Communicating benefits and risks of screening for prostate, colon, and breast cancer

BACKGROUND: Screening for cancer has become a standard of practice in contemporary health care. Screening tests are often ordered routinely, without discussion of risks and benefits. For clinicians who want to inform patients and undertake shared decision-making, the goal of effective communication presents a number of challenges. To begin with, the probabilities to be discussed are small. For each screening test done, the chance of finding and effectively treating an early cancer is quite low. Likewise, the chance of causing harm, such as a false positive screen followed by an invasive test resulting in complications, is also very unlikely but possible. Using accurate terms that patients can understand is only the first step, however, as the decision-making process should take into account the patient's perceptions, values, and preferences. This paper briefly reviews the current state of evidence for prostate, colon, and breast cancer screening, then outlines several strategies toward effective clinical communication. The concepts of absolute risk, relative risk, and number needed to screen are reviewed. Natural frequency presentation, a relatively new method for portraying benefits and harms, is introduced and encouraged, as recent evidence suggests that natural frequencies are better understood and are more concordant with patients' values than alternative formats.     

Psychological benefits of prostate cancer screening: the role of reassurance

Objectives The role of reassurance in decision‐making about screening for health problems is largely unknown. We examined the reassurance value of prostate cancer screening in primary care patients. Setting and participants One hundred and sixty eight men, aged 45–70 years, who had no history of prostate cancer, from three family medicine practices in southeast Texas. Methods A hypothetical scenario was developed where men were asked to assume they did not have prostate cancer, and then to rank three predefined screening states with regard to reassurance value: (A) unknown (no screening), (B) normal by screening [a prostate‐specific antigen (PSA) test and a digital rectal examination (DRE)] and (C) normal by biopsy (abnormal PSA test and DRE results but a negative ultrasound‐guided prostate biopsy). Results Most of the men (96.8%) associated some reassurance value with screening, considering health state A to be the worst possible health state. Results from a multivariate analysis showed that preference for screening state C was associated with a family history of prostate cancer and perceived greater risk for prostate cancer compared with other men. Conclusion These findings suggest that prostate cancer screening may have some reassurance value for men, and that increased risk status may explain why some men prefer the added reassurance afforded by screening.     

Effectiveness of screening for prostate cancer: A nested case-control study

Although screening for prostate cancer with prostate-specific antigen (PSA) or digital rectal exam (DRE) is commonly done, evidence is currently lacking to show a benefit of such testing on survival. The current study used a nested case-control design to assess the impact of screening with PSA (with or without DRE) on mortality.Among 71,661 patients receiving ambulatory care during 1989–1990 at any of ten VA Medical Centers in New England, case subjects were men diagnosed with prostate cancer from 1991–1995 who died during 4–9 years of follow-up. Control subjects (1:1 sampling ratio) were men who are alive at the time of death of the corresponding case, matched for year of birth and VA facility. The exposure variables were screening with PSA alone, or PSA and DRE, done for screening purposes; potential screening tests must have occurred prior to the diagnosis of prostate cancer for the cases or the corresponding date for controls. The assessment of screening was also done blind to case-control status, and tests were classified by an algorithm that took into account the clinical context of the exams.A total of 501 matched case and control subjects (1002 total patients) were included in final analyses. The frequency of screening with PSA was similar among cases (14.0%) and controls (13.0%); with an unadjusted odds ratio of 1.10 (95% C.I. 0.75 to 1.62). After adjusting for race and comorbidity, the odds ratio remained quantitatively and statistically non-significant at 1.08 (95% C.I. 0.71 to 1.64). Screening was also not associated with improved survival in analyses involving screening with PSA or DRE, among men less than 70 years of age, and using data from patients during last three years of intake when PSA testing was more commonly done.The results do not support the effectiveness of PSA or DRE in screening for prostate cancer.     

Patient outcomes in hospital-based respite: a study of potential risks and benefits.

