Changes in breast cancer patients’ weight with adjuvant palbociclib treatment – A retrospective review.

Introduction: Palbociclib, a CDK4/6 selective inhibitor first approved in 2016, is potentially the most efficacious, adjuvant treatment for hormone receptor-positive (HR+) and human epidemic growth factor 2 (HER2−) in advanced BC (breast cancer). Data are limited regarding its long-term efficacy in overweight or obese patients. These individuals are already at higher risk of cancer due to elevated oestrogen levels, hyperactivation of adipokines and poor oxidative stress regulation. There is also evidence for a higher risk of BC recurrence and obesity-related mortality during palbociclib treatment, thus variations in patient weight during treatment warrant investigation. Aims: To retrospectively review BC patients’ weight variation during palbociclib treatment and explore addressing any clinically significant outcomes. Objectives: Review trends in body mass index (BMI) during treatment and suggest future pharmacological/ lifestyle interventions for patients and increase the chances of progression-free survival (PFS). Perform statistical analysis via Minitab 17 Statistical Software, displaying descriptive/regression statistics per BMI category for 33 cycles (long-term data). Methods: NHS Foundation Trust X provided raw data (N = 89) to audit weight variation in postmenopausal women receiving palbociclib as part of their first-line adjuvant treatment for advanced HR+ and HER2- BC who had completed 33 cycles (January 2018 – October 2021). Microsoft Excel processed/illustrated the findings (N = 72 were deemed eligible for inclusion) and Minitab was used for statistical analyses between the baseline and final BMI reading. Statistical analysis was conducted using the 2-sample t-test to determine the p-value to review if palbociclib-associated weight variation was statistically significant. Results: Pre-treatment 22% of patients (N = 16) had a BMI’s classed as healthy, 46% (N = 33) overweight and 32% (N = 23) obese. Post-treatment clinically significant weight variation was evident with 7% (N = 5) of patients previously deemed healthy, 49% (N = 35) overweight p: 0.001 and 44% (N = 32) obese. Many palbociclib-treated patients are overweight/obese posttreatment, thus at higher risk of HR+/HER2− BC recurrence and mortality. Pooled long-term data illustrates the weight progression in 2–3 years of treatment and represents clinically significant weight variation in healthy and overweight BC patients. Discussion/conclusions: The findings suggest, fewer patients are a healthy weight following palbociclib treatment. This poses greater challenges in patient care and disease management with regard to obesity in advanced BC patients. Centred on these challenges, further investigations are warranted to assess the effective treatment and prophylaxis mechanisms needed to successfully target weight gain during BC treatment in overweight/obese patients with palbociclib. These could include providing support with smoking cessation, maintaining a healthy diet, promoting weight loss and reducing alcohol intake and ensuring this is within recommended limits. [ABSTRACT FROM AUTHOR]