Survival Outcomes After Breast-Conserving Therapy Compared With Mastectomy for Patients With Early-Stage Invasive Micropapillary Carcinoma of the Breast: A SEER Population-Based Study

Abstract

BackgroundInvasive micropapillary breast carcinoma (IMPC) is a relatively rare pathological type of invasive breast cancer. Little is currently known on the efficacy and safety of breast-conserving treatment (BCT, lumpectomy plus postsurgical radiation) compared with mastectomy in women diagnosed with early-stage IMPC. Accordingly, we sought to investigate the long-term prognostic differences between BCT and mastectomy in patients with T1-3N0-3M0 invasive micropapillary breast carcinoma using data from the Surveillance, Epidemiology, and End Results (SEER) database.Materials and MethodsWe retrospectively analyzed 1,203 female patients diagnosed with early-stage IMPC between 2004 and 2015 from the SEER database. The impact of different surgical approaches on patient prognosis was assessed by the Kaplan-Meier method and Cox proportional risk models.ResultsA total of 609 and 594 patients underwent mastectomy and BCT, respectively. Compared with patients who underwent a mastectomy, patients in the BCT group were older and had lower tumor diameters, lower rates of lymph nodes metastasis, and higher rates of ER receptor positivity and PR receptor positivity (p < 0.05). Kaplan-Meier plots showed that the overall survival (OS) and breast cancer-specific survival (BCSS) were higher in the BCT group than in the mastectomy group. In subgroup analysis, patients with T2 stage in the BCT group had better OS than the mastectomy group. Multivariate analysis showed no statistical difference in OS and BCSS for patients in the mastectomy group compared with the BCT group (hazard ratio (HR) = 0.727; 95% confidence interval (95% CI) 0.369–1.432, p = 0.357; HR = 0.762; 95% CI 0.302–1.923, p = 0.565; respectively). During the multivariate analysis and stratifying for the T stage, a better OS was found for patients with T2 stage in the BCT group than the mastectomy group (HR = 0.333, 95% CI: 0.149–0.741, p = 0.007). There was no significant difference in OS for patients with T1 and T3 stages between the BCT and mastectomy groups (p > 0.05).ConclusionIn women with early-stage IMPC, BCT was at least equivalent to mastectomy in terms of survival outcomes. When both procedures are feasible, BCT should be recommended as the standard surgical treatment, especially for patients with T2 disease.

Development and validation of nomograms to predict survival in patients with invasive micropapillary carcinoma of the breast

“…Meanwhile, a previous finding also demonstrated that the survival outcomes of patients with early-stage IMPC who underwent breast-conserving surgery were not inferior to those with mastectomy. 12 Moreover, we confirmed that patients with IMPC benefited significantly from radiotherapy in terms of both OS and BCSS, an issue that has long been controversial. 26 27 Additionally, consistent with a previous study, chemotherapy was inappropriate for use as a predictor for BCSS after adjustment for other factors.…”

“…8 In addition to the factors included in the tumor-node-metastasis classification, evidence indicates that other elements, such as demographic characteristics and treatment strategies, impact the prognosis of patients with IMPC. [9][10][11][12] Therefore, it is important to…”

Invasive micropapillary breast carcinoma: A retrospective study on the clinical imaging features and pathologic findings

“…Pathologists have described IMPC lesions as having an inside-out reversed polarity pattern with a typical cuticle-like microvillous secretory surface facing the stroma, resulting in a gap between the stroma and the neoplastic epithelial cells (4). Prior studies have demonstrated that as an aggressive variant, IMPC is linked to a larger tumor size, more advanced Tumor, Node, Metastasis (TNM) staging, a greater proportion of nodal involvement, and a higher degree of lymphovascular invasion (LVI); these characteristics can contribute to a high early recurrence rate and a poorer prognosis (5).…”

COX-2 expression in mammary invasive micropapillary carcinoma is associated with prognostic factors and acts as a potential therapeutic target in comparative oncology

“…In both species, surgery and chemotherapy are the most common standard treatments for breast cancer, as well as hormonal and target therapies available for human patients. However, depending on the patient's clinical staging, satisfactory therapeutic results for invasive micropapillary carcinoma are a challenge due to its high capacity of invasion and metastasis ( 24 – 26 ).…”