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Issues concerning the impact of predictive genetic testing on colonoscopic surveillance in an extended family with hereditary non-polyposis colorectal cancer (HNPCC) are discussed. Predictive genetic testing ensures that many individuals can be withdrawn from regular colonoscopic surveillance.

* Objective: To quantify any risk for colorectal cancer in first-degree relatives of patients with common colorectal cancer and to define possible markers for increased risk. * Design: Case-control family study. * Patients: Relatives of colorectal cancer patients and of matched control patients from a one-surgeon practice. * Mothods: Family medical histories were obtained for 7493 first-degree relatives and 1015 spouses of 523 case-control pairs. Reported diagnoses of colorectal cancer in relatives were verified in 79% of instances. * Results: By case-control analysis, the odds ratio was 1.8 (95% Cl, 1.2 to 2.7) for one and 5.7 (Cl, 1.7 to 19.3) for two affected relatives. By matched analysis of risk in relatives, the increased risk to parents and siblings was 2.1 times greater for case patients than for control patients (Cl, 1.4 to 3.1); 3.7 times greater (Cl, 1.5 to 9.1 ) with case patients diagnosed before 45; and 1.8 times greater (Cl, 1.2 to 2.9) with case patients diagnosed at 45 years or older; and was independent of gender, type of relative, site of cancer, and type of cancer (single or multiple). The cumulative incidence among first-degree relatives was greater for case patients than for control patients (P < 0.001), and in case patients, greater for those diagnosed before 55 years of age (P < 0.001). The cumulative incidence ([+ or -] S.E.) to age 80 was 11.1% [+ or -] 1.3%, 7.3% [+ or -] 0.8%, and 4.4% [+ or -] 1.0% among relatives of case patients diagnosed before age 45 years, between 45 and 54 years, and at 55 years or older, respectively, and was 2.4% [+ or -] 0.6% in relatives of control patients. * Conclusions: First-degree relatives of patients with common colorectal cancer have an increased risk for colorectal cancer. This risk is greater if diagnosis was at an early age and is greater when other first-degree relatives are affected. This increased risk should be considered when formulating screening strategies., First-degree relatives of patients with common colorectal cancer may have a higher risk of developing this type of cancer than other individuals. A study compared the incidence of colorectal cancer among 7,493 first-degree relatives and 1,015 spouses of 523 colorectal cancer patients and 523 healthy individuals. The risk of developing colorectal cancer was twice as high for parents and siblings of colorectal cancer patients than for those of healthy individuals. This risk was higher for individuals with two first-degree relatives with colorectal cancer than for those with only one. The cumulative risk was higher among first-degree relatives of patients who were under 45 years old at the time of diagnosis. First-degree relatives of colorectal cancer patients should consider having routine screening for colorectal cancer beginning at the age of 40 years old.

Relapse is a common sequel of antibiotic‐associated colitis due to Clostridium difficile. It has been suggested that Cl. difficilemay persist in the stools in spite of the resolution of symptoms after treatment and this may cause the relapse. Our study was designed to define the factors that predispose to relapse and to determine if prolonging treatment to clear Cl. difficilefrom the stools might prevent relapse. Of 60 consecutive patients, 36 with more severe disease required treatment. Treatment with either vancomycin or bacitracin was continued until the results of the examination of stools for cytotoxin became negative and Cl. difficilecould no longer be cultured (sensitivity of culture was 10–100 organisms/mL). This was achieved in 35 patients who were then followed for one month. Symptoms reappeared in 10 (28.6%) of the treated patients while Cl. difficilereappeared in the stools of an additional seven patients (20%) without the recurrence of diarrhoea. On comparing those who relapsed with those who did not, the age (67.3 ± 5.5 years in those who relapsed compared with 51.6 ± 4.4 years; P< 0.025, x¯ ± SE) and a history of recent abdominal surgery (59% of those who relapsed compared with 17%; P< 0.05) were significantly different. Although those who relapsed had received therapy with multiple antibiotic agents more often, this was not statistically significant. Disease was not more severe in patients who relapsed, nor was it more difficult to clear the pathogen from these patients. The 24 untreated patients did not suffer symptomatic relapse. Continuation of treatment until Cl. difficileapparently is absent from the stools is expensive and does not prevent relapse. Elderly patients and those who have recently undergone abdominal sugery are more likely to suffer a relapse.

Information on the relative incidence of Crohn's disease and ulcerative colitis was obtained by a prospective investigation at six Melbourne teaching hospitals. One hundred and eleven patients who presented with chronic inflammatory bowel diseases between 1980‐1981 were admitted to the study. Forty (36%) patients were diagnosed as having Crohn's disease and 63 (57%) patients as having ulcerative colitis. The type of chronic inflammatory bowel disease could not be determined in eight (7%) patients. These findings suggest that the relative frequency of Crohn's disease and ulcerative colitis in Melbourne hospitals is within the range that is reported for northern Europe and the United States.

Background:Hemoccult II, the guaiac-based fecal occult blood test used in most colorectal cancer screening programs, has an unsatisfactory sensitivity for asymptomatic colorectal neoplasms. We evaluated the relative performance of four fecal occult blood tests, directed against various components of the hemoglobin molecule. Methods:All tests, Hemoccult II, HemoccultSENSA (a more sensitive guaiac test), HemeSelect (an immunochemical test specific for human hemoglobin), and HemoQuant (the heme-porphyrin assay), were performed by 107 patients with symptomatic colorectal cancer and 81 patients with predominantly asymptomatic adenoma. Hemoccult-SENSA and HemeSelect were performed by 1,355 screenees. Results:HemeSelect and HemoccultSENSA had significantly higher sensitivity for colorectal cancer (97% and 94%, respectively) than the other tests. HemeSelect had the highest sensitivity for adenomas; in 45 patients with large (⩾10 mm) adenomas, sensitivity was 76% for HemeSelect, 60% for HemoccultSENSA, and 42% for both Hemoccult and HemoQuant. In the screenees, estimated specificity was 97.8% for HemeSelect and 96.1% for HemoccultSENSA. Conclusions:HemeSelect and HemoccultSENSA have the highest levels of sensitivity for detection of colorectal neoplasia, but the immunochemical test HemeSelect provides the best combination of specificity and sensitivity.

Non‐compliance in screening programmes for colorectal cancer is likely to be the most important factor limiting the impact of screening on mortality. This study aimed to determine risk factors and correlates of compliance that could be readily identified by general practitioners. A total of 581 eligible subjects aged 40 to 75 years completed a questionnaire that covered demographic factors, personal medical history, family history of colorectal cancer and smoking status. Faecal occult blood tests were then offered by the general practitioner and compliance correlated with responses. The over‐all compliance was 44% and increased to 51% for those who accepted the self‐testing kit at consultation. For men, compliance increased with increasing level of education and was significantly greater for non‐smokers than for smokers. For women, compliance increased with increasing age, and was greater for those with either symptoms and/or a family history of colorectal cancer. A doctor group‐practice factor appeared to influence acceptance versus refusal of the test kit from the doctor. A triage approach to screening in general practice may improve over‐all compliance and the yield of tumours. With this strategy, patients at high risk (for example, those with a family history of colorectal cancer or in older age groups) are identified first. Particular attention should be given during consultation to those at high risk who have poor compliance profiles (for example male smokers with a family history of colorectal cancer). High‐risk subjects with high compliance profiles would need less attention and low‐risk individuals would need least attention.