Differences in prognostic factors and patterns of failure between invasive micropapillary carcinoma and invasive ductal carcinoma of the breast: Matched case–control study
Received 21 October 2009; received in revised form 25 January 2010; accepted 27 January 2010. published online 22 March 2010.
Abstract
Purpose
We designed this study to identify differences in prognostic factors and patterns of failure between invasive micropapillary carcinoma (IMPC) and invasive ductal carcinoma (IDC) in patients with breast cancer.
Experimental design
We identified 72 cases of IMPC who were diagnosed between 1999 and 2007 at the Samsung Medical Center. These patients were matched with 144 controls who were diagnosed with IDC during the same period. Exact matches were made for age (±3 years), pathologic tumour and node stage, and treatment methods (surgery and radiation therapy).
Results
The median follow-up period was 45 months (13–116) for IMPC and 50 months (16–122) for IDC. Lymphovascular invasion (LVI, p<0.0001), axillary lymph node extracapsular extension (ECE, p=0.001) and high nuclear grade (p=0.032) were more frequently detected in patients with IMPC. During the follow-up period, treatment failed in 15 IMPC patients (20.8%) and in 26 IDC patients (18.1%). Loco-regional recurrences developed in 11 IMPC patients (15.3%) and eight IDC patients (5.6%). Importantly, of 57 IMPC patients who had positive axillary nodes, seven patients (12.3%) had axilla and/or supraclavicular recurrence. Therefore, at 5 years, the loco-regional recurrence-free survival was 79.1% in the IMPC patients vs. 93.3% in the IDC patients (p=0.0024).
Conclusion
Our study showed that IMPC is associated with LVI, ECE, high nuclear grade, and a greater degree of loco-regional recurrence, especially in the axilla and supraclavicular areas. Therefore, axillary and supraclavicular radiation therapy should be considered in IMPC patients with axillary node metastasis.
aDepartment of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, South Korea
bDepartment of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
cDepartment of Hematology–Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
dDepartment of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
ABSTRACT