Age as a determining factor in decision-making in older patients with HER2-positive and triple-negative breast cancer

Breast cancer incidence is increasing among older women, yet data on aggressive subtypes such as triple-negative and HER2-positive remain limited. This retrospective study aimed to evaluate the real-world management of these tumors, specifically examining whether chronological age, beyond comorbidity or anesthetic risk, is a determining factor in therapeutic decision-making.

A retrospective observational study was conducted, including women aged ≥70 years who underwent surgery for triple-negative or HER2-positive breast cancer between 2014 and 2024. Clinical, tumor, and treatment variables were collected. Comorbidity was assessed using the Charlson Comorbidity Index, and anesthetic risk by ASA classification. Undertreatment was defined as omission of NCCN-recommended therapies. Logistic regression analysis was used to identify independent predictors of therapeutic decisions.

Among 129 patients aged ≥70 years, undertreatment was observed in 58.1%, reaching near-universal levels in those over 80 years. Chronological age emerged as the primary determinant of omission of sentinel lymph node biopsy, chemotherapy, anti-HER2 therapy, and radiotherapy, independent of comorbidity, anesthetic risk, or tumor stage.

This study underscores the disproportionate influence of chronological age on therapeutic decision-making in older women with triple-negative and HER2-positive breast cancer, reflecting entrenched ageism in oncological practice. Such bias contributes to undertreatment and undermines equity in cancer care for this high-risk population. Integrating geriatric assessment tools is essential to identify patients capable of tolerating guideline-concordant therapies and to support individualized, evidence-based treatment decisions.