Cancer family syndrome manifested in an extended kindred.

A large midwestern kindred exhibiting the CFS is described. In the branches of the family identified as "cancer-prone," malignant lesions of the colon, endometrium, ovary and skin have persisted through as many as five successive generations. In all, 29 family members have had 43 primary malignant growths of the CFS target organs. Eighty-three per cent of these lesions were colonic in origin. Cancers in these family members almost always occur at young ages (x = 40 years), and it is not uncommon for family members to have a second, third or even fourth primary malignant lesion develop. In branches determined "cancer-resistant," only isolated cancers have been diagnosed. Recommendations on the management of families, such as this one, are presented.