Screening for colorectal cancer: what is the most cost-effective approach?

Diversity of model approaches for breast cancer screening: a review of model assumptions by The Cancer Intervention and Surveillance Network (CISNET) Breast Cancer Groups

The National Cancer Institute-sponsored Cancer Intervention and Surveillance Network program on breast cancer is composed of seven research groups working largely independently to model the impact of screening and adjuvant therapy on breast cancer mortality trends in the US from 1975 to 2000. Each of the groups has chosen a different modeling methodology without purposeful attempt to be in contrast with each other. The seven groups have met biannually since November 2000 to discuss their methodology and results. This article investigates the differences in methodology. To facilitate this comparison, each of the groups submitted a description of their model into a uniformly structured web based ‘model profiler’. Six of the seven models simulate a preclinical natural history that cannot be observed directly with parameters estimated from published evidence concerning screening and therapy effects. The remaining model regards published evidence on intervention effects as prior information and updates that with information from the US population in a Bayesian type analysis. In general, the differences between the models appear to be small, particularly among the models driven by natural history assumptions. However, we demonstrate that such apparently small differences can have a large impact on surveillance of population trends. We describe a systematic approach to evaluating differences in model assumptions and results, as well as differences in modeling culture underlying the differences in model structure and parameters.

[Cost-effectiveness of colorectal cancer screening]

Colorectal cancer (CRC) screening in France is based on a faecal occult blood test every two years in average risk subjects 50-74 years of age while other endoscopic or non-endoscopic screening methods are used in Europe and in the USA. Beside the reduced incidence of and mortality from CRC found in available studies, cost-effectiveness data need to be taken into account. Because of the delay between randomized controlled trials and clinical results, transitional probabilistic models of screening programs are useful for public health policy makers. The aim of the present review was to promote the implementation of cost-effectiveness studies, to provide a guide to analyze cost-effectiveness studies on CRC screening and, to propose a French cost effectiveness study comparing CRC screening strategies. Most of these trials were performed by US or UK authors and demonstrate that the incremental cost-effectiveness ratio varies between 5 000 and 15 000 US dollars/one year life gained, with wide variations: these results were highly dependent on the unit costs of the different devices as well as the predictive values of the screening tests. Although CRC screening programs have been implemented in several administrative districts of France since 2002, and the results of these randomized controlled trials using fecal occult blood have been updated, cost-effectiveness criteria need to be integrated; especially since the results of screening campaigns based on other tools such as flexible sigmoidoscopy should be available in 2007.

Re-interpreting the data on the cost and effectiveness of population screening for colorectal cancer in Australia

Three studies report estimates of the cost and effectiveness of alternate strategies for screening the average-risk Australian population for colorectal cancer. The options considered are faecal occult blood testing, double contrast barium enema, sigmoidoscopy and colonoscopy. At present, there is no consensus over which screening method is optimal by the economic criterion. Also, the existing studies report a mixture of average and incremental cost-effectiveness ratios derived from data collected between 1994 and 2002. We suggest average cost-effectiveness ratios are not useful for decision-making and illustrate how they differ from the preferred incremental cost-effectiveness ratio. We then update the cost data reported in the three studies to 2002 prices and calculate incremental cost-effectiveness ratios where not previously available. Our re-analysis of one study contradicts the conclusions drawn by the authors, who had only calculated average cost-effectiveness ratios. In particular, we find their recommendation of population screening with colonoscopy would cause, annually, between 33 and 1,322 years of life to be lost and between $M17 and $M87 to be wasted. Based on updated cost data and the incremental analysis, our findings indicate that population screening using biennial faecal occult blood testing ($39,459 per life-year gained), annual faecal occult blood testing ($30,556 per life-year gained) and colonoscopy ($26,587 per life-year gained) are cost-effective. Hence, the decision over which method of screening is optimal remains ambiguous across the three studies. We recommend policy-makers choose the study they believe produces the most accurate estimates of cost and health effect, identify their willingness to pay for health benefits and consider other issues relevant to the decision.