BACKGROUND: Primary care physicians provide increasing care for elderly patients with chronic disabilities. To maintain these individuals in the community, families and other caregivers are supplying more intensive support in the home. Services, such as short-term respite care, can relieve the caregiver burden and allow the patient to continue community living. Whether hospital-based respite can be an effective option for patients is unclear. METHODS: To determine the patient outcomes in hospital-based respite, 15 elderly male respite patients (mean age 71 years) were matched and compared during a 6-month period with 14 elderly acute care control patients and 16 community-based elderly control patients who were chronically ill and were enrolled in a hospital-based home-care program. RESULTS: The average respite stay was 15 days. The respite group did not experience increased risk of mortality or iatrogenesis. Benefits at 6 months included fewer admissions for acute medical care for the respite group (P less than 0.05). Total number of hospital days was equivalent for the respite group and community-based control patients and was fewer than that for the acute care group. CONCLUSION: The results do not indicate any harm and argue that a slight benefit is associated with hospital-based respite for chronically ill older adults. Because of potential complications that can develop for chronically ill geriatric patients, a hospital setting for respite can be a viable respite alternative. A valid concern for physicians, however, remains the potential danger of a greater rate of iatrogenic illness and expectation of more aggressive care based on a tertiary care model.     

A nested case-control study of the effectiveness of screening for prostate cancer: research design

Although prostate-specific antigen (PSA) and digital rectal examination (DRE) are commonly used to screen for prostate cancer, available data do not confirm that either test improves survival. This report describes the methodological aspects of a nested case-control study addressing the question of whether PSA screening, with or without DRE, is effective in increasing survival. Potential sources of bias are discussed, as well as corresponding strategies used to avoid them. Results are expected in the year 2002.     

Perceived barriers and benefits to cervical cancer screening in Latin America

BACKGROUND: This article describes the results of studies on the barriers and benefits of cervical cancer screening from the perspective of women, men, and health providers in five Latin American countries and compares them to other findings from the literature. METHODS: Five separate qualitative studies (focus groups and interviews) were conducted among low-income women in Venezuela, Ecuador, Mexico, El Salvador, and Peru regarding barriers and benefits of cervical cancer screening. Views from health providers and men were also included. RESULTS: The main barriers identified by all participants are accessibility and availability of quality services, facilities that lack comfort and privacy, costs, and courtesy of providers, which interact with poor service delivery. Barriers that pertain to women's beliefs are anxiety borne by women awaiting test results, associated with negligence and fear of cancer (although not to a particular cancer or a particular procedure). Benefits of screening are peace of mind and being in control of their health, which then enable other life activities to continue unhindered. CONCLUSIONS: Except for the accessibility and availability of quality services, these results are consistent with findings from other studies in developed and developing countries. Barriers could be lifted if health service delivery was enhanced, for instance, through quality improvement techniques that are available at low cost. Women's anxiety over test results still needs to be further assessed to devise risk communication strategies that take into account broader cultural frameworks. It is to be noted that such strategies should permeate the way health services are provided for cervical cancer prevention regardless of the specific test used. Vulnerability perceived by low-income women with respect to their capacity to cope with diseases and trust the health services and how this affects their perceptions of risk and their behaviors have not been studied as yet.     

Informed consent for mammography screening: modelling the risks and benefits for American women

INTRODUCTION: In order to facilitate informed decision making, women require information on the probabilities of different outcomes with mammography screening. This paper derives these probabilities for a US population and illustrates them visually in a readily understandable format. METHODS: Probabilities of the breast cancer mortality, all cause mortality and further investigation are derived from published data on mortality from breast cancer and published estimates of effectiveness using a life-table method. Probabilities are calculated of surviving to age 75 from age 40 with and without two-yearly mammography screening from age 40 and age 50. Probabilities are also calculated that a woman will be referred for further assessment or biopsy or die from breast cancer despite screening. To avoid being misled, these outcomes are presented in the form of a single decision aid illustrating the outcomes for 1000 women choosing each alternative: mammography screening or no mammography screening. RESULTS: Of 1000 women undergoing two-yearly mammography screening from age 40 an additional four (3.7 per 1000) will reach the age of 75; of the survivors 514 will be referred for further investigation and 138 will undergo biopsy. Of 1000 women screened from age 50 an additional three (3.3 per 1000) will reach age 75; of the survivors 408 will be referred for further investigation and 94 will undergo biopsy. Mammography from age 40 to 49 reduces mortality by 0.4 in 1000. This information is readily presented visually. CONCLUSIONS: It is possible to provide realistic estimates of the effects of mammography screening on mortality in a readily understandable format. Women require this information if they are to make informed choices about mammography screening.     

