Abstract：
OBJECTIVE: Although both localization of breast cancer and body mass index (BMI) are associated with prognosis, the association between localization of breast cancer and BMI remains unclear. This study aimed to investigate the association between localization of breast cancer and BMI at diagnosis.
METHODS: Patients who underwent surgery for stage 0-III breast cancer July 2010-March 2017 were identified retrospectively in a Japanese nationwide inpatient database. Multinomial logistic regression analyses adjusting for patient\'s age were conducted to compare the outcomes among five BMI groups: < 18.5 kg/m2 (n = 31,724; 9.3%), 18.5-24.9 kg/m2 (n = 218,244; 64.3%), 25.0-29.9 kg/m2 (n = 69,813; 20.6%), 30.0-34.9 kg/m2 (n = 16,052; 4.7%), and ≥ 35.0 kg/m2 (n = 3716; 1.1%). The outcomes were the quadrant and side of the breast where tumors were detected.
RESULTS: In total, about half of the patients had breast cancer in the upper-outer quadrant (49.7%) and in the left breast (51.1%). In the multinomial analysis, BMI ≥ 25.0 kg/m2 was associated with the occurrence of breast cancer in the upper-inner and lower-outer quadrants and in the central area, whereas BMI < 18.5 kg/m2 was associated with the occurrence of breast cancer in the central area only. The side of breast cancer did not differ significantly among the five BMI groups.
CONCLUSIONS: Localization of breast cancer was associated with BMI in this large nationwide cohort. The findings may benefit patients\' self-checks and doctors\' examinations, potentially resulting in early detection and treatment.
METHODS: Patients who underwent surgery for stage 0-III breast cancer July 2010-March 2017 were identified retrospectively in a Japanese nationwide inpatient database. Multinomial logistic regression analyses adjusting for patient\'s age were conducted to compare the outcomes among five BMI groups: < 18.5 kg/m2 (n = 31,724; 9.3%), 18.5-24.9 kg/m2 (n = 218,244; 64.3%), 25.0-29.9 kg/m2 (n = 69,813; 20.6%), 30.0-34.9 kg/m2 (n = 16,052; 4.7%), and ≥ 35.0 kg/m2 (n = 3716; 1.1%). The outcomes were the quadrant and side of the breast where tumors were detected.
RESULTS: In total, about half of the patients had breast cancer in the upper-outer quadrant (49.7%) and in the left breast (51.1%). In the multinomial analysis, BMI ≥ 25.0 kg/m2 was associated with the occurrence of breast cancer in the upper-inner and lower-outer quadrants and in the central area, whereas BMI < 18.5 kg/m2 was associated with the occurrence of breast cancer in the central area only. The side of breast cancer did not differ significantly among the five BMI groups.
CONCLUSIONS: Localization of breast cancer was associated with BMI in this large nationwide cohort. The findings may benefit patients\' self-checks and doctors\' examinations, potentially resulting in early detection and treatment.
摘要：
目的：尽管乳腺癌的定位和体重指数（BMI）与预后相关，乳腺癌定位与BMI之间的关联尚不清楚.本研究旨在探讨诊断时乳腺癌定位与BMI之间的关系。
方法：2010年7月至2017年3月接受手术治疗的0-III期乳腺癌患者在日本全国住院患者数据库中进行回顾性鉴定。进行了调整患者年龄的多项逻辑回归分析，以比较五个BMI组之间的结果：<18.5kg/m2（n=31,724;9.3％），18.5-24.9kg/m2(n=218,244;64.3%),25.0-29.9kg/m2(n=69,813;20.6%),30.0-34.9kg/m2(n=16,052;4.7%),≥35.0kg/m2（n=3716；1.1%）。结果是检测到肿瘤的乳房的象限和侧面。
结果：总计，大约一半的患者在上-外象限(49.7%)和左乳腺(51.1%)患有乳腺癌.在多项式分析中，BMI≥25.0kg/m2与上内下外象限和中央区乳腺癌的发生有关，而BMI<18.5kg/m2仅与中央区乳腺癌的发生有关。乳腺癌的一面在五个BMI组中没有显着差异。
结论：在这个庞大的全国性队列中，乳腺癌的定位与BMI相关。这些发现可能有利于患者的自我检查和医生的检查，可能导致早期发现和治疗。
方法：2010年7月至2017年3月接受手术治疗的0-III期乳腺癌患者在日本全国住院患者数据库中进行回顾性鉴定。进行了调整患者年龄的多项逻辑回归分析，以比较五个BMI组之间的结果：<18.5kg/m2（n=31,724;9.3％），18.5-24.9kg/m2(n=218,244;64.3%),25.0-29.9kg/m2(n=69,813;20.6%),30.0-34.9kg/m2(n=16,052;4.7%),≥35.0kg/m2（n=3716；1.1%）。结果是检测到肿瘤的乳房的象限和侧面。
结果：总计，大约一半的患者在上-外象限(49.7%)和左乳腺(51.1%)患有乳腺癌.在多项式分析中，BMI≥25.0kg/m2与上内下外象限和中央区乳腺癌的发生有关，而BMI<18.5kg/m2仅与中央区乳腺癌的发生有关。乳腺癌的一面在五个BMI组中没有显着差异。
结论：在这个庞大的全国性队列中，乳腺癌的定位与BMI相关。这些发现可能有利于患者的自我检查和医生的检查，可能导致早期发现和治疗。
