Health · Medical Research · 1 day ago
No bowel cancer recurrences seen after pre-surgery immunotherapy in small trial
A UK trial tested pembrolizumab, an immunotherapy drug, before surgery in 32 people with stage two or three bowel cancer.
The patients had a genetic form of the disease called MMR-deficient or MSI-high bowel cancer.
They received up to nine weeks of treatment before their planned surgery, instead of the usual approach of surgery followed by chemotherapy.
After 33 months, none of the patients had a cancer recurrence, including those with small amounts of disease left after treatment.
The trial is small, so the result does not show that the treatment will work this well for everyone with bowel cancer.
Researchers also developed personalized blood tests to look for signs of cancer and help identify who may benefit from treatment.
The findings suggest this approach could offer lasting cancer control for this specific group, while further work may help guide how much treatment individual patients need.
None of the patients in a small trial had a bowel cancer recurrence during 33 months of follow-up after receiving pembrolizumab before surgery.
The NEOPRISM-CRC trial enrolled 32 people with stage two or three bowel cancer and a particular genetic profile.
Participants received up to nine weeks of pembrolizumab before planned bowel surgery, instead of surgery followed by chemotherapy.
Earlier trial results found no detectable disease after treatment and surgery in 59% of patients.
Researchers say personalized blood tests may help identify who benefits from treatment and who may need additional therapy.
- Who
- The NEOPRISM-CRC trial enrolled 32 patients with stage two or three bowel cancer and MMR-deficient/MSI-high disease.
- What
- Patients received pembrolizumab before surgery; none had a recurrence during 33 months of follow-up.
- When
- The follow-up period was 33 months. The findings are due to be presented at the AACR Annual Meeting 2026 in April.
- Where
- The trial took place at five hospitals across the UK.
- Why
- Researchers are studying whether pre-surgery immunotherapy can improve cancer control and whether blood tests can identify who benefits.
This story does not have two clearly opposing sides.
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.
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.
Earlier trial results showed major tumor shrinkage after pembrolizumab before surgery.
Earlier data showed 59% of patients had no detectable signs of disease.
None of the patients had experienced a cancer recurrence.
- Trial
- NEOPRISM-CRC
- Participants
- 32 patients
- Treatment
- Up to nine weeks of pembrolizumab before bowel surgery
- Follow-up
- 33 months, with no recurrences reported
- Trial sites
- Five hospitals across the UK









