Cost benefits of hemoccult screening for colorectal carcinoma

Early detection for colorectal cancer: new aspects in fecal occult blood screening

The authors report on promising diagnostic methods of occult intestinal bleeding and discusses the potential new strategy of early detection of colorectal carcinomas in respect to old and new diagnostic measures available. Because of the limited sensitivity and specificity of classical methods used for the demonstration of occult fecal blood, the authors recommend the introduction of new techniques and markers in screening practice. It is presumed that new discoveries in molecular biology will improve the accuracy of early colorectal cancer prevention. Their implementation into routine screening, however, will not take place in the near future. Until their realization, improved screening efficacy is expected from the use of more specific and sensitive blood tests.

Screening for colorectal cancer

Colorectal cancer is the third most commonly diagnosed cancer and the second leading cause of cancer deaths in the United States. Fortunately, both the incidence and mortality associated with the disease have declined during the past 2 decades. This is likely due, at least in part, to improved efforts at screening and more aggressive removal of adenomatous polyps. However, colorectal cancer screening is still generally underutilized. This article reviews the current status and future outlook for colorectal cancer screening, including a discussion of risk factors for the disease, its anatomic distribution, proposed mechanisms of development from adenomatous polyps, rationale for screening, and screening options. Published literature concerning the cost-effectiveness of colorectal cancer screening is also summarized. The article concludes with a discussion of the emerging consensus regarding the importance of and approaches to screening.

Colorectal carcinoma: etiology, diagnosis, and screening

Colorectal carcinoma is a leading cause of death in the United States. Risk factors include genetic predisposition, diet, obesity, and inflammatory bowel disease. Early detection and chemoprevention can lead to a lower death rate. Future developments will include sensitive and specific large-scale screening.

Active detection of chronic obstructive pulmonary disease and asthma in the general population. Results and economic consequences of the DIMCA program

The aim of this prospective study was to detect subjects in the general population with objective signs of chronic obstructive pulmonary disease (COPD) or asthma at an early stage. This was done by means of a two-stage protocol involving screening and a subsequent 2-yr monitoring of all subjects with positive results of screening. The study was done in 10 general practices located in the eastern part of the Netherlands. A random sample was taken from the general population aged 25 to 70 yr. All known COPD and asthma patients were excluded. A total of 1,749 subjects met the inclusion criteria: 1,155 subjects (66%) agreed to participate in the screening stage of the study. A total of 604 subjects (52.3%) showed symptoms or objective signs of COPD or asthma during the screening and were considered "positive." Of those with positive screening results, 384 subjects (64%) agreed to participate in the second, 2-yr monitoring stage of the study. The costs involved in detection were calculated for three different scenarios, as follows: (1) The detection of subjects with persistently decreased lung function or an increased level of bronchial hyperresponsiveness (BHR) during 6 mo of monitoring; (2) Scenario 1 plus the detection of subjects with a rapid decline in lung function with signs of BHR during 12 mo of monitoring; (3) Scenario 2 plus the detection of subjects with a moderate increase in the decline in lung function or signs of BHR during 24 mo of monitoring. The costs of lung function assessments, organization, transportation, and patient time were included. The costs were converted to United States dollars on the basis of purchasing power (1 United States dollar = 2.08 Netherlands guilders). During the second stage, 252 subjects were detected with objective signs of COPD or asthma at an early stage. Smoking status as a screening criterion was neither sensitive nor specific. Because there was no evidence of biased recruitment or selection during the program, the proportions of subjects found to have objective signs of COPD or asthma at an early stage could be extrapolated to the general population. Of the general population, 7.7% showed persistently reduced lung function or increased BHR. Another 12.5 % of the general population showed a rapid decline in lung function (> 80 ml/yr) in combination with signs of BHR, and a further 19.4% of the general population showed mild objective signs of COPD or asthma. The average costs per detected case varied from US$953 (Scenario 1) to US$469 (Scenario 3). In conclusion, detection of COPD or asthma at an early stage by means of a two-stage protocol was feasible at relatively little expense in comparison with other mass screening programs. Persistently decreased lung function or a rapid decline in lung function (Scenario 2) was observed in approximately 20% of the general adult population.

