Immunotherapy Breakthrough: New Treatments Eliminate Certain Cancers Without Invasive Surgery
Recent advancements in oncology are demonstrating that stimulating the body’s own immune system can lead to the complete disappearance of tumors in some patients, bypassing the need for traditional invasive procedures such as surgery or chemotherapy. This shift toward less invasive options marks a significant milestone in cancer care, offering hope for improved patient quality of life and the preservation of vital organs.
A pivotal clinical study coordinated by the Memorial Sloan Kettering Cancer Center (MSKCC) in the United States has highlighted the potential of immunotherapy for patients with Mismatch Repair Deficiency (MMRd). MMRd is a genetic anomaly that impairs the ability of cells to correct errors during DNA replication. When this essential biological mechanism fails, mutations accumulate, significantly increasing the risk of developing various cancers, particularly colorectal, stomach, endometrial, and ovarian cancers.
The findings, which were presented at the 2025 annual congress of the American Association of Cancer Research (AACR) and published in the New England Journal of Medicine (NEJM), are striking: 80% of patients with MMRd-associated cancers did not require surgery, radiotherapy, or chemotherapy after six months of immunotherapy. These results suggest that for a significant portion of patients, immunotherapy may effectively replace standard invasive treatments.
The clinical application of this technology is exemplified by the case of a 71-year-old patient from New York. Initially treated surgically for colon cancer in 2008, she was diagnosed with esophageal cancer 14 years later. As part of a clinical trial at MSKCC, she received a monoclonal antibody called dostarlimab via 45-minute infusions administered every three weeks.
Dostarlimab functions by blocking the PD-1 (programmed cell death protein 1) protein. Located on the surface of T-lymphocytes, PD-1 normally acts as an immune “checkpoint” or “brake,” limiting excessive immune reactions to protect healthy tissues. Though, some cancer cells exploit this mechanism to evade the body’s natural defenses. By blocking PD-1, dostarlimab releases this brake, enabling the immune system to recognize and destroy malignant cells.
While these therapies do not perform for every patient, the ability to eliminate tumors without the physical toll of surgery or the systemic impact of chemotherapy represents a critical evolution in oncological care. These findings could guide future treatment strategies, prioritizing genomic screening to identify patients who may benefit from non-invasive immunotherapy.
