A critical analysis of the largest reported mass fecal occult blood screening program in the United States

Physician Recommendations for Follow-Up of Positive Fecal Occult Blood Tests

Following a positive fecal occult blood test (FOBT), physician recommendation of complete diagnostic evaluation (CDE) is an important first step to ensure identification and treatment of preinvasive or invasive colorectal cancer. Physicians may not recommend CDE, however, potentially compromising the effectiveness of colorectal cancer screening programs and the quality of care for individual patients. The authors used a theoretical model of health behavior and two national physician samples to explore factors associated with recommendations for CDE. Overall, 63 percent of the sample of physicians providing primary care and 76 percent of the gastroenterologist and general surgeon sample reported recommending CDE. Variables representing the theoretical model constructs of physician background, experience, and practice patterns; practice environment; physician psychosocial representations; and patient characteristics were significantly associated with recommendations of CDE. Development of interventions to improve recommendations of CDE is an important area for future research.

Costs and outcomes evaluation of patient navigation after abnormal cancer screening: evidence from the Patient Navigation Research Program

BACKGROUND

Navigators can facilitate timely access to cancer services, but to the authors' knowledge there are little data available regarding their economic impact.

METHODS

The authors conducted a cost-consequence analysis of navigation versus usual care among 10,521 individuals with abnormal breast, cervical, colorectal, or prostate cancer screening results who enrolled in the Patient Navigation Research Program study from January 1, 2006 to March 31, 2010. Navigation costs included diagnostic evaluation, patient and staff time, materials, and overhead. Consequences or outcomes were time to diagnostic resolution and probability of resolution. Differences in costs and outcomes were evaluated using multilevel, mixed-effects regression modeling adjusting for age, race/ethnicity, language, marital status, insurance status, cancer, and site clustering.

RESULTS

The majority of individuals were members of a minority (70.7%) and uninsured or publically insured (72.7%). Diagnostic resolution was higher for navigation versus usual care at 180 days (56.2% vs 53.8%; P = .008) and 270 days (70.0% vs 68.2%; P < .001). Although there were no differences in the average number of days to resolution between the 2 groups (110 days vs 109 days; P = .63), the probability of ever having diagnostic resolution was higher for the navigation group versus the usual-care group (84.5% vs 79.6%; P < .001). The added cost of navigation versus usual care was $275 per patient (95% confidence interval, $260-$290; P < .001). There was no significant difference in stage distribution among the 12.4% of patients in the navigation group vs 11% of the usual-care patients diagnosed with cancer.

CONCLUSIONS

Navigation adds costs and modestly increases the probability of diagnostic resolution among patients with abnormal screening test results. Navigation is only likely to be cost-effective if improved resolution translates into an earlier cancer stage at the time of diagnosis.

Classification tree analysis to enhance targeting for follow-up exam of colorectal cancer screening

BACKGROUND

Follow-up rate after a fecal occult blood test (FOBT) is low worldwide. In order to increase the follow-up rate, segmentation of the target population has been proposed as a promising strategy, because an intervention can then be tailored toward specific subgroups of the population rather than using one type of intervention for all groups. The aim of this study is to identify subgroups that share the same patterns of characteristics related to follow-up exams after FOBT.

METHODS

The study sample consisted of 143 patients aged 50-69 years who were requested to undergo follow-up exams after FOBT. A classification tree analysis was performed, using the follow-up rate as a dependent variable and sociodemographic variables, psychological variables, past FOBT and follow-up exam, family history of colorectal cancer (CRC), and history of bowel disease as predictive variables.

RESULTS

The follow-up rate in 143 participants was 74.1% (n = 106). A classification tree analysis identified four subgroups as follows; (1) subgroup with a high degree of fear of CRC, unemployed and with a history of bowel disease (n = 24, 100.0% follow-up rate), (2) subgroup with a high degree of fear of CRC, unemployed and with no history of bowel disease (n = 17, 82.4% follow-up rate), (3) subgroup with a high degree of fear of CRC and employed (n = 24, 66.7% follow-up rate), and (4) subgroup with a low degree of fear of CRC (n = 78, 66.7% follow-up rate).

CONCLUSION

The identification of four subgroups with a diverse range of follow-up rates for CRC screening indicates the direction to take in future development of an effective tailored intervention strategy.

