Abstract：
OBJECTIVE: To compare the clinicopathologic features and prognosis of pleomorphic invasive lobular carcinoma (P-ILC) and classic ILC (C-ILC) according to the biomarker profile.
METHODS: A total of 667 C-ILCs and 133 P-ILCs between 2011 and 2021 were included. Clinicopathologic features and stromal tumor-infiltrating lymphocytes (sTILs) status were evaluated. P-ILCs were divided into subtypes based on ER/PR and HER2 expression. The overall survival and disease-free survival (DFS) of patients were compared among matched P-ILCs, C-ILCs, and invasive ductal carcinomas (IDCs) with biomarker subtypes.
RESULTS: Compared to C-ILCs, P-ILCs had greater tumor sizes and stages, fewer ER-positive, more HER2-positive, triple negative (TN), and Ki-67 > 20% tumors (P < 0.05). P-ILCs were subdivided into ER+ (63.1%), HER2+ (21.1%) and TN (15.8%). ER+ P-ILCs were mainly showed trabecular and solid growth patterns. Apocrine and solid features were more strongly associated with HER2+ P-ILCs and TN-P-ILCs, respectively. The prognosis of each biomarker group (ER+, HER2+ and TN) differed by subtype. The P-ILC biomarker subtypes had worse prognosis than the same subtypes in the IDC group, while there was no difference between the P-ILC and the C-ILC counterparts. Solid variants of P-ILC had the worst prognosis. Bone was the most common metastatic site in ER+ P-ILCs and TN-P-ILCs. HER2+ P-ILCs tended to metastasize to the brain and liver. DFS of HER2+ P-ILCs and TN-P-ILCs were worse than that of ER+ P-ILCs. Lacking lobular carcinoma in situ and sTILs ≤ 10% were associated with worse survival of ER+ P-ILCs and TN-P-ILCs, respectively. For HER2+ P-ILCs, Ki-67 > 20% and sTILs ≤ 10% were significant factors for lower DFS.
CONCLUSIONS: P-ILCs is an aggressive subtype of ILCs. Analyzing the prognostic factors of P-ILCs with heterogeneous morphological and biomarker characteristics is helpful for creating an individualized treatment.
METHODS: A total of 667 C-ILCs and 133 P-ILCs between 2011 and 2021 were included. Clinicopathologic features and stromal tumor-infiltrating lymphocytes (sTILs) status were evaluated. P-ILCs were divided into subtypes based on ER/PR and HER2 expression. The overall survival and disease-free survival (DFS) of patients were compared among matched P-ILCs, C-ILCs, and invasive ductal carcinomas (IDCs) with biomarker subtypes.
RESULTS: Compared to C-ILCs, P-ILCs had greater tumor sizes and stages, fewer ER-positive, more HER2-positive, triple negative (TN), and Ki-67 > 20% tumors (P < 0.05). P-ILCs were subdivided into ER+ (63.1%), HER2+ (21.1%) and TN (15.8%). ER+ P-ILCs were mainly showed trabecular and solid growth patterns. Apocrine and solid features were more strongly associated with HER2+ P-ILCs and TN-P-ILCs, respectively. The prognosis of each biomarker group (ER+, HER2+ and TN) differed by subtype. The P-ILC biomarker subtypes had worse prognosis than the same subtypes in the IDC group, while there was no difference between the P-ILC and the C-ILC counterparts. Solid variants of P-ILC had the worst prognosis. Bone was the most common metastatic site in ER+ P-ILCs and TN-P-ILCs. HER2+ P-ILCs tended to metastasize to the brain and liver. DFS of HER2+ P-ILCs and TN-P-ILCs were worse than that of ER+ P-ILCs. Lacking lobular carcinoma in situ and sTILs ≤ 10% were associated with worse survival of ER+ P-ILCs and TN-P-ILCs, respectively. For HER2+ P-ILCs, Ki-67 > 20% and sTILs ≤ 10% were significant factors for lower DFS.
