gastric cancer family, two breast cancer families and a cancer family without organ specificity are reported, and familial clustering of cancer was investigated clinically. It was strongly suggested that familial clustering of cancer was related to genetic factors. The clinical characteristics of cancer-prone families were a familial tendency to cancer, early age of onset, an extraordinary frequency of multiple primary malignant neoplasms and an autosomal dominant mode of gentic transmission. The clinical significance of noting familial clustering of cancer is to extract groups at high risk for cancer, to detect early cancerous lesions and to make early therapeutic decisions.