Colorectal cancer screening in asymptomatic populations

Colorectal cancer is the second commonest cause of cancer death in the UK. An effective national screening programme is urgently required to reduce the substantial morbidity and mortality from the disease. The success of any screening programme will depend on the screening test detecting early Dukes's A carcinomas and adenomatous polyps. Prognosis is directly related to tumour staging and a proportion of carcinomas are thought to arise from polyps. Two screening methods exist--faecal occult blood testing and sigmoidoscopy. Large trials of faecal occult blood testing show that it detects more early lesions than in patients presenting with symptoms, but whether this reduces mortality is not yet confirmed and lack of sensitivity for cancers and polyps may ultimately limits its usefulness. The role of sigmoidoscopy in screening, particularly flexible sigmoidoscopy, has not been fully investigated. Flexible sigmoidoscopy has a greater sensitivity for distal lesions than stool testing and a randomised controlled trial of its efficacy is planned in Britain. Compliance with screening is essential to ensure its cost effectiveness in both health and economic terms. Large trials of faecal occult blood testing conducted over several years achieved compliance rates in excess of 60%, although in smaller studies these are often much less. Women frequently participate more than men. There are many reasons for non-compliance including lack of appreciation of the concept of asymptomatic illness and fear of the screening tests and cancer itself. Colorectal cancer screening is relatively cheap compared with breast and cervical cancer screening. Provisional cost estimates suggest that the amount spent to detect or prevent cancer by screening is similar to the amount required to treat a symptomatic patient.

Screening for colorectal cancer: what are the costs?

We examined a screening program for colorectal cancer in South Australia in terms of its overall direct costs to society and costs to participants. The best estimate of the cost per cancer detected was $18,924 (Australian dollars). Potential improvements in health outcome through screening are discussed in light of these costs.

Screening and the costs of treating colorectal cancer

The objective of this paper is to compare the hospital costs of treating patients with colorectal cancers detected as a result of a faecal occult blood screening programme with those of patients whose cancers present symptomatically (control group). Patient-specific cost estimates are made, using case records and hospital accounts, for 360 patients over 3 years. Mean treatment costs for the group offered screening and for the control group are calculated to be 3,179 pounds and 2,966 pounds respectively, although the difference between these means is insignificant. Low treatment costs in the case of screen-detected cancers are largely accounted for by polypectomy with no subsequent readmission; in the control group case, they tend to be accounted for by early patient death. For the sample as a whole, the costs of treating very early-, and very late-, stage cancer are significantly lower than those of treating cancers in the intermediate stages. On the basis of trial evidence, the introduction of mass screening for colorectal cancer is unlikely to give rise to substantial economies in the costs of treatment.

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.

Cost-effective management of colon and rectal cancer

Health care costs in the United States of America continue to rise. Legislators, economists and third party payers are becoming increasingly concerned with intervention outcomes and the distribution of resources. It is the responsibility of the medical profession to assume a leading role in assessing the cost-effectiveness of health care interventions. Although many physicians perform informal cost-effectiveness analyses on a daily basis, health economists employ a variety of more complex methodologies. This article will attempt to provide physicians with an understanding of the value and limitations of the tools used in formal cost-effectiveness analyses and demonstrate how these tools may be applied to the management of colon and rectal cancer.

A retrospective cost-effectiveness analysis of colorectal cancer screening in a public hospital. Savings from reduced hospitalization

We compared the actual diagnosis and treatment costs for nine colon cancer and 19 polyp patients detected by occult blood screening with excess hospitalization costs incurred by a comparable group of traditionally detected patients. Program benefits were calculated from data on group differentials in surgical length of stay, readmissions in the year following surgery, and preventive polypectomies. A sensitivity analysis was performed to evaluate varying estimates of the percentage of polyps that may have become cancers, the urgency of presentation of clinically apparent cancer, and the inclusion or exclusion of the observed differences for hospitalization in the year after surgery. Two year program benefits varied from 59% to 185% of program costs. Adjusting estimates with DRG weightings for resource intensity produced considerably higher benefits. All estimates of program benefits are conservative because screened patients were compared with the 15-20% least severely ill, most favorably staged of all traditionally detected colon cancer patients admitted. Results indicate that occult blood screening programs may produce significant benefits derived from outpatient diagnosis, preventive polypectomies, coordination of care between medical and surgical services, and enhanced patient education.

