Laboratory for Translational Breast Cancer Research, Department of Oncology, KU Leuven, Leuven, Belgium; Department of Gynecological Oncology, University Hospitals Leuven, Leuven, Belgium.
Laboratory for Translational Breast Cancer Research, Department of Oncology, KU Leuven, Leuven, Belgium.
Eur J Cancer. 2023 Sep;191:112988. doi: 10.1016/j.ejca.2023.112988. Epub 2023 Jul 13.
Invasive lobular carcinoma (ILC) represents up to 15% of all breast carcinomas. While the proportion of women with overweight and obesity increases globally, the impact of body mass index (BMI) at primary diagnosis on clinicopathological features of ILC and the prognosis of the patients has not been investigated yet.
We performed a multicentric retrospective study including patients diagnosed with non-metastatic pure ILC. The association of BMI at diagnosis with clinicopathological variables was assessed using linear or multinomial logistic regression. Univariable and multivariable survival analyses were performed to evaluate the association of BMI with disease-free survival (DFS), distant recurrence-free survival (DRFS), and overall survival (OS).
The data of 2856 patients with ILC and available BMI at diagnosis were collected, of which 2570/2856 (90.0%) had oestrogen receptor (ER)-positive and human epidermal growth factor receptor (HER2) not amplified/overexpressed (ER+/HER2-) ILC. Of these 2570 patients, 80 were underweight (3.1%), 1410 were lean (54.9%), 712 were overweight (27.7%), and 368 were obese (14.3%). Older age at diagnosis, a higher tumour grade, a larger tumour size, a nodal involvement, and multifocality were associated with a higher BMI. In univariable models, higher BMI was associated with worse outcomes for all end-points (DFS: hazard ratio (HR) 1.21, 95CI 1.12-1.31, p value<0.01; DRFS: HR 1.25, 95CI 1.12-1.40, p value<0.01; OS: HR 1.25, 95CI 1.13-1.37, p value<0.01). This association was not statistically significant in multivariable analyses (DFS: HR 1.09, 95CI 0.99-1.20, p value 0.08; DRFS: HR 1.03, 95CI 0.89-1.20, p value 0.67; OS: HR 1.11, 95CI 0.99-1.24, p value 0.08), whereas grade, tumour size, and nodal involvement were still prognostic for all end-points.
Worse prognostic factors such as higher grade, larger tumour size, and nodal involvement are associated with higher BMI in ER+/HER2- ILC, while there was no statistical evidence for an independent prognostic role for BMI. Therefore, we hypothesise that the effect of BMI on survival could be mediated through its association with these clinicopathological variables.
浸润性小叶癌（ILC）占所有乳腺癌的 15%。随着全球超重和肥胖女性比例的增加，诊断时的体重指数（BMI）对 ILC 的临床病理特征和患者预后的影响尚未得到研究。
我们进行了一项多中心回顾性研究，纳入了诊断为非转移性纯 ILC 的患者。使用线性或多项逻辑回归评估诊断时 BMI 与临床病理变量之间的关联。进行单变量和多变量生存分析，以评估 BMI 与无病生存（DFS）、远处无复发生存（DRFS）和总生存（OS）之间的关联。
共收集了 2856 例 ILC 患者的资料和可获得的诊断时 BMI，其中 2570/2856（90.0%）为雌激素受体（ER）阳性且人表皮生长因子受体（HER2）未扩增/过表达（ER+/HER2-）ILC。在这 2570 例患者中，80 例为体重不足（3.1%），1410 例为偏瘦（54.9%），712 例为超重（27.7%），368 例为肥胖（14.3%）。诊断时年龄较大、肿瘤分级较高、肿瘤较大、淋巴结受累和多灶性与较高的 BMI 相关。在单变量模型中，较高的 BMI 与所有终点的预后较差相关（DFS：风险比（HR）1.21，95%CI 1.12-1.31，p 值<0.01；DRFS：HR 1.25，95%CI 1.12-1.40，p 值<0.01；OS：HR 1.25，95%CI 1.13-1.37，p 值<0.01）。多变量分析中这种关联无统计学意义（DFS：HR 1.09，95%CI 0.99-1.20，p 值 0.08；DRFS：HR 1.03，95%CI 0.89-1.20，p 值 0.67；OS：HR 1.11，95%CI 0.99-1.24，p 值 0.08），而分级、肿瘤大小和淋巴结受累仍然是所有终点的预后因素。
在 ER+/HER2-ILC 中，与预后较差相关的因素（如较高的分级、较大的肿瘤大小和淋巴结受累）与较高的 BMI 相关，而 BMI 对生存的独立预后作用没有统计学证据。因此，我们假设 BMI 对生存的影响可能是通过其与这些临床病理变量的关联介导的。
