Low-Risk Prostate Cancer Called Over-Treated Disease

ANN ARBOR, Mich., Aug. 15 -- About 10% of men with early-stage prostate cancer have unnecessary surgery and 45% receive unnecessary radiation, according to researchers here.

More than half of 24,405 men with low-risk prostate cancer who were candidates for expectant management (watchful waiting) instead received aggressive treatments, wrote John T. Wei, M.D., of the University of Michigan, and colleagues, in the Aug. 16 issue of the Journal of the National Cancer Institute.

It was the latest chapter in a long-running contentious debate over how to treat men with localized prostate cancer.

The authors reviewed data from 13 Surveillance, Epidemiology, and End Results (SEER) registries to identify 71,602 men diagnosed with localized or regional prostate cancer from 2000 through 2002.

From that population, they narrowed the study to 24,405 men, defined as those whose age at diagnosis or stage at diagnosis, or both, gave them a low 20-year risk of dying from prostate cancer.

On the basis of that low risk, an expectant management approach with regular monitoring of prostate specific antigen (PSA) levels was the "evidence-based option for initial treatment" of these men, asserted the authors.

"In our view, if the treatment decision is inappropriate for an individual patient, then, no matter how skillfully surgery is performed, or radiation is delivered, it is poor-quality treatment," they wrote.

Among the men identified as low risk, 55% had initial curative treatment, 10% prostatectomy and 45% radiotherapy.

The risk of over-treatment increased with patient age, and the greatest absolute risk of over-treatment occurred in men age 70 or older who had moderately differentiated cancers. "Among this group, 12,680 men were potentially over-treated with initial surgery or radiation therapy from 2000 through 2002," they wrote.

The authors cautioned that expectant management of localized prostate cancer, which can include use of hormonal therapy, is "not necessarily benign" so there are no guarantees that all adverse quality-of-life effects will be avoided, a point that should be made when counseling patients.

Moreover, they acknowledged that some clinicians will disagree with their "classification of lower-risk cancers and with the general notion that some prostate cancers require do not initial intervention."

The authors said the study had a number of limitations including a possible age bias because excluded men were significantly older at diagnosis (mean age 70.1 versus 67.2 P<0.001). The low-risk cohort also included some men with higher grade cancers, which might have inflated the estimates of over-treatment. Additionally, a number of the men with well differentiated tumors were Gleason stage 2 to 4, and few men today present with these stages because they are "rarely, if ever, diagnosed on contemporary needle biopsy specimens."

The authors also lumped brachytherapy and external-beam radiation into a single radiation cohort, another limiting factor. Finally, they wrote that they recognized "that our ability to draw concrete conclusions regarding the 'right rate' of expectant management is limited by an absence, in SEER public-use data, of detailed patient-level information regarding cancer severity, health status, life expectance, and treatment preferences."

Nonetheless, the authors conclude that "greater attention to the factors that influenced the use of expectant management among men with prostate cancer is essential insofar as initial patient counseling and shared decision making mark the most important role that physicians play during the course of caring for patients with localized prostate cancer."