Abstract P5-07-07: Feasibility of a Whole-Food, Plant-Based Intervention Among Women with Metastatic Breast Cancer and its Effect on Patient-Reported Outcomes
Authors: Campbell Thomas , Campbell Erin , Culakova Eva , Wixom Nellie , Guido Joseph , Blanchard Lisa , Janelsins Michelle , Mustian Karen , Fetten James , Peppone Luke 
Published: March 2023

Background: Women diagnosed with breast cancer commonly gain weight during and after treatment; this obesity/weight change is associated with decreased quality of life (QOL) and other patient-reported outcomes (PROs) such as cognitive dysfunction. Whole-food, plant-based (WFPB) dietary interventions lead to weight loss and cardiometabolic improvements, but their feasibility among metastatic breast cancer patients and their effect on cancer-related PROs have not previously been studied.

Methods: Women with stage 4 breast cancer and stable disease were randomized 2:1 into: 1) a WFPB dietary intervention (N=21) or 2) usual care (N=11) for 8 weeks with assessments at baseline, 4 and 8 weeks. Our WFPB diet consisted of weekly educational visits and an ad libitum whole-food, plant-based diet. Three prepared meals a day were provided for the duration of the trial. The diet included fruits, vegetables, whole grains, legumes, nuts and seeds and excluded meat, dairy, eggs, and added oils/solid fats. Effects of the WFPB diet on the outcomes were assessed by comparing marginal means by arm estimated at 8 weeks from the analysis of covariance model controlling for baseline.

Results: Of 32 subjects randomized, 20 intervention subjects and 10 control subjects completed all 3 assessments. Baseline and week 8 dietary intake among the intervention subjects is shown in table 1. Cognitive function, as measured by the Functional Assessment of Cancer Therapy – Cognitive Function (FACT-COG) questionnaire and a modified MD Anderson Symptom Inventory (MDASI), showed significant improvement within the intervention group as well as in comparison to the control group (Table 2). Overall quality of life, emotional and physical wellbeing, and breast cancer-specific symptoms, as measured by Functional Assessment of Cancer Therapy – Breast (FACT-B) questionnaire improved significantly within the intervention group. Mean fatigue was lower at 8 weeks within the intervention group as measured by the Brief Fatigue Inventory (BFI), but this did not reach statistical significance (p=0.10). When intervention subjects were asked, “On a scale from 1 to 10 [1 being “would not recommend” and 10 being “highly recommend”], how strongly would you recommend that other cancer patients be given this type of nutrition and support intervention if they were able and willing to participate?” participants’ mean score was 9.5.

Conclusion: Our WFPB intervention was feasible and acceptable, with high compliance despite asking subjects to make major changes in dietary intake. Clinically and statistically significant improvements in several PROs, including cognitive function, overall QOL, physical and emotional wellbeing were noted for those in the WFPB group. Given the benefits to QOL and PROs, longer studies are required to demonstrate durability of behavior changes and outcomes.

Table 1: Nutrient Intake of the Intervention Group (n=19*) *One participant was missing one three-day food record

Table 2. Patient-Reported Outcomes

Citation Format: Thomas Campbell, Erin Campbell, Eva Culakova, Nellie Wixom, Joseph Guido, Lisa Blanchard, Michelle Janelsins, Karen Mustian, James Fetten, Luke Peppone. Feasibility of a Whole-Food, Plant-Based Intervention Among Women with Metastatic Breast Cancer and its Effect on Patient-Reported Outcomes [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-07-07.