A new clinical trial found that some cancers can be treated effectively with an immunotherapy drug alone, sparing patients from invasive surgery, chemotherapy, or radiation.

Researchers at Memorial Sloan Kettering Cancer Center in New York found that 80% of specific forms of solid tumor cancers could be treated with just the immunotherapy drug, dostarlimab, according to The New York Times.

Immunotherapy enhances the body's natural defenses against disease by stimulating or restoring the immune system's ability to recognize and attack cancer cells.

The trial, led by Dr. Luis A. Diaz Jr. and Dr. Andrea Cercek, found that 80% of the 103 participants did not require standard treatments after six months of immunotherapy. The best results were seen in all 49 patients with rectal cancer, says CBS News. Their cancers completely disappeared. In addition, 35 of 54 patients who had other cancers, including in the prostate, stomach, esophagus, liver, endometrium, and urinary tract, also had their cancer resolve.

Experts say that the reason immunotherapy works on these cancers is because the tumors have mismatch repair mutations in their genes that prevented them from fixing DNA damage. The tumors contain proteins that signal the immune system to destroy them, but they put up a shield that blocks the immune system from attacking them. Immunotherapy works by unblocking the immune system and allowing it to destroy the tumors.

Diaz noted that the results indicate that immunotherapy treatments could be a game-changer for certain patients, sparing them the from having to endure surgery, radiation or chemotherapy.

"Current treatments like surgery, radiation and chemotherapy can seriously affect quality of life," he said in a statement. "For example, treating rectal cancer this way can lead to infertility and problems with bowel, bladder and sexual function, as well as other daily challenges.”

The stunning results could bring hope to the number of patients suffering with these types of cancer.

“This study represents a significant shift in treatment for a number of solid tumor cancers,” said Julian Adams, president and CEO of Stand Up To Cancer, the organization that funded the research. “Eliminating invasive surgeries that often carry significant risks and lifelong challenges not only saves lives — it sustains the quality of those lives.”