Regional differences in patient age and prostate cancer characteristics and rates of treatment modalities in favorable and unfavorable intermediate risk prostate cancer across United States SEER registries

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Introduction

D’Amico intermediate risk (IR) prostate cancer (PCa) is a highly heterogeneous entity and accounts for the majority of PCa patients [ 1234 ]. This heterogeneity of IR PCa is based on a wide range of possible combinations of PSA values, cT stage and biopsy Gleason score [ 2 ]. Due to the highly heterogeneous entity of IR PCa, NCCN guidelines recommend distinguishing between favorable and unfavorable IR PCa, also taking the percentage of positive prostate biopsy cores into account, in order to further risk stratify these patients [ 5 ]. In consequence, differences in PCa characteristics such as PSA, cT stage, biopsy Gleason score, as well as the distinction into favorable and unfavorable IR PCa may in turn translate into differences in treatment type. For example, some studies suggest that favorable IR PCa patients may good candidates for no local therapy (NLT) strategies, such as Active Surveillance [ 6 ]. It is possible that differences in selected treatment type may also depend on geography. Specifically, in some regions, active treatments such as radical prostatectomy (RP) may be used more frequently than external beam radiation therapy (EBRT) and vice versa in IR PCa. Such phenomenon may be indicative of differences in quality of care or experiences in PCa treatment [ 7891011 ]. Our analysis focused to test this concept and to elaborate differences according to geographical region of residence in favorable and unfavorable IR PCa. Specifically, we tested for differences in active treatment rates between Surveillance, Epidemiology and End Results (SEER) registries within favorable and unfavorable IR PCa patients.

The current SEER database samples approximately 34.6 % of the US population and approximates it in demographic composition and cancer incidence [ 12 ]. The SEER database is divided into 18 different geographical registries. We hypothesized that interregional differences may remain between individual SEER registries even after detailed adjustment for baseline PCa characteristics.