TY - JOUR T1 - The Real-world Outcomes of Patients With Advanced Invasive Lobular Carcinoma of the Breast Compared With Invasive Ductal Carcinoma: A Review at a Single Institution JF - Anticancer Research JO - Anticancer Res SP - 4619 LP - 4627 DO - 10.21873/anticanres.15275 VL - 41 IS - 9 AU - JUNICHIRO WATANABE AU - SHOGO NAKAMOTO AU - TAKASHI SUGINO Y1 - 2021/09/01 UR - http://ar.iiarjournals.org/content/41/9/4619.abstract N2 - Background: The real-world outcomes of patients with advanced invasive lobular carcinoma (ILC) of the breast are unclear because of its rarity. Patients and Methods: We identified 435 patients with estrogen receptor-positive (ER+), HER2-negative (HER2−) advanced breast cancer treated at our Institute between 2002 and 2019, and analyzed their outcomes retrospectively. Results: We identified 29 patients with advanced ILC. At presentation, they had a lower rate of lung metastasis (p=0.0053) but a higher rate of stomach metastasis (p=0.0379) compared with other patients with advanced breast cancer. Median overall survival did not differ; however, multivariate analyses showed that ILC histopathology was a risk factor for poorer overall survival (hazard ratio=3.43, p=0.0038) in patients with de novo stage IV ER+ HER2− breast cancer. Patients with ILC showed a markedly different patten of subsequent metastasis, such as less in the lung and more in the stomach, leptomeninges, and bone marrow. Conclusion: According to our retrospective study, in patients with de novo stage IV ER+ HER2− breast cancer, ILC histopathology was associated with increased risk of death. ER -