Screening for colorectal cancer: virtually there

A national rollout of faecal occult-blood screening, federally funded, is the best approach.

The view from two sides: a qualitative study of community and medical perspectives on screening for colorectal cancer using FOBT

BACKGROUND

Population-wide screening for people at average risk of colorectal cancer (CRC) by faecal occult blood test (FOBT) is under consideration in Australia.

METHODS

Qualitative methods were used to examine the views of community members who did (n = 18) or did not (n = 12) participate in a pilot program of FOBT screening. In addition, views were obtained from general practitioners (GPs) and specialist gastroenterologists directly involved in the implementation of the program. Two focus group sessions were conducted with screening participants and interviews were conducted with nonparticipants, GPs and gastroenterologists.

RESULTS

The findings suggest that CRC screening by FOBT distributed to households by mail was well accepted by the community and by the medical practitioners involved in its implementation. The trial had little negative effect on general practice. Both medical practitioners and consumers raised concerns about the efficacy of FOBT screening. Medical practitioners were also concerned about the potential burden mass screening could place on the public (government-funded) health care sector.

CONCLUSIONS

It would seem that CRC screening using FOBT will not enjoy unqualified support from the community or from medical practitioners involved in the continuum of screening. Information about the objectives of screening programs, in general, and the efficacy of FOBT screening in particular, needs to be provided to the community to ensure informed individual choice.

Barriers to endoscopic colorectal cancer screening: are women different from men?

OBJECTIVES

The goals of this study were to compare women and men's understanding of screening flexible sigmoidoscopy (FS) and to identify predictors of endoscopic colorectal cancer (CRC) screening.

METHODS

We mailed a 36-item questionnaire to asymptomatic patients aged 50 years or older who were scheduled for routine health assessments at a large multispecialty health-care group. Data collection included demographics, health behaviors, psychosocial factors, and CRC screening compliance. We followed participants for 1 year and assessed completion of endoscopic CRC screening. Both cross-sectional results examining previous screening and prospective results examining screening 1 year later were evaluated.

RESULTS

554 (54%) of 998 patients responded to the survey. Responses of 13 patients were excluded in the analyses due to unverifiable screening outcome. The majority of the respondents were white, and their average age was 62 years. Women reported significantly more embarrassment and fear about having FS than men. Women were more willing to consider having a FS if a female endoscopist performed the procedure. Of the 334 participants who were eligible to have endoscopic CRC screening, 53 (16%) had the procedure within a year. The odds of having the endoscopic procedures increased with the length of time the patients were under the care of their primary care providers and how strongly patients believed that one should have an FS even without symptoms.

CONCLUSION

Our findings suggest some unique gender-specific attitudes and beliefs that act as potential barriers for CRC screening and further support the important role of primary care providers in facilitating timely completion of screening.

Reduction of the incidence and mortality of rectal cancer by polypectomy: a prospective cohort study in Haining County

AIM: To reduce the incidence and mortality of rectal cancer and address the hypothesis that colorectal cancer often arise from precursor lesion (s), either adenomas or non-adenomatous polyps, by conducting a population-based mass screening for colorectal cancer in Haining County, Zhejiang, PRC.

METHODS: From 1977 to 1980, physicians screened the population of Haining County using 15 cm rigid endoscopy. Of over 240000 participants, 4076 of them were diagnosed with precursor lesions, either adenomas or non-adenomatous polyps, which were then removed surgically. All individuals with precursor lesions were followed up and reexamined by endoscopy every two to five years up to 1998.

RESULTS: After the initial screening, 953 metachronous adenomas and 417 non-adenomatous polyps were detected and removed from the members of this cohort. Further, 27 cases of colorectal cancer were detected and treated. Log-rank tests showed that the survival time among those cancer patients who underwent mass screening increased significantly compared to that of other colorectal cancer patients (P < 0.0001). According to the population-based cancer registry in Haining County, age-adjusted incidence and mortality of rectal cancer decreased by 41% and 29% from 1977-1981 to 1992-1996, respectively. Observed cumulative 20-year rectal cancer incidence was 31% lower than the expected in the screened group; the mortality due to rectal cancer was 18% lower than the expected in the screened group.

