Adjuvant Dose Dense Chemotherapy in Patients With Obesity: Short-Term Toxicities and Breast Cancer Outcome

Abstract

Background: Dose dense adjuvant chemotherapy is associated with improved outcomes in breast cancer compared to standard dosing. Despite current guidelines recommending that chemotherapy is dosed according to actual body weight, reviews have shown patients with obesity often receive a capped chemotherapy dose. The latter is commonly undertaken as clinicians have concerns that adverse events are more frequent if full doses are administered. This study assessed surgical, radiotherapy and chemotherapy related adverse events between patients with and without obesity receiving dose dense adjuvant chemotherapy for breast cancer.

Materials and methods: A retrospective review of prospective collected data for patients receiving adjuvant chemotherapy from 30 April 2018 from a single institution was analyzed. Data collected included demographic data, height, weight, pathological information, comorbidities, surgical, radiotherapy chemotherapy treatment, and toxicity. Primary outcomes were surgical complications at 30 days, radiotherapy skin toxicity at 30 days and chemotherapy side-effects. Secondary outcomes were rates of recurrence and time to recurrence.

Results: A total of 280 patients were included in the analysis: 55 obese and 225 nonobese. Obese status was associated with higher rates of grade >2 skin toxicity and this difference was significant after adjusting for age, comorbidity and radiotherapy field (P = .017). Obese status was not associated with higher rates of surgical or chemotherapy related adverse events. All patients regardless of obese status received adequate dose intensity with similar rates of recurrence and time to recurrence.

Conclusion: Patients with obesity who receive dose dense adjuvant chemotherapy do not experience higher rates of surgical or chemotherapy related adverse events although they do experience higher rates of grade >2 radiotherapy related skin toxicity. This supports the use of dose dense chemotherapy being based on actual body weight in patients with obesity.

Keywords: Adverse events; Breast cancer; Dose dense chemotherapy; Obesity.