Problems in the Diagnosis of Cancer of the Colon

Abstract

We cannot view with complacency the fact that almost a year has elapsed before the average patient with cancer of the colon has an accurate diagnosis made. Furthermore, there are no symptoms which can be designated as distinctive of a malignant growth of the colon, these varying widely, depending on the location and the gross form of the tumor and on the presence or absence of complicating factors such as ulceration, perforation, obstruction, secondary infection, and hemorrhage. The colon is the site of many other pathological processes which resemble cancer in their clinical and roentgenologic manifestations. Many patients are operated on for appendicitis only to have a cancer in the proximal colon disclosed. Ileocecal tuberculosis and regional enteritis may also simulate carcinoma. In the distal colon, diverticulitis, especially with an inflammatory mass, often cannot be differentiated from cancer. In the rectum, operations are frequently done for hemorrhoids only to have a cancer disclosed at a later date. Symptoms Cancer of the Colon: According to Rankin, it is impossible to correlate symptoms and signs referable to the entire colon as if it were a single organ, because of the wide differences in the proximal and distal portions, both structurally and functionally. On his basis of symptomatology, cancer in the proximal colon may be divided into three groups: (1) the dyspeptic group, usually diagnosed as chronic appendicitis or cholecystitis; (2) the group characterized by unexplained anemia and weakness; (3) the group in which a tumor is discovered accidentally, or in the course of a routine examination. Twenty-six per cent of carcinomas of the cecum and ascending colon falling in Group 1 were diagnosed as appendicitis; 90 per cent of these patients complained of pain and soreness in the lower right quadrant of the abdomen from two to nine months before exploratory operation. In Group 2, the weakness and anemia are not accompanied by visible bleeding from the rectum. It is in this group that a thorough roentgenographic study is indicated, not only of the colon but of the entire gastro-intestinal tract. In the distal colon, obstructive phenomena dominate the clinical picture, since cancers in this region tend to be encircling in type, causing progressive stenosis. Furthermore, the fecal content in the left half of the colon is hard and formed and can be forced only with difficulty through a closing segment. A history of progressive constipation can be obtained in from 50 to 60 per cent of these cases. In acute obstruction of the colon, the symptoms are very similar to those of small bowel obstruction, with marked abdominal distention and evidence of hyperactive peristalsis. In these cases a “scout” roentgenogram of the abdomen is indicated, as it will aid materially in localizing the point of obstruction.