Screening for colorectal cancer

Second only to lung cancer in mortality, colon cancer is amenable to cure if detected early. Because fecal occult blood testing and flexible sigmoidoscopy are effective individually but have limitations, both are now recommended for screening. However, after successful polyp removal, surveillance colonoscopy does not need to be performed as often as previously thought.     

Indication for surgery of asymptomatic carotid lesions

The incidence of cerebrovascular diseases with transient or persistent neurologic dysfunction has increased significantly. Although patients with symptomatic carotid artery stenosis clearly benefit from operative therapy, the indication to prophylactic surgery of asymptomatic carotid lesions however is still controversial. Based on data from a recently completed prospective randomized study and on analysis of the literature the indication and results of surgical treatment of asymptomatic stenoses of the carotid arteries are discussed. From 1970 to 1990 a total of 744 uni-or bilateral reconstructions of the internal carotid artery were performed in 631 patients. The perioperative morbidity (permanent neurologic deficiency) and mortality was 1.1% (n = 8) resp. 0.8% (n = 6). During the follow up period up to 18 years another 9 patients suffered from stroke (1.2%). The annual stroke incidence amounted to 0.2%. An important prerequisite for surgery is the so called critical internal carotid artery stenosis, implying reduced cerebral vasomotor reactivity or high embolic risk of an ulcerative plaque. Proper selection of patients (exclusion of multiple concomitant diseases) and an experienced team of vascular surgeons with operative morbidity and mortality below 1-2% validates surgical treatment of asymptomatic carotid artery stenoses.     

Oesophageal cancer coexisting with colorectal lesions

OBJECTIVE: To investigate the incidence of colorectal lesions in patients who present with oesophageal cancer. DESIGN: Prospective open study. SETTING: University hospital, Japan. SUBJECTS: 135 of 218 patients who presented with squamous cell carcinoma of the oesophagus during the seven year period 1988-1994 were randomly allocated to have a barium enema examination. INTERVENTIONS: Barium enema examinations, and if colorectal lesions were found, colonoscopy and biopsy. MAIN OUTCOME MEASURE: Incidence of coexistent colorectal lesions. RESULTS: No abnormal findings were found in 52 (39%), diverticula were present on 37 (27%), benign polypoid lesions in 51 (38%), and malignant lesions in 6 (4%). We examined the clinical and histopathological details of all patients to see if it was possible to distinguish the patients at high risk of developing oesophageal and colorectal cancer but could find no differences among the groups. CONCLUSION: Asymptomatic colorectal lesions are relatively common in patients with squamous cell carcinoma of the oesophagus in Japan.     

Screening for colorectal cancer by immunochemical fecal occult blood testing

Screening for colorectal cancer using the conventional Hemoccult test has been shown to reduce mortality associated with cancer by 33% through a randomized controlled trial. However, the magnitude of effectiveness is small in terms of cost-effectiveness. The recently developed immunochemical fecal occult blood test (IFOBT) provides a potential replacement for the Hemoccult test as a screening test, due to its superior performance characteristics such as higher sensitivity shown in preliminary studies and the fact that it does not require any dietary restriction. The IFOBT method is reviewed, especially in relation to its specificity. In known colorectal cancer subjects, IFOBTs have shown both higher sensitivity and specificity than the Hemoccult test. Similarly, IFOBT has demonstrated a higher sensitivity than Hemoccult for colorectal cancer in an asymptomatic population. A nationwide screening program in Japan has demonstrated the feasibility of this approach for large population screening. However, the positivity rate varied according to the conditions at each screening facility. Therefore, technical factors that influence the positivity rate of IFOBTs in the screening program are discussed. Case-control studies have strongly suggested that screening using IFOBT would reduce mortality from colorectal cancer by 60% or more. Several observational studies have provided support for this estimate. The feasibility and effectiveness of population-based screening by IFOBT are discussed.     

The relationship between brain atrophy and asymptomatic cerebral lesions]

Serratia marcescens has emerged in the last few years as an important nosocomial pathogen. Many methods for typing this organism have been described. In this study the random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was shown to be a convenient typing method for S. marcescens. Different combinations of primers previously used for typing other gram-negative bacilli were assessed. The combination of primer HLWL-74 and 1254 gave distinguishable patterns for different serotypes and proved to be the most satisfactory. By applying this combination to 175 isolates of S. marcescens, which could be classified into 38 groups on the basis of serotyping and phage typing, 73 different RAPD patterns with good reproducibility were obtained. This is, to our knowledge, the first application of the method to a large collection of S. marcescens representing a wide range of serotypes.     

