This therapy drug can eliminate cancerous tumours and help patients recover without harsh surgeries

For many, the word cancer brings images of hospitals, surgeries, and long, exhausting treatments. But a new drug therapy—dostarlimab—has quietly created a ripple of hope in the cancer world. A hope where the body can recover without harsh surgeries or debilitating therapies.


In a recent study published in the , a group of 103 cancer patients received dostarlimab, an immunotherapy drug, without undergoing any surgery. Surprisingly, 82 patients saw such dramatic tumour shrinkage that surgery was no longer necessary.
In another group of 49 rectal cancer patients, tumours disappeared completely after six months of dostarlimab infusions. No knives. No radiation. Just the immune system, strengthened to do what it does best: fight back.

It sounds too good to be true—but here's the fine print. These remarkable results came from patients whose tumours had a rare genetic glitch known as a “mismatch repair defect” (MMRd). This flaw makes tumours more vulnerable to the immune system, making them ideal targets for immunotherapy drugs like dostarlimab.


Take the case of Maureen Sideris, a 71-year-old woman diagnosed with gastroesophageal junction cancer. Surgery would’ve cost her months of recovery, the ability to eat or lie flat, and possibly her voice for a while. But instead, she entered this experimental program, receiving dostarlimab infusions for nine months. Her tumour disappeared. She didn’t need the surgery.
And she isn’t alone. Of the first rectal cancer patients treated five years ago, all are still disease-free. Two even became mothers—something impossible if they’d gone through traditional therapies.

Cancer treatments often come with life-altering side effects. Removing a bladder, part of the stomach, or reproductive organs can permanently alter how a person eats, moves, or even starts a family.
This new approach gave back something many cancer survivors never expected to reclaim: normalcy. That’s not just science—it’s deeply human.


While these results feel like a breakthrough, experts are careful. This was a single-centre study conducted at Memorial Sloan Kettering. Some patients haven’t been followed long enough to say for sure if their cancer might return.
And since many types of cancer were included in the study, each with only a few patients, researchers are urging caution before generalising these results. It’s still early, but incredibly promising.