Prostate cancer clinical trial end points: "RECIST"ing a step backwards

Area of Science:

• Oncology
• Clinical Trial Design
• Prostate Cancer Research

Background:

• Prostate cancer presents diverse clinical manifestations across localized, recurrent, and metastatic stages.
• Current clinical trial eligibility and outcome criteria, such as Response Evaluation Criteria in Solid Tumors (RECIST), may not fully capture these diverse presentations.

Purpose of the Study:

• To evaluate the applicability of RECIST criteria to various prostate cancer disease states.
• To determine if RECIST criteria adequately relate clinical issues to the manifestations of prostate cancer across different disease states.

Main Methods:

• Analysis of lesion characteristics (site, size, distribution) in patients with progressive metastatic prostate cancer (castrate and noncastrate).
• Assessment of prostate-specific antigen (PSA) levels.
• Application of RECIST-defined outcome measures to metastatic, rising PSA, and localized disease states.

Main Results:

• A significant proportion of metastatic prostate cancer patients lacked measurable target lesions (>2 cm) according to RECIST criteria.
• RECIST criteria rendered patients with rising PSA and localized disease ineligible for trials.
• RECIST-based eligibility and outcomes conflict with established reporting standards for rising PSA and castrate metastatic disease.

Conclusions:

• Sole reliance on RECIST for tumor regression is insufficient for evaluating the majority of prostate cancer clinical manifestations.
• Tailoring eligibility criteria to specific clinical questions and disease states is essential.
• Focusing on duration of benefit (biochemical, radiographic, clinical) will provide more precise assessment of treatment effects.