Should Medicare provide reimbursement for prostate-specific antigen testing for early detection of prostate cancer? Part III: Management strategies and outcomes

Quantifying the role of PSA screening in the US prostate cancer mortality decline

OBJECTIVE

To quantify the plausible contribution of prostate-specific antigen (PSA) screening to the nearly 30% decline in the US prostate cancer mortality rate observed during the 1990s.

METHODS

Two mathematical modeling teams of the US National Cancer Institute's Cancer Intervention and Surveillance Modeling Network independently projected disease mortality in the absence and presence of PSA screening. Both teams relied on Surveillance, Epidemiology, and End Results (SEER) registry data for disease incidence, used common estimates of PSA screening rates, and assumed that screening, by shifting disease from distant to local-regional clinical stage, confers a corresponding improvement in disease-specific survival.

RESULTS

The teams projected similar mortality increases in the absence of screening and decreases in the presence of screening after 1985. By 2000, the models projected that 45% (Fred Hutchinson Cancer Research Center) to 70% (University of Michigan) of the observed decline in prostate cancer mortality could be plausibly attributed to the stage shift induced by screening.

CONCLUSIONS

PSA screening may account for much, but not all, of the observed drop in prostate cancer mortality. Other factors, such as changing treatment practices, may also have played a role in improving prostate cancer outcomes.

PSA testing in office-based clinics: are we testing as much as we think?

BACKGROUND

Self-report studies of widespread use of routine prostate-specific antigen (PSA) testing have fueled concerns about overuse and possible harm. The purpose of this study was to examine use of PSA testing during physician office visits in a national sample of prostate-cancer-free men ages 40 years and older.

METHODS

Bivariate and multivariate logistic regression models of receiving a PSA test by prostate-cancer-free men ages 40 years and older were performed using the 2000 National Ambulatory Medical Care Survey.

RESULTS

There were 2,709 primary care and urology office visits by prostate-cancer-free men 40 years of age and older, and 10.2% resulted in a PSA test. In a multivariate model, men in their 70s had considerably higher odds (odd ratio, 1.60; 95% CI, 1.11-2.32) and men with multiple medical comorbidities had considerably lower odds (odds ratio, 0.28; 95% CI, 0.10-0.65) of receiving a PSA test.

CONCLUSIONS

We report lower use of PSA testing than previously published. Greater insight into use of PSA testing based on clinic and hospital administrative data are required to determine the impact of PSA testing on the cost of health care and prostate cancer incidence and mortality.

Population Screening for Prostate Cancer and Emerging Concepts for Young Men

Prostate cancer is the most common malignancy in American men, accounting for > 29% of all diagnosed cancers and approximately 13% of all cancer deaths. Nearly 1 of every 6 men will be diagnosed with the disease at some time in their lives. In 2003 alone, an estimated 221000 men in the United States will be diagnosed with prostate cancer and > 28000 will die of the disease. An elevated level of prostate-specific antigen (PSA) is correlated with the presence of prostate cancer, and since 1989 we have been living in the "PSA era," in which the PSA screening test is widely used in clinical practice. This article summarizes what has been learned about the use of PSA screening, including the intricacies of free PSA, PSA doubling time, and various factors that may affect PSA and confound screening in young men. Although population-based screening for prostate cancer has yet to be definitively proven to affect disease-specific mortality, PSA testing is detecting cancers in younger men and at earlier stages of disease progression and, partly as a result, 5-year cancer-specific survival is increasing. Even though this lead-time effect may not translate into long-term improvement, these changes are very promising and are a necessary prerequisite to effective screening. For patients at high risk with a family history of the disease and for black men, a strategy consisting of an annual PSA blood test and digital rectal examination for men >or=40 years of age appears to be prudent. Use of age- and race-specific reference ranges for PSA based on sensitivity, or maximal cancer detection, is the most appropriate approach in this high-risk group. Specifically among black men 40-49 years of age, those with a PSA value > 2.0 ng/mL should consider further evaluation. Many men at low/average risk aged 40-49 years also request testing and it is reasonable to offer testing and risk assessment to these young men. The exact screening threshold for total PSA in these men is unknown, but 95% of these men will have a PSA < 2.5 ng/mL. Prostate-specific antigen velocity, percentage of free PSA, and perhaps complexed PSA may be used to help determine risk, but further study of young men is needed. In the future, a risk-stratified approach using molecular biomarkers and/or proteomics in young men is anticipated.

An evidence-based analysis of the management of localized prostate cancer

PURPOSE

Patients with localized prostate cancer and their doctors face complex trade-offs when deciding on treatment. In this study, we modify the "number needed to treat" method to compare radical prostatectomy with radiotherapy.

METHODS

A MEDLINE search was performed to identify all studies of radical protatectomy or radiotherapy for prostate cancer. Number needed to treat formulas were modified to account for not only survival but also for complications and their utilities.

RESULTS

The unadjusted number needed to treat value for overall survival was 6 favoring prostatectomy (six patients have to undergo prostatectomy to have one more 10-year survivor than if they had undergone radiotherapy). Radiotherapy patients were 4 years older than prostatectomy patients. Because overall survival is strongly linked to patients' age and overall health, the numbers needed to treat for disease-specific and distant metastasis-free survival were analyzed to minimize patient selection bias. The unadjusted number needed to treat values for disease-specific and distant metastasis-free survival were 14 and 18, respectively. When number needed to treat is adjusted for complications and utilities, its value for overall survival is 14, disease-specific survival is -25, and distant metastasis free survival is -22, these last two favoring radiotherapy.

