Abstract P6-07-23: Proportion of invasive micropapillary carcinoma lesion and primary breast cancer prognosis

Abstract

Abstract Background: Invasive micropapillary carcinoma (IMPC) has been classified as a special type of breast cancer and has a high incidence of lymph node metastases and lymphatic invasion with poor prognosis. IMPC is often mixed with other histological types. This study examined whether the prognosis is correlated with proportion of the IMPC. Methods: The subjects included 124 patients with IMPC that were surgically resected at St. Luke's International Hospital between February 2000 and January 2011. The resected specimens were reviewed histopathologically to determine the proportion of IMPC lesion. Patients were classified into two groups based on three cut-points of the proportion of IMPC lesion, 25%, 50%, and 75%. For each of these dichotomous classifications, we examined overall survival (OS), recurrence rate (RR) and pathological histology between the two groups. We used the Kaplan-Meier curve method and log-rank test to evaluate overall and disease-free survival time and the chi-squared test for pathological histology. Results: The subjects were 124 cases, and two of them were male breast cancer. The patient's age at presentation ranged from 29 to 83 years (mean 54.5 years). At a median follow-up of 52 months (interquartile range, 7 to 115 months). For all cut off points, there was no significant difference in survival rate and recurrence rate. We observed high-rates of lymphatic invasion and lymph node metastasis even in patients with a low proportion of IMPC lesion. Conclusion: Our results provide no evidence to support a relationship between proportion of IMPC lesion and breast cancer prognosis. However, lymphatic invasion and lymph node metastasis was a high frequency with low proportion of the IMPC. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-23.