Colonoscopic detection of early colorectal cancers. Impact of a surgical endoscopy service

The nurse endoscopist: reality or fiction?

In this article, the author describes a study conducted to determine whether advanced practice registered nurses (APRNs) should perform endoscopic procedures, such as colonoscopy and esophagogastroduodenoscopy. Questionnaires were mailed to APRNs belonging to the Society of Gastroenterology Nurses and Associates. Questionnaire items pertained to demographics, current activities, interest in performing GI endoscopic procedures, and barriers to performing GI endoscopic procedures. Over 70% of respondents approved of nurses performing diagnostic endoscopic procedures, yet 80.6% did not think that nurses should perform therapeutic endoscopic procedures. Training opportunities were limited. The barriers to performing endoscopic procedures included liability, third-party reimbursement, lack of physician support, lack of policies, and lack of education. APRNs should develop policies and establish acceptable training guidelines and competency rates in performing GI endoscopic procedures.

Colonoscopic screening for neoplasms in asymptomatic first-degree relatives of colon cancer patients. A controlled, prospective study

Individuals with a family history of colorectal cancer are believed to be at an increased risk of developing colorectal neoplasia. To estimate this risk and the potential yield of screening colonoscopy in this population, we recruited and prospectively colonoscoped 181 asymptomatic first-degree relatives (FDR) of colorectal cancer patients and 83 asymptomatic controls (without a family history of colorectal cancer). The mean ages for the FDR and control groups were 48.2 +/- 12.5 and 54.8 +/- 11.0, respectively. Adenomatous polyps were detected in 14.4 percent of FDRs and 8.4 percent of controls. Although 92 percent of our FDRs had only one FDR afflicted with colon cancer, those subjects with two or more afflicted FDRs had an even higher risk of developing colonic adenomas (23.8 percent) than those with only one afflicted FDR (13.1 percent). A greater proportion of adenomas was found to be beyond the reach of flexible sigmoidoscopy in the FDR group than in the controls (48 percent vs. 25 percent, respectively). Logistic regression analysis revealed that age, male sex, and FDR status were independent risk factors for the presence of colonic adenomatous polyps (RR = 2.32, 2.86, and 3.49, respectively; P less than 0.001). Those at greatest risk for harboring an asymptomatic colonic adenoma are male FDRs over the age of 50 (40 percent vs. 20 percent for age-matched male controls). Based on probability curves, males with one FDR afflicted with colon cancer appear to have an increased risk of developing a colonic adenoma beginning at 40 years of age. Our results document, for the first time, an increased prevalence of colonoscopically detectable adenomas in asymptomatic first-degree relatives of colon cancer patients, as compared with asymptomatic controls, and support the use of colonoscopy as a routine screening tool in this high-risk group.

Colon cancer incidence: recent trends in the United States

Between 1976-78 and 1985-87, the age-adjusted incidence rates of invasive colon cancer in the United States rose by 15 percent, 3 percent, 21 percent, and 16 percent among White males, White females, Black males, and Black females, respectively. The increases in incidence occurred in all age groups over age 54 and affected each of the major subsites of the colon nearly equally. The larger rates of increase have resulted in higher incidence among Blacks than Whites by the mid-1980s and an increasingly greater excess of this cancer in males. Trends toward earlier diagnosis of invasive colon cancer were found, with increasing rates for localized and regional diseases coupled with stable or decreasing distant-stage disease-rates. The incidence of in situ colon cancer also rose substantially. The findings suggest that changes in diagnostic trends and risk-factor prevalence may be contributing to these patterns, and that the era when colon cancer predominated among White females is clearly over.

Evaluation of effectiveness of mass screening for colorectal cancer

As the first step in the epidemiological evaluation of the effectiveness of mass screening for colorectal cancer, we compared clinicopathological features and survival rates of patients with cancer detected by mass screening (screened group) with those for patients treated in our outpatient clinic in the same period (outpatient group). The screened group consisted of 53 patients with colorectal cancer detected by 2-day or 3-day screening for fecal occult blood by guaiac slides. Their background factors were comparable to those of 120 patients of the outpatient group in regard to age, sex ratio, location of cancer, and histological type of cancer. In the screened group, 90% of patients had no complaints, and positive occult blood tests led to the detection of cancers. More than 60% of the patients had Dukes' A and B1 early cancers while only about 30% had advanced cancers. In the outpatient group, nearly 90% of patients were symptomatic, most commonly from rectal bleeding. Early-stage cancers made up only 20%, and large, advanced-stage cancers accounted for 80%. The 5-year survival rate of the screened group was 91.5%, being significantly higher than the 60% survival rate for the outpatient group. It is anticipated that mass screening for colorectal cancer by guaiac fecal occult blood testing will significantly reduce the mortality due to this neoplasm.

Screening for colorectal carcinoma

Colorectal carcinoma will occur in some 147,000 Americans this year. This disease accounts for 15% of all cancers and 12% of all cancer deaths. Screening for colorectal carcinoma may allow the disease process to be found earlier and, in some situations such as when polyps are found and removed, may even prevent the disease. The two main modalities of screening are fecal occult blood tests and sigmoidoscopy. By general screening of asymptomatic patients as well as by selective screening of those at high risk, there is hope that the incidence and mortality of this cancer will diminish. Absolute confirmation of this benefit is still lacking, making the evaluation of the cost-effectiveness of this screening somewhat questionable. Current educational efforts are designed to increase compliance and to help solve some of these unanswered questions.