CONCLUSION: Mass screening for rectal cancer and precursor lesions with protocoscopy in the general population and periodical following-up with routine endoscopy for high-risk patients may decrease both the incidence and mortality of rectal cancer.

Colorectal cancer screening: an overview of current trends

Colorectal cancer can be cured and, in some cases, even prevented if detected early through screening. Studies have demonstrated that regular screening for colorectal cancer with fecal occult blood testing, sigmoidoscopy, or colonoscopy can reduce mortality from this disease. Unfortunately, rates of participation in these screening tests are unacceptably low among the U.S. population. Nurses have a significant role to play in assisting individuals to incorporate regular colorectal cancer screening into their health maintenance routines.

Flexible sigmoidoscopy screening for colorectal neoplasia in average-risk people: evaluation of a five-year rescreening interval

OBJECTIVE

To determine the prevalence of colorectal neoplasia detected by rescreening people with average risk five years after initial screening by flexible sigmoidoscopy.

DESIGN

Prospective survey of results of a colorectal cancer screening program.

PARTICIPANTS

People aged 55-64 years with no symptoms or family history of colorectal cancer who were recruited from the community for flexible sigmoidoscopy screening five years previously (July 1995 to December 1996) and had no colorectal neoplasms detected.

SETTING

Fremantle Hospital, Western Australia, a community-based teaching hospital, December 2000 to June 2001.

MAIN OUTCOME MEASURES

Number and size of colorectal neoplasms (adenomas or cancer) compared between rescreened patients and initial screening population (all 982 people screened between July 1995 and December 1996).

RESULTS

803 people were eligible for rescreening; 138 were no longer at the recorded address, and 361 of the remaining 665 (54%) were rescreened. Rescreening found a significantly lower prevalence of colorectal adenomas than initial screening (8% [95% CI, 5%-11%] versus 14% [95% CI, 13%-15%]; P < 0.05) and also a lower percentage of adenomatous polyps over 5 mm in diameter (32% [95% CI, 15%-49%] versus 51% [95% CI, 46%-56%]; no significant difference).

CONCLUSION

Average-risk people who have been screened for colorectal neoplasms, with none found, have a low prevalence of neoplastic lesions five years later. Longer rescreening intervals need to be considered.

Colonoscopic surveillance for family history of colorectal cancer: are NHMRC guidelines being followed?

OBJECTIVES

To assess whether referrals for surveillance colonoscopy and subsequent follow-up recommendations for patients with a family history of colorectal cancer concurred with the published National Health and Medical Research Council (NHMRC) guidelines.

DESIGN

A prospective audit of patients with a family history of colorectal cancer referred for surveillance colonoscopy. Follow-up recommendations were assessed retrospectively.

SETTING AND SUBJECTS

All patients referred to a major teaching hospital for surveillance colonoscopy on the basis of a family history of colorectal cancer from 2 January 2000-15 April 2001.

MAIN OUTCOME MEASURES

Concurrence of referrals and recommendations with NHMRC guidelines.

RESULTS

Of 340 patients referred because of a family history of colorectal cancer, 202 (83 men, 119 women) were asymptomatic. Their mean age was 50 years (95% CI, 48.3-51.6 years). The family history of 95 (47%) of these patients satisfied the NHMRC criteria for colonoscopic surveillance. Another 20 patients (17%) satisfied the criteria, but were referred before the recommended age to commence surveillance. Analysis by referral source showed that the proportion of referrals meeting NHMRC guidelines was higher from specialists than from general practitioners (75% v 45%), and this difference was significant. Follow-up recommendations, when made, concurred with NHMRC guidelines in 81% of cases.

CONCLUSIONS

Further education of the medical community is required to increase understanding of colorectal screening strategies and ensure appropriate resource allocation.