A cooperative study on the detection of colorectal cancer and polyps in France.

Systematic investigations testing for the presence of polyps and cancers of the large bowel were conducted in a population of 1,369 inpatients and outpatients, aged 45-70 years, in eight university departments of gastroenterology or abdominal surgery (Toulouse, Dijon, Paris, Marseille, and Strasbourg). Double-contrast barium enema and proctosigmoidoscopy examinations were carried out in all cases, whereas total coloscopy was performed only in the case of detected tumors. A questionnaire including 233 parameters (age, sex, family, and personal history and symptoms) was completed for each patient. A total of 414 lesions were detected in 252 patients, including 245 adenomatous or villous polyps, 8 transformed polyps, and 30 carcinomas; 3 of 4 lesions were located in the rectum or sigmoid. Cancer or adenomatous or villous polyps were found in 13% of the patients. The prevalence of these lesions in the population studied was increased in patients with rectorrhagia (19%) or with a personal history of surgery for colorectal cancer or polyp (23%). In the patients without rectorrhagia or a history of intestinal tumor, the incidence was 9.7%. It was significantly increased in males and patients more than 50 year old. The efficacy of proctosigmoidoscopy and double-contrast barium enema was compared in 909 patients. Sensitivity and specificity were, respectively, 35% and 99% for endoscopy, 96% and 94% for radiology.

Screening for colorectal tumors - results of two years experience.

The experience after two years of systematic colorectal tumors screening of 603 subjects, aged between 40 and 70, is reported. All subjects were submitted to proctoscopy (P) and air filled barium enema (AFBE). Total frequency of screened tumors: 15.25%. More than 85% of the tumors were found in the recto-sigmoid. Two subgroups were identified in this population. In subgroup A, 125 subjects were submitted to P, AFBE and flexible pansigmoidoscopy (FP). Percentage of screened tumors is 19.2%. Sensitivity rate of radiology for exploration of the recto-sigmoid area, as compared to FP is rather low: 0.41. In subgroup B, 165 subjects were submitted to hemoccult, P, AFBE and colonoscopy when an abnormal or dubious image was shown by AFBE. The comparative study of these different means of investigation shows a very low rate of sensitivity of hemoccult: 0.16. In addition, the percentage of screened colorectal tumors is significantly higher (p less than 0.01) in subjects with personal or family history of polyp or carcinoma: 22%, compared to the incidence in the remaining population of 13%. Flexible pansigmoidoscopy is recommended for systematic screening of colorectal tumors in subjects older than 40.

[Problem posed by the prevention and detection of colorectal cancers]. / Problèmes posés par la prévention et le dépistage des cancers colo-rectaux.

The incidence of colonic and rectal carcinoma is in constant progression. The detection and destruction of polyps is the only effective means of reducing the number of adenocarcinomas. The technical means of detection are well known and fully proved: rectosigmoidoscopy, thin layer double contrast enema, colonoscopy. The true problem is that of the cost of this prevention. It is important to define high risk groups in which these tests should be carried out as a routine. Furthermore it is necessary to know whether blood tests or examination of the stools may be considered as a means of detection of polyp or at least certain types of potentially malignant polyp. without suggesting a considerable increase in the number of medical investigations, one may hope for better use of sigmoidoscopy and double contrast barium enema. These two examinations represent undoubtedly the essential factor in the diagnosis of colonic and rectal tumours.