CONCLUSIONS: P-ILCs is an aggressive subtype of ILCs. Analyzing the prognostic factors of P-ILCs with heterogeneous morphological and biomarker characteristics is helpful for creating an individualized treatment.
摘要：
目的：比较多形性浸润性小叶癌（P-ILC）和经典ILC（C-ILC）的临床病理特征和预后。
方法：纳入了2011年至2021年的667例C-ILC和133例P-ILC。评估临床病理特征和间质肿瘤浸润淋巴细胞（sTIL）状态。基于ER/PR和HER2表达将P-ILC分为亚型。在匹配的P-ILC之间比较患者的总生存期和无病生存期（DFS），C-ILC,和具有生物标志物亚型的浸润性导管癌（IDC）。
结果：与C-ILC相比，P-ILC具有更大的肿瘤大小和分期，ER阳性较少，更多的HER2阳性，三负（TN），Ki-67>20%肿瘤(P<0.05)。P-ILC细分为ER+（63.1%），HER2+(21.1%)和TN(15.8%)。ER+P-ILC主要表现为骨小梁和固体生长模式。分泌和固体特征与HER2+P-ILC和TN-P-ILC的相关性更强，分别。每个生物标志物组的预后(ER+，HER2+和TN)不同亚型。在IDC组中，P-ILC生物标志物亚型的预后比相同亚型差，而P-ILC和C-ILC对应物之间没有差异。P-ILC的固体变体具有最差的预后。骨是ER+P-ILC和TN-P-ILC中最常见的转移部位。HER2+P-ILC倾向于转移至脑和肝。HER2+P-ILC和TN-P-ILC的DFS比ER+P-ILC的DFS差。缺乏小叶原位癌和sTILs≤10%与ER+P-ILC和TN-P-ILC的生存率较差相关，分别。对于HER2+P-ILC，Ki-67>20%和sTIL≤10%是降低DFS的显著因素。
结论：P-ILC是一种侵袭性的ILC亚型。分析具有异质性形态学和生物标志物特征的P-ILC的预后因素有助于制定个体化治疗方案。
方法：纳入了2011年至2021年的667例C-ILC和133例P-ILC。评估临床病理特征和间质肿瘤浸润淋巴细胞（sTIL）状态。基于ER/PR和HER2表达将P-ILC分为亚型。在匹配的P-ILC之间比较患者的总生存期和无病生存期（DFS），C-ILC,和具有生物标志物亚型的浸润性导管癌（IDC）。
结果：与C-ILC相比，P-ILC具有更大的肿瘤大小和分期，ER阳性较少，更多的HER2阳性，三负（TN），Ki-67>20%肿瘤(P<0.05)。P-ILC细分为ER+（63.1%），HER2+(21.1%)和TN(15.8%)。ER+P-ILC主要表现为骨小梁和固体生长模式。分泌和固体特征与HER2+P-ILC和TN-P-ILC的相关性更强，分别。每个生物标志物组的预后(ER+，HER2+和TN)不同亚型。在IDC组中，P-ILC生物标志物亚型的预后比相同亚型差，而P-ILC和C-ILC对应物之间没有差异。P-ILC的固体变体具有最差的预后。骨是ER+P-ILC和TN-P-ILC中最常见的转移部位。HER2+P-ILC倾向于转移至脑和肝。HER2+P-ILC和TN-P-ILC的DFS比ER+P-ILC的DFS差。缺乏小叶原位癌和sTILs≤10%与ER+P-ILC和TN-P-ILC的生存率较差相关，分别。对于HER2+P-ILC，Ki-67>20%和sTIL≤10%是降低DFS的显著因素。
结论：P-ILC是一种侵袭性的ILC亚型。分析具有异质性形态学和生物标志物特征的P-ILC的预后因素有助于制定个体化治疗方案。
