A new study uses T cell receptor sequencing to identify immune signatures that could help clinicians assess personal cancer risk in asymptomatic carriers.

Researchers at the University of Texas MD Anderson Cancer Center identified a blood-based biomarker that can help characterize asymptomatic individuals with Lynch syndrome (LS) who are more susceptible to developing cancer.

The study, published in Nature Communications, suggests that early immune detection signatures can allow clinicians to stratify patients based on their personal risk level. LS is a hereditary condition involving germline mutations in DNA mismatch repair genes, predisposing individuals to cancers with microsatellite instability, such as colorectal cancer and endometrial cancer.

“Providing a potential non-invasive blood test to track cancer risk and immune activity in patients with Lynch Syndrome is a tremendous step forward for this patient population,” says Eduardo Vilar-Sanchez, chair ad interim of clinical cancer prevention, in a release. “These are valuable insights into immune responses that can help personalize the way we monitor and direct prevention strategies.”

Analyzing T Cell Responses

The research team examined T cell receptors (TCR), which help the immune system identify and attack tumor-specific neoantigens created by DNA mutations. They characterized the TCRs found in peripheral blood mononuclear cell (PBMC) samples from 277 participants, including 102 LS survivors, 130 carriers without a history of cancer, and 45 controls.

The researchers also performed TCR sequencing in the colorectal tissues of three cancers and 11 pre-cancers matched to those PBMC samples. In colon tumors and pre-cancer tissues, certain T cells were expanded in response to tumor-specific neoantigens.

The study found that up to 41% of the expanded TCRs from colon pre-cancers and tumors were detected in LS carriers but not in individuals without the syndrome. This suggests that the immune system is actively surveilling and responding to early signs of cancer in these patients.

Clinical Implications for Risk Assessment

Using this data, the researchers generated a classification model to distinguish LS carriers from control samples simply by looking at TCR patterns in the blood. This model identified LS carriers regardless of their cancer history, as well as cancer-free carriers.

The findings indicate that circulating cancer-associated TCRs can be identified in blood samples, providing unique immune signatures that could detect individuals at higher risk of cancer development. While the researchers note that further validation is needed, the blood-based biomarker could serve as a non-invasive tool for early cancer detection, risk assessment, and personalized surveillance for patients with LS.

The results advance the understanding of T cell responses in LS carriers, potentially providing personalized insights for monitoring and therapeutic interventions.

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