32 patients received the immunotherapy drug before having surgery (Image: Getty)
A blockbuster drug could triple survival chances for some bowel cancer patients by “melting away” their tumours, research suggests.
The immunotherapy treatment, pembrolizumab, boosts the immune system’s ability to recognise and attack cancer cells.
A study found that 59 percent of patients treated saw their tumours shrink so much that there were no signs of the cancer when the affected section of their bowel was removed during surgery.
This could at least triple those patients’ chances of long-term survival, said Dr Kai-Keen Shiu, chief investigator of the trial from UCL Cancer Institute.
It is hoped the drug could one day allow people who respond well to avoid having an operation and harsh chemotherapy altogether.
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Dr Shiu, added: “Pembrolizumab has completely changed the face of cancer treatment. Immunotherapy can make tumours disappear before surgery.
“If patients have a complete response to pembrolizumab it can triple their chance of survival. Patients also don’t need any chemotherapy after so they avoid all those side effects.”
The drug was given to people with stage two or three MMR deficient/MSI-high bowel cancer, which has a lot more DNA mutations than other kinds.
This type accounts for 10-15 percent of cases, affecting up to 3,000 people each year in the UK.
Sufferers with stage two and three disease have “bulky, high-risk tumours” that can spread through the bowel wall and into lymph nodes, Dr Shiu said.
They would usually be treated with surgery, followed by three to six months of chemotherapy.
The drug is administered via a 30-minute IV drip (Image: Getty)
For the NEOPRISM-CRC study, 32 patients at five hospitals were given three doses of pembrolizumab over nine weeks. Each dose was administered via a 30-minute intravenous infusion into the hand.
They then had surgery to remove the affected part of their bowel, and it was examined to check how much their cancer had shrunk.
After surgery, all patients in the trial were deemed cancer-free, including the 41 percent who did not respond so well to the new treatment.
Dr Shiu said pembrolizumab could “increase the chances of curing the disease at an early stage” and halve risk of the cancer returning.
He added: “We are now extending the trial to over 70 patients in the hope of demonstrating the impact of this drug on relapse-free survival.
“We hope that we will see the risk of relapse within three years cut by half, from around 20 percent to less than 10 percent.”
Pembrolizumab is already available on the NHS to treat later stage bowel cancer which has spread around the body, as well as other cancers including breast, cervical and lung.
The latest findings, presented at the American Society of Clinical Oncology’s annual conference in Chicago, suggest its use could be extended.
Professor Mark Saunders, a consultant clinical oncologist at The Christie in Manchester, said: “This is a really very exciting new treatment for the 10-15 percent of patients who have the right genetic make-up.
“Immunotherapy prior to surgery could well become a ‘game-changer’ for these patients with this type of cancer.
“Not only is the outcome better, but it saves patients from having more conventional chemotherapy, which often has more side-effects.”
Prof Saunders added: “In the future, immunotherapy may even replace the need for surgery. However, more trials are needed to confirm these exciting early results.”
Bowel cancer is the fourth most common cancer in the UK, with around 43,000 cases diagnosed every year.
Dr Lisa Wilde, director of research and external affairs at Bowel Cancer UK, said: “The results of this trial are certainly promising for people with the right genetic variants, but additional research is needed before it could be available to patients.
“Finding a way to repurpose existing cancer drugs like pembrolizumab to treat bowel cancer has the potential to widen the options available to patients quickly, and in a cost-effective way.
“Every fifteen minutes someone in the UK is diagnosed with bowel cancer, making it the fourth most common cancer in the country.
“Driving forward research and finding new ways to treat the disease is essential in improving patients’ experiences and ultimately, saving lives.”
