Management and Outcomes in Metaplastic Breast Cancer

Breast conservation versus mastectomy for metaplastic breast cancer: A systematic review and meta-analysis

Metaplastic breast cancer is a rare aggressive subtype of breast cancer for which there are no clear treatment guidelines regarding the optimal surgical approach. This systematic review and meta-analysis aimed to evaluate survival outcomes of patients with metaplastic breast cancer undergoing breast conservation compared with mastectomy. We identified studies from MEDLINE, Pubmed, EMBASE, Google Scholar, the Cochrane Library Register of Controlled Trials and the EBM Reviews Register. Studies were deemed suitable for inclusion where they compared breast-conserving surgery to mastectomy with the primary outcome of overall survival. Survival data were pooled using a random-effects model. From the 456 citations screened by our search, three studies were assessed as eligible for inclusion. There were a total of 2995 patients who underwent mastectomy and 1909 who underwent breast conservation. The median follow-up time was 43 months. Meta-analysis demonstrated no significant difference between breast conservation and mastectomy (pooled HR 0.89, 95% CI, 0.56-1.42, p = 0.631). Wide local excision, in conjunction with adjuvant radiation and judicious use of chemotherapy, may be a reasonable alternative to mastectomy as surgical management of metaplastic breast cancer as part of an individualized, multidisciplinary approach.

Targeted DNA Sequencing in Diagnosis of Malignant Phyllodes Tumors With Emphasis on Tumors With Keratin and p63 Expression

The differential diagnosis of malignant spindle cell neoplasms in the breast most frequently rests between malignant phyllodes tumor (MPT) and metaplastic carcinoma (MBC). Diagnosis of MPT can be challenging due to diffuse stromal overgrowth, keratin (CK) and/or p63 immunopositivity, and absent CD34 expression, which can mimic MBC, especially in core biopsies. Distinction of MPT from MBC has clinical implications, with differences in surgical approach, chemotherapy, and radiation. In this study, we evaluated MPTs (78 tumors, 64 patients) for stromal CK, p63, and CD34 expression and profiled a subset (n = 31) by targeted next-generation DNA sequencing, with comparison to MBC (n = 44). Most MPTs (71%) were CK+ and/or p63+, including 32% CK+ (25/77 focal) and 65% p63+ (32/66 focal, 10/66 patchy, and 1/66 diffuse). Thirty percent of MPTs expressed both CK and p63 (20/66), compared with 95% of MBCs (40/42, P < .001). CK and/or p63 were positive in CD34+ and CD34- MPTs. Recurrent genetic aberrations in MPTs involved TERT, TP53, MED12, CDKN2A, chromatin modifiers, growth factor receptors/ligands, and phosphoinositide-3 kinase (PI-3K) and MAPK pathway genes. Only MED12 (39%, 12/31) and SETD2 (13%, 4/31) were exclusively mutated in MPTs and not MBCs (P < .001 and P = .044, respectively), whereas PIK3R1 mutations were only found in MBCs (37%, 13/35, P < .001). Comparative literature review additionally identified ARID1B, EGFR, FLNA, NRAS, PDGFRB, RAD50, and RARA alterations enriched or exclusively in MPTs vs MBCs. MED12 was mutated in MPTs with diffuse stromal overgrowth (53%, 9/17), CD34- MPTs (41%, 7/17), and CK+ and/or p63+ MPTs (39%, 9/23), including 36% of CD34- MPTs with CK and/or p63 expression. Overall, MED12 mutation and/or CD34 expression were observed in 68% (21/31) MPTs, including 61% (14/23) of CK+ and/or p63+ tumors. Our results emphasize the prevalence of CK and p63 expression in MPTs and demonstrate the diagnostic utility of next-generation DNA sequencing, especially in MPTs with confounding factors that can mimic MBC.

Curative Approaches for Metaplastic Breast Cancer: A Retrospective Cohort Outcome Review

PURPOSE

Metaplastic breast cancer (MBC) is a rare and heterogeneous breast cancer subtype, and there are critical gaps in our understanding of its long-term outcomes. This retrospective cohort study aimed to address these gaps by scrutinizing the pathologic and clinical aspects of MBC to enhance clinical decision-making and refine patient care strategies.

METHODS AND MATERIALS

This registry-based retrospective cohort study included women aged ≥21 years diagnosed with MBC or matrix-producing carcinoma. The data were obtained from January 2001 to August 2020 from the Joint Breast Cancer Registry of Singapore Health Services, which included 23,935 patients. Demographic and clinicopathologic characteristics, neoadjuvant chemotherapy responses, and survival outcomes were analyzed. Statistical assessments involved univariate and multivariate Cox proportional hazards models and Kaplan-Meier survival analyses.

