{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T11:11:38Z","timestamp":1788865898865,"version":"build-2803163510"},"reference-count":56,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:p>Immune checkpoint inhibitors (ICI) have revolutionized the treatment of TNBC, leading to durable responses and improved survival. With the adoption of immunotherapy into high-risk early-stage and selected metastatic triple-negative breast cancer (TNBC), clinicians\u2019 ability to recognize and treat immune-related adverse events has become increasingly important. There is no prospectively validated or FDA-approved predictive biomarker of toxicity; however, candidate biomarkers involving circulating blood counts, immune-cell phenotypes, cytokines, transcriptomics, immune age, germline genetics, human leukocyte antigen genotypes, autoantibodies, and the gut microbiome have been described, with many more currently under investigation. Most evidence remains exploratory and is derived from non-TNBC populations. Going forward, incorporating these investigational tools within prospective TNBC trials and validating them in real-world, multicenter TNBC cohorts are critical to ensure these predictive biomarkers translate into clinically useful tools for risk-adapted monitoring. This mini-review highlights the current landscape of predictive biomarkers of ICI toxicity, with a focus on TNBC.<\/jats:p>","DOI":"10.3389\/fimmu.2026.1950429","type":"journal-article","created":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T10:49:49Z","timestamp":1788864589000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Emerging biomarkers of immune checkpoint inhibitor toxicity in triple-negative breast cancer: a mini-review"],"prefix":"10.3389","volume":"17","author":[{"given":"Erin","family":"McGillivray","sequence":"first","affiliation":[{"name":"Department of Internal Medicine, Moores Cancer Center, University of California, San Diego","place":["La Jolla, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Savannah","family":"Kane","sequence":"additional","affiliation":[{"name":"University of California, San Diego, School of Medicine","place":["La Jolla, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Armina","family":"Saadatkhah","sequence":"additional","affiliation":[{"name":"University of California, San Diego, School of Medicine","place":["La Jolla, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kay T.","family":"Yeung","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Moores Cancer Center, University of California, San Diego","place":["La Jolla, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,8]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.6004\/jnccn.2020.7554","article-title":"Role of immunotherapy in triple-negative breast cancer","volume":"18","author":"Keenan","year":"2020","journal-title":"J Natl Compr Canc Netw"},{"key":"B2","doi-asserted-by":"publisher","first-page":"91","DOI":"10.1038\/s41571-021-00565-2","article-title":"Treatment landscape of triple-negative breast cancer - expanded options, evolving needs","volume":"19","author":"Bianchini","year":"2022","journal-title":"Nat Rev Clin Oncol"},{"key":"B3","doi-asserted-by":"publisher","first-page":"121","DOI":"10.1186\/s13045-022-01341-0","article-title":"Recent advances in therapeutic strategies for triple-negative breast cancer","volume":"15","author":"Li","year":"2022","journal-title":"J Hematol Oncol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.3390\/cancers15051629","article-title":"Predictive biomarkers for checkpoint inhibitor immune-related adverse events","volume":"15","author":"Les","year":"2023","journal-title":"Cancers (Basel)"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1007\/s12094-020-02397-5","article-title":"Anti-PD-1\/L1-associated immune-related adverse events as harbinger of favorable clinical outcome: systematic review and meta-analysis","volume":"23","author":"Baclig","year":"2021","journal-title":"Clin Transl Oncol"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1016\/j.clbc.2026.07.026","article-title":"Incidence, risk factors, and survival implications of immune-related adverse events in patients with metastatic breast cancer","author":"Baclig","year":"2026","journal-title":"Clin Breast Cancer"},{"key":"B7","doi-asserted-by":"publisher","first-page":"18","DOI":"10.1007\/s10549-026-07930-8","article-title":"Impact of immune-related adverse events on response to neoadjuvant chemoimmunotherapy in triple-negative breast cancer: a single-institution retrospective study","volume":"216","author":"Sterpi","year":"2026","journal-title":"Breast Cancer Res Treat"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1038\/s41416-024-02887-1","article-title":"Cancer and treatment specific incidence rates of immune-related adverse events induced by immune checkpoint inhibitors: a systematic review","volume":"132","author":"Jayathilaka","year":"2025","journal-title":"Br J Cancer"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2023.1167975","article-title":"Immune-related adverse events of immune checkpoint inhibitors: a review. 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