Treatment Approach for Rare Histologic Subtypes of Breast Cancer: A Review

Rare histological subtypes of breast cancer introduce unique challenges to treatment and require a more personalized approach. Subtypes with favorable prognoses, such as mucinous, tubular, and cribriform carcinomas, generally respond well to less aggressive treatments such as endocrine therapy. However, certain triple-negative breast cancer subtypes that are typically considered aggressive also demonstrate unexpectedly better outcomes in specific cases. Conversely, more aggressive subtypes, including invasive micropapillary carcinoma and high-grade metaplastic breast cancer, often present greater treatment challenges due to their resistance to conventional therapies. Recent advancements in targeted treatments, such as immune checkpoint inhibitors, have shown promise in improving outcomes in some of these difficult cases. This review emphasizes the need for ongoing research and a tailored approach that considers both molecular and histological characteristics to improve the management and survival outcomes of patients with these rare and complex breast cancer subtypes.