Genetic and familial factors in colorectal cancer.

Of the patients with colorectal cancer, there are some with hereditary disorders such as familial polyposis coli, Gardner's syndrome, Turcot's syndrome, and cancer family syndrome in which colorectal adenocarcinoma develops at a significantly high frequency, and these hereditary diseases are very important and interesting from the viewpoint of carcinogenesis as well as tumorigenesis. On the other hand, Peutz-Jeghers syndrome and juvenile polyposis which likewise are hereditary diseases are often considered to be accompanied with colorectal cancer. On these grounds, 49 cases of familial polyposis coli (including Gardner's syndrome), 12 cases of Peutz-Jeghers syndrome, one case of juvenile polyposis, six pedigrees of cancer family syndrome, experienced at the National Cancer Center Hospital from 1962 to 1984 were reviewed with particular emphasis placed on the recent progress and the natural history of these diseases. Furthermore, a comparative study between single colorectal cancers (1,034 cases) and multiple ones (89 cases) was carried out from the standpoint of familial aggregation and cumulative age incidence. A high association with genetic factors was found in multiple primary colorectal cancer with a family history of colorectal cancer as well as in the well-known hereditary diseases mentioned above. The author presented a conception of the relationship between the human body and tumors from the viewpoint of a comparison among infantile and childhood tumors, hereditary tumors, familial aggregative tumors and the usual tumors observed in old age.