Survey results presented at the 2021 San Antonio Breast Cancer Symposium reported on oncologists’ perspectives about treatment-related side effects and individualized dosing for patients with metastatic breast cancer.

The 28-question online survey was disseminated to US medical oncologists by patient advocates and oncologists from the Patient-Centered Initiative via professional organizations, social media, and email lists.

The survey aimed to assess oncologists’ perspective regarding the prevalence and severity of treatment-related toxicity, increase recognition of the impact of dosage-related mitigation strategies on clinical outcomes, and determine oncologists’ willingness to discuss flexible dosing approaches when patients with metastatic breast cancer begin a new systemic treatment or experience side effects.

A total of 131 medical oncologists responded to the survey; 12 were excluded from further analysis because they were not based in the Unites States or lacked experience treating patients with metastatic breast cancer.

Of the 119 eligible participants, 85% specialized in breast cancer, 66% worked in an academic setting, and 82% practiced for >5 years.

Survey results showed physicians estimated that 47% of patients reported a distressing treatment-related side effect, 15% visited the emergency room or hospital, and 37% required a treatment break. The most common mitigation strategies were prescribing supportive medication, offering suggestions for palliation, and lowering the dose (96% each).

Overall, 74% of oncologists reporting patient improvement after dose reduction. In addition, 87% of physicians indicated that they had started patients at a lower dose for various reasons, and 60% noted that these patients felt better than patients commencing the same therapy on the recommended starting dose.

The most commonly prescribed therapies at lower initial doses were capecitabine (91%), taxanes (60%), and palbociclib (50%). A total of 85% of oncologists surveyed do not believe the recommended starting dose is always more effective than a lower dose, and 97% would be willing to discuss drug dosing options with patients based on their personal attributes.

“Medical oncologists reported that a high percentage of patients experience distressing toxicity, a need for acute care, and dose interruptions with standard delivery of therapy for [metastatic breast cancer]. Many elect to decrease the starting dose for select drugs, and almost all are open to discussing lower initial and successive doses,” wrote study authors.

“We conclude that these patient-centered dosing discussions should be part of routine care and may consequently improve QOL [quality of life] for patients with [metastatic breast cancer],” they concluded.

Loeser AL, Bardia A, Burkard ME, et al. Patient-centered dosing: Oncologists’ perspectives about treatment-related side effects and individualized dosing for patients with metastatic breast cancer (MBC). Presented at: 2021 San Antonio Breast Cancer Symposium; December 7-10, 2021; virtual. Abstract P4-10-09.