A narrative review of the challenges and impact of breast cancer treatment in older adults beyond cancer diagnosis.

Background and objective: Breast cancer is the most prevalent cancer among women worldwide, with 45% of them over 65 years old. Older breast cancer patients tend to be underrepresented and understudied in major clinical trials. This narrative review provides a comprehensive overview of the current evidence regarding treatment decision-making, treatment toxicities, and proposed survivorship management recommendations for geriatric cancer patients.

Methods: A literature search was conducted on PubMed and Google Scholar. The search strategy included a combination of keywords related to clinical management and treatment toxicities of older cancer breast cancer patients. English articles published between May 1990 to May 2024 were included.

Key content and findings: Older breast cancer patients represent a heterogeneous group with specific needs and treatment considerations. Treatment decisions for geriatric cancer patients should be based on a comprehensive geriatric assessment (CGA), which considers the patient's functional status, comorbidities, and preferences, rather than relying solely on chronological age. Breast cancer surgery is generally well tolerated in older patients, with a low rate of systemic complications and 30-day post-surgery mortality. In selected elderly patients, axillary surgery may be omitted to minimize side effects. The choice of endocrine therapy should take into account the side effect profile, patient's comorbidities, concomitant medications, and preferences. While aromatase inhibitors provide better efficacy, musculoskeletal side effects and osteoporosis may be a concern for older patients. CDK4/6 inhibitors have a similar efficacy in elderly patients as younger patients, but the incidence of neutropenia and dose modifications or interruptions are more frequent. Reported radiotherapy side effects are similar across age groups, although the occurrence of radiationinduced pulmonary toxicities was found to be associated with old age. Chemotherapy is reserved for triplenegative and HER2-positive disease in elderly patients due to known side effects. such as neutropenia, cardiotoxicity, and cognitive impairment. Data on the efficacy and safety of immunotherapy use in older patients are limited.

Conclusions: Physicians should make additional efforts to evaluate age-specific treatment efficacy and treatment-induced toxicities. Further efforts to enhance the representation of older patients in breast cancer trials are warranted.