Long-term outcomes following positive fecal occult blood test results in older adults: benefits and burdens

BACKGROUND

In the United States, older adults have low rates of follow-up colonoscopy after a positive fecal occult blood test (FOBT) result. The long-term outcomes of these real world practices and their associated benefits and burdens are unknown.

METHODS

Longitudinal cohort study of 212 patients 70 years or older with a positive FOBT result at 4 Veteran Affairs (VA) facilities in 2001 and followed up through 2008. We determined the frequency of downstream outcomes during the 7 years of follow-up, including procedures, colonoscopic findings, outcomes of treatment, complications, and mortality based on chart review and national VA and Medicare data. Net burden or benefit from screening and follow-up was determined according to each patient's life expectancy. Life expectancy was classified into 3 categories: best (age, 70-79 years and Charlson-Deyo comorbidity index [CCI], 0), average, and worst (age, 70-84 years and CCI, ≥4 or age, ≥85 years and CCI, ≥1).

RESULTS

Fifty-six percent of patients received follow-up colonoscopy (118 of 212), which found 34 significant adenomas and 6 cancers. Ten percent experienced complications from colonoscopy or cancer treatment (12 of 118). Forty-six percent of those without follow-up colonoscopy died of other causes within 5 years of FOBT (43 of 94), while 3 died of colorectal cancer within 5 years. Eighty-seven percent of patients with worst life expectancy experienced a net burden from screening (26 of 30) as did 70% with average life expectancy (92 of 131) and 65% with best life expectancy (35 of 51) (P = .048 for trend).

CONCLUSIONS

Over a 7-year period, older adults with best life expectancy were less likely to experience a net burden from current screening and follow-up practices than are those with worst life expectancy. The net burden could be decreased by better targeting FOBT screening and follow-up to healthy older adults.

Improving follow-up of abnormal cancer screens using electronic health records: trust but verify test result communication

Background

Early detection of colorectal cancer through timely follow-up of positive Fecal Occult Blood Tests (FOBTs) remains a challenge. In our previous work, we found 40% of positive FOBT results eligible for colonoscopy had no documented response by a treating clinician at two weeks despite procedures for electronic result notification. We determined if technical and/or workflow-related aspects of automated communication in the electronic health record could lead to the lack of response.

Methods

Using both qualitative and quantitative methods, we evaluated positive FOBT communication in the electronic health record of a large, urban facility between May 2008 and March 2009. We identified the source of test result communication breakdown, and developed an intervention to fix the problem. Explicit medical record reviews measured timely follow-up (defined as response within 30 days of positive FOBT) pre- and post-intervention.

Results

Data from 11 interviews and tracking information from 490 FOBT alerts revealed that the software intended to alert primary care practitioners (PCPs) of positive FOBT results was not configured correctly and over a third of positive FOBTs were not transmitted to PCPs. Upon correction of the technical problem, lack of timely follow-up decreased immediately from 29.9% to 5.4% (p < 0.01) and was sustained at month 4 following the intervention.

Conclusion

Electronic communication of positive FOBT results should be monitored to avoid limiting colorectal cancer screening benefits. Robust quality assurance and oversight systems are needed to achieve this. Our methods may be useful for others seeking to improve follow-up of FOBTs in their systems.

Using a multifaceted approach to improve the follow-up of positive fecal occult blood test results

OBJECTIVES

Inadequate follow-up of abnormal fecal occult blood test (FOBT) results occurs in several types of practice settings. Our institution implemented multifaceted quality improvement (QI) activities in 2004-2005 to improve follow-up of FOBT-positive results. Activities addressed precolonoscopy referral processes and system-level factors such as electronic communication, provider education, and feedback. We evaluated their effects on timeliness and appropriateness of positive-FOBT follow-up and identified factors that affect colonoscopy performance.

METHODS

Retrospective electronic medical record review was used to determine outcomes before and after QI activities in a multispecialty ambulatory clinic of a tertiary care Veterans Affairs facility and its affiliated satellite clinics. From 1869 FOBT-positive cases, 800 were randomly selected from time periods before and after QI activities. Two reviewers used a pretested standardized data collection form to determine whether colonoscopy was appropriate or indicated based on predetermined criteria and if so, the timeliness of colonoscopy referral and performance before and after QI activities.