RESULTS

This study enrolled 170 patients; 87.1% had non-metastatic disease, and 12.9% had metastatic disease. The age of patients at diagnosis ranged from 46 to 65 years (median, 56 years). The cohort's predominant characteristics were triple negative breast cancer (64%), advanced clinical stage (77.6%), node negativity (67.6%), and grade 3 disease (74.1%). In patients receiving neoadjuvant chemotherapy with curative intent treatment (17.6%), neoadjuvant chemotherapy yielded a pathologic complete response of 19.2% and a disease progression rate of 46.2%. Multivariate analysis showed that adjuvant radiation therapy significantly improved overall survival and disease-free survival, with hazard ratios of 0.29 (95% CI, 0.13-0.62; P < .005) and 0.23 (95% CI, 0.10-0.50; P < .005), respectively. Clinical T3 and T4 stages and nodal involvement were associated with poor outcomes. Stable disease after neoadjuvant chemotherapy was associated with poor overall survival and disease-free survival.

CONCLUSIONS

This study sheds light on the complex landscape of MBC and emphasizes the pivotal role of adjuvant radiation therapy in enhancing patient outcomes. Despite advancements, challenges persist that warrant continued research to refine neoadjuvant chemotherapy strategies and delve into the nuanced factors that influence treatment responses.

Metaplastic Breast Cancer: A Case Report on a Rare Neoplasm of the Breast

Metaplastic breast cancer represents a very rare and histopathologically diverse subtype of breast cancer. It shows neoplastic epithelial differentiation into squamous cells and/or mesenchymal-like components, resulting in its aggressive behavior and poor prognosis compared to other types of breast cancer. Here, we describe the case of a 43-year-old woman diagnosed with metaplastic carcinoma of the breast who presented like any other case of breast lump in the right breast for six months. The tumor had a large size with an ulcerative lesion of the breast. Ultrasound showed heterogeneous echogenicity and lymph node involvement. Surgical resection with axillary lymph node dissection was done. The microscopic examination after tissue processing showed highly pleomorphic tumor cells along with chondromyxoid stroma and osseous differentiation, suggestive of metaplastic breast cancer which was triple-negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 on immunohistochemistry. The axillary lymph nodes identified were negative for tumor cells. The rarity and aggressive nature of this cancer pose diagnostic challenges and highlight the importance of multidisciplinary approaches for effective management.

Better Local Disease Control With Mastectomy in Metaplastic Breast Carcinoma: Findings of a Retrospective Cohort

BACKGROUND

Metaplastic breast cancer (MBC) is a rare type of breast carcinoma with clinicopathological differences. The prognosis and treatment strategies for MBC are usually conflicting. In this study, we aim to present the clinicopathologic features, treatment strategies, and prognosis of our MBC patients.

MATERIAL AND METHODS

In our retrospective study, 18 metaplastic breast cancer patients treated in our institution between January 2005 and December 2022 were evaluated. Demographic and clinicopathological characteristics, surgical and systemic treatment options, locoregional recurrences, distant metastases, and overall survival (OS) of the MBC patients were retrieved from the patient files.

RESULTS

All patients were female; the median age was 54.42 ± 12.37 years. Most of the patients (n = 15, 83.33%) presented with palpable masses. Tumors were mostly triple-negative, with a high grade and a high Ki‑67 proliferation index. Spindle cell carcinoma and MBC with mesenchymal differentiation were the most common subtypes. Most of the patients underwent mastectomy (n = 11, 61.11%); breast-conserving surgery (BCS) was performed on seven (38,88%) patients. Lymph node positivity was detected in six of 18 patients (33.33%). Fewer patients (n = 4, 22.22%) received neoadjuvant chemotherapy. While local recurrence developed in two out of seven patients (28.57%) who underwent BCS, there was no local recurrence in patients who had mastectomy. The OS time varied according to tumor size and the presence of lymph node metastases (p <0.001; p = 0.005).

CONCLUSION

Metaplastic breast cancer is genetically heterogeneous and resistant to conventional treatment strategies. Mastectomy is still the surgical treatment method that is performed more frequently and provides better local control for patients with metaplastic breast cancer.

Metaplastic breast cancer with a unique presentation and complete response to chemotherapy: a case report

BACKGROUND

Metaplastic breast carcinomas are a rare variant group of breast carcinomas. They are usually high-grade and triple-negative tumors. They often present with large primary tumor sizes. However, the involvement of axillary lymph nodes is infrequent at the time of diagnosis. Metaplastic breast carcinomas are associated with a worse prognosis and a poorer response to chemotherapy in comparison with other non-metaplastic triple-negative breast cancers. Up until this point, there are no specific treatment recommendations for metaplastic breast carcinomas beyond those intended for invasive breast cancer in general.

