Reporting results from chemotherapy trials. Does response make a difference in patient survival?

Area of Science:

• Oncology
• Clinical Trials
• Evidence-Based Medicine

Background:

• Chemotherapy is a common cancer treatment for many solid tumors.
• Evidence supporting the effectiveness of chemotherapy in improving survival is often limited.
• Assessing true treatment benefit requires rigorous evaluation of clinical trial endpoints.

Purpose of the Study:

• To evaluate whether chemotherapy trials reporting effectiveness demonstrated actual increased survival in treated patients.
• To critically examine the endpoints used in common solid tumor chemotherapy trials.
• To identify potential biases in reporting chemotherapy effectiveness.

Main Methods:

• A systematic review of chemotherapy trials for four common solid tumors published over a two-year period.
• Analysis of reported endpoints, focusing on objective response rates and survival data.
• Examination of studies claiming treatment effectiveness based on survival comparisons.

Main Results:

• 95% of 80 reviewed studies used chemotherapy response as an endpoint.
• Of studies showing >=15% objective response, 76% reported significantly greater survival for responders.
• 95% of 21 studies supporting treatment effectiveness cited superior responder survival, a comparison potentially flawed by lead-time bias.

Conclusions:

• Comparisons of survival between chemotherapy responders and non-responders may not accurately reflect treatment benefit.
• This methodology can lead to an overestimation of chemotherapy's effectiveness.
• Journal editors should scrutinize survival comparisons in published chemotherapy trials to ensure validity.