RESULTS

In cases where a colonoscopy was indicated, the proportion of patients who received a timely colonoscopy referral and performance were significantly higher post-implementation (60.5% vs. 31.7%, P<0.0001 and 11.4% vs. 3.4%, P=0.0005). A significant decrease also resulted in median times to referral and performance (6 vs. 19 days, P<0.0001 and 96.5 vs. 190 days, P<0.0001) and in the proportion of positive-FOBT test results that had received no follow-up by the time of chart review (24.3% vs. 35.9%, P=0.0045). Significant predictors of absence of the performance of an indicated colonoscopy included performance of a non-colonoscopy procedure such as barium enema or flexible sigmoidoscopy (OR=16.9; 95% CI, 1.9-145.1), patient non-adherence (OR=33.9; 95% CI, 17.3-66.6), not providing an appropriate provisional diagnosis on the consultation (OR=17.9; 95% CI, 11.3-28.1), and gastroenterology service not rescheduling colonoscopies after an initial cancellation (OR=11.0; 95% CI, 5.1-23.7).

CONCLUSIONS

Multifaceted QI activities improved rates of timely colonoscopy referral and performance in an electronic medical record system. However, colonoscopy was not indicated in over one third of patients with positive FOBTs, raising concerns about current screening practices and the appropriate denominator used for performance measurement standards related to colon cancer screening.

Reasons patients with a positive fecal occult blood test result do not undergo complete diagnostic evaluation

PURPOSE

Screening for fecal occult blood reduces colorectal cancer mortality by identifying patients with positive results for complete diagnostic evaluation (CDE). CDE rates are suboptimal, however. We sought to determine common reasons for nonperformance of a CDE as recorded by the primary care physician.

METHODS

We undertook a descriptive analysis of reasons reported by physicians for nonperformance of CDE in a nested sample of patients with positive fecal occult blood test (FOBT) results from a randomized controlled trial designed to evaluate the impact of a physician intervention (CDE reminder-feedback and educational outreach) on recommendation and performance rates in primary care practices. Inspection of administrative data for 1,468 patients with positive results showed that 661 (45%) did not undergo CDE. We reviewed patient follow-up forms, which were completed by physicians for patients who did not have a CDE, to identify reasons for nonperformance.

RESULTS

Nonperformance of CDE was due to physician decision for 217 patients (33%). In 123 patients (19%), reasons for nonperformance were compatible with the guidelines, and in 94 patients (14%), they were not. Reasons wholly or partially due to factors other than physician decision were noted in 212 patients (32%); physician action was considered to be appropriate in these patients. For the 232 patients (35%) without a clearly documented reason for CDE nonperformance, the appropriateness of the physicians' action could not be determined.

CONCLUSIONS

Decision making by primary care physicians had a major effect on nonperformance of CDE after a positive FOBT result. Colorectal cancer screening programs should include guidance for physicians about when a CDE should and should not be performed.

Improvement in the diagnostic evaluation of a positive fecal occult blood test in an integrated health care organization

BACKGROUND

Screening for fecal occult blood can be effective in reducing colorectal cancer mortality only if positive tests are appropriately followed up with complete diagnostic evaluation (ie, colonoscopy or flexible sigmoidoscopy with double contrast barium enema) and treatment.

OBJECTIVES

To examine whether rates of complete diagnostic evaluation after a positive fecal occult blood test (FOBT) have improved over time after the implementation of tracking systems and physician guidelines within a large integrated health care organization.

RESEARCH DESIGN

From 1993 to 2005, 8513 positive FOBTs were identified on 8291 enrollees aged 50-79 of a large health care system. Automated records were used to identify repeat FOBTs, colonoscopy, flexible sigmoidoscopy, and double-contrast barium enema within 1 year after the positive FOBT. National rates of complete diagnostic evaluation were estimated from the 2005 National Health Interview Survey.

RESULTS

In this integrated health care organization, the percentage of positive FOBTs followed by complete diagnostic evaluation within 1 year increased from 57-64% in 1993-1996 to 82-86% from 2000-2005. Use of repeat FOBT after a positive FOBT decreased from 28-31% in 1993-1996 to 6-11% in 2000-2005. Based on the National Health Interview Survey, only 52% of positive FOBTs in 2000-2005 were followed by complete diagnostic evaluation nationally.

