New bowel cancer treatment shows zero recurrences nearly 3 years after surgery
London: A small but substantial change to bowel cancer treatment has delivered remarkable results, with no patients experiencing a recurrence almost three years after surgery.
The findings from the NEOPRISM-CRC clinical trial will be presented at the American Association for Cancer Research Annual Meeting in April 2026. Led by teams from University College London and UCL Hospital, the study swapped post-surgery chemotherapy for a short course of the immunotherapy drug pembrolizumab before surgery.
Initial results showed 59% of patients had no signs of disease after pembrolizumab and their operation. Now, 33 months later, none of the treated patients have seen their cancer return. That includes patients who were clear of cancer after treatment and those who still had small amounts remaining, which did not grow or spread during follow-up.
“Seeing that no patients have experienced a cancer recurrence after almost three years of follow-up is extremely encouraging and strengthens our confidence that pembrolizumab is a safe and highly effective treatment to improve outcomes in patients with high-risk bowel cancers,” said Dr. Kai-Keen Shiu, Chief Investigator from UCL Cancer Institute and Consultant Medical Oncologist at UCLH.
Around 25% of patients who have standard surgery and post-op chemotherapy typically relapse within three years. This study suggests a short course of immunotherapy before surgery can provide more durable, long-lasting cancer control for high-risk bowel cancer.
Researchers also analyzed blood samples to understand why the treatment works and to identify who benefits most. They designed personalized blood tests that can show early on whether the treatment worked and whether any cancer remains in the bloodstream.
“What is particularly exciting is that we now may be able to predict who will respond to the treatment using personalized blood tests and immune profiling,” Dr. Shiu added. “These tools could help us tailor our approach, identifying patients who are doing well and may need less therapy before and after surgery versus patients at higher risk of disease progression or relapse who need additional treatment.
”The results build on earlier findings that pembrolizumab led to major tumor shrinkage in patients with stage 2 or 3 bowel cancer, pointing to a shift toward more precise, effective care.