Isolated proteinuria in asymptomatic patients

Regional cerebral blood flow (rCBF) was measured by 133Xe inhalation in 17 patients with chronic spinal cord transection. This was done to investigate any effects such spinal cord deafferentation might have on resting rCBF and to test whether resulting chronic preganglionic sympathectomy influenced cerebral vasomotor CO2 responsiveness and autoregulation. Thirteen patients had complete cervical cord transection (CCT) at levels C4--C6 (age 37 +/- 15 years, time interval, 2 months--20 years). Four patients had complete thoracic cord transection at levels T3--4, T8 and T12 (TCT; age 49 +/- 22 years; time interval 2--5 months). CO2 responsiveness was tested by induced hypercapnia in 11 patients with CCT and 2 patients with TCT. Autoregulation was tested in 10 patients with CCT and 4 patients with TCT by decreasing cerebral perfusion pressure during postural tilting. Mean resting hemispheric Fg values (MHFg) were significantly reduced only in patients with CCT (MHFg = 69 +/- 12 ml/100 g brain/min), while brain stem-cerebellar Fg values (BSC Fg) were reduced significantly both in patients with CCT (BSC Fg = 85 +/- 10) and with TCT (BSC Fg = 88 +/- 12) compared to values measured in healthy normals (N = 21, MHFg = 81 +/- 10, BSC Fg = 98 +/- 10). Hemispheric CO2 responsiveness showed a trend toward reduction in patients with CCT but this was not statistically significant. Hemispheric autoregulation was significantly impaired in CCT compared to healthy normals but improved with time and rehabilitation.     

Screening for prostate cancer in asymptomatic men: clinical, legal, and ethical implications

PURPOSE/OBJECTIVES: To describe the opposing recommendations of the major medical organizations related to screening for prostate cancer and to explore the impact of these opposing recommendations on advanced practice nurses (APNs) who are in a position to decide who gets screened and when. DATA SOURCES: Published medical, legal, and economic articles, published legal verdicts and settlements, case law, and news reports. DATA SYNTHESIS: The national recommendations for screening for prostate cancer are conflicting and have legal, economic, and ethical implications for healthcare practitioners. Both the current early diagnostic tests, age- and race-based prostate specific antigen ranges, and the resultant treatment have significant problems and further contribute to the national controversy about whether to screen asymptomatic men. Lack of coverage for early detection of prostate cancer by many managed-care plans and Medicare also contribute to the dilemma practitioners face. However, electing not to screen "at-risk" men may subject APNs to charges of negligence or other legal theories. CONCLUSIONS: Present recommendations by the leading national medical, cancer, and policy organizations related to prostate cancer screening are contradictory. Adding to this national quagmire is the lack of financial support from Medicare and most health maintenance organization plans to pay for early detection of prostate cancer. These conflicting recommendations place APNs in a legally and ethically precarious position. APNs and nurses with patient education responsibilities should individualize decision-making and counsel their asymptomatic patients who may be at risk for prostate cancer about the benefits and complications of screening. IMPLICATIONS FOR NURSING PRACTICE: Considering the multiple implications of the decision to screen for prostate cancer, counseling patients who may be at risk for the disease and involving them and their spouses may be the best approach in deciding whether to screen for prostate cancer in asymptomatic men.     

Frequency and type of colorectal tumors in asymptomatic high-risk individuals in families with hereditary nonpolyposis colorectal cancer

