TILs Versus Gene-Expression Signatures: Which Has Greater Prognostic Value in Early-Stage Breast Cancer?

By: Jenna Carter, PhD
Posted: Wednesday, February 22, 2023

In an article published in JAMA Oncology, Lisa A. Carey, MD, of the University of North Carolina (UNC), Chapel Hill, and colleagues reported their findings on the use of tumor-infiltrating lymphocytes (TILs) and immune-related, gene-expression signatures as prognostic and predictive tools in patients with early-stage ERBB2/HER2-positive breast cancer. They examined pathologic complete responses and event-free survival in patients with breast cancer across two different clinical trials. Their findings revealed that “when both TILs and gene expression are available, the prognostic value of immune-related signatures appears to be superior.”

“The analysis of these data will provide essential information for biomarker development and precision medicine in HER2-positive breast cancer, and the insights will inform clinicians when someone may need more (or less) chemotherapy, and more (or less) anti-HER2 drugs,” stated coauthor Aranzazu Fernandex-Martinez, MD, PhD, also of UNC, in a UNC press release.

A total of 305 women with stage II to III ERBB2/HER2-positive breast cancer from the CALGB 40601 clinical trial and a total of 151 patients with stage I to IIIA ERBB2/HER2-positive breast cancer from the PAMELA trial were included in this study. The primary endpoint was pathologic complete response, defined as no invasive tumor in the breast at surgery. The secondary endpoints were event-free survival and the ability of the HER2-enriched subtype to predict pathologic complete response.

Overall findings revealed that 82.2% of immune-related, gene-expression signatures were significantly correlated with TILs in both clinical trials. In addition, TILs were significantly associated with pathologic complete response (odds ratio = 1.01; 95% confidence interval = 1.01–1.02; P = .02) across both trials. In addition, 36 (17.8%) of the immune-related, gene-expression signatures were significantly associated with pathologic complete response independently of the treatment group and trial.

Disclosure: For the study authors’ disclosures, visit jamanetwork.com.

JAMA Oncology

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