A case-cohort study on prostate cancer risk in relation to family history of prostate cancer

We investigated the risk of prostate cancer in relation to a family history of prostate cancer in 58,279 men ages 55-69 years. We found 704 incident cases after 6.3 years of follow-up. Rate ratios and 95% confidence intervals for having an affected vs nonaffected father and brother were, respectively 1.44 (0.80-2.58) and 5.57 (1.61-19.26). We found no evidence for an increasing risk with an increasing percentage of affected family members. The associations we observed were stronger for cases diagnosed before age 70 compared with cases diagnosed after age 70 and for advanced compared with localized tumors.     

A randomized controlled trial of shared decision making for prostate cancer screening.

OBJECTIVE: To evaluate a patient-educational approach to shared decision making for prostate cancer screening. DESIGN: Randomized controlled trial with preoffice visit assessment and 2-week follow-up. SETTING: University-based family practice center. PATIENTS: Men aged 45 through 70 years with no history of prostate cancer or treatment for prostate disease (N = 160). Two patients were unavailable for follow-up. INTERVENTION: Twenty-minute educational videotape on advantages and disadvantages of prostate-specific antigen (PSA) screening for prostate cancer. MAIN OUTCOME MEASURES: A measure of patients' core knowledge of prostate cancer developed for this study, reported preferences for PSA testing, and ratings of the videotape. RESULTS: Patients' core knowledge at baseline was poor. At 2-week follow-up, subjects undergoing videotape intervention showed a 78% improvement in the number of knowledge questions answered correctly (P = .001), and knowledge increased about mortality due to early-stage prostate cancer, PSA screening performance, treatment-related complications, and disadvantages of screening. No overall change was observed for control subjects. At follow-up, 48 (62%) of 78 intervention patients planned to have the PSA test compared with 64 (80%) of 80 control patients (18.5% absolute reduction; 95% confidence interval, 4.6%-32.4%; P = .009). Intervention subjects rated favorably the amount of information provided and the clarity, balance, and length of the videotape and would recommend the videotape to others. CONCLUSIONS: Patient education regarding the potential benefits and harms of early detection of prostate cancer can lead to more informed decision making. Incorporating the PSA videotape into the periodic health examination for asymptomatic men aged 50 years and older is recommended.     

Further evidence of benefits of a (non-randomised) breast cancer screening programme: the DOM project.

STUDY OBJECTIVE--The aim was to demonstrate the benefits of breast cancer screening on mortality. DESIGN--The study was an evaluation of a breast cancer screening programme by means of different approaches: (1) a case-control study, breast cancer deaths being the cases; (2) comparing the numbers of breast cancer deaths in screened and unscreened women; (3) comparing breast cancer mortality before and after start of the programme; (4) comparing breast cancer mortality in different large cities; (5) comparing screening activity with mortality reduction. SETTING--The setting was a breast cancer screening programme in the city of Utrecht, the DOM project, for women aged 50-64 years old at intake, birth cohort 1911-1925. The programme started in 1974, and there were five screening rounds up to 1984. Participation rate in the first round was 72% (14,697 women). MAIN RESULTS--(1) Screening was protective against dying from breast cancer, odds ratio 0.52, with a stronger effect in older women and no evidence of confounding; (2) risk ratio of dying from breast cancer for women in the response group was the same as the odds ratio, 0.52; (3) breast cancer death rate after the start of the project was nearly 20% lower than before the project started; after correcting for women who could not have benefited from screening the reduction was 33%; (4) a rise in breast cancer mortality in birth cohort 1911-1925 seen in other large cities without a screening programme due to aging of the cohort was not seen in the city of Utrecht; (5) mortality reduction followed the screening activity with a time lag of approximately 5 years. CONCLUSIONS--Early diagnosis of breast cancer by mammography reduces breast cancer mortality in women 50-64 years old at intake; different approaches to the evaluation of the project give different estimates of the screening effect, making clear that the effect depends on the intensity of the programme.