Prognosis of invasive micropapillary carcinoma compared with invasive ductal carcinoma in breast: A meta-analysis of PSM studies.

BACKGROUND

Invasive micropapillary carcinoma (IMPC) is a rare histological subtype of breast cancer. The outcome of IMPC remains controversial; we conducted a meta-analysis of propensity score matching (PSM) studies to evaluate the prognostic difference between IMPC and invasive ductal carcinoma (IDC).

METHODS

We searched PubMed, EMBASE and the Cochrane library for PSM studies comparing survival data between IMPC and IDC. The summarized odds ratios (ORs) and 95% confidence interval (95% CI) are calculated by STATA software utilizing fixed-effect or random-effect models, depending on the heterogeneity of the eligible studies.

RESULTS

Eight PSM studies including 2102 IMPC patients are included in the meta-analysis. Compared with IDC, IMPC has a similar overall survival (OS) (estimated OR = 0.87, 95% CI: 0.61-1.25), but a shorter relapse free survival (RFS) (estimated OR = 1.31, 95% CI: 1.06-1.61); the shorter RFS might owe to the significantly higher loco-regional recurrence rate of IMPC (estimated OR = 3.60, 95% CI: 1.99-6.52). Funnel plots and Egger's tests are used to evaluate publication bias and the p value for OS and RFS are 0.036 and 0.564 respectively.

CONCLUSIONS

Our results demonstrate that compared with IDC, IMPC exhibits a similar, even favorite OS, but a shorter RFS; and the shorter RFS might owe to the significantly higher loco-regional recurrence rate of IMPC. These results could contribute to the individualized therapy and follow-up strategies for IMPC patients.