Association between genomic classifier scores and initial management of localized prostate cancer in the United...

Tissue-based gene expression assays provide prognostic information in prostate cancer, but their influence on decisions regarding immediate treatment versus conservative management, including active surveillance (AS) and watchful waiting (WW), remains uncertain.

Using a linkage with the Surveillance, Epidemiology, and End Results program, we evaluated the association between a 22-gene genomic classifier (GC) and initial management among patients with low or intermediate clinical-risk prostate cancer diagnosed from 2015 through 2018. Initial management was classified as immediate therapy or AS/WW, and GC scores were grouped as low (<0.45), intermediate (0.45-0.60), or high (>0.60). Multivariable logistic regression assessed associations between GC category and immediate treatment, stratified by clinical-risk group and adjusted for demographic and clinical covariates.

Among 2,547 patients, 286 of 1,030 (27.8%) with low- and 1,113 of 1,517 (73.4%) with intermediate clinical-risk prostate cancer received initial treatment. Use of initial treatment increased with higher GC category. Among patients with low and intermediate clinical-risk prostate cancer, respectively, 20.5% and 57.5% with low GC, 28.3% and 75.8% with intermediate GC, and 46.2% and 88.3% with high GC scores received initial treatment. Higher GC category was independently associated with greater odds of immediate treatment versus AS/WW (versus low GC: intermediate GC, odds ratio [OR] 1.98, 95% confidence interval [CI] 1.57-2.49, p < 0.001; high GC, OR 4.42, 95% CI 3.41-5.71, p < 0.001).

Higher GC scores were associated with greater use of immediate treatment and less use of AS/WW, underscoring the need to determine whether GC testing also predicts long-term outcomes among patients managed with AS.