Some Rectal Cancer Patients May Be Able to Skip Surgery, Chemo, and Radiation

A new FDA approval could potentially change how some patients with rectal cancer are treated. The drug dostarlimab, also known by the brand name Jemperli, is designed to target a specific type of rectal cancer called microsatellite instability-high (MSI-H)/mismatch repair deficient cancer. This form of the disease accounts for 5-10% of all rectal cancers and is caused by genetic mutations that impair the body's ability to repair DNA damage.

In a study of 154 patients with this type of rectal cancer, 68% achieved a complete clinical response to dostarlimab treatment after one year. This means doctors could no longer detect tumors through imaging or other tracking methods. Dr. Andrea Cercek, the study's principal investigator and section head of colorectal cancer at Memorial Sloan Kettering Cancer Center, reported that some patients remained tumor-free for even longer periods.

The treatment involves nine infusions of the drug, administered once every three weeks for six months. Dostarlimab works as a checkpoint inhibitor, removing the brakes on the immune system and allowing it to recognize and attack cancer cells. Dr. Luis Diaz, head of solid tumor oncology at Memorial Sloan Kettering and a trial investigator, believes this immunotherapy could replace aggressive standard treatments like chemotherapy, radiation, and surgery.

Standard treatment for rectal cancer typically requires patients to undergo chemotherapy, radiation, and surgery, which can have significant long-term effects, including the need for colostomy bags and potential fertility loss. Dr. Diaz emphasized that this new treatment could spare patients from those life-altering procedures and preserve their ability to have children.

Two patients who benefited from the treatment are Kelly Spill and Sascha Roth. Spill, diagnosed with rectal cancer at 29 and recently having her first baby, had hoped to have more children in the future. However, the aggressive standard treatment threatened to prevent that from happening. After joining the study, Spill's tumor disappeared after four infusions, and she avoided the need for chemo, radiation, and surgery.

Roth, diagnosed with rectal cancer in 2019, was also a candidate for the study. She had blood in her stool, leading to a diagnosis of Stage III colorectal cancer. Roth's tumor was located in a low area of the rectum, making it unsuitable for surgery. The surgery and chemo she had previously been expected to undergo were not an option for her either.

Despite skepticism about the trial's success, Roth decided to participate and was the first patient to receive the treatment. Within weeks, she saw significant improvements in her condition.