Polyps of the colon and rectum: approach to prophylaxis in colorectal cancer

Is follow-up of colorectal cancer patients worthwhile?

Between 1978 and 1989, 1,045 of 1,399 patients (580 male and 474 female) underwent curative surgery for colorectal carcinoma. Of these patients, 350 (33 percent) had recurrences, another 16 (1.5 percent) developed a metachronous colorectal cancer, and 23 (2 percent) had cancers of other organs. An isolated locoregional recurrence was found in 75/350 (21 percent). The remaining 275/350 patients (79 percent) showed systemic dissemination of the carcinoma. Reoperations with curative intent were performed on 56/350 patients (16 percent). Only 21 of the 56 resected patients (38 percent), i.e., 21/350 (6 percent), were without recurrence at the end of the follow-up period on December 31, 1990. Despite a curative reoperation, 62 percent of the patients again developed recurrent growths. There is an imbalance between the efforts invested in tumor follow-up and the benefits gained. Further follow-up programs should be investigated in a controlled, prospective fashion.

Clinical results of transanal endoscopic microsurgery

Using the "transanal endoscopic microsurgery" technique, 140 patients were treated at the Department of Surgery in Cologne and Mainz. Of the patients with adenomas, 68.2% had typical symptoms preoperatively. The postoperative hospital attendance was 8.7 days, with an average resection size of 14.4 cm2. The postoperative complication rate was 5%, and there were no deaths related to the technique. In a prospective controlled trial, 2.2% of the patients with adenomas treated endoscopically in Mainz showed recidivation, requiring reoperation. The follow-up rate was 100%. In 30 cases, microscopic examination revealed carcinoma. Radical reoperation in 8 pT1 tumours showed neither remaining tumour nor lymph node metastases. Twelve patients with pT1 carcinoma treated by local surgery alone were recurrence-free with an average follow-up period of 12.3 months. So far, there have been no late results.

Radiation dose in investigations of the large bowel. Comparison of radiation doses in examinations of the colon with double-contrast barium enema with the Welin modification and colonoscopy

Because of the increasing and repeated application of colonoscopy and double-contrast barium enema with the Welin modification in connection with the checking of patients who have been treated for neoplastic polyps, we have found it valuable to examine the amount of radiation that the patients are exposed to in the two kinds of examinations. The radiation dose in the examination of the colon with the Welin modification (35 examinations) and at colonoscopy (114 examinations) was, on an average, 387 and 10 mSv, respectively. Since colonoscopy gives a possibility not only of diagnosis but also of treatment and also exposes the patients to 40 times less radiation than X-ray examination with the Welin modification, we recommend colonoscopy for diagnosis and treatment of neoplastic colonic polyps.

Follow-up study after colorectal polypectomy. The predictive value of a negative double-contrast barium enema

In this study the predictive value of a negative double-contrast barium enema for colonic polyps has been calculated as the ratio of the number of true negative radiologic examinations to the total number of negative radiologic examinations. The total number of negative double-contrast barium enemas for polyps of the colon was 357 in 228 consecutive patients with previous or suspected neoplastic colonic polyps examined in the period 1977-84. The predictive value of a negative double-contrast barium enema for all colonic polyps regardless of size was 87% (95% confidence interval, 84-91%). The corresponding predictive value of a negative result for polyps larger than 10 mm in diameter was 98% (95% confidence interval, 97-100%). Polyps that had not been detected by radiography were removed by colonoscopy, and 85% of them were available for histological examination. No cancers were found. The polyps were primarily neoplastic, but metaplastic and juvenile polyps were also ascertained.

Reproducibility and diagnostic value of Hemoccult-II test. A colonoscopic evaluation in asymptomatic patients

Inter-observer agreement rate in double readings of 246 Hemoccult-II tests was 0.88 (Kappa analysis). The slides were not rehydrated. The Hemoccult-II test was performed immediately before 748 total colonoscopies in asymptomatic patients after previous polypectomy or radical surgery for cancer to estimate the diagnostic value of the test in mass screening, accepting a higher prevalence of neoplasia in the study group but realizing that colonoscopy can only be performed in high-risk groups. Another purpose was to investigate the possibility of replacing colonoscopy with Hemoccult-II in surveillance after previous adenoma or cancer. The 79 colonoscopies after a positive test showed cancer in 3, adenomas in 13, and other intestinal pathology in 34 cases. The 669 colonoscopies after negative tests showed cancer in 1, adenomas in 67, and other pathology in 141 cases. In conclusion, the test cannot be used as a guideline for colonoscopy in follow-up programs for patients who have had adenomas, since it missed 84% of the new cases in the present series. The test does not exclude the presence of colorectal carcinoma, but the risk of cancer is probably several times less in patients with negative tests (1 of 669) than in patients with positive tests (3 of 79), which may justify the use of the Hemoccult-II test for mass screening in asymptomatic populations.