CASE PRESENTATION

A 40-year-old woman complained of a palpable mass in her left axilla. On ultrasonography, the mass was solid, spindle-shaped, hypoechoic with regular borders, and exhibited decreased vascularity. At first, the mass appeared to be of a muscular origin. There was not any clinical nor ultrasonic evidence of a primary breast tumor. On magnetic resonance imaging, the axillary mass was a well-defined with regular borders, measuring 24 × 35 mm. Needle biopsy showed a spindle cell tumor with mild to moderate atypia. The subsequent surgical resection revealed a spindle cell neoplasm within a lymph node, favoring a metastatic origin of the tumor. The tumor cells lacked expression of estrogen, progesterone, and HER2 receptors. PET-CT scan indicated pathological uptake in the left breast. Accordingly, the patient was diagnosed with metaplastic breast cancer that had metastasized to the axillary lymph node. She commenced a combined chemotherapy regimen of doxorubicin and cyclophosphamide. After six treatment cycles, she underwent left modified radical mastectomy with axillary lymph node dissection. Pathological examination of the specimens revealed a total burn-out tumor in the breast due to excellent treatment response. There were no residual tumor cells. All dissected lymph nodes were free of tumor. At the one-year follow-up, the patient showed no signs of tumor recurrence.

CONCLUSION

This report sheds light on a distinctive presentation of metaplastic breast carcinoma, emphasizing the need for vigilance in diagnosing this rare and aggressive breast cancer variant. In addition, the patient's remarkable response to chemotherapy highlights potential treatment avenues for metaplastic breast cancer.

Translational Aspects in Metaplastic Breast Carcinoma

Breast cancer is the most common cancer among women. Metaplastic breast carcinoma (MpBC) is a rare, heterogeneous group of invasive breast carcinomas, which are classified as predominantly triple-negative breast carcinomas (TNBCs; HR-negative/HER2-negative). Histologically, MpBC is classified into six subtypes. Two of these are considered low-grade and the others are high-grade. MpBCs seem to be more aggressive, less responsive to neoadjuvant chemotherapy, and have higher rates of chemoresistance than other TNBCs. MpBCs have a lower survival rate than expected for TNBCs. MpBC treatment represents a challenge, leading to a thorough exploration of the tumor immune microenvironment, which has recently opened the possibility of new therapeutic strategies. The epithelial-mesenchymal transition in MpBC is characterized by the loss of intercellular adhesion, downregulation of epithelial markers, underexpression of genes with biological epithelial functions, upregulation of mesenchymal markers, overexpression of genes with biological mesenchymal functions, acquisition of fibroblast-like (spindle) morphology, cytoskeleton reorganization, increased motility, invasiveness, and metastatic capabilities. This article reviews and summarizes the current knowledge and translational aspects of MpBC.

A Single-Center 18-Year Series of 73 Cases of Metaplastic Carcinoma of the Breast

Aim

To examine the clinical management of metaplastic breast cancer (MeBC), particularly the role of chemotherapy.

Methods

This retrospective study included patients with MeBC (n = 73) from a tertiary breast cancer center: the "Centre des Maladies du Sein of the CHU de Québec-Université Laval." The specimens were reviewed by two pathologists. Patient and tumor characteristics, systemic therapy (neoadjuvant and adjuvant), disease-free survival (DFS), and overall survival (OS) were recorded.

Results

The median follow-up was 57.2 months. The mean tumor size was 39.5 ± 32.1 (range, 1-200) mm. Most were in grade 3 (75.3%), without evidence of clinical nodal involvement (75.3%), and triple-negative (79.5%). Chemotherapy was given to 49 (67.1%) patients. Thirty-seven patients (50.7%) underwent a mastectomy, and 22/37 (59.5%) received radiotherapy. Adjuvant chemotherapy was given to 36 patients (49.3%), and nine (12.3%) patients were treated with neoadjuvant chemotherapy. The 5-year OS and DFS rates were 60.2% and 66.8%. Among the nine patients who received neoadjuvant chemotherapy, three (33.3%) achieved a partial response, three (33.3%) had stable disease, and three (33.3%) had disease progression. The use of chemotherapy, especially in the adjuvant setting, had a significant positive effect on 5-year OS (P=0.003) and 5-year DFS (P=0.004). Nodal involvement was associated with worse OS (P=0.049) but similar DFS (P=0.157). Lumpectomy was associated with better 5-year OS (P < 0.0001) and DFS (P=0.0002) compared with mastectomy.

Conclusion

MeBC represents a rare heterogeneous group of malignancies with poor prognosis. Adjuvant chemotherapy was associated with improved OS and DFS. Patients should be carefully selected for neoadjuvant chemotherapy.

