Impact of obesity on pathological complete remission in early stage breast cancer patients after neoadjuvant chemotherapy: a retrospective study from a German University breast center

Purpose: Breast cancer is a primary cause of cancer-related death among women worldwide. Neoadjuvant chemotherapy (NACT) is a cornerstone treatment for locally advanced, non-metastatic breast cancer. Achieving pathological complete response (pCR) is often used as a surrogate marker for long-term outcomes. This study examines the impact of obesity, defined by a body mass index (BMI) over 30 kg/m², on achieving pCR in patients with early stage breast cancer (eBC) undergoing NACT.

Methods: A retrospective analysis was conducted on patients with eBC treated with NACT at the University of Tübingen. The primary objective was to assess the impact of obesity on achieving pCR. Logistic regression analysis was used to determine the association between pre-treatment BMI and pCR, adjusting for covariates such as age, tumor stage, grading, and chemotherapy intensity.

Results: The study included 325 patients, with 24% classified as obese. While the univariate logistic regression analysis showed no significant impact of obesity on the odds ratio of achieving pCR, the multivariate analysis, accounting for covariates, demonstrated that obese patients had a significantly higher likelihood of achieving pCR.

Conclusion: In this retrospective study, obesity significantly affected the likelihood of achieving pCR in patients with eBC cancer undergoing NACT after adjusting for covariates. While obesity is a known risk factor for breast cancer development and progression, its impact on the efficacy of NACT in terms of achieving pCR was positive in our study. These findings contribute to the ongoing debate in the literature, though the retrospective design and potential uncontrolled factors should be considered.