Prognostic Analysis of Primary Breast Signet Ring Cell Carcinoma and Mucinous Breast Adenocarcinoma: A SEER Population-Based Study.

Song Wang,Xiaohong Wang,Yiyuan Zhang,Xiangsheng Zhang,Zhenlin Yang,Fangxu Yin

doi:10.3389/fonc.2021.783631

Abstract

BackgroundPrimary breast signet ring cell carcinoma (SRCC) is a rare type of breast cancer with typical morphological characteristics, high aggressiveness, and poor prognosis. SRCC is different from mucinous breast adenocarcinoma (MBC). However, only a few studies have explored the clinicopathological features and prognosis of SRCC and MBC.MethodsData retrieved from the Surveillance, Epidemiology, and End-Results (SEER) database (2004–2015) were used to explore the prognostic effect of clinicopathological features and treatment modalities on survival outcomes of SRCC and MBC patients. Kaplan–Meier plot analysis, multivariate Cox proportional risk model, propensity score matching (PSM), and subgroup analysis were performed.ResultsA total of 167 patients with SRCC and 11,648 patients with MBC were included in the study. SRCC patients exhibited higher histological grade (p < 0.001), larger tumor volume (p < 0.001), higher rate of lymph node metastasis (p < 0.001), and higher frequency of distal metastasis (p < 0.001) compared with MBC patients. Cox proportional hazards regression analysis showed that SRCC patients had lower overall survival (OS) and breast cancer-specific survival (BCSS) compared with MBC patients. Subgroup survival analysis showed that the SRCC patients had lower OS and BCSS in subgroups including younger than 60 years old, white race, married, without chemotherapy, and received radiotherapy compared with the MBC patients in these subgroups. In addition, the SRCC patients had lower BCSS in subgroups including other races (including Asian or Pacific Islander and American Indian/Alaska Native), without surgery, and lymph node metastasis.ConclusionThe findings showed that primary breast SRCC patients have unique clinical characteristics and worse prognosis compared with MBC patients. Notably, different treatment methods resulted in different prognosis for SRCC and MBC types; therefore, SRCC patients should be distinguished from MBC patients to improve efficacy of treatment.

Highlights

Breast cancer is the most common cancer type in the world and is associated with a high number of cancer-related deaths [1]
The findings showed higher number of patients with high-grade tumor in the signet ring cell carcinoma (SRCC) group compared with the number of patients with high-grade tumor in the mucinous breast adenocarcinoma (MBC) group (>I, 69.4% vs. 34.4%, p < 0.001)
Analysis after adjustment showed that SRCC patients had worse prognosis compared with MBC patients (Table 3)

Summary

Introduction

Breast cancer is the most common cancer type in the world and is associated with a high number of cancer-related deaths [1]. Primary signet ring cell carcinoma (SRCC) is a rare variant of adenocarcinoma [2]. The classification of breast cancer groups by WHO in 2003 includes SRCC in mucinous carcinoma and other mucinous tumors [4]. Some studies report that SRCC mainly presents as high-grade lesions, and signet ring cells are associated with poor prognosis [6,7,8]. Primary breast SRCC should be treated as an independent breast cancer type. Primary breast signet ring cell carcinoma (SRCC) is a rare type of breast cancer with typical morphological characteristics, high aggressiveness, and poor prognosis. SRCC is different from mucinous breast adenocarcinoma (MBC). Only a few studies have explored the clinicopathological features and prognosis of SRCC and MBC

Methods

Results

Discussion

Conclusion