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# pCR May Not be Valid Rectal Cancer Endpoint: Study
- URL: https://www.fdaweb.com/pcr-may-not-be-valid-rectal-cancer-endpoint-study/
- Published: 2025-07-17T12:00:00.000Z
- Updated: 2026-09-14T15:16:50.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5159526

A study raises questions about the ability of an FDA-approved surrogate endpoint — pathologic complete response (pCR) — to reliably predict improvement in long-term survival in patients diagnosed with rectal cancer. The study, by Tulane University researcher **Kavin Sugumar** in association with Mayo Arizona and other medical centers, was [published](https://medicalxpress.com/news/2025-07-fda-metric-effectiveness-rectal-cancer.html?ref=fdaweb.com) in *JAMA Network Open*.

A Tulane [statement](https://medicalxpress.com/news/2025-07-fda-metric-effectiveness-rectal-cancer.html?ref=fdaweb.com) says that traditionally, the success of treatments for rectal cancers has been determined by measuring overall survival, the years between a patient’s diagnosis and death. “Since 2012,” it says, “FDA has allowed pharmaceutical companies to use tumor-free status post-therapy as a surrogate for overall survival to cut down on time and expenses needed to approve new cancer treatments.”

Through a meta-analysis of 25 clinical trials involving nearly 12,000 rectal cancer patients, Sugumar and his colleagues found no statistical relationship between pCR and overall survival.

“This is about patient outcomes,” Sugumar says, “but it’s also about how we evaluate whether a new drug works. FDA has approved pCR as a substitute for a result that would normally take years to determine, but we found that pCR should not be used as a sole endpoint to determine if a cancer treatment has been effective.”

Sugumar suggests that instead of relying solely on pCR, it might be better to use a combination of surrogate endpoints, one of which could be pCR.