Optimizing Treatment for Geriatric Patients With Breast Cancer

Reshma Mahtani, DO

While treatment options for patients with breast cancer continue to evolve, patients aged 65 and older remain at significant risk of breast cancer mortality. While chemotherapy and monoclonal antibody therapies are the standard-of-care, they come with toxicity risks.

In an interview with Targeted Oncology^TM, Reshma Mahtani, DO, chief of breast medical oncology at Miami Cancer Institute, Baptist Health South Florida, discussed findings from a retrospective study that was presented at the 2023 San Antonio Breast Cancer Symposium that aimed to identify a potential age cutoff for patients with HER2-positive breast cancer to receive chemotherapy.

Targeted Oncology: Can you provide some background to this study and what prompted it?

Mahtani: We know that the incidence of breast cancer increases with age, and patients who are 65 years and older account for a significant proportion of breast cancer mortality. Standard treatment for these patients includes monoclonal antibody therapy in combination with chemotherapy given in either the neoadjuvant or adjuvant setting, but this treatment can be associated with significant toxicity, especially in elderly patients.

Our study was a retrospective analysis of [National Cancer Database] data in which we aimed to compare the survival of geriatric patients with early-stage HER2-positive breast cancer who were treated with standard treatment—meaning chemotherapy in combination with monoclonal antibodies therapy either in the neoadjuvant or adjuvant setting—vs monoclonal antibody therapy alone or no treatment, with the caveat being that patients that had hormone receptor-positive, HER2-positive breast cancer in the no treatment arm may have received endocrine therapy. The goal of our analysis was to identify an age cutoff for which survival may vary between the treatment groups.

In terms of what prompted our study, practicing here in South Florida, we recognize that a significant proportion of our patients are elderly, with multiple comorbidities, so for us, this is an extremely relevant clinical question.

Could you summarize the findings?

There were 2 survival comparisons that were done: chemotherapy plus monoclonal antibody therapy vs monoclonal antibody therapy alone, as well as chemotherapy plus monoclonal antibody therapy vs no treatment. What we found was that both 1- and 3-survival rates favored the standard chemo plus monoclonal antibody treatment arm for both comparisons. We then performed Cox regression analyses for both comparisons, and we made adjustments for various factors including age, race, insurance, income, a comorbidity score, stage, and hormone receptor status. The hazard ratios for both analyses favored the receipt of standard therapy and were 0.72 for the comparison with monoclonal antibody therapy alone and 0.48 for the comparison with no treatment. Notably, we could not identify an age cutoff in which patients did not have a benefit to standard treatment.

Were there any limitations to this study?

We recognize this was a heterogeneous population. Treatment patterns varied quite a bit and we did not have access to all the information that may have informed decision making. Additionally, we did not perform propensity score matching or have information on breast cancer-specific mortality.

What are the implications of these findings?

Despite the caveats and limitations, I do think that our work highlights the importance of individualizing treatment plans for our patients and recognizing that it's difficult to have a prescriptive approach to care, especially when it comes to age. We know that there is a difference between chronologic age and biologic age, and certainly all these factors need to be taken into account when we are moving forward.