npj Breast Cancer (Aug 2022)

The association between adiposity and anti-proliferative response to neoadjuvant endocrine therapy with letrozole in post-menopausal patients with estrogen receptor positive breast cancer

  • Edoardo Isnaldi,
  • François Richard,
  • Maxim De Schepper,
  • Sophia Leduc,
  • Marion Maetens,
  • Tatjana Geukens,
  • Karen Van Baelen,
  • Ha-Linh Nguyen,
  • Ghizlane Rouas,
  • Gabriele Zoppoli,
  • Fatima Cardoso,
  • Christos Sotiriou,
  • Denis Larsimont,
  • Giuseppe Floris,
  • Elia Biganzoli,
  • Christine Desmedt

DOI
https://doi.org/10.1038/s41523-022-00453-7
Journal volume & issue
Vol. 8, no. 1
pp. 1 – 10

Abstract

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Abstract The impact of adiposity on the efficacy of endocrine treatment in patients with estrogen receptor positive breast cancer is poorly investigated. Here, we retrospectively investigated in a cohort of 56 patients whether body mass index and/or mammary adiposity are associated with anti-proliferative response in the neoadjuvant setting. Anti-proliferative response was defined as high Ki67 at baseline (Ki67bl) and low Ki67 at surgery (Ki67srg), using the 14% cut-off. Mammary adipocyte size was assessed on hematoxylin and eosin slides from the surgical samples using digital pathology. A higher proportion of tumors with an anti-proliferative response was observed in patients with obesity (54.5%) as compared to patients with normal weight (9.0%) and patients with overweight (40.0%) (p = 0.031), confirmed by multivariable regression analysis adjusted for baseline Ki67 (OR, obese vs normal weight: 13.76, 95%CI: 1.49–207.63, p = 0.020). Larger adipocyte diameter was identified as predictor of anti-proliferative response (OR per increase in diameter of 5 μm for adipocytes distant from the tumor: 2.24, 95%CI: 1.01–14.32, p = 0.046). This study suggests that anti-proliferative response to neoadjuvant letrozole might be more frequent in patients with increased systemic or mammary adiposity.