CONCLUSIONS

Utility-adjusted numbers needed to treat for prostatectomy and radiotherapy are greatly influenced by the likelihood of complications and the utility loss ascribed to them. When literature-reported values are used, radiotherapy is superior, but the differences in outcomes are small. With prostate-specific antigen screening and refined treatment methods, these values will change, and the modified number needed to treat can be used to evaluate, report and compare results. The consequences of treatment in terms of both survival and quality of life determine patient choice and physician recommendations.

Prostate cancer staging: should MR imaging be used?--A decision analytic approach

PURPOSE

To determine the appropriate use of magnetic resonance (MR) imaging for preoperative staging of prostate cancer.

MATERIALS AND METHODS

Literature review was performed by using the principles of evidence-based medicine and medical technology assessment. A decision analytic model was used to compare (a) the strategy that radical prostatectomy is performed on the basis of clinical staging with (b) the strategy that extracapsular disease detected at MR imaging contraindicates radical prostatectomy in patients who were considered surgical candidates on the basis of clinical staging.

RESULTS

After review of the literature, expert panel opinion did not recommend MR staging. No studies in which therapeutic efficacy was addressed were found. The decision analytic model indicated that the strategy including MR staging decreased costs (MR imaging, $10,568; radical prostatectomy, $11,669) and resulted in almost equal life expectancy (MR imaging, 12.59 years; radical prostatectomy, 12.60 years) and quality-adjusted life-years ([QALYs] MR imaging, 12.53; radical prostatectomy, 12.52). Results of sensitivity analyses demonstrated that the MR strategy was both more effective and less costly if the prior probability of extracapsular disease was at least 39% when considering QALY and 50% when considering unadjusted life expectancy.

CONCLUSION

It is not yet conclusively determined whether preoperative MR staging is appropriate, but results of decision analysis suggest that MR staging is cost-effective for men with moderate or high prior probability of extracapsular disease.

An evaluation of radical prostatectomy at Veterans Affairs Medical Centers: time trends and geographic variation in utilization and outcomes

OBJECTIVE

To examine temporal trends and geographic variation in utilization of radical prostatectomy (RP) as well as 30-day mortality and complication rates.

DESIGN

Administrative data-base study of radical prostatectomy (RP) using the Department of Veterans Affairs Patient Treatment File and Outpatient Clinic File between 1986 to 1996. Logistic regression was used to estimate temporal and geographic effects on the use of RP.

SETTING

All Departments of Veterans Affairs Medical Centers (VAMC) in the contiguous United States.

PATIENTS

Men aged 45 to 84 years who underwent RP at a VAMC (n = 13,398).

MAIN OUTCOME MEASURES

Number and utilization of RP, rate of 30-day mortality, major cardiopulmonary or vascular complications, and colorectal injuries requiring surgical repair within 30 days of RP.

RESULTS

From 1986 to 1996, the annual number of RP at VAMCs (range, 695-1,545 RP) more than doubled, and the rate of RP at VAMCs per male VA user increased by 40% (range, 48/100,000-66/100,000). After controlling for age and year, the utilization of RP in West North Central, Mountain, West South Central, and Pacific census divisions was 70%, 14%, 10%, and 8% higher, respectively, whereas the utilization of RP in New England, East North Central, and Mid-Atlantic divisions was 38%, 31%, and 25% lower, respectively, than the rest of the nation (P<0.001). Geographic variation in utilization decreased during the period between 1986 and 1996, but a twofold difference in RP utilization in 1996 remained between high- and low-utilization divisions. Major cardiopulmonary complications, vascular complications, and colorectal injuries occurred in 1.7%, 0.2%, and 1.8% of men, respectively. Thirty-day mortality was 0.73%, declined from 1986 to 1996, and was associated with a history of diabetes and congestive heart failure.

CONCLUSION

Utilization of RP at VAMCs increased over time and varied across geographic areas. Thirty-day mortality was less than 1% and decreased with time. Differences in utilization may be caused by uncertainty regarding the effectiveness of early detection and treatment of prostate cancer.

Prostate disease in older men: 2. Cancer

Proof is lacking that early detection and treatment reduce mortality from prostate cancer. Indeed, many patients die with the tumor, not from it. In the absence of better data, the clinician must, when making treatment recommendations, weigh the biology of the disease, the potential morbidity of treatment, other factors that affect the patient's longevity, and the patient's attitude toward risk.

Screening for prostate cancer is neither appropriate nor cost-effective

Seen from a societal perspective, the health gains that might result from prostate screening are too uncertain to justify the substantial associated costs and adverse health effects. Clinicians who rely on observational screening studies to justify current screening practices should be aware of the potential biases that render conclusions suspect. Medical history documents numerous cases of medical interventions that appeared reasonable at the time, but ultimately proved worthless and even harmful. Before embarking on an ambitious screening program for prostate cancer, clinicians should demand that five basic criteria are satisfied: (1) that prostate cancer is a significant health burden, (2) that screening can identify localized disease, (3) that tests used in screening programs have acceptable performance among the population being tested, (4) that the potential for cure is greater among patients with screen-detected disease, and (5) that screen-detected patients have improved health outcomes compared with those who are not screened. Randomized trials provide the best methodology for determining the efficacy of screening and treatment. Clinicians are often too quick to credit medical intervention for successful outcomes and blame tumor biology for disease progression. Furthermore, when faced with a decision of administering or withholding therapy, physicians generally wish to err on the side of having done everything possible. Data modeling can provide critical insights concerning these issues using currently available information. Three recently published models suggest that the overall benefit to a population of men screened for prostate cancer can be measured in days of additional time of life gained, not months or years. Furthermore, models suggest that a substantial number of men need to undergo treatment in order to avert a single cancer death. The costs of implementing a screening program are enormous and deflect resources away from alternative uses, such as increased basic science funding to identify a cure for this disease. Therefore, based on the evidence presented, I believe that without more substantial data supporting the efficacy of screening programs, screening for prostate cancer is neither appropriate nor cost-effective.