Heterogeneity in subgroup reporting across clinical trials assessing systemic therapies in metastatic castration resistant prostate cancer: A report from a living systematic review.
Authors: Anjum Muhammad Umair , Naqvi Syed Arsalan Ahmed , Khakwani Kaneez Zahra Rubab , Raina Ammad , Jajja Salman Ayub , Khan Muhammad Ali , Rumble Bryan , Garje Rohan , Zakharia Yousef , Singh Parminder , Parikh Rahul Atul , Bryce Alan Haruo , Riaz Irbaz Bin 
Published: February 2025

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Background:
Inconsistent reporting of subgroup data across clinical trials makes interpretation and application of the evidence from trials challenging. We conducted a living systematic review to summarize evidence for American Society of Clinical Oncology (ASCO) guidelines for management of metastatic castration resistant prostate cancer (mCRPC). Here, we provide an overview of reporting patterns of subgroup data across mCRPC trials.
Methods:
MEDLINE and EMBASE were systematically searched from each database's inception through September 20
th
, 2024, to identify phase II/III/IV randomized clinical trials assessing the efficacy and safety of treatment options in mCRPC. For outcomes of overall survival (OS) and progression free survival (PFS), data from the subgroup analyses was collected and compared across trials to assess heterogeneity in the reporting of subgroups.
Results:
This analysis included 141 trials (phase II: 83; phase III: 56; phase IV: 2). OS was reported by 113 (80%) trials; 32 (28%) reported OS by any subgroups with 95 unique subgroup categories. PFS was reported by 110 (78%) trials; 23 (21%) reported PFS by any subgroups with 63 unique subgroup categories. Even among consistently reported subgroups, such as age, ECOG performance status, race, geographical area, and Gleason score, considerable heterogeneity in different subgroup levels/thresholds was observed across trials. Top ten most commonly reported subgroups are summarized (Table).
Conclusions:
Lack of consistent reporting for subgroup analysis in mCRPC trials preclude meaningful conclusions about clinically relevant subgroup and synthesizing evidence for clinical guidelines. A standardized framework for consistent reporting of subgroup data across trials can help inform clinical practice and clinical practice guidelines.

OS
PFS

Number of trials
113
110

Reporting subgroup analysis – N (%)
32 (28)
23 (21)

Commonly reported subgroups – (N)
Age (26)ECOG-PS (26)LDH (21)PSA (18)Geographic area (15)Alkaline phosphatase (14)Visceral disease (14)Gleason score (9)Race (9)Brief pain inventory level (8)
Age (21) ECOG-PS (19)PSA (18)LDH (14)Geographic area (13)Visceral disease (11)Gleason score (10)Alkaline phosphatase (9)Bone metastasis (9)Disease location (9)

Age – (N)
<65 (14); ≥65 (9); ≤68 (1); ≥69 (1); <70 (5); ≥70 (5); ≤74 (4); 65-75 (5); ≤ 71 (1); >71 (1); ≥75 (11); >Median (1); <Median (1)
<65 (12); 65-74 (6); ≥65 (6); <70 (5); ≥70 (5); <75 (4); ≥75 (10); 76-80 (1); >80 (1)

ECOG-PS – (N)
0 (15); 0-1 (11), 1 (11); 1-2 (5); 2 (12)
0 (15); 0-1 (5), 1 (12); 1-2 (2); 2 (6)

Race – (N)
White (9)Non-white (6)African American/black (2)Asian (2)
White (8)Non-white (5)African American/black (2)Asian (4)

Geographic Area – (N)
Europe (8)North America (14)United States (1)Australia (1)Asia (2)
Europe (11)North America (13)United States (1)Australia (1)Asia (2)North and South America (2)

Gleason Score – (N)
2-6 (1); 7 (1); 8 (1); <8 (8); ≥ 8 (8); 9-10 (1)
<8 (10); ≥ 8 (10)