CONCLUSIONS

Adherence to recommendations for complete diagnostic evaluation after a positive FOBT has greatly improved over time in an integrated group medical practice. Through the use of tracking systems and screening guidelines, it may be possible to reach levels of follow-up that are comparable to those observed in randomized trials.

As tests evolve and costs of cancer care rise: reappraising stool-based screening for colorectal neoplasia

BACKGROUND

Colorectal cancer screening and treatment are rapidly evolving. Aims To reappraise stool-based colorectal cancer screening in light of changing test performance characteristics, lower test cost and increasing colorectal cancer care costs.

METHODS

Using a Markov model, we compared faecal DNA testing every 3 years, annual faecal occult blood testing or immunochemical testing, and colonoscopy every 10 years.

RESULTS

In the base case, faecal occult blood testing and faecal immunochemical testing gained life-years/person and cost less than no screening. Faecal DNA testing version 1.1 at $300 (the current PreGen Plus test) gained 5323 life-years/100 000 persons at $16 900/life-year gained and faecal DNA testing version 2 (enhanced test) gained 5795 life-years/100 000 persons at $15 700/life-year gained vs. no screening. In the base case and most sensitivity analyses, faecal occult blood testing and faecal immunochemical testing were preferred to faecal DNA testing. Faecal DNA testing version 2 cost $100 000/life-year gained vs. faecal immunochemical testing when per-cycle adherence with faecal immunochemical testing was 22%. Faecal immunochemical testing with excellent adherence was superior to colonoscopy every 10 years.

CONCLUSIONS

As novel biological therapies increase colorectal cancer treatment costs, faecal occult blood testing and faecal immunochemical testing could become cost-saving. The cost-effectiveness of faecal DNA testing compared with no screening has improved, but faecal occult blood testing and faecal immunochemical testing are preferred to faecal DNA testing when patient adherence is high. Faecal immunochemical testing may be comparable to colonoscopy every 10 years in persons adhering to yearly testing.

Effectiveness of complete diagnostic examination in clinical practice settings

BACKGROUND

Thorough follow-up of a positive fecal occult blood test (FOBT) result, or a complete diagnostic evaluation (CDE), is recommended as routine care on the basis of findings from colorectal cancer (CRC) screening trials. CDE involves either colonoscopy or the combination of flexible sigmoidoscopy and double contrast barium enema X-ray. However, little evidence outside clinical screening trial settings has been reported in the literature to support CDE performance. The focus of this study was to determine the impact of CDE in primary care practice settings.

METHODS

We determined diagnostic outcomes for 461 adult patients with a positive FOBT result in 318 primary care practices in southeastern Pennsylvania and southern New Jersey. Sociodemographic data were collected and CDE status was ascertained for these patients. Polytomous logistic models were used to identify whether having CDE was associated with subsequently being diagnosed with lower gastrointestinal "neoplastic disease" or "other gastrointestinal disease" as compared to "normal findings.

RESULTS

Patients who underwent CDE were significantly more likely to have a reported diagnosis of colorectal neoplasia than normal findings (adjusted odds ratio = 3.65, 95% confidence interval = 1.58-8.39, p = 0.02). CDE performance did not result in the differential diagnosis of other gastrointestinal disease.

CONCLUSIONS

Patients with a positive screening FOBT who underwent CDE were more likely to be diagnosed with colorectal neoplasia than with less serious conditions or have normal findings. Results support the use of CDE in CRC screening.

What Factors Are Associated with Diagnostic Follow-Up after Abnormal Mammograms? Findings from a U.S. National Survey