In hereditary nonpolyposis colorectal cancer (HNPCC, or Lynch syndrome) a close surveillance is usually proposed to high-risk family members with the ultimate goal of reducing cancer incidence and mortality. Through a specialized registry, between 1984 and 1996, we identified 31 families with clinical features of HNPCC. A total of 390 first-degree relatives of affected patients were considered at high risk for colorectal cancer. The main purposes of this study were: (a) to assess overall compliance; and (b) to evaluate the frequency and morphological features of tumors detected at endoscopy. Two hundred twenty-three subjects could be directly interviewed and colonoscopy strongly recommended. Each of the 86 individuals who underwent colonoscopy was matched to a control of the same age (+/-3 years) and sex (control subjects were seeking endoscopy for constipation, rectal bleeding or abdominal discomfort). Of the 390 individuals traced as "at risk," 223 (57.2%) could be contacted, and, of these, 86 (38.6%, or 22.0% of the total) underwent colonoscopy. One or more colorectal lesions were found in 35 of 86 (40.7%) HNPCC asymptomatic family members and in 15 (17.4%; P < 0.001) controls. In the former group, 29 adenomas were detected in 20 individuals as opposed to 11 adenomas in 9 subjects among controls (P < 0.03). Moreover, adenomas in family members were significantly larger [9.1 +/- 5.9 mm (mean +/- SD) versus 5.8 +/- 3.7 mm; P < 0.02] and more frequently showed a tubulovillous histological type and a high degree of dysplasia. Five colorectal carcinomas (in four patients) were detected among cases (four of which were located between the cecum and the hepatic flexure); only one was detected among controls. Surveillance of high-risk subjects in HNPCC families can be carried out only in a fraction of them, because the majority cannot be reached or refuse to collaborate. On the other hand, the frequency of newly detected lesions among family members and the possible aggressive behavior of the lesions render pancolonoscopy necessary at regular intervals of time.     

Screening for colorectal cancer: a survey of New Zealand general practitioners

AIM: To determine the attitudes and reported behaviours of New Zealand general practitioners concerning colorectal cancer screening and diagnosis with special consideration of the use of faecal occult blood tests. METHOD: A postal survey of a random sample of 400 New Zealand general practitioners. RESULTS: The response rate to the survey was 63%. Most of the respondents did not support a screening programme for average risk patients but did support screening in high risk groups. General practitioners favoured a screening programme offered by themselves rather than a centrally organised screening programme. A majority of respondents agreed that there was a lack of clear guidelines and a need for education regarding screening for bowel cancer. CONCLUSION: Guidelines for colorectal cancer screening are required for New Zealand general practitioners. There appears to be a need for medical education concerning screening for colorectal cancer in particular and screening and prevention in general.     

Screening for colorectal cancer with the Haemoccult test (author's transl)

Results are reported of a 5 year trial with the Haemoccult stool-test in a diagnostic center (DKD), and of a 1 year trial in the offices of 110 physicians. In the DKD 8 000 patients were tested: In a non-selected group 2,4% and in a selected one 3,8% of tests performed turned out to be positive; the diagnosis of carcinoma of the colon or rectum was established in 32 of these cases and 45 large polyps were traced. In most of the offices the test was positive in less than 3% of the patients tested, 57 of these patients had a carcinoma and 26 polyps. In 54 of all 89 cases with carcinoma and in 46 out of 71 polyps the lesions could not be found by digital or rectoscopic examination, due to a higher localization; 17 of the cancer patients were asymptomatic except for a positive Haemoccult test. Using only 3 tests per patients, 7 out of 96 colorectal cancers and 27 out of 98 large polyps were negative. 6 haemoccult tests to be done on three successive stools (as originally proposed by Greegor) are recommended as a yearly routine procedure in all persons about 40 years of age for early detection of carcinoma or polyps of the colon.     

Screening for colorectal cancer in Catalonia. Results of a population survey

This CT study was designed to assess brain morphology in agoraphobia. 21 patients and 21 normal control subjects matched in age and sex were investigated. Frontal and parietooccipital cortex, temporal cortex, lateral ventricles and third ventricle were evaluated by qualitative assessment on a 3-point scale (normal, questionable, abnormal). Patients showed significant bilateral enlargement of prefrontal cortical cerebrospinal fluid (CSF) spaces (p < .05). The rating "abnormal" was given to none (0%) of the normal controls, but to 6 (28.6%) of the patients in the left hemisphere, and to 4 patients (19%) in the right hemisphere, respectively. No qualitative differences were seen in the temporal cortex, lateral ventricles and third ventricle. These findings support the hypothesis that alterations in brain morphology are involved in the etiology of agoraphobia. The lack of a correlation between CSF enlargement and duration of illness suggests that prefrontal CSF enlargement is a neurobiological vulnerability marker in agoraphobia.