Prognosis of lymphotropic invasive micropapillary breast carcinoma analyzed by using data from the National Cancer Database

Abstract

BackgroundInvasive micropapillary carcinoma (IMPC) is an uncommon subtype of breast cancer. Previous studies of this subtype demonstrated a higher propensity for lymph node metastases as compared with invasive ductal carcinoma (IDC). The purpose of the present study was to determine the clinical characteristics, outcomes, and propensity for lymph node metastasis of patients with IMPC of the breast recorded in the National Cancer Database (NCDB).MethodsRecords of patients with IMPC diagnosed between 2004 and 2014 were retrieved from the NCDB. Log-rank test was performed to evaluate associations of clinical characteristics with overall survival (OS). Cox proportional hazards model was used to determine variables associated with OS.ResultsOverall, 2660 patients with IMPC met the selection criteria; the 5-year OS rate was 87.5% and 24.9% of patients had nodal involvement at presentation. Patients with ≥ 4 positive lymph nodes had shorter OS than node-negative patients, whereas patients with 1–3 positive nodes had similar OS to node-negative patients. Age < 65 years, receipt of radiotherapy, and estrogen receptor positivity were also associated with prolonged OS. The benefit of radiotherapy was limited to IMPC patients undergoing lumpectomy; there was no benefit for the patients undergoing mastectomy (regardless of nodal positivity/negativity).ConclusionsFavorable prognostic factors of IMPC patients included age < 65 years, < 4 positive lymph nodes, receipt of radiotherapy, and estrogen receptor positivity. The results presented herein suggest a survival benefit associated with radiotherapy in IMPC treatment, though this may be limited to the patients treated with lumpectomy.

MRI and the pathology of breast invasive micropapillary carcinoma

“…Complete surgical resection of the lesion is an important therapy in IMPC (5). However, IMPC is typically irregular in shape on MRI and the border is unclear (8,10).…”

“…Lymphatic invasion and lymph node metastasis are common in IMPC, with an incidence of nodal metastases of 24.9%, leading to frequent recurrence and poor prognosis in patients, with a 5-year overall survival rate of 87.5% (5). Even when the proportion of micropapillary structures is <10%, the invasive ability of the cancer is significantly higher compared with that of the same pathological type of breast cancer without IMPC components (6,7).…”

Nomogram Predicting the Risk of Locoregional Recurrence After Mastectomy for Invasive Micropapillary Carcinoma of the Breast

“…Invasive micropapillary carcinoma (IMPC) is a relatively rare but highly aggressive histological subtype that accounts for 0.9% to 8.4% of breast cancer cases, [1][2][3][4][5][6][7][8][9][10] which is often accompanied by extensive lymph node metastasis (LNM), lymphovascular invasion (LVI), high histologic grade, lymph node extracapsular extension, etc. 1,5,[7][8][9][10][11][12][13][14] Although these factors related to the highly local aggressive biological behavior of IMPC have been reported, it remained inconclusive whether this malignant behavior could translate into unfavorable prognosis, 7,15,16 even though that relationship has been widely accepted.…”

Comparison of clinicopathological characteristics and prognosis among patients with pure invasive ductal carcinoma, invasive ductal carcinoma coexisted with invasive micropapillary carcinoma, and invasive ductal carcinoma coexisted with ductal carcinoma in situ

“…Our data showed that the IDC + IMPC patients had significantly worse DFS and OS compared to those with pure IDC and IDC + DCIS ( P < .001). Lewis et al [ 39 ] carried out a retrospective analysis and reported that patients of IMPC with triple-negative molecular subtypes had worse OS (hazard ratio 7.28, P < .001). Therefore, based on the above reports and our findings, we believe that IMPC is a unique subtype with poor prognosis, and its malignancy is significantly higher than that of patients without an IMPC component.…”