Immunotherapy Before Surgery Shows Promise for Colorectal Cancer

A clinical trial indicates that immunotherapy administered before surgery may significantly improve outcomes for specific colorectal cancer patients. Patients in the NEOPRISM-CRC study received a short course of immunotherapy. These patients have remained cancer-free for nearly three years. This outcome challenges the standard approach of surgery followed by months of chemotherapy.

The trial was led by researchers at University College London (UCL) and University College London Hospitals (UCLH). It found that nine weeks of pembrolizumab treatment before surgery led to strong and lasting responses. This was observed in patients with stage two or three colorectal cancer. These patients had a specific genetic subtype, which accounts for 10 to 15 percent of colorectal cancer cases.

Early results showed that 59 percent of patients had no detectable cancer after immunotherapy and surgery. After 33 months of follow-up, none of the patients experienced a relapse. This includes patients whose tumors completely disappeared and those with small traces of cancer. The remaining cancer did not grow or spread over time. This contrasts with standard care, where about 25 percent of patients typically see their cancer return within three years.

Researchers also developed personalized blood tests to predict treatment success. These tests detect cancer DNA in the bloodstream. They may help doctors determine early on if the treatment has been successful. Immune profiling from tumor tissue also helped predict response. These tools could guide treatment decisions. The findings were presented at the American Association for Cancer Research (AACR) Annual Meeting 2026.