Evaluation of immune density, PD-L1, and CXCR4 expressions in metaplastic breast carcinoma to predict potential immunotherapy benefit

Metaplastic breast carcinoma (MBC) -rare but fatal subtype of invasive breast carcinomas- provides limited benefit from conventional triple-negative breast carcinoma chemotherapy. We aimed to determine the immune density of this tumor and to evaluate of programmed death-ligand 1 (PD-L1) and chemokine receptor type 4 (CXCR4) expressions to determine whether it would benefit from immunotherapy. Clinicopathological characteristics of 85 patients diagnosed as MBC between 1997 and 2017 were retrospectively assessed. We evaluated the immunohistochemical expression of PD-L1 and CXCR4, and the extent of tumour infiltrating lymphocytes (TILs), with survival data. TILs groups were statistically significantly associated with lymph node status, histological subtype, squamous component, local recurrence and/or systemic metastasis, and disease-related deaths (p < 0.05). PD-L1 positivity in immune cells (ICs) has a statistically significant relationship with the presence of squamous component (p = 0.011) and HER2 positivity (p = 0.031). PD-L1 positivity in tumor cells (TCs) was found to be significantly more frequent in high-TILs density (p = 0.003). PD-L1 combined positive score was significantly associated with the tumors containing high-TILs density (p = 0.012) and squamous component (p = 0.035). Disease-free and disease-specific survival rates were found to be longer for the cases displaying PD-L1 positivity in ICs; and also PD-L1 positivity in ICs was found to be an independent prognostic factor. When the expression of CXCR4 was compared with clinicopathological and survival parameters, no statistically significant association was found (p > 0.05). Based on the results of this retrospective study, PD-L1 and TILs appear to be prognostic. This study provides rationale for further studies to determine whether a subset of patients with metaplastic breast cancer could derive a meaningful benefit from immune-targeting therapies.

Clinicopathological characteristics and prognosis of metaplastic breast cancer versus triple-negative invasive ductal carcinoma: a retrospective analysis

BACKGROUND

Metaplastic breast cancer(MBC) is a specific pathological type of invasive breast cancer. There are few studies related to MBC due to its rarity. This study aimed to analyse the differences in clinicopathological characteristics and prognosis between Metaplastic breast cancer and triple-negative invasive ductal carcinoma (TN-IDC).

METHODS

We retrospectively compared the clinicopathological characteristics of patients diagnosed with MBC and TN-IDC at the Fourth Hospital of Hebei Medical University between 2011 and 2020 in a 1:2 ratio. The log-rank test was used to compare the two groups' disease-free survival (DFS) and overall survival (OS). For MBCs, we performed univariate and multivariate analyses using the Cox proportional hazards model to determine the characteristics that impacted OS and DFS.

RESULTS

A total of 81 patients with MBC and 162 patients with TN-IDC were included in this study. At initial diagnosis, MBC patients had larger tumour diameters(P = 0.03) and fewer positive lymph nodes (P = 0.04). Patients with MBC were more likely to have organ metastases after surgery (P = 0.03). Despite receiving the same treatment, MBC patients had worse DFS (HR = 1.66, 95%CI 0.90-3.08, P = 0.11) and OS (HR = 1.98, 95% CI 1.03-3.81, P = 0.04), and OS was statistically significant. Positive lymph nodes at initial diagnosis were associated with worse DFS (HR = 3.98, 95%CI 1.05-15.12, P = 0.04) and OS (HR = 3.70, 95%CI 1.03-13.34, P = 0.04) for patients with MBC. The efficacy of platinum-based agents is insensitive for MBC patients receiving chemotherapy. In addition, patients treated with preoperative chemotherapy had worse DFS compared to patients treated with postoperative chemotherapy (HR = 3.51, 95%CI 1.05-11.75, P = 0.04).

CONCLUSIONS

The clinicopathological characteristics and prognosis of MBC and TN-IDC differ in many ways. Further studies are required to determine suitable treatment guidelines for patients with MBC.

Metaplastic breast carcinoma with osseous differentiation: A report of a rare case and literature review

Metaplastic matrix-producing breast carcinoma is a type of metaplastic breast carcinoma (MBC), which is a rare malignancy, accounting for 0.2-1% of breast carcinomas. A 52-year-old female visited a hospital because of a palpable painless mass in the right breast and was diagnosed with Breast Imaging Reporting and Data System (BI-RADS) category 4A via ultrasound (US) with a suspected positive lymph node at the right axillary region. Excision of the breast mass was performed and histopathologically confirmed that it was MBC with osseous differentiation. No distant metastasis was revealed before a modified radical mastectomy; however, metastasis to a lymph node of the right axillary region was observed (1/22). She received six cycles of TEC scheme chemotherapy (docetaxel, epirubicin, and cyclophosphamide, 21 days) and 5 weeks of radiotherapy (48 Gy/25 f/5 days a week), but without any follow-up examinations since radiotherapy. Twenty-four months after surgery, distant metastases to lungs and liver were confirmed and died 3 months later. This case provides valuable information for clinicians on MBC and suggests that further examination or biopsy should be performed to US BI-RADS 4A masses before surgery. In addition, regular postoperative follow-up plays important roles in detecting metastases early and improving prognosis.

