Bowel cancer breakthrough as immunotherapy before surgery proven to improve survival rate
Treating some bowel cancer patients with immunotherapy before surgery improves survival and cuts the need for chemotherapy, research suggests.
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A new study found zero relapses among patients given a new treatment regime, with far better results than would be expected otherwise.
The trial was led by University College London (UCL) and University College London Hospitals NHS Foundation Trust (UCLH), with experts presenting their findings at the American Association for Cancer Research (AACR) meeting in San Diego, California.
The work builds on earlier results showing that nine weeks of pre-operative immunotherapy using the drug pembrolizumab led to major tumour shrinkage in patients with stage two or three bowel cancer.
Read More: NHS to change bowel screening in bid to pick up thousands more cases that could be detected earlier
Some 59% of patients had no signs of disease after having pembrolizumab and then their planned bowel cancer operation.
Now, 33 months later, none of the patients have seen a return of their cancer – including those who had no signs of cancer after treatment and those who still had small amounts remaining. Of those with remaining cancer, it did not grow or spread during follow-up.
Normally, around a quarter of people who have standard surgery and post-op chemotherapy see cancer come back after three years, but the new study suggests a short course of immunotherapy before surgery is far more effective.
The NEOPRISM-CRC trial involved 32 patients recruited with stage two or three bowel cancer and a certain genetic profile (MMR deficient/MSI-high bowel cancer) from five hospitals around the UK.
Around 10-15% of patients with stage two or three bowel cancer have this genetic profile, making up around 2,000-3,000 bowel cancer cases per year in the UK.
While the study looked at this specific group of patients, researchers are hopeful their approach can be extended to others with bowel cancer.
Dr Kai-Keen Shiu, chief investigator from the UCL Cancer Institute and a consultant medical oncologist at UCLH, said: “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 personalised blood tests and immune profiling.
“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.”
Patients were given up to nine weeks of pembrolizumab prior to bowel surgery, instead of the usual treatment of surgery followed by three to six months of chemotherapy, then monitored over time.
UCLH patient Christopher Burston was diagnosed with bowel cancer in February 2023 after taking part in routine screening.
Mr Burston, 73, of Portland, Dorset, received three doses of immunotherapy over nine weeks, followed by surgery.
He said: “The outcome of the surgery was essentially that the cancer had melted away – these were the doctor’s words.
“The immunotherapy had an almost immediate effect.”
Over three years later, he remains cancer-free.
“The recovery went fine,” he said. “I didn’t have any problems. And since then, I’ve been feeling pretty much back to normal.
“I feel very lucky that I’ve reached the stage where my main problem is age rather than cancer or any illness.
“I am able to play guitar, tend my garden and walk the dog very much as before and I look forward to spending time with friends and family.”