Cost-benefit impact on cancer screening

Prevention and early detection of cancer programs can double the survival rate in the next 5 years. For many programs it will cost more dollars than savings realized. Only through education can government, insurance carriers, and individuals realize that the value of these far exceeds cost when compared to cost of so many lifestyle things of temporary value.

Rescreening of a group at high risk for colorectal neoplasia using immunochemical tests for faecal occult blood

The results of a screening programme for colorectal neoplasia in a high risk group using an immunochemical test for blood has been reported recently. This test is known as the faecal human haemoglobin (FHH) test. This paper reports the results of rescreening this group after an interval of 1-2 years. The FHH test was compared with a paper disc method. All individuals with positive tests were investigated and those with negative tests were offered investigation. The results confirm the value of the FHH test in screening a high risk group: 19 individuals in 1,153 participants were found to have a significant neoplasm (1.6%). The predictive value of the test for a significant neoplasm was 42%. A false negative rate of 2.6% was found, all lesions being benign. It appears to be more reliable than the paper disc method but the differences do not reach statistical significance. The FHH test is recommended for screening the general population over the age of 40 years, with rescreening annually.

Cost effectiveness of HemoQuant versus Hemoccult for colorectal cancer screening

Initial reports on HemoQuant, a new quantitative test for occult gastrointestinal bleeding, suggest it is more sensitive than Hemoccult. Increased detection of upper gastrointestinal tract bleeding and dietary hemoglobin may reduce HemoQuant's specificity in the screening setting. The authors performed a cost effectiveness analysis comparing Hemoccult and HemoQuant for colorectal cancer screening using assumptions based on probabilities and costs in the current literature, varying the specificity of HemoQuant. The analysis showed the marginal cost effectiveness of Hemoccult versus no test to be $43,000, and HemoQuant versus Hemoccult to be $296,000 if HemoQuant specificity is 0.95. The marginal cost effectiveness ratio increased to $601,000 if three HemoQuant tests were used. Survival benefit was small and highly dependent on Hemoccult sensitivity and mortality from colonoscopy if HemoQuant specificity was less than 0.9. The authors conclude that unless the high sensitivity reported for HemoQuant is accompanied by a specificity comparable to that of Hemoccult, HemoQuant may not be an acceptable alternative for colorectal cancer screening.

Evaluation of an immunochemical test for faecal occult blood in screening for colorectal neoplasia in a high risk group

A group of 1615 asymptomatic individuals presumed to be at increased risk of colorectal neoplasia were selected as the study group. All were tested by an immunochemical test for faecal occult blood. In the second half of the study, individuals who were occult blood negative were offered colonoscopy. Ninety-nine individuals (6.1%) returned stools which were occult blood positive. Investigation by full colonoscopy was possible in 90 cases, revealing nine patients (10%) with invasive cancers, four patients (4.4%) with carcinomata in situ, and 36 patients (40%) with adenomata. Non-neoplastic pathology capable of producing occult blood positive stools was found in 31 individuals (34.4%). No pathology was found in 10 instances (11.1%). Of the 53 occult blood negative subjects who underwent colonoscopy, eight were found to have adenomata. Only one of these was larger than 5 mm in diameter (18 mm). No carcinomata were found. The site within the large bowel of the tumour did not appear to significantly affect the occult blood status of the faeces but the size of the tumours detected suggests that the presence of blood within the stool is more likely to be associated with larger lesions. The frequency of detection of both carcinomata and adenomata was greatest in individuals who had a past history of colorectal neoplasia. The individual cost of this immunochemical test is nominal. The high diagnostic yield and low false positive and negative rates suggest that case follow-up, surveillance, or screening utilizing this test is justified.

Colorectal carcinoma and Haemoccult. A study of its value in mass screening using meta-analysis

Meta-analysis has been performed on the world literature relating to Haemoccult screening for colorectal cancer. The analysis indicated a sensitivity of about 50%, specificity of about 97%, positive predictive value of 4.3% and negative predictive value of 99.85%. These figures assume a prevalence of colorectal cancer in the population of 0.3%. A model calculation using these figures together with some additional realistic assumptions suggests no reduction in mortality compared to an unscreened population. It is concluded that many questions about faecal occult blood screening remain and that uncontrolled mass population screening is not justified at this stage.

