- • Differences exist regarding PCa characteristics in favorable and unfavorable IR PCa.
- • Differences in active treatment rates exist across SEER registries.
- • Differences in treatment rates are explained by differences in PCa characteristics.
Intermediate risk (IR) prostate cancer (PCa) is a highly heterogeneous entity and can be distinguished into favorable and unfavorable IR PCa according to biopsy, PSA and cT-stage characteristics. These differences may translate into differences in treatment type.
We tested for differences in PCa tumor characteristics and differences in active treatment rates (radical prostatectomy [RP], external beam radiotherapy [EBRT]) according to Surveillance, Epidemiology and End Results (SEER) registry (2010−2015) in favorable and unfavorable IR PCa. Data were stratified according to individual SEER registries. Further analyses additionally adjusted for PCa baseline characteristics (PSA, cT stage, biopsy Gleason group grading [GGG], percentage of positive biopsy cores).
Tabulations according to SEER registries showed that, in favorable IR vs. unfavorable IR, the rates of RP and EBRT respectively ranged from 30.0 to 54.3% vs. 30.3–55.5 % and 8.3–44.7 % vs. 11.5–45.5 %. Differences in age and baseline PCa tumor characteristics also existed in both favorable and unfavorable IR across SEER registries. After adjustment for those baseline patient and PCa characteristics (PSA, cT stage, GGG, percentage of positive biopsy cores), RP and EBRT rates exhibited virtually no residual differences across individual SEER registries, in both favorable (36.0–41.0 % and 26.8–28.1 %) and unfavorable IR PCa (39.2−42.0% and 31.1–33.5 %).
Important differences may be identified in treatment rates within the examined 18 SEER registries in favorable and in unfavorable IR PCa. However, the observed differences are virtually entirely explained by differences in baseline PCa characteristics.
D’Amico intermediate risk (IR) prostate cancer (PCa) is a highly heterogeneous entity and accounts for the majority of PCa patients [ ]. This heterogeneity of IR PCa is based on a wide range of possible combinations of PSA values, cT stage and biopsy Gleason score [ ]. 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 [ ]. 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 [ ]. 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 [ ]. 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 [ ]. 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.