The purpose of this study was to identify factors associated with diagnostic follow-up after an abnormal mammogram in a national sample of women in the U.S. The sample was selected from the year 2000 National Health Interview Survey and included 1901 women aged 30 and above who reported ever having an abnormal mammogram. The outcome measure was receipt of at least some diagnostic follow-up after an abnormal mammogram. Bivariate and multivariate logistic regression analyses were used to explore the associations between sociodemographic characteristics, general health and health behaviors, cancer risk and risk perceptions, and health care utilization characteristics and follow-up. Approximately 9% of women who reported ever having abnormal mammograms reported not completing any additional diagnostic follow-up. Controlling for all other factors, women with less than a high school education were less likely to report follow-up after an abnormal mammogram than were women who had at least completed college (odds ratio = 0.56; 95% confidence interval: 0.32, 0.98). Younger women and women in poorer health were also less likely to report follow-up. Women who perceived a high versus low level of cancer in their family were more likely to report follow-up (odds ratio = 1.65; 95% confidence interval: 1.04, 2.62), controlling for all other factors. In a national sample of women with abnormal mammograms, a substantial number did not complete any diagnostic follow-up, potentially reducing the effectiveness of mammography screening programs in the U.S. Additional research on subsequent screening behaviors for women with incomplete follow-up and in-depth exploration of the roles of patient-provider interactions and health care system factors related to the index abnormal mammogram is warranted.

Is the promise of cancer-screening programs being compromised? Quality of follow-up care after abnormal screening results

Cancer screening has increased dramatically in the United States, yet in some populations, particularly racial minorities or the poor, advanced disease at diagnosis remains high. One potential explanation is that follow-up of abnormal tests is suboptimal, and the benefits of screening are not being realized. The authors used a conceptual model of access to care and integrated constructs from models of provider and patient health behaviors to review published literature on follow-up care. Most studies reported that fewer than 75 percent of patients received some follow-up care, indicating that the promise of screening may be compromised. They identified pervasive barriers to follow-up at the provider, patient, and health care system levels. Interventions that address these barriers appear to be effective. Improvement of data infrastructure and reporting will be important objectives for policy makers, and further use of conceptual models by researchers may improve intervention development and, ultimately, cancer control.

Fecal occult blood testing in a general medical clinic: comparison between guaiac-based and immunochemical-based tests

PURPOSE

Guaiac-based fecal occult blood tests are limited by poor patient compliance, and low sensitivity, specificity, and positive predictive value. Newer immunochemical-based tests are designed to improve accuracy and patient compliance. We compared patient compliance and the test characteristics of these two types of tests.

METHODS

The laboratory outcomes associated with use of different fecal occult blood tests were examined in a Veterans Affairs-based general medicine clinic that was divided into two firms with similar patient and provider characteristics. Tests were ordered for colorectal cancer screening or for symptom evaluation. Patients were given one of the two tests depending on their firm. The completion and positivity rates, time to test completion, completion of diagnostic follow-up, and positive predictive values were compared.

RESULTS

The percentage of returned test cards was similar between the two groups (47% [1369/2964] for guaiac-based tests vs. 48% [1410/2965] for immunochemical-based tests) as was the positivity rate (9.0% [122/1396] and [128/1410] for both groups). In patients with positive tests who underwent further colon evaluation, the proportion with adenomas was similar between groups (59% [38/64] vs. 58% [40/69]). However, 17% (12/69) with a positive immunochemical-based test had an adenoma >1 cm or a colorectal malignancy, versus 30% (19/64) for guaiac-based tests (P = 0.09).

CONCLUSION

Overall, immunochemical-based and guaiac-based fecal occult blood tests had comparable performance. However, although immunochemical-based testing is reported to be easier for patients than guaiac-based testing, we found that patients were no more likely to return cards for analysis. The similar positive predictive value and additional cost of immunochemical-based tests call into question their utility in general practice.

Factors that influence the decision to do an adequate evaluation of a patient with a positive stool for occult blood

OBJECTIVE

The factors that influence the decision to do an adequate evaluation for a positive test for fecal occult blood in a middle-aged or elderly patient are largely unknown. Our study was undertaken to determine whether factors such as the number of positive Hemoccult II card windows, age, gender, family history of colon cancer, the patient's concern that he or she might have colon cancer, or history of rectal bleeding influence the evaluation performed.

METHOD

A mass screening program for colon cancer was performed using unrehydrated Hemoccult II cards in the Boston area.

RESULTS

Among the 23,593 Hemoccult II cards returned to Beth Israel Deaconess Medical Center, cards from 1,112 patients (4.7%) were found to be positive for one or more of the six possible card windows. Ninety percent, or 940 patients, over 40 yr of age had follow-up information available. As the number of positive windows increased from one to four, there was a significant trend (p < 0.001) for the adequacy of the evaluation to increase. Family history (p = 0.044) and a patient's worry that he or she might have colon cancer (p = 0.003) significantly improved a patient's chance for an adequate evaluation.

