Prognostic impact of tumor-infiltrating lymphocytes in HER2+ metastatic breast cancer receiving first-line treatment
Breast cancer (BC) is a leading cause of death among women, with approximately 30% HER2-positive (HER2+). Although HER2-targeted therapies have improved outcomes for patients with HER2+ metastatic breast cancer (mBC), clinical challenges and prognostic variability remain. Tumor-infiltrating lymphocytes (TILs) have emerged as prognostic and predictive biomarkers in various tumors, including BC, but their role in HER2+ mBC is poorly understood. This multicentric retrospective cohort study evaluated the prognostic significance of TILs in 110 patients with HER2+ mBC treated with pertuzumab, trastuzumab, and taxane-based chemotherapy at two Italian institutes from June 2013 to May 2024. TILs were assessed on metastatic or primary tumor samples. High TILs levels (>5%) were independently associated with longer PFS and OS. TILs levels were higher in primary tumours than in metastases (p = 0.009), with significant variation by metastatic site. These findings underscore the potential of TILs as prognostic biomarkers in HER2+ mBC, necessitating further prospective studies.
Authors
- Carmen Criscitiello (ORCID: https://orcid.org/0000-0001-9064-0113)
- Giuseppe Curigliano (ORCID: https://orcid.org/0000-0003-1781-2518)
- Paola Zagami (ORCID: https://orcid.org/0000-0002-2687-6436)
- Carlo Pescia (ORCID: https://orcid.org/0000-0003-0657-506X)
- Pier Paolo Maria Berton Giachetti (ORCID: https://orcid.org/0000-0001-5559-7279)
- Fabiola Giudici (ORCID: https://orcid.org/0000-0002-4160-3479)
- Bruna Cerbelli (ORCID: https://orcid.org/0000-0001-5419-2309)
- Beatrice Taurelli Salimbeni (ORCID: https://orcid.org/0000-0002-7345-4148)
- Andrea Botticelli (ORCID: https://orcid.org/0000-0002-6425-9893)
- Nicola Fusco (ORCID: https://orcid.org/0000-0002-9101-9131)
- Dario Trapani (ORCID: https://orcid.org/0000-0003-1672-9560)
- Simone Scagnoli (ORCID: https://orcid.org/0000-0003-4943-5622)
- Elisabetta Munzone (ORCID: https://orcid.org/0000-0003-3371-3878)
- Roberta Scafetta
- Antonio Marra (ORCID: https://orcid.org/0000-0002-7310-7824)
- Angela Espósito
Institutions
- AOL (United States) (US)
- Università Campus Bio-Medico (IT)
- University of Milan (IT)
- Centro di Riferimento Oncologico (IT)
- Istituti di Ricovero e Cura a Carattere Scientifico (IT)
- European Institute of Oncology (IT)
- Sapienza University of Rome (IT)
Publication Details
- Journal
- npj Breast Cancer
- Published
- 2025-05-09
- DOI
- https://doi.org/10.1038/s41523-025-00760-9
- Citations
- 4
- Primary Topic
- Cancer Immunotherapy and Biomarkers
- Type
- article
- Field-Weighted Citation Impact
- 4.18