Theories of carcinogenesis and their impact on surgical treatment of colorectal cancer. A historical review.

From the time of Hippocrates until the late 19th century, physicians and surgeons were convinced that surgical attempts at treating colorectal cancers were doomed to failure. This opinion stemmed from prevailing views on carcinogenesis. The three dominant theories, the humoral, mineral, and lymph theories, held that all cancers developed in tissue that had a diseased disposition. Thus, excision of the gross tumor mass alone seemed unlikely to cure the patient. Consequently, surgical treatment of all cancers, and in particular colorectal cancer, was vehemently condemned. The 19th century represented a transition period. Advances in surgical technique made excision of rectal cancers feasible. Unfortunately, classical views that resection of cancer was futile delayed the development of surgical treatment for colorectal cancer. Indeed, it was not until the late 19th century that a few individuals ignored these tenets of classical medicine and attempted local resections of rectal cancers. By the second quarter of the 20th century, a radical change occurred in the prevailing theories of carcinogenesis. Wide acceptance of the unicellular origin of cancer and the mucosal origin of colorectal cancers washed away admonitions against surgical treatment of colorectal cancers. It became axiomatic that all cancers, including colorectal cancers, could be cured surgically if treated while still local diseases.