July 13, 2024

Promising Cancer Test Expands Access to Immunotherapy

A recent study conducted by investigators from Brigham and Women’s Hospital has identified more cancer patients who could benefit from immunotherapy. Immunotherapy is a highly effective treatment for patients with cancers that have a condition called mismatch repair deficiency. However, the current standard of care test, immunohistochemistry, misses nearly six percent of endometrial cancer patients and one percent of colorectal cancer patients with this condition. The study suggests that using next-generation sequencing as a complimentary testing practice could identify an additional 6,000 patients in the United States who would otherwise not be offered immunotherapy.

Colorectal cancer and endometrial cancer are the two types of cancer where mismatch repair deficiency is most commonly seen. Immunotherapy is not the standard treatment for these cancers unless a patient has this condition. However, for patients with mismatch repair deficiency, even those with late-stage cancer, immunotherapy can lead to long-term survival and potential cure. Incorporating next-generation sequencing as a complimentary test could benefit patients at all stages of cancer, from pre-treatment to advanced stages.

In the United States, over 150,000 people are diagnosed with colorectal cancer and over 65,000 people are diagnosed with endometrial cancer each year. These cancers often have high rates of mismatch repair deficiency, a genetic state where DNA repair proteins are lacking. Mismatch repair deficiency impairs the ability of DNA to repair itself, leading to various types of cancer. Previous research has shown that cancer patients with this condition respond well to immunotherapy.

The study analyzed 1,655 patients from Brigham and Women’s Hospital and Dana-Farber Cancer Institute who had colorectal or endometrial cancer and received both immunohistochemistry and next-generation sequencing tests. The researchers found that nearly six percent of endometrial cancer patients and one percent of colorectal cancer patients were missed as mismatch repair deficient by immunohistochemistry, but detected by next-generation sequencing. These patients responded better to immunotherapy and had similar survival and treatment outcomes as patients identified as deficient by both tests.

Next-generation sequencing is a more sensitive diagnostic tool compared to immunohistochemistry because it detects more mutation characteristics. While the study suggests that next-generation sequencing is a more sensitive diagnostic tool, further research is needed to confirm and generalize these findings.

The study also revealed that patients with the same type and stage of cancer who did not receive immunotherapy had worse outcomes compared to those who did.

The senior author of the study, Amin Nassar, emphasized the importance of not missing patients who could benefit from immunotherapy, as it deprives them of a treatment with long-term benefits. The goal is to treat patients with the appropriate therapy, avoiding treatments that may be more toxic or less effective.

The researchers aim to explore if these findings apply to other sequencing panels and other types of cancer. They also plan to investigate the role of other genetic deficiencies in mismatch repair deficiency.

The study’s authors include researchers from Brigham and Women’s Hospital, Yale Cancer Center, Dana-Farber Cancer Institute, and other institutions.

1. Source: Coherent Market Insights, Public sources, Desk research
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