Rare subtypes of triple negative breast cancer: Current understanding and future directions

Rare subtypes of triple-negative breast cancers (TNBC) are a heterogenous group of tumors, comprising 5-10% of all TNBCs. Despite accounting for an absolute number of cases in aggregate approaching that of other less common, but well studied solid tumors, rare subtypes of triple-negative disease remain understudied. Low prevalence, diagnostic challenges and overlapping diagnoses have hindered consistent categorization of these breast cancers. Here we review epidemiology, histology and clinical and molecular characteristics of metaplastic, triple-negative lobular, apocrine, adenoid cystic, secretory and high-grade neuroendocrine TNBCs. Medullary pattern invasive ductal carcinoma no special type, which until recently was a considered a distinct subtype, is also discussed. With this background, we review how applying biological principals often applied to study TNBC no special type could improve our understanding of rare TNBCs. These could include the utilization of targeted molecular approaches or disease agnostic tools such as tumor mutational burden or germline mutation-directed treatments. Burgeoning data also suggest that pathologic response to neoadjuvant therapy and circulating tumor DNA have value in understanding rare subtypes of TNBC. Finally, we discuss a framework for advancing disease-specific knowledge in this space. While the conduct of randomized trials in rare TNBC subtypes has been challenging, re-envisioning trial design and technologic tools may offer new opportunities. These include embedding rare TNBC subtypes in umbrella studies of rare tumors, retrospective review of contemporary trials, prospective identification of patients with rare TNBC subtypes entering on clinical trials and querying big data for outcomes of patients with rare breast tumors.

Metaplastic carcinoma of the breast: matched cohort analysis of recurrence and survival

PURPOSE

Metaplastic breast carcinoma (MBC) is a rare subtype of breast cancer, defined as mammary carcinoma with squamous or mesenchymal differentiation, that may include spindle cell, chondroid, osseous, or rhabdomyoid differentiation patterns. The implications of MBC recurrence and survival outcomes remains unclear.

METHODS

Cases were ascertained from a prospectively maintained institutional database of patients treated from 1998 to 2015. Patients with MBC were matched 1:1 to non-MBC cases. Cox proportional-hazards models and Kaplan-Meier estimates were used to evaluate outcome differences between cohorts.

RESULTS

111 patients with MBC were matched 1:1 with non-MBC patients from an initial set of 2400 patients. Median follow-up time was 8 years. Most patients with MBC received chemotherapy (88%) and radiotherapy (71%). On univariate competing risk regression, MBC was not associated with locoregional recurrence (HR = 1.08; p = 0.8), distant recurrence (HR = 1.65; p = 0.092); disease-free survival (HR = 1.52; p = 0.065), or overall survival (HR = 1.56; p = 0.1). Absolute differences were noted in 8-year disease-free survival (49.6% MBC vs 66.4% non-MBC) and overall survival (61.3% MBC vs 74.4% non-MBC), though neither of these reached statistical significance (p = 0.07 and 0.11, respectively).

CONCLUSION

Appropriately-treated MBC may exhibit recurrence and survival outcomes that are difficult to distinguish from those of non-MBC. While prior studies suggest that MBC has a worse natural history than non-MBC triple-negative breast cancer, prudent use of chemotherapy and radiotherapy may narrow these differences, although studies with more power will be required to inform clinical management. Longer follow-up among larger populations may further elucidate the clinical and therapeutic implications of MBC.

Metaplastic Breast Carcinoma in U.S. Population: Racial Disparities, Survival Benefit of Adjuvant Chemoradiation and Future Personalized Treatment with Genomic Landscape

PURPOSE

In this population-based study, we aim to identify factors that are influential on the survival outcome in MBC and investigate novel molecular approaches in personalized disease management.

METHODS

The data of this study were collected from the SEER database from 2000-2018. A total of 5315 cases were extracted from the database. The data were evaluated for demographics, tumor characteristics, metastasis, and treatment. Survival analysis was completed by using SAS software for multivariate analysis, univariate analysis, and non-parametric survival analysis. The molecular data with the most common mutations in MBC were extracted from the Catalogue of Somatic Mutations in Cancer (COSMIC) database.

RESULTS

The mean age at the time of presentation was 63.1 with a standard deviation (SD) of 14.2 years. Most patients were White (77.3%) with 15.7% Black patients, 6.1% Asian or Pacific Islander, and 0.5% American Indian. Histologically, most of the reported tumors were grade III (74.4%); 37% of the cases were triple negative (ER-, PR- and HER2-), whereas the hormone status was unknown in 46% of the cases. Spread was localized in 67.3% of patients while 26.3% had regional spread and 6.3% had distant metastases. Most tumors were unilateral (99.9%) and between 20-50 mm in size (50.6%). The lungs were the most common site for distant metastasis at diagnosis (3.42%) followed by bone (1.94%), liver (0.98%), and brain (0.56%). A combination of surgery, chemotherapy, and radiation therapy was the most common treatment with a cause-specific survival rate of 78.1% (95% CI = 75.4-80.4). The overall survival rate at 5 years was 63.6% (95% confidence interval (CI) = 62.0-65.1) with a cause-specific survival of 71.1% (95% CI = 69.5-72.6). Cause-specific survival was found to be 63.2% (95% CI = 58.9-67.1) in Black patients as compared to 72.4% (95% CI = 70.1-74.1) in White patients. Black patients also presented with higher rates of grade III disease, distant metastasis, and larger tumor size. On multivariate analysis, age > 60, grade III+, metastasis, and tumor size > 50 mm were associated with worse survival. The most common mutations in MBC identified in COSMIC data were TP53, PIK3CA, LRP1B, PTEN, and KMT2C.

