Date of Award

January 2020

Document Type

Thesis

Degree Name

Medical Doctor (MD)

Department

Medicine

First Advisor

Tara Sanft

Abstract

Lifestyle factors such as lower BMI, higher levels of physical activity, and increased fruit and vegetable intake, have been shown to benefit breast cancer survival, but the association between these factors and the pathologic complete response (pCR) to chemotherapy, has not been studied. We investigated whether lifestyle factors including BMI, physical activity, diet and alcohol use are associated with pCR from neoadjuvant chemotherapy for breast cancer treatment. Secondarily, we assessed whether the relative dose intensity (RDI) of neoadjuvant chemotherapy is associated with pCR.

We conducted a retrospective study of women treated with neoadjuvant chemotherapy for stage I-III breast cancer between 2010 and 2016 at Yale New Haven Hospital-Smilow Cancer Hospital. Through medical record review, we determined BMI, tumor characteristics, pCR vs residual disease, and chemotherapy dates and doses. The RDI of treatment was calculated for each patient using published methods. A telephone survey administered to a subset of women assessed physical activity, fruit and vegetable intake, and alcohol intake during the year prior to diagnosis. Unconditional logistic regression models identified factors associated with pCR.

In our cohort (n=243), the average age was 53 years (SD 13) and mean BMI was 29.5 kg/m2 (SD 7.0). Seventy-five (31%) patients had pCR and 168 (69%) had residual disease. Patients with pCR had lower mean BMI than those with residual disease (28.2 (SD) vs. 30.1 (SD), p=0.04). Fifty-eight patients (24%) received <85% RDI. pCR was not associated with optimal (>85%) RDI.

The results of our study suggest that lower BMI is associated with pCR. Although we did not find an association between RDI and pCR, a high proportion of patients in our study received suboptimal RDI <85%, highlighting the need for interventions targeting the tolerability of and adherence to chemotherapy. Future research should be done to assess if adoption of healthy behaviors to achieve weight loss during treatment produces similar results in terms of pathologic outcomes from treatment.

Comments

This thesis is restricted to Yale network users only. It will be made publicly available on 09/10/2021

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