[The comparison of characters between invasive micropapillary carcinoma and invasive ductal carcinoma not otherwise specified of the breast].

To analyze the differences of clinicopathological characters and prognostic factors between invasive micropapillary carcinoma of the breast (IMPC) and invasive ductal carcinoma (IDC) not otherwise specified of the breast. Patients who were treated from June 2008 to April 2016 in Breast Center of Beijing Hospital were retrospectively analyzed to evaluate the differences between IMPC (=59) and IDC (=1 080). Follow-up was done every 3 to 6 months postoperatively with a deadline of July 31, 2016. The curves of disease free survival (DFS) and overall survival (OS) were drawn by Kaplan-Meier method, and survival rates were compared by means of the Log-rank test. Potential prognostic variables which were identified on univariate analysis were analyzed with Cox's proportional hazards regression model for multivariate analysis. More lymph nodes were involved in IMPC group (χ(2)=12.168, =0.007) which led to more later stage in this group (χ(2)=8.950, =0.011). IMPC group displayed a significantly increased rate of lymphovascular invasion (LVI) compared to IDC group (χ(2)=13.511, = 0.001). The expression rate of estrogen receptor (ER) and progesterone receptor (PR) was higher in IMPC group than that in IDC group (89.8% . 76.3% and 88.1% . 70.7%, respectively, χ(2)=5.786, 8.332, all <0.05). In multivariate analysis performed with the variables found significant in univariate analysis, the only variable found significantly affecting DFS of IMPC group was the T stage (T1-2 and T3-4, =5.217, 95%: 1.401 to 19.430, =0.014), while in IDC group, pathological stage (stage Ⅰ to Ⅱ and stage Ⅲ to Ⅳ, =1.870, 95% : 1.262 to 2.771, =0.002), lymph node positive ratio (LNR) (=2.222, 95%: 1.561 to 3.162, =0.000), PR (=1.856, 95% 1.118 to 3.082, =0.017), and age (<50 years old and ≥50 years old, =0.695, 95% 0.488 to 0.989, =0.043) were prognostic factors. There were two variables found significantly affecting OS of IMPC group, which were T stage (=3.713, 95% 1.539 to 8.959, =0.004) and LNR (=2.850, 95%: 1.033 to 7.862, =0.043). While in IDC group, LNR was the only variable found significantly affecting OS (=2.129, 95% 1.324 to 3.425, =0.002). Compared with IDC, the patients with IMPC were more likely to have local or regional recurrence (=0.006). Although the median DFS interval was longer in IDC group (χ(2)=9.739, =0.002), the median OS interval was comparable between the two groups (χ(2)=0.787, =0.375). Although IMPC has lymphotropic feature, tendency of LVI and local or regional recurrence, it has an OS which is comparable with IDC.