Diagnosis of localized prostate cancer declines following task force recommendations

The diagnosis of localized prostate cancer diagnosis declined by more than 20% since the release of the 2012 U.S. Preventive Services Task Force recommendations against PSA–based screening for prostate cancer for healthy men, according to a research letter published in JAMA Oncology.

Although the decrease was greatest for low-risk disease, researchers also observed a decrease in incidence of high-risk disease.

The U.S. Preventive Services Task Force recommended against prostate cancer screening to address overdiagnosis and overtreatment. However, if these recommendations are fully implemented, overdiagnosis could decrease at the expense of increasing preventable deaths, according to the researchers.

Robert Abouassaly , MD, MS, FRSC, assistant professor of urology and oncology at Case Western Reserve University School of Medicine and urology surgeon at University Hospitals Case Medical Center, and colleagues used the National Cancer Data Base to identify patients diagnosed with clinically localized (cT1-3a, NO, MO) prostate cancer between 2010 and 2013.

“We wanted to see on a national level how the recommendations have altered the diagnosis but also the treatment of the disease,” Abouassaly told HemOnc Today. “We've been observing a decrease in prostate cancer mortality over the last 10 to 15 years, and we need to see if that trend continues or reverses following the new recommendations."

Researchers used D’Amico criteria to classify patients into three risk groups: low risk (cT1-T2a; Gleason score s6; PSA < 10 ng/mL), intermediate risk (cT2b-3a; Gleason score 7; PSA 10-20 ng/mL) or high risk (cT2c-3a; Gleason score 8; PSA > 20 ng/mL).

Prostate cancer diagnoses fell from a high of 90,419 cases in 2011 to a low of 71,945 cases in 2013. These data equated to an average decrease of 7,200 cases per year.

The decrease occurred across all age and risk groups; however, it appeared greatest among men aged younger than 70 years (21% decrease) and patients with low-risk disease (36% decrease).

Researchers then evaluated trends in whether patients underwent active surveillance, watchful waiting, hormonal therapy alone (ADT), and active treatment (surgery or radiation therapy with or without ADT).

For patients categorized as low-risk, use of watchful waiting (range, 3.9%-5.2%) and active surveillance (range, 7.4%-18.4%) increased significantly, whereas use of active treatment decreased (range, 73%-83.6%). These patients were more likely to receive active surveillance (OR = 1.4; 95% CI, 1.4-1.4) or watchful waiting (OR = 1.2; 95% CI, 1.1-1.2) than active treatment.

Use of active surveillance or watchful waiting also increased among patients with intermediate-risk disease, although to a lesser extent (P < .01).

Among patients categorized as high risk, use of active treatment decreased significantly (range, 59%-64.4%), whereas use of active surveillance (range, 1.2%-1.8%) and ADT (range, 30.6%-34.8%) increased significantly.

Compared with undergoing ADT, patients with high-risk prostate cancer were 7% less likely to receive active treatment (OR = 0.93; 95% CI, 0.92-0.94).

Maurice and colleagues acknowledged that the retrospective nature of the research, as well as the possibility for selection bias may have limited findings.

“I expected to see more active surveillance and watchful waiting for low-risk patients, but I didn't anticipate the effect on the diagnosis and treatment on high-risk prostate cancer,” Abouassaly said. “At some point the task force will reconvene to update recommendations and I hope they take this and other research into account when formulating future recommendations so that we minimize the overtreatment and overdiagnosis of low-risk prostate cancer, but so that we don't ignore those patients are at some risk for prostate cancer death.”– by Nick Andrews

For more information:

Robert Abouassaly , MD, MS, FRSC, can be reached at robert.abouassaly@uhhospitals.org.

Disclos ure: The researchers report no relevant financial disclosures.