Effect of obesity on the toxicity profile of patients with breast cancer treated with adjuvant chemotherapy.

Abstract

e12033 Background: There is increasing evidence that obesity is strongly associated with breast cancer (BC) and has a major impact on the patient tolerance, overall survival (OS) and progression free survival (PFS). Chemotherapy dosing as per body surface area (BSA) or the actual body weight is a major dilemma among the oncologists. Moreover, the side effects of chemotherapy in obese patients in an Indian population has not been described previously in literature. We intended to evaluate the major toxicity, OS and PFS in obese BC patients who received adjuvant chemotherapy (ADC) with Adriamycin/cyclophosphamide (AC) and paclitaxel (T). Methods: A retrospective analysis of 331 patients of BC who received 4 cycles of adjuvant AC + T from a single tertiary centre in South India between 2006-2014 were included . All patients were treated as per their BSA which were capped at 2. Body Mass Index (BMI) was divided into normal (18-22.99), Overweight (23-24.99) and Obese ( ≥25 as per Asian guidelines). The toxicity was scored as per NCI-CTCAE criteria. Results: Out of 331 patients, 213 were obese. On comparison of normal and over weight with obese patients, 65 (30.5%) in obese group had significant all grade neuropathy (p = 0.027), 65 (30.5%) had Grade 2 and 3 myelosuppression (p <0.001), 31 (14.5%) had all grade emesis (p = 0.031) and 28 (13.1%) had myalgia (0.001). The 5 year OS and PFS were 93.7% and 82.3% respectively in obese patients, higher than the patients with normal weight with a 5 year OS and PFS of 92.4 % and 76.9% , but was not statistically significant. Conclusions: Higher rates of severe toxicities were seen in obese BC patients who received ADC as per their BSA. The 5 year OS and PFS was better in obese BC patients, but was not statistically significant. [Table: see text]