Clinico-pathological features and prognosis of invasive micropapillary carcinoma compared to invasive ductal carcinoma: a population-based study from China.

Wen-Biao Shi,Qiang Zhang,Zhi-Ming Shao,Xin Hu,Jian Zhou,Lin-Jun Yang,William B Coleman

doi:10.1371/journal.pone.0101390

Abstract

BackgroundInvasive micropapillary carcinoma (IMPC) of the breast is a rare subtype of breast cancer that is associated with a high incidence of regional lymph node metastases and a poor clinical outcome. However, the clinico-pathological features and prognostic factors of IMPC are not well understood.Patients and MethodsA total of 188 IMPC cases and 1,289 invasive ductal carcinoma (IDC) cases were included. The clinical features, breast cancer-specific survival (BCSS) and recurrence/metastasis-free survival (RFS) of the patients were compared between these two groups.ResultsThe IMPC patients exhibited more features of aggressive carcinoma than the IDC patients, including larger tumor size, higher tumor stage, a greater proportion of nodal involvement and an increased incidence of lymphovascular invasion. Patients with IMPC had lower 5-year BCSS and RFS rates (75.9% and 67.1%, respectively) than patients with IDC (89.5% and 84.5%, respectively). Compared to IDC patients, the patients with IMPC had a significantly higher percentage of stage III breast cancer (51.3% versus 21.7%). In a stage-matched Kaplan-Meier analysis, the patients with stage III IMPC had lower 5-year BCSS and RFS rates than patients with stage III IDC (BCSS, P = 0.004; RFS, P = 0.034). A multivariate analysis revealed that TNM stage was an independent prognostic factor for patients with IMPC. The proportion of cancers with a luminal-like subtype was significantly higher in IMPC than in IDC (P<0.001). However, after matching by molecular subtype, the patients with IMPC had significantly worse clinical outcomes than patients with IDC.ConclusionsIn Chinese women, IMPCs displayed more aggressive behaviors than IDCs, resulting in poorer clinical outcomes for patients with IMPC, regardless of a favorable molecular subtype. Our findings illustrate that the poorer survival of patients with IMPC might be due to an increased incidence and aggressiveness of tumors in TNM stage III.

Highlights

Invasive micropapillary carcinoma (IMPC) of the breast is an uncommon and distinct variant of breast cancer that is characterized by pseudopapillary and tubuloalveolar arrangements of tumor cell clusters in sponge-like, clear empty spaces, thereby mimicking extensive lymphatic invasion [1]
A multivariate analysis revealed that TNM stage was an independent prognostic factor for patients with IMPC
Our findings illustrate that the poorer survival of patients with IMPC might be due to an increased incidence and aggressiveness of tumors in TNM stage III

Summary

Introduction

Invasive micropapillary carcinoma (IMPC) of the breast is an uncommon and distinct variant of breast cancer that is characterized by pseudopapillary and tubuloalveolar arrangements of tumor cell clusters in sponge-like, clear empty spaces, thereby mimicking extensive lymphatic invasion [1]. This carcinoma has been reported to exhibit lymphovascular invasion, lymph node metastasis, local recurrence and distant metastasis at relatively high frequencies, exhibiting a more aggressive behavior than invasive ductal carcinoma (IDC) [2,3]. The clinico-pathological features and prognostic factors of IMPC are not well understood

Methods

Results

Conclusion