title: Interaction between body mass index and hormone-receptor status as a prognostic factor in lymph-node-positive breast cancer.
abstract: The aim of this study was to determine the relationship between the body mass index (BMI) at a breast cancer diagnosis and various factors including the hormone-receptor, menopause, and lymph-node status, and identify if there is a specific patient subgroup for which the BMI has an effect on the breast cancer prognosis. We retrospectively analyzed the data of 8,742 patients with non-metastatic invasive breast cancer from the research database of Asan Medical Center. The overall survival (OS) and breast-cancer-specific survival (BCSS) outcomes were compared among BMI groups using the Kaplan-Meier method and Cox proportional-hazards regression models with an interaction term. There was a significant interaction between BMI and hormone-receptor status for the OS (P = 0.029), and BCSS (P = 0.013) in lymph-node-positive breast cancers. Obesity in hormone-receptor-positive breast cancer showed a poorer OS (adjusted hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 0.92 to 2.48) and significantly poorer BCSS (HR = 1.80, 95% CI = 1.08 to 2.99). In contrast, a high BMI in hormone-receptor-negative breast cancer revealed a better OS (HR = 0.44, 95% CI = 0.16 to 1.19) and BCSS (HR = 0.53, 95% CI = 0.19 to 1.44). Being underweight (BMI < 18.50 kg/m2) with hormone-receptor-negative breast cancer was associated with a significantly worse OS (HR = 1.98, 95% CI = 1.00-3.95) and BCSS (HR = 2.24, 95% CI = 1.12-4.47). There was no significant interaction found between the BMI and hormone-receptor status in the lymph-node-negative setting, and BMI did not interact with the menopause status in any subgroup. In conclusion, BMI interacts with the hormone-receptor status in a lymph-node-positive setting, thereby playing a role in the prognosis of breast cancer.
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Il Yong
authors.initials: IY
authors.lastname: Chung
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Clinical Research Center, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Ji Sung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Clinical Research Center, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Yu Rang
authors.initials: YR
authors.lastname: Park
authors.affiliation: Gachon University College of Nursing, Incheon, Republic of Korea.
authors.forename: Yul Ha
authors.initials: YH
authors.lastname: Min
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.|Clinical Research Center, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Yura
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Tae In
authors.initials: TI
authors.lastname: Yoon
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Guiyun
authors.initials: G
authors.lastname: Sohn
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Sae Byul
authors.initials: SB
authors.lastname: Lee
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Jisun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Hee Jeong
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Beom Seok
authors.initials: BS
authors.lastname: Ko
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Byung Ho
authors.initials: BH
authors.lastname: Son
authors.affiliation: Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Sei Hyun
authors.initials: SH
authors.lastname: Ahn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D012189:Retrospective Studies; D015996:Survival Rate