ASPO Abstracts
Trends in managing low-risk prostate cancer
Category: Early Detection & Risk Prediction
Conference Year: 2020
Abstract Body:
Purpose
The advent of prostate-specific antigen (PSA) testing in the late 1980s dramatically increased
the incidence of prostate cancer (PCa). Although many PSA-detected PCa were indolent, for
decades the majority of men were treated with surgery, radiation therapy, or hormone therapy.
In more recent years, active surveillance (AS), a monitoring strategy that defers active
treatment in the absence of disease progression, has emerged as a recommended strategy for
men with a low-risk PCa. AS enables these men to avoid treatment complications without
increasing their risk for cancer mortality. We used SEER-Medicare data to evaluate trends in
treatment practice patterns for men with a low-risk or a very low-risk PCa diagnosed from
January 1, 2010 through December 31, 2013 with follow up through December 31, 2014.
Methods
We identified 7,791 men ages 66 and older who were diagnosed with a low-risk PCa (PSA < 10
ng/ml, Gleason score ≤ 6, and stage T1c or T2a). A subset of 2,929 men also met criteria for
having a very low-risk cancer based on PSA < 10 ng/ml, Gleason score ≤ 6, and stage T1c with
< 25% positive prostate biopsy cores. We determined the proportions of these men who
deferred treatment (observation cohorts) for at least one year. We further determined the
proportions of these men who subsequently underwent treatment. We used descriptive
statistics and Kaplan-Meier curves.
Results
During their first year of follow up, 36.2% of men with a low-risk cancer and 44.3% of the subset
of men with a very low-risk cancer deferred treatment. Across years of diagnosis, the proportion
of men with a low-risk PCa managed with observation increased from 28.6% to 48.4%; the
increase in men with a very low-risk PCa was from 34.0% to 57.9%. At a median follow-up of
2.6 years after diagnosis, 28.5% of men in the low-risk observational cohort underwent
treatment versus 27.0% among those in the subset with a very low-risk PCa.
Conclusions
Increasing proportions of men with low-risk or very low-risk PCa were initially managed with
observation, consistent with guideline recommendations. However, the majority of men with a
low-risk PCa still underwent cancer treatment. Most men initially managed with observation
continued to defer treatment.
Keywords: Prostatic neoplasms Active surveillance Risk assessment