The Prognosis and Clinicopathological Characteristics of Metaplastic Breast Cancer: A Meta-Analysis.

Background: Due to the rarity of metaplastic breast cancer (MBC), the prognosis and clinicopathologic-al characteristics of MBC patients are still inconclusive. Large-sample retrospective analysis is still lacking at present.This study aims to conduct a meta-analysis of relevant literature on MBC at home and abroad to obtain the prognostic and clinicopathological characteristics of MBC.Methods: Cohort studies or case-control studies comparing MBC and triple-negative breast cancer (TNBC) were searched through the internet, and the quality of the included studies was evaluated using the Newcastle-Ottawa scale (NOS). A total of 9 studies with NOS scores of > 6 were included. Meta-analysis was performed using the Review Manager 5.3 provided by the Cochrane Collaboration Network. The hazard ratio (HR) evaluate the disease-free survival (DFS) and overall survival (OS), and the odds ratio (OR) was used to evaluate clinicopathological characteristics, including age, tumor diameter, lymph node metastasis status, distant metastasis status, TNM staging, and histological grade. According to the heterogeneity of the included studies, random effects model or fixed effects model was used.Results: Compared with TNBC patients, the HR value for 5-year DFS and 5-year OS of MBC patients was 1.64 (95%CI: 1.36-1.98) and 1.52 (95%CI: 1.27-1.81), respectively. The total OR value for age> 50 years old, tumor diameter ≤ 2cm, lymph node positive, distant metastasis, TNM stage III and above, and histological grade 3 was 1.63 (95%CI: 1.45-1.84), 0.29 (95% CI: 0.14-0.58), 0.68 (95%CI: 0.53-0.88), 1.59 (95%CI: 0.89-2.81), 1.49 (95 %CI: 0.80-2.77), and 2.25 (95%CI: 0.85-5.97), respectively.Conclusion: MBC patients are less likely to have lymph node metastasis and had worse DFS and OS than TNBC patients, which may be related to the pathological characteristics of MBC patients being related to sarcoma. But this also requires verification and further research with large sample sizes. In addition, there were no statistical differences in distant metastasis, TNM staging, and histological grade between MBC and TNBC patients.

METAPLASTIC CARCINOMA OF BREAST : A CASE REPORT

Metaplastic breast cancer constitute nearly 1 % of all breast carcinoma cases. There is metaplasia of normal epithelial components of the breast into other types. They are highly aggressive with very poor prognosis. Here we present a case of 30 year old female who presented with a breast lump in her left breast associated with dull aching pain. It was 10 x 10 cm in size involving upper inner, upper outer, lower outer quadrants and retroareolar area of left breast. USG was suugestive of BIRADS VI lesion. Axillary lymph nodes were not found enlarged clinically or radiologically. Core biopsy report showed Phylloides tumor of breast. The patient underwent simple mastectomy of left breast and histopathology revealed spindle cell variant of metaplastic breast cancer. The cell blocks sent for immunohistochemistry were negative for estrogen, progesterone receptors and Her2neu receptor. The post surgical treatment of this type of breast cancer is still under study.

Mammary-specific expression of Trim24 establishes a mouse model of human metaplastic breast cancer

Conditional overexpression of histone reader Tripartite motif containing protein 24 (TRIM24) in mouse mammary epithelia (Trim24COE) drives spontaneous development of mammary carcinosarcoma tumors, lacking ER, PR and HER2. Human carcinosarcomas or metaplastic breast cancers (MpBC) are a rare, chemorefractory subclass of triple-negative breast cancers (TNBC). Comparison of Trim24COE metaplastic carcinosarcoma morphology, TRIM24 protein levels and a derived Trim24COE gene signature reveals strong correlation with human MpBC tumors and MpBC patient-derived xenograft (PDX) models. Global and single-cell tumor profiling reveal Met as a direct oncogenic target of TRIM24, leading to aberrant PI3K/mTOR activation. Here, we find that pharmacological inhibition of these pathways in primary Trim24COE tumor cells and TRIM24-PROTAC treatment of MpBC TNBC PDX tumorspheres decreased cellular viability, suggesting potential in therapeutically targeting TRIM24 and its regulated pathways in TRIM24-expressing TNBC.

The different outcomes between breast-conserving surgery plus radiotherapy and mastectomy in metaplastic breast cancer: A population-based study

Background Metaplastic breast cancer (MBC) are rare. The survival outcomes of MBC patients after breast conserving surgery plus radiotherapy (BCS+RT) or mastectomy have not been established. The study aimed to compare survival outcomes of MBC patients subjected to BCS+RT or mastectomy therapeutic options. Methods Patients who were subjected to BCS+RT or mastectomy between 2004 and 2014 were enrolled in this study through the Surveillance, Epidemiology and End Results (SEER) database. Breast cancer-specific survival (BCSS) and the overall survival (OS) of the participants were determined. Cox proportional hazard model and the Kaplan Meier method were used to determine the correlation between the two surgical methods and survival outcomes. Results A total of 1197 patients were enrolled in this study. Among them, 439 patients were subjected to BCS+RT, while 758 patients were subjected to mastectomy. After propensity score matching (PSM), the BCS+RT and mastectomy groups consisted of 321 patients, respectively. The univariate and multivariate analysis with a 6-month landmark all indicate that patients receiving BCS+RT has higher OS than patients receiving mastectomy (HR = 0.701,95% CI = 0.496–0.990, P = 0.044; HR = 0.684,95% CI = 0.479–0.977, P = 0.037) while the BCSS was no difference between the two groups (HR = 0.739,95% CI = 0.474–1.153, P = 0.183; HR = 0.741,95% CI = 0.468–1.173, P = 0.200). Conclusion The BCS+RT therapeutic option exhibits a higher OS in MBC patients compared to the mastectomy approach.

Metaplastic Breast Cancer with Chondroid Differentiation

Background: Metaplastic breast cancer (MBC) cancer is a rare subtype of breast carcinoma and carries a worse prognosis. Chondroid differentiation is the rarest among all its histologic subtypes. We report a case of MBC with chondroid differentiation and review its clinicopathological details, genetic basis, and management.Case presentation: A 56-year female presented with right-sided large breast lump. She noticed this lump 4 months before presenting. Trucut biopsy was suggestive of invasive ductal carcinoma. She underwent breast conservation surgery and histology was consistent with MBC with chondroid differentiation, pT2N3aM0. Tumour was triple-negative for ER, PR, and Her-2- neu receptors. Adjuvant treatment with chemotherapy followed by radiotherapy was given and she has been doing fine during 11 months of follow-up.Conclusion: The MBC is an uncommon subtype with heterogeneity in biological and morphological features and its knowledge is paramount while evaluating a breast lump. Understanding the pathologic and molecular basis is imperative in developing the targeted therapy to improve outcomes.