None of the twelve study participants with rectal cancer have tumors after treatment. “This is the first time this has happened in the history of cancer,” says one of the research’s co-authors.
Results that “incite great optimism”. American researchers from Memorial Sloan Kettering Cancer Center published on Sunday in the New England Journal of Medicine, the results of their work for a treatment against rectal cancer. Several months after the start of the clinical trial, the 12 patients treated with dostarlimab for six months are tumor free.
“I do believe this is the first time this has happened in the history of cancer,” the New York Times Dr. Luis A. Diaz, co-author of the study. “We’ve never seen anything work in 100% of people in cancer medicine,” writes the NPR paper Hanna Sanoff, of the University of North Carolina Cancer Center, who didn’t participated in the study, but who applauds these results.
How does this treatment work?
Rectal cancer “is a disease of the cells that line the inside of the rectum. It develops from an initially normal cell that transforms and multiplies in an anarchic way, until it forms a mass called a malignant tumor”, explains the e-cancer website. It is one of the colorectal cancers, the third type of “most common cancer in men and the second in women”, according to Health Insurance.
In their study, the researchers looked at a particular type of rectal cancer, one with a genetic mutation called MMrD (mismatch repair deficiency). The mutations are found “in certain genes that are involved in correcting errors made when copying DNA in a cell”, explains the American National Cancer Institute. And these mutations “can lead to cancer.”
To compensate for this abnormality, study participants took dostarlimab once every three weeks for six months. This treatment is already known, and usually used against endometrial cancer.
It is part of drugs “called immune checkpoint inhibitors”, says Hanna Sanoff, “these are immunotherapy drugs that do not work by directly attacking the cancer itself, but by causing the immune system to ‘a person essentially does the work’.
No trace of cancer two years later
Of the 12 patients treated with dostarlimab, none experienced clinically significant complications, writes the New York Times, but the number of participants is a little low to really realize any harmful effects. The journal notes that with this treatment, “on average, one in five patients has some form of adverse reaction”.
The study published on Sunday is the result of several months – up to two years – of follow-up of the participants, at the end of which no sign of tumor was identified in the patients, whether by digital rectal examination, biopsy or even MRI. . Additionally, none required subsequent chemoradiotherapy or surgery, “and no cases of progression or recurrence were reported,” the researchers write.
However, as encouraging as these results are, to be validated they must be supplemented by tests on larger cohorts of patients, to confirm the various data. In addition, “we know very little about the time required to know if a complete clinical response to dostarlimab is equivalent to a cure”, underlines for example Hannah Sanoff in an editorial on the NEJM site.
She, however, speaks of a “small but compelling” study, and results that “provide great optimism”, writing that the research team has provided “what could be early insight into a breakthrough treatment change. “