Real-world Evidence on Baseline Characteristics and Treatment in Metastatic Hormone-sensitive Prostate Cancer: Findings from the PIONEER 2.0 Big Data Investigation Group.

Background and objective: As first-line therapies for metastatic hormone-sensitive prostate cancer (mHSPC) expand, real-world insights into the baseline characteristics and treatment patterns of mHSPC patients are critical. This study characterises baseline patient profiles and treatment patterns in a multinational real-world cohort from the PIONEER 2.0 Big Data Investigation Group. Methods: This longitudinal observational study utilised health records, insurance claims, and cancer registries from eight European and North American databases. Men diagnosed with mHSPC between January 2016 and December 2020 were included. First-line regimes were classified into four cohorts: (1) androgen deprivation therapy (ADT) monotherapy, (2) ADT + chemotherapy, (3) ADT + androgen receptor pathway inhibitors (ARPIs), and (4) ADT + ARPI + chemotherapy. Baseline characteristics were analysed across treatment groups, and treatment patterns were evaluated over time. Key findings and limitations: A total of 69 680 mHSPC patients were identified across eight databases, of whom 71% presented with synchronous mHSPC. The median age ranged from 70 to 79 yr, and the most prevalent comorbidities were arterial hypertension peaking at 71% (OPTUM ADT monotherapy), obesity (up to 46%), and diabetes mellitus (up to 32%). Patients aged 70-79 yr were most often treated with ADT monotherapy or ADT + ARPI, whereas those aged 60-69 yr more frequently received ADT + chemotherapy or ADT + ARPI + chemotherapy. From 2016 through 2020, the adoption of ARPI-based combinations rose steadily, use of ADT + chemotherapy declined, and ADT monotherapy remained stable. Conclusions and clinical implications: In this expansive real-world analysis of nearly 70 000 mHSPC patients, age and comorbidity burden emerged as the primary determinants of frontline therapy, alongside a clear shift towards the increased use of ADT + ARPI regimes from 2016 to 2020. Embedding these real-world insights into clinical guidelines and decision-making can enhance treatment personalisation, accelerate adoption of evidence-backed combinations, and ultimately enhance mHSPC patient outcomes. Patient summary: In this study of nearly 70 000 men with metastatic hormone-sensitive prostate cancer, doctors' treatment decisions were influenced strongly by patients' age and other health issues, highlighting a growing preference for combination therapies. The findings highlight the importance of real-world evidence, which captures diverse, often under-represented, patients to complement clinical trials and guide more inclusive, evidence-based care.