CONCLUSIONS

Hemoccult testing is not followed by an adequate evaluation in a significant proportion of patients. Our study points out for the first time that the number of positive Hemoccult windows significantly influences the decision-making.

Diagnostic testing following fecal occult blood screening in the elderly

BACKGROUND

Screening with a fecal occult blood test (FOBT) has been shown to reduce colorectal cancer mortality in controlled trials. Recently, Medicare approved payment for FOBT screening. We evaluated the pattern of diagnostic testing following the initial FOBT in elderly Medicare beneficiaries. Such follow-up testing would in the long run influence both the cost and the benefit of widespread use of FOBT.

METHODS

Using Medicare's National Claims History System, we identified 24 246 Americans 65 years old or older who received FOBT at physician visits between January 1 and April 30, 1995. Prior to FOBT, these people had no evidence of any conditions for which FOBT might be used diagnostically. We examined relevant diagnostic testing in this cohort during the subsequent 8 months and determined what proportion of those received an evaluation recommended by the American College of Physicians.

RESULTS

For every 1000 Medicare beneficiaries who received FOBT, 93 (95% confidence interval = 89-96 per 1000) had positive findings and relevant testing in the subsequent 8 months. Of these, 34% had the recommended evaluation of either colonoscopy or flexible sigmoidoscopy with an air-contrast barium enema. Another 34% received a partial colonic evaluation with either flexible sigmoidoscopy or a barium enema. The remaining 32% received other gastrointestinal (GI) testing without evaluation of the colonic lumen: computed tomography or magnetic resonance imaging of the abdomen (15%), upper GI series (10%), carcinoembryonic antigen (7%), and upper endoscopy (2%). Restricting the analysis to testing performed within 2 months of the initial FOBT yielded similar results.

CONCLUSION

Following FOBT, many Medicare beneficiaries get further diagnostic testing, but only a small proportion receives the recommended evaluation. With this pattern of practice, population screening is likely to be more costly and less effective than estimated from controlled trials.

Screening for colorectal cancer: present, past and future

Colorectal cancer results in 18,000 deaths annually in England and Wales, with 24,000 new cases diagnosed each year. Despite a better understanding of the genetics, and advancement in surgical and anaesthetic techniques, there has been little reduction in mortality and morbidity from this disease over the past 25 years. Colorectal cancer fits recognized criteria for a disease that should be screened in asymptomatic individuals. The putative duration of the adenoma to carcinoma sequence gives an ample window of opportunity to detect and treat colorectal cancer. In this article we have reviewed the strategies involved in screening for colorectal cancer in an asymptomatic population. We have presented trials and arguments for and against the different screening methods and discussed cost effectiveness of screening. In the USA and Canada, major professional organizations and societies now endorse screening; in the UK it is still far from being accepted. We feel that the available evidence shows that colorectal cancer screening has the potential to reduce the morbidity and mortality from this disease and that funding for a mass screening and public education programme should be sought.

The value of tumor markers in colorectal cancer

Currently CEA is the most accurate tumor marker for colorectal cancer. Preoperative determination of this marker can assist staging, treatment planning and in particular postoperative follow-up of colorectal cancer. Postoperative CEA monitoring should be performed every 3 months. Further evaluation for local recurrence or metastatic disease is mandatory if elevated or increasing CEA levels occur after radical surgery. However, present data do not justify using CEA alone for postoperative follow-up and monitoring of adjuvant therapy. Molecular genetic techniques are now increasingly performed to detect genetic alterations that can be used as prognostic markers. In the future, identification and quantification of these genes may even be valuable in defining the susceptibility of healthy individuals for colorectal cancer.