Hyperplasia or neoplasia. Macroscopic versus microscopic appearance of colorectal polyps

Small light-red sessile colorectal polyps, 1-5 mm in diameter, are generally believed to be hyperplastic (non-neoplastic), whereas polyps that are dark-red in contrast to the surrounding mucosa are thought to be adenomas. This hypothesis was tested prospectively in a series of 209 polyps removed by one endoscopist in a 6-month period. A 'blinded' pathologist provided the histopathological diagnosis. Twenty-two per cent of polyps described as hyperplastic by the endoscopist were adenomas, whereas 40% of those believed to be adenomas, 1-5 mm in diameter, were hyperplastic. The diagnostic effectivity of the endoscopist increased with increasing size of the polyps. In conclusion, all colorectal polyps must be removed to prevent possible precancerous lesions from being left behind and to define a group of patients with increased risk of new adenomas, in whom follow-up examinations should be considered.

Endoscopic follow-up after colorectal cancer surgery. Early detection of local recurrence?

This study deals with 188 consecutive patients who had a radically resected colorectal carcinoma and who were later controlled by colonoscopy. The median interval between resection and endoscopy was 2.5 (0.5-19) years. In 20 patients, a local recurrence was found (10.6%). In 11 of these 20 patients the indication for colonoscopy was the clinical suspicion of a recurrence. The remaining nine patients were asymptomatic, and colonoscopy was done as a routine procedure. In six of nine asymptomatic patients, a potentially curative resection of the recurrent tumor was possible, which was not possible in any of the 11 symptomatic patients. Nineteen of the 20 patients with a local recurrence could be followed up. Five of the six patients with potentially curative resection of the recurrence were asymptomatic for a median time of 38 (12-72) months after surgery; in contrast, 9 of 13 patients without curative operation died after a median survival period of 8 (1-24) months. The results of this study suggest that good long-term prognosis may be expected in patients in whom local recurrence is detected at an early asymptomatic stage with the possibility of potentially curative resection. Therefore, the authors propose regular endoscopic examinations in the first years after curative colorectal cancer surgery.

The remaining colon after radical surgery for colorectal cancer. The first three years of a prospective study

This study investigates the possible gain and limitation by performing colonoscopy and double-contrast enema immediately after, and every six months after, radical surgery for colorectal cancer. It was possible to perform a complete colonoscopy within three months of surgery in 80 per cent of the 239 patients and at the follow-up time in 90 per cent. Incompleteness was related to insufficient bowel preparation, narrow anastomosis, and long transverse colon. Five patients had synchronous cancers, and 64 had adenomas at the time of surgery. The risk of recurrent adenomas in the latter was higher (17/64) than in those without adenomas (15/175). The adenomas were located above the rectum in 57 of 80 patients who had polypectomy. Four patients with metachronous cancer and one of five patients with local recurrence had another radical operation, while this was possible in none of 40 patients with recurrence diagnosed by other means than colonoscopy and enema. Radical colorectal surgery should be followed by colonoscopy and double-contrast enema, but how often and for how long remains to be established.

A prospective, partly randomized study of the effectiveness of repeated examination of the colon after polypectomy and radical surgery for cancer

Results of 629 colonoscopies and 130 double-contrast examinations, performed during the first 2 years of a prospective, partly randomized cancer prophylactic programme, are reported. The patients were not more than 75 years old and had no previous diagnosis of adenoma or cancer. Repeated colonoscopy 3 months after polypectomy in 80 patients increased the chance of obtaining a complete colonoscopy from 70% to 86%, and the hepatic flexure was reached in a further 9%. Thirteen had polypectomy during the second colonoscopy. The gain in number of patients with adenomas was highest in those with sessile villous adenomas, carcinoma in situ, and mucosal carcinoma. Repeated colorectal examinations every 6 months in these resulted in recurrence rates of 13 of 33, 3 of 23, and 2 of 15 (18 months), respectively. The same figures for patients with stalked polyps, allocated to examination every 6 months, were 3 of 34, 1 of 21, and 2 of 14. Colonoscopy was also performed within 3 months of radical surgery for colorectal cancer, and 35 of 142 patients had polypectomy. Repeated examinations every 6 months resulted in recurrence rates for adenomas of 11 of 85, 3 of 46, and 1 of 34. One new cancer after 12 months could be treated radically. Five uncomplicated laparotomies were performed after the 629 colonoscopies because of perforation or bleeding.