Abstract
The genetics of cancer resistance and susceptibility has been the subject of intensive inquiry at the infra-human level, aided considerably by development of highly inbred animal strains. Findings from these studies have been applied to the testing of hypotheses about etiology and carcinogenesis in man. The present survey has briefly considered the way in which some familial cancer is distributed in human populations, demographic factors which contribute to variation in cancer susceptibility, and specific tissue susceptibility in hereditary cancer. Such examples as carcinoma of the breast, colon, von Recklinghausen's neurofibromatosis, and multiple primary malignant neoplasms emphasize these variables. With respect to multiple primaries, consideration has been given to the possible consequence of certain cancer therapies in those individuals who have a familial susceptibility to cancer. Problems in genetic heterogeneity, mechanisms involved in biological markers in cancer, and the phenomenon of cancer resistance have been discussed.