Prostate cancer screening: what we have learned from the PLCO and ERSPC trials

The efficacy of prostate-specific antigen screening: Impact of key components in the ERSPC and PLCO trials

BACKGROUND

The European Randomized Study of Screening for Prostate Cancer (ERSPC) demonstrated that prostate-specific antigen (PSA) screening significantly reduced prostate cancer mortality (rate ratio, 0.79; 95% confidence interval, 0.69-0.91). The US Prostate, Lung, Colorectal, and Ovarian (PLCO) trial indicated no such reduction but had a wide 95% CI (rate ratio for prostate cancer mortality, 1.09; 95% CI, 0.87-1.36). Standard meta-analyses are unable to account for key differences between the trials that can impact the estimated effects of screening and the trials' point estimates.

METHODS

The authors calibrated 2 microsimulation models to individual-level incidence and mortality data from 238,936 men participating in the ERSPC and PLCO trials. A cure parameter for the underlying efficacy of screening was estimated by the models separately for each trial. The authors changed step-by-step major known differences in trial settings, including enrollment and attendance patterns, screening intervals, PSA thresholds, biopsy receipt, control arm contamination, and primary treatment, to reflect a more ideal protocol situation and differences between the trials.

RESULTS

Using the cure parameter estimated for the ERSPC, the models projected 19% to 21% and 6% to 8%, respectively, prostate cancer mortality reductions in the ERSPC and PLCO settings. Using this cure parameter, the models projected a reduction of 37% to 43% under annual screening with 100% attendance and biopsy compliance and no contamination. The cure parameter estimated for the PLCO trial was 0.

CONCLUSIONS

The observed cancer mortality reduction in screening trials appears to be highly sensitive to trial protocol and practice settings. Accounting for these differences, the efficacy of PSA screening in the PLCO setting is not necessarily inconsistent with ERSPC results. Cancer 2018;124:1197-206. © 2017 American Cancer Society.

Is prostate cancer screening cost-effective? A microsimulation model of prostate-specific antigen-based screening for British Columbia, Canada

Prostate-specific antigen (PSA) screening for prostate cancer may reduce mortality, but it incurs considerable risk of over diagnosis and potential harm to quality of life. Our objective was to evaluate the cost-effectiveness of PSA screening, with and without adjustment for quality of life, for the British Columbia (BC) population. We adapted an existing natural history model using BC incidence, treatment, cost and mortality patterns. The modeled mortality benefit of screening derives from a stage-shift mechanism, assuming mortality reduction consistent with the European Study of Randomized Screening for Prostate Cancer. The model projected outcomes for 40-year-old men under 14 combinations of screening ages and frequencies. Cost and utility estimates were explored with deterministic sensitivity analysis. The incremental cost-effectiveness of regular screening ranged from $36,300/LYG, for screening every four years from ages 55 to 69 years, to $588,300/LYG, for screening every two years from ages 40 to 74 years. The marginal benefits of increasing screening frequency to 2 years or starting screening at age 40 years were small and came at significant cost. After utility adjustment, all screening strategies resulted in a loss of quality-adjusted life years (QALYs); however, this result was very sensitive to utility estimates. Plausible outcomes under a range of screening strategies inform discussion of prostate cancer screening policy in BC and similar jurisdictions. Screening may be cost-effective, but the sensitivity of results to utility values suggests individual preferences for quality versus quantity of life should be a key consideration.

PSA mass screening: is there enough evidence?

Prostate cancer plays an important role in widely understood aspects of men's health, and is becoming a growing problem in terms of public life. Prostate cancer is one of the most common neoplasms among men. Male patients can live with prostate cancer for a long time so it is important to offer appropriate males adequate diagnostic tools and treatments. Prostate cancer and PSA potentially represent a “pair” of a disease and an appropriate indicator to be used in mass screening, but regardless of that there is still active debate about it. Extensive use of PSA screening has modified epidemiology of the diseases. Randomized controlled studies provided sufficient results regarding a reduction in mortality through PSA mass screening, while all agreed on risks of overdiagnosis and overtreatment. New and accurate screening tools are necessary, along with adequate counseling and risk stratification.

Cancer in long-term care

This article describes the range of cancer patients in longterm care and provides a framework for clinical decision making. The benefits and burdens of providing standard therapy to a vulnerable population are discussed. To give more specific guidelines for advocates of treatment, skeptics, and others, the authors present best estimates of the current burden of cancer in the long-term care population and current screening guidelines that apply to the elderly under long-term care. Experience-based suggestions are offered for oncologists and clinicians involved in long-term care to help them respond to patient and family concerns about limitations of cancer care.

Predictive value of digital rectal examination for prostate cancer detection is modified by obesity

The American Cancer Society's updated screening guidelines for prostate cancer (CaP) render digital rectal examination (DRE) optional. We investigated the impact of DRE on CaP detection among obese men. Data from 2794 men undergoing initial prostate biopsy at three centers were analyzed to assess CaP risk attributed to abnormal DRE across body mass index (BMI) categories. Predictive accuracies of a combination of PSA, age, race, center and biopsy year including or excluding DRE findings were compared by areas under the receiver-operating characteristics curves. In all cohorts, obese men were less likely to have abnormal DREs diagnosed than non-obese men. As BMI category increased, abnormal DREs became stronger predictors for overall CaP in individual (P-trends ≤ 0.05) and combined (P-trend<0.001) cohorts, and for high-grade CaP in the Italian (P-trend=0.03) and combined (P-trend=0.03) cohorts. DRE inclusion improved the predictive accuracy for overall and high-grade CaP detection among all obese men (P ≤ 0.032) but not normal-weight men (P ≥ 0.198). DRE inclusion also near-significantly improved overall CaP detection in obese men with PSA<4 ng ml(-1) (P=0.081). In conclusion, the predictive value of DRE is dependent on obesity and is significantly higher among obese men than normal-weight men.