The association of patient and disease characteristics with the overtreatment of low-risk prostate cancer from 2010 to 2016.

Background: Although active surveillance is the preferred management for low-risk prostate cancer (PCa), some men remain at risk of overtreatment with definitive local therapy. We hypothesized that baseline characteristics may be associated with overtreatment and represent a potential source of health disparities. We therefore examined the associations of patient and disease characteristics with the surgical overtreatment of low-risk PCa.

Methods: We identified men aged 45-75 years with cT1 cN0 cM0 prostate adenocarcinoma with biopsy Gleason score 6 and PSA < 10 ng/ml from 2010-2016 in the National Cancer Database (NCDB) and who underwent radical prostatectomy (RP). We evaluated the associations of baseline characteristics with clinically insignificant PCa (iPCa) at RP (i.e., "overtreatment"), defined as organ-confined (i.e., pT2) Gleason 3 + 3 disease, using multivariable logistic regression.

Results: We identified 36,088 men with low-risk PCa who underwent RP. The unadjusted rate of iPCa decreased during the study period, from 54.7% in 2010 to 40.0% in 2016. In multivariable analyses adjusting for baseline characteristics, older age (OR 0.98, 95% CI 0.97-0.98), later year of diagnosis (OR 0.62, 95% CI 0.57-0.67 for 2016 vs. 2010), Black race (OR 0.85, 95% CI 0.79-0.91), treatment at an academic/research program (OR 0.82, 95% CI 0.73-0.91), higher PSA (OR 0.91, 95% CI 0.90-0.92), and higher number of positive biopsy cores (OR 0.87, 95% CI 0.86-0.88) were independently associated with a lower risk of overtreatment (iPCa) at RP. Conversely, a greater number of biopsy cores sampled (OR 1.01, 95% CI 1.01-1.02) was independently associated with an increased risk of overtreatment (iPCa) at RP.

Conclusions: We observed an ~27% reduction in rates of overtreatment of men with low-risk PCa over the study period. Several patient, disease, and structural characteristics are associated with detection of iPCa at RP and can inform the management of men with low-risk PCa to reduce potential overtreatment.