CONCLUSION

Though rare, MBC is aggressive, with poor prognosis associated with high-grade tumors, metastasis, tumor size over 50 mm, and advanced age at the time of presentation. Overall, Black women had worse clinical outcomes. MBC is difficult to treat and carries a poor prognosis that affects various races disproportionately. Continued enhancement of treatment strategies to foster more individualized care as well as continued enrollment in clinical trials are needed to improve outcomes among patients with MBC.

Cavitary lung metastases of mixed metaplastic breast cancer mimicking aspergilloma

We report a case of a 57-year-old woman with pulmonary metastasis of breast cancer presenting with a characteristic cavitary shadow resembling aspergilloma. The primary tumor and metastases showed multiple histopathologic components, including squamous cell carcinoma. Although a fungal ball-like shadow may indicate the presence of a pulmonary aspergilloma, a comprehensive examination, including bronchoscopy, should be considered.

TROP2, androgen receptor, and PD-L1 status in histological subtypes of high-grade metaplastic breast carcinomas

AIMS

High-grade metaplastic breast carcinoma (HG-MBC) is a rare subtype of invasive breast carcinoma, mostly triple-negative. Metaplastic carcinomas are less responsive to neoadjuvant chemotherapy and are associated with a worse outcome than invasive carcinomas of no special type.

METHODS

Clinicopathological characteristics and immunophenotype were retrospectively assessed in a series of 65 patients diagnosed with HG-MBC between 2005 and 2017 at the Curie Institute (antibody panel: oestrogen receptor [ER], progesterone receptor [PR], androgen receptor [AR], human epidermal growth factor receptor 2 [HER2], programmed death ligand-1 [PD-L1], and trophoblast cell surface antigen 2 [TROP2]).

RESULTS

The median age at diagnosis was 59.5 years. Six (9%) patients had metastatic disease at diagnosis. Among the nonmetastatic patients receiving neoadjuvant therapy, 26% (5/19) achieved pathological complete response. Most tumours were pT1/pT2 (77%) and 12% were pN+. Histological subtypes (mixed, squamous, mesenchymal, and spindle cell) were 40%, 35.5%, 15.5%, and 9%, respectively. Tumour-infiltrating lymphocytes were low or moderate except when squamous differentiation was present. Most tumours were triple-negative (92%). AR and TROP2 were positive in 34% and 85% of the cases, respectively. PD-L1 was positive in tumour cells in 18% (cutoff: 1% of positive tumour cells) of the cases and in tumour-infiltrating immune cells in 40% (cutoff: 1% of tumour area) of the cases. Notably, spindle cell and mesenchymal metaplastic breast carcinomas were mostly PDL1-negative. Lastly, 21 (32.3%) cases were HER2-low, all being HER2 1+, with no HER2 2+.

CONCLUSION

Metaplastic breast carcinoma could benefit from tailored therapeutic strategies adapted to the phenotypic specificities of histological subtypes.

Clinical Characteristics and Prognosis of Metaplastic Breast Cancer Compared with Invasive Ductal Carcinoma: A Propensity-Matched Analysis

BACKGROUND

Metaplastic breast cancer (MpBC) is an aggressive histologic type of breast cancer. Although MpBC has a poor prognosis and is responsible for a large proportion of breast cancer mortalities, the clinical features of MpBC compared with invasive ductal carcinoma (IDC) are not well known, and the optimal treatment has not been identified.

METHODS

We retrospectively reviewed medical records of 155 MpBC patients and 16,251 IDC cases who underwent breast cancer surgery in a single institution between January 1994 and December 2019. The two groups were matched 1:4 by age, tumor size, nodal status, hormonal receptor status, and HER2 status using propensity-score matching (PSM). Finally, 120 MpBC patients were matched with 478 IDC patients. Disease-free survival and overall survival of MpBC and IDC patients both before and after PSM were analyzed by Kaplan-Meier survival, and multivariable Cox regression analysis was performed to identify variables affecting long-term prognosis.