The pros and cons of fecal occult blood testing for colorectal neoplasms

Testing feces for occult blood is widely recommended as a means of detecting subclinical colorectal tumors. Guaiac tests such as Hemoccult are the most widely used, but chemical sensitivity is relatively low and the tests are affected by dietary peroxidases, the state of fecal hydration, and certain drugs. The newly devised HemoQuant and immunologic techniques appear more sensitive and specific, but they require further evaluation before widespread clinical usage can be recommended. Occult blood screening has both merits and weaknesses. Testing does uncover subclinical colorectal cancer, often at a relatively early stage, but whether this actually improves the prognosis remains to be proven. Benign neoplastic polyps are also detected, although it is debatable whether this is a valid rationale for screening. Test sensitivity for malignancy varies from good to moderate, but is poor for benign polyps. Specificity is usually around 97%-98%, yet the predictive value of a positive test for cancer is only about 10%; hence most test-positive individuals are needlessly subjected to invasive colonic investigations. Reported figures on public compliance with occult blood testing vary widely from excellent to poor. Published costs of screening are usually quite low, but these overlook important indirect and hidden expenses and are therefore misleading. On balance, the problems of occult blood testing currently appear to outweight the merits. This could change, however, with the newer testing techniques and with awaited mortality data from controlled clinical trials now underway.

Effect of workup strategy on the cost-effectiveness of fecal occult blood screening for colorectal cancer

Physicians respond to a positive fecal occult blood test with a variety of workup strategies. To study the effect of the choice of strategy on the net costs and health benefits of colorectal cancer screening using this test, we used a decision analysis model to compare seven strategies that physicians might choose to examine a positive "screenee." Strategies using rigid or flexible sigmoidoscopy alone are not only insensitive, but also have high cost-effectiveness ratios. The strategy of air contrast barium enema alone had the lowest cost-effectiveness ratio. Rigid sigmoidoscopy combined with barium enema had a lower cost-effectiveness ratio than primary colonoscopy, but the strategy of primary colonoscopy could have an equal or better ratio depending on assumptions about test costs and the benefit of removing benign polyps. The primary colonoscopy strategy is both more effective and less costly than the combination of flexible sigmoidoscopy and barium enema. The optimal strategy will vary with local factors, and with the perspective of the decision-maker.

Mass screening for colorectal cancer in Hungary

Haemoccult screening for colorectal tumours was carried out in Hungary in small cities and villages around Budapest. Haemoccult slides were supplied to 17,662 individuals over 40 years of age, and 15,431 (87%) were returned. Of these, 346 (2.2%) were positive and 18 colorectal carcinomas were detected. Additionally, 24 patients with one or more polyps greater than 1 cm diameter were found. Of the screened cases of cancer 39% were in Dukes' stage A and B, a rate twice as good as when screening was not done. The cost per tumour detected amounted to about three times more than one monthly income, indicating that the costs of screening for colorectal cancer are relatively much higher in Hungary than in Western countries. All expenses were met from state funds.

Screening of colorectal cancer

Colorectal cancer (CRC) remains a cancer in a disappointing location. However, its location clearly has an advantage that could theoretically permit efficient secondary prevention: the preceding of the cancer by a benign lesion, ie, the adenoma. Complete colonoscopy and its substitute, the double-contrast barium enema, and their specific limitations, must be reserved for high-risk patients: hereditary cancers and ulcerative colitis. For all the others, ie, adults of 45 years of age and with standard risks, the proposal is either to select the patients to be colonoscoped through occult blood testing of the stools or to perform a fiber sigmoidoscopy or a combination of both. Although imperfect, both methods allow the detection of polyps and cancers at a presymptomatic stage, when they are either benign or malignant, but localized and with a better prognosis. However, the absolute proof of the benefits of this strategy of screening would be the demonstration by controlled studies of a prolonged survival rate or a decrease in morbidity. Until now, this proof is not fully available.