Immunotherapy is very successful in colon cancer: ‘The results are unprecedented’

In two-thirds of patients, the tumor appeared to have completely disappeared at the time of surgery. The cancer cells are removed by the body’s immune system. The results have been published in New England Journal of Medicine It is called a pioneer.

Patients received two courses of immunotherapy in the month before surgery. In 95% of patients, only 10% or fewer cancer cells were present at the time of surgery. In 68%, no live cancer cells were found. In addition, none of the patients developed cancer again during an average of more than two years of their follow-up, the hospital reported.

The results are promising

The findings stem from a study begun several years ago by internal oncologist Myriam Chalabi. Chalabi says success was achieved quickly. “We wanted to investigate what immunotherapy could mean for people with non-metastatic colon cancer. Then we saw something that almost never happens, which is that all the patients in the study group responded well to the new treatment.”

The results of this study were published four years ago. After its success, the study was expanded to include a larger group of patients to see if immunotherapy could also prevent metastases in the long term. The results are once again promising: of the 111 patients with MSI-stable colon cancer who were treated, almost all responded very well to this very short pretreatment with immunotherapy.

Much better than chemotherapy

“This specific type of colon cancer has many errors in the DNA, which makes the cancer cells easier to detect by the immune system. The immune system only needs a small stimulus to successfully attack those cancer cells,” Chalabi explains of the success of the treatment. . “The results are unprecedented. Both the effect and the side effects are much better than, for example, preoperative chemotherapy, to which only 1 in 20 patients responds.”

It will take some time before treatment becomes available to all patients with this type of colon cancer. At the end of this year, the treated patients were followed up for three years. If the majority of patients remain disease-free, the new treatment may be considered standard treatment. “We are currently working hard on this,” Chalabi says. “We hope to eventually be able to omit the procedure for patients who respond well.”