Familial cancer of the colon and rectum.

A familial relationship between intestinal polyposis and the predisposition of polyposis to colonic cancer has been accepted since the publication in 1952/1953 of Dukes's paper. He collected information on every patient presenting at St Mark's Hospital with polyposis coli and investigated the family background in each case. He was able to study 41 families, trace 156 cases of polyposis, and 114 cases of cancer of colon and rectum in this group of families. Other diseases are known to predispose to the development of colonic and rectal cancer. The most clearly documented of these is ulcerative colitis in which a polygenic aetiology has been suggested (McConnell, 1966). Solitary colonic polyps have been considered by some recent authors (Woolf, Richards, and Gardner, 1955; Morson and Bussey, 1970) to have a familial relationship, and some of these polyps are regarded as precancerous. By contrast, the presence of a familial tendency to cancer of the colon has only rarely been reported (Kluge, 1964; Fielding, 1969). In postulating a familial predisposition to cancer of the colon, one must take into account that this is a common disease in the western world (accounting for 2 6% of all deaths in England and Wales in 1969 and 13-9% of all cancer deaths) and consequently the fact that several members of a family die of this disease may be purely coincidental. The present report concerns a large family in which the incidence of colonic cancer appears too great to be attributed to chance.