RESULTS

The most common subtype of MpBC was triple-negative breast cancer, and nuclear and histologic grades were higher than those of IDC. Pathologic nodal staging of the metaplastic group was significantly lower than that of the ductal group, and more frequent adjuvant chemotherapy was performed in the metaplastic group. Multivariable Cox regression analysis indicated that MpBC was an independent prognostic factor for disease-free survival (HR = 2.240; 95% CI, 1.476-3.399, p = 0.0002) and overall survival (HR = 1.969; 95% CI, 1.147-3.382, p = 0.0140). However, survival analysis revealed no significant difference between MpBC and IDC patients in disease-free survival (HR = 1.465; 95% CI, 0.882-2.432, p = 0.1398) or overall survival (hazard ratio (HR) = 1.542; 95% confidential interval (CI), 0.875-2.718, p = 0.1340) after PSM.

CONCLUSION

Although the MpBC histologic type had poor prognostic factors compared with IDC, it can be treated according to the same principles as aggressive IDC.

Metastatic Metaplastic Breast Cancer Successfully Treated with Adriamycin and Cisplatin

Metaplastic breast cancer (MBC) is characterized by the histological presence of a mixture of epithelial and mesenchymal-like elements. However, MBC responds poorly to chemotherapy. Due to its rarity, there is no well-defined treatment for MBC. Herein, we report the case of a 56-year-old woman who underwent a mastectomy and was diagnosed with MBC with osseous differentiation classified as pT4N0M1. After the operation, she was treated with adriamycin and cisplatin, which are standard osteosarcoma treatments, resulting in a partial response. However, to determine the proper chemotherapy treatment, knowledge of the metaplastic elements of the tumor is required.

Metaplastic breast cancer: A review

Metaplastic breast cancer (MpBC) is an uncommon aggressive malignancy that is associated with a poor prognosis. Due to its rarity, the relationships between the clinical and pathological features of MpBC, treatment approach, and clinical outcomes remain underexplored. In the following review article, we synthesize the existing data on the clinical, pathological and genomic features, management, and outcomes of MpBC. We also identify potential targets for future clinical trials.

Metaplastic Breast Cancer: Mesenchymal Subtype Has Worse Survival Outcomes

Background

Metaplastic breast carcinoma (MBC) is a rare type of breast cancer that accounts for 0.2-1% of all breast cancers. To date, there are only few institutional studies comparing survival rates between different subtypes. In this retrospective cohort study, we aim to evaluate factors effecting survival rates of different subtypes of MBC.

Methods

This retrospective cohort study observed 118 nonmetastatic MBC patient records extracted from 15,244 breast cancer cases between December 2000 and December 2020. In order to analyze factors effecting survival rates of mesenchymal subtype of MBC, all cases are classified as mesenchymal (n = 45) and other (n = 48). Twenty-five cases could not be sub-classified due to the missing data. Univariate and multivariate logistic regression analyses were performed to define factors associated with survival rates.

Results

Of the 15,244 cases, 118 (0.8%) were nonmetastatic MBC. 105 were triple negative and 12 were nonluminal HER2. There was no significant difference between mesenchymal and other subgroups for age, median tumor size, AJCC staging, and type of surgery. Of the five local recurrences with known subgroup, four of them had mesenchymal subtype. It is demonstrated that mesenchymal subtype was significantly associated with worse 5-year disease-free survival and disease-specific survival (HR: 2.35 [1.01-5.48], p = 0.049, and HR: 3.16 [1.06-9.47], p = 0.040 with 95% CI, respectively).

Conclusion

This study is one of the few studies presenting the survival outcomes of subtypes of MBCs. Nonetheless, it is the only study demonstrating that mesenchymal subtype had worse survival outcomes. Further studies are needed to determine the outcome of different subtypes of MBCs.

Metaplastic Breast Cancer: Characteristics and Survival Outcomes

Objectives

Metaplastic breast cancer (MBC) is a rare neoplasm accounting for <1% of all breast cancer. We evaluated the clinical characteristics and survival outcomes of MBC.

Methods

Patients diagnosed with pathologically proven MBC were reviewed from the institutional breast cancer database from 2000 to 2017.

Results

A total of 136 patients diagnosed with MBC were included in the study. The median age of the diagnosis was 60 years, and 60% of patients were stage II at diagnosis, and 22% were stage III. About two-thirds of the patients were triple-negative; 93% had nuclear grade III, and 25% had a lymphovascular invasion. Squamous differentiation (29%) was the most common histologic subtype, followed by the spindle subtype (21%). The most common distant metastases were lung (22%), followed by bone (13%). Moreover, 60% had a mastectomy, 19% had endocrine therapy, 58% had radiation, 51% received anthracycline-based chemotherapy, 26% had non-anthracycline chemotherapy, and 22% received no chemotherapy. In the entire cohort, the two-year overall survival (OS) and five-year OS were 79% and 69%, respectively, and the two-year progression-free survival (PFS) and five-year PFS were 72% and 61%, respectively. On multivariable analysis, the stage of MBC (stage III: hazard ratio (HR), 5.065 (95% confidence interval (CI), 1.02-25.27) (p=0.048)), poor functional status (Eastern Cooperative Oncology Group (ECOG) score, 2; HR, 24.736 (95% CI, 1.92-318.73) (p=0.014)), and distant metastasis to the brain (HR, 8.453 (95% CI, 1.88-38.04) (p=0.005)) and lung (HR, 42.102 (95% CI, 7.20-246.36) (p<0.001)) were significant predictors of decreased OS.

