Abstract P1-09-07: Effects of breast cancer treatment on markers of metabolic syndrome in a predominantly hispanic patient population
Authors: Gaur S , Ochoa C , Sanchez L , Nahleh Z 
Published: May 2016

Background: Adjuvant chemotherapy improves survival in early breast cancer, however has been reported to contribute to weight gain and insulin resistance. Hispanics are reported to have higher levels of insulin resistance and features of metabolic syndrome as compared to caucasians and as such may be at higher risk of metabolic decompensation during treatment of their cancer. We sought to evaluate the effects of adjuvant/ neo-adjuvant breast cancer treatment on markers of metabolic syndrome in a predominantly hispanic population. Study was funded by the institutions department of medicine seed grant funds.

Methods: We enrolled 35 consecutive patients who were about to commence adjuvant or neo-adjuvant chemotherapy for breast cancer. Patients with diabetes mellitus or hyperlipidemia were excluded. Fasting glucose, HBA1C, insulin levels, HDL cholesterol, triglyceride levels, waist circumference and blood pressure were measured before starting chemotherapy and then every 3 months for 1 year. Results were analyzed using repeated measures ANOVA for normally distributed data. For data that was not normally distributed, Friedmans non parametric test was utilized.

A survey of dietary habits, exercise frequency and life style factors was administered before initiating treatment and at completion of the study.

Results:

Baseline characteristics: Of the 35 patients enrolled 31 were hispanics (89%). Median age was 47 years (33-68). 31 (82.8%) were over weight or obese. 13 (37%) had insulin resistance as assessed by HOMA (homeostatic model assessment)-IR, and 12 (34%) met the international diabetic federation (IDF) criteria for metabolic syndrome. 17% had stage 1, 52% had stage 2 and 31% had stage 3 disease. Most common chemotherapy regimen used was dose dense doxorubicin, cyclophosphamide and weekly paclitaxel.

No significant change was noted in the fasting glucose, HBA1C levels, insulin levels, HOMA-IR, weight or waist circumference at any point during the 1 year follow up. Triglyceride levels increased from a mean of 162.2mg/dl prior to therapy to 202.8mg/dl by 3 months, p=0.014. HDL-cholesterol fell from a mean of 50.6 mg/dl to 44mg/dl by 3 months, p=0.04.

Both triglyceride levels and HDL levels returned to baseline by 9 months and there was no change noted by 12 months. Overall 12 patients (34%) met the IDF criteria for metabolic syndrome before initiating adjuvant therapy as compared to 14 (40%) at 1 year.

Subgroup analysis of patients with preexisting metabolic syndrome, obesity or insulin resistance (HOMA-IR &gt;3.8) showed similar results.

Analysis of the survey data showed 22 of the 35 patients (62%) had improved their dietary and exercise habits over the course of the study.

Conclusions: Contrary to other studies, we did not find a significant difference in most of the parameters of metabolic syndrome in a predominantly hispanic patient population. A transient increase in triglyceride levels and a decline in HDL cholesterol level was noted at 3 months, however resolved by the 9th month of treatment. Our data suggests that life style modification may mitigate most of the metabolic adverse effects of therapy and women, at the time of diagnosis, may be particularly motivated to make such changes.

Citation Format: Gaur S, Ochoa C, Sanchez L, Nahleh Z. Effects of breast cancer treatment on markers of metabolic syndrome in a predominantly hispanic patient population. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-09-07.