Department of Surgery, University of California, San Francisco, 1825 4th St, 3rd Floor, Box 1710, San Francisco, CA, 94143, USA.
Department of Pathology, University of California, San Francisco, San Francisco, CA, USA.
Breast Cancer Res Treat. 2020 May;181(1):23-29. doi: 10.1007/s10549-020-05606-5. Epub 2020 Apr 2.
Pleomorphic invasive lobular carcinoma (ILC) has long been thought to have worse outcomes than classic ILC and is therefore often treated with chemotherapy. However, recent data question the utility of the pleomorphic designation, as the poor outcomes seen may be related to other associated high-risk features. Importantly, mitotic count may better define a subset of ILC with high risk of recurrence. We sought to determine the impact of pleomorphic histology versus mitotic count on disease-free survival (DFS) in pure ILC. Additionally, we evaluated whether pleomorphic histology was associated with receipt of chemotherapy when adjusting for other factors.
We analyzed a cohort of 475 patients with stage I-III pure ILC. We used Kaplan-Meier estimates, and Cox proportional hazards and logistic regression for multivariate analyses. Pleomorphic histology was confirmed by central pathology review.
In a multivariate model, pleomorphic histology was not associated with reduced DFS. Only mitotic score, receptor subtype, and pathologic stage were independently and significantly associated with DFS. Patients with pleomorphic ILC were significantly more likely to receive chemotherapy than patients with classic ILC (adjusted odds ratio 2.96, p = 0.026).
The pleomorphic designation in ILC does not have clinical utility and should not be used to determine therapy. Rather, mitotic count identified clear prognostic groups in this cohort of pure ILC.
多形性浸润性小叶癌（ILC）长期以来被认为比经典型 ILC 预后更差，因此常采用化疗治疗。然而，最近的数据对多形性的诊断意义提出了质疑，因为较差的预后可能与其他相关的高危特征有关。重要的是，有丝分裂计数可能更好地定义了一组复发风险较高的 ILC。我们旨在确定多形性组织学与纯 ILC 无病生存（DFS）之间的关系。此外，我们还评估了在调整其他因素后，多形性组织学与接受化疗之间的关系。
我们分析了 475 例 I 期至 III 期纯 ILC 患者的队列。我们使用 Kaplan-Meier 估计、Cox 比例风险和逻辑回归进行多变量分析。多形性组织学通过中心病理复查确认。
在多变量模型中，多形性组织学与 DFS 降低无关。只有有丝分裂评分、受体亚型和病理分期与 DFS 独立且显著相关。多形性 ILC 患者比经典型 ILC 患者更有可能接受化疗（调整后的优势比为 2.96，p=0.026）。
ILC 中的多形性诊断没有临床意义，不应用于确定治疗方案。相反，在本纯 ILC 队列中，有丝分裂计数确定了明确的预后分组。
