Endpoints in cancer clinical trials

Area of Science:

• Oncology
• Clinical Trial Methodology
• Biostatistics

Background:

• Endpoints are critical for evaluating cancer treatments, categorized as patient-centered (e.g., overall survival, OS) or tumor-centered (e.g., progression-free survival).
• Surrogate endpoints, often tumor-centered, aim to substitute for patient-centered outcomes like OS in clinical trials.
• The selection and definition of endpoints significantly impact trial conclusions, statistical power, and cost.

Purpose of the Study:

• To highlight the challenges in selecting and defining endpoints for cancer clinical trials.
• To emphasize the need for standardized definitions and validated surrogate endpoints.
• To advocate for health-related quality of life (QoL) as a useful surrogate endpoint.

Main Methods:

• Review of current practices and challenges in oncology trial endpoint selection.
• Discussion of the limitations of traditional endpoints like OS in the context of evolving cancer treatments.
• Exploration of the potential of surrogate endpoints, including QoL.

Main Results:

• Overall survival (OS) remains the gold standard but poses logistical challenges (cost, duration) due to effective salvage therapies.
• Many tumor-centered surrogate endpoints lack standardized definitions, hindering cross-trial comparisons and validation.
• Health-related quality of life (QoL) is identified as a viable and valuable surrogate endpoint for assessing treatment benefits.

Conclusions:

• Standardized definitions and validated surrogate endpoints are essential for robust cancer clinical trials.
• Further methodological research is needed to standardize QoL data analysis and endpoint definitions.
• QoL offers a patient-centered perspective crucial for evaluating treatment efficacy and public health impact.