British researchers have reported promising results from a clinical trial involving 32 patients with colorectal cancer, showing that all participants remained free of disease recurrence after receiving immunotherapy instead of standard chemotherapy before surgery.
The study, conducted by University College London, focused on patients with stage II or III colorectal cancer who also had a specific genetic marker known as mismatch repair deficiency (MMR-D) or microsatellite instability-high (MSI-H). Rather than undergoing six months of chemotherapy prior to tumor removal, these patients received nine weeks of pembrolizumab, an immune checkpoint inhibitor marketed as Keytruda.
After 33 months of follow-up, none of the 32 participants experienced a cancer relapse. 59% of the patients showed complete disappearance of tumors, although the remaining cases demonstrated stable disease with no progression.
Dr. Kai-Keen Shiu, a physician at University College London Hospitals involved in the research, described the findings as “encouraging,” noting that seeing no cancer recurrence in nearly three years is highly positive. He added that future personalized blood tests and immune profiling may help predict which patients are most likely to benefit from this approach.
One trial participant, 73-year-old Christopher Burston from Portland, Dorset, said his cancer had “basically disappeared” according to his doctors, and that he now feels back to normal, with age being his primary health concern rather than cancer.
The researchers emphasized that this trial shifts the treatment paradigm for a subset of colorectal cancer patients by replacing lengthy preoperative chemotherapy with a shorter immunotherapy course. In the UK, over 47,000 people are diagnosed with bowel cancer annually, with rising cases among younger adults.
While traditional treatments witness about one in four patients with similar cancer stages experience recurrence within the same timeframe, this trial showed no relapses among those receiving pembrolizumab. The study’s authors suggest that blood-based monitoring and immune analysis could eventually help identify ideal candidates for such therapy.