Participation in colorectal cancer screening: a review

The purpose of this review is to evaluate the published literature on adherence to colorectal cancer (CRC) screening with fecal occult blood testing (FOBT) and sigmoidoscopy. Specifically, the review addresses the following: 1) prevalence of FOBT and sigmoidoscopy; 2) interventions to increase adherence to FOBT and sigmoidoscopy; 3) correlates or predictors of adherence to FOBT and sigmoidoscopy; and 4) reasons for nonadherence. Other objectives are to put the literature on CRC screening adherence in the context of recently reported findings from experimental interventions to change prevention and early detection behaviors and to suggest directions for future research on CRC screening adherence. CRC screening offers the potential both for primary and for secondary prevention. Data from the 1992 National Health Interview Survey show that 26% of the population more than 49 years of age report FOBT within the past 3 years and 33% report ever having had sigmoidoscopy. The Year 2000 goals set forth in Healthy People 2000 are for 50% of the population more than 49 years of age to report FOBT within the past 2 years and for 40% to report that they ever had sigmoidoscopy. Thus, systematic efforts to increase CRC screening are warranted. To date, attempts to promote CRC screening have used both a public health model that targets entire communities, e.g., mass media campaigns, and a medical model that targets individuals, e.g., general practice patients. Most of these efforts, however, did not include systematic evaluation of strategies to increase adherence. The data on FOBT show that the median adherence rate to programmatic offers of FOBT is between 40% and 50%, depending on the type of population offered the test, e.g., patients or employees. Approximately, 50% of those initially offered testing in unselected populations will respond to minimal prompts or interventions. A salient issue for FOBT, however, is whether or not the behavior can be sustained over time. Fewer studies examined adherence to sigmoidoscopy. Adherence was highest in relatives of CRC cases and in employer-sponsored programs offered to workers at increased risk of CRC. At present, we know very little about the determinants of CRC screening behaviors, particularly as they relate to rescreening.

Colorectal cancer screening

The decision whether to launch a screening program in asymptomatic patients of average risk for colorectal cancer and the selection of the appropriate protocol for screening are complex issues. There are still many unanswered questions. Many organizations such as the American Cancer Society, the World Health Organization Collaborating Center for the Prevention of Colorectal Cancer, and the U.S. National Cancer Institute advocate screening with annual Hemoccult tests and screening with flexible sigmoidoscopy every 3 to 5 years in patients more than 50 years of age. The U.S. Preventive Services Task Force, the Canadian Task Force on Periodic Health Examination, and the International Union Against Cancer have not recommended screening asymptomatic average-risk patients for colorectal cancer. One study showed a small but significant benefit (3 per 1000) of the rehydrated annual Hemoccult test in reducing mortality from colorectal cancer. To embark on a mass screening strategy as recommended, however, would require significant costs, increases in physician training, improved access to the requisite technology, and enhancements in patient and physician compliance. Furthermore, the high false-positive rates of the rehydrated Hemoccult tests would lead to many unnecessary tests, causing greater expense as well as patient discomfort and anxiety. It is, therefore, premature to recommend mass screening for colorectal cancer in asymptomatic individuals at this time. Further research is needed to identify risk factors (such as genetic markers) better and to develop and evaluate screening strategies targeted at those with high risk for colorectal cancer. In the meantime, efforts at primary prevention for the general population should be increased (through nutrition and exercise). Patients over the age of 50 who desire screening should be given information of the benefits and risks of screening and together with their physicians decide on a screening strategy that suits their needs and values.

Colorectal carcinoma: analysis of management in two medical eras

Trends in presentation, diagnosis, management, and outcome were analyzed for 503 patients with colorectal cancer seen at the UCLA Medical Center between 1960 and 1970 (Group A; n = 210) and 1980 and 1985 (Group B; n = 293). Patients in the latter group exhibited a shift in site to the right side of the colon (18% in Group A vs. 31% in Group B; P < .01), an increase in the number of primary resections without colostomy (38% vs. 61%; P < .01), a lower overall complication rate (28% vs. 18%; P = .01), and a decline in 30-day mortality (6.2% vs. 2%; P = .01). Although little difference was seen in detection of asymptomatic tumors, earlier lesions were treated in the latter group, accounting for substantially reduced rate of recurrence (69% in Group A vs. 44% in Group B; P < .01). Future management should include an emphasis on earlier detection in order to continue the trend toward enhanced survival.

Perspectives in colorectal cancer

This paper presents an overview of recent developments pertaining to colorectal adenocarcinoma. It is aimed toward the practicing clinician. Topics discussed include epidemiologic observations; genetic predispositions; molecular biology findings; screening and early detection programs; endoscopy; principles of surgical resection; laser and radioimmunoguided surgery; staging; selection of patients for adjuvant chemotherapy; and considerations regarding biologic response modifiers and pain control in the advanced-disease setting.