Conclusions

MBC demonstrated early disease progression and poor overall survival. The stage of MBC, decreased performance status, and metastasis to the lung and brain were independent poor prognostic factors.

The Effect of Post-Mastectomy Radiotherapy in Patients With Metaplastic Breast Cancer: A Propensity Score-Matched Analysis of the SEER Database

Background

Metaplastic breast cancer (MBC) is a rare tumor with aggressive biological behavior. This study aimed to evaluate the efficacy of post-mastectomy radiotherapy (PMRT) on patients with low-risk (T1N0M0), intermediate-risk (T1-2N1M0 and T3N0M0), and high-risk (T1-4N2-3M0 and T4N0-1M0) MBC via propensity-score matching (PSM).

Methods

We analyzed information from the Surveillance, Epidemiology, and End Results (SEER) public-use database from 1975 to 2016 for MBC incidence trends and compared overall survival (OS) and breast cancer-specific survival (BCSS) between groups of MBC women diagnosed from 2001 to 2016 using Kaplan–Meier analysis and the multivariate Cox proportional model. PSM was used to make 1:1 case–control matching.

Results

Joinpoint analyses identified 1984 and 2003 as the inflection points among 4,672 patients. 1,588 (42.4%) of the 3,748 patients diagnosed with MBC between 2001 and 2016 received PMRT. According to multivariate analyses, PMRT provided better OS (p < 0.001) and BCSS (p < 0.001) before PSM, and better prognosis after PSM (n = 2528) for patients receiving PMRT (n = 1264) compared to those without PMRT (OS, p < 0.001 and BCSS, p < 0.001). When stratifying the case–control matching patients into low-risk, intermediate-risk, and high-risk groups, PMRT could improve BCSS compared with that in non-PMRT patients in the high-risk groups; it also improved OS in both the intermediate- and high-risk groups.

Conclusions

Per findings of the PSM analysis, PMRT could provide better BCSS in high-risk groups, and better OS in intermediate- and high-risk groups.

Chemotherapy significantly improves long-term survival of small lesion node negative metaplastic breast carcinoma in T1c population rather than T1a and T1b

Metaplastic breast carcinoma (MpBC) is considered a highly aggressive disease, the outcome of chemotherapy on small lesions (T1abcN0M0) MpBC patients remain unclear. We identified 890 female MpBC patients in the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2016. After propensity score matching (PSM), 584 patients were matched. Survival probability was compared among T1a, T1b, and T1c patients and between patients with and without chemotherapy using Kaplan-Meier analysis and Cox proportional hazard analysis. Significance was set at two-sided P < 0.05. We classified 49, 166, and 675 patients as T1a, T1b, and T1c MpBC, respectively. The chemotherapy group included 404 patients (45.4%). Following PSM, survival analysis indicated that the patients who underwent chemotherapy had higher OS (P = 0.0002) and BCSS (P = 0.0276) in the T1c substage, but no significant difference was detected in T1a or T1b patients. In this population-based study, small lesion MpBC showed a favorable prognosis. Chemotherapy improved the prognosis of T1c MpBC patients but not T1a and T1b patients to a beneficial extent. Our findings may offer novel insight into a therapeutic strategy for MpBC.

The Effect of HER2 Status on Metaplastic Breast Cancer A Propensity Score-Matched Analysis

BACKGROUND

The role of human epidermal growth factor receptor 2 (HER2) in metaplastic breast cancer (MBC) patients remains unclear. The present study aimed to evaluate the effect of HER2 status on MBC patients by propensity-score matching (PSM).

METHODS

The SEER data from 2010 to 2016 were extracted. The breast cancer-specific survival (BCSS) of MBC patients, diagnosed from 2001 to 2016, was compared using Kaplan-Meier analysis. The multivariate Cox proportional model between groups was performed. PSM was used to make 1:1 case-control matching.

RESULTS

We included 1887 patients with a median follow-up time of 28 months (range 1-83 months). 1749 (92.7%) and 138 (7.3%) patients presented in the HER2-negative group and HER2-positive group. 833 (44.1%) patients received post-mastectomy radiotherapy (PMRT). The HER2-positive group had younger patients, lower tumor grades, and more advanced tumor stages. The prognoses were related to age of diagnosis, race/ethnicity, TNM stage, and PMRT in multivariate Cox analysis. ER status and HER2 status had no impact on BCSS. In the Kaplan-Meier analysis, PMRT was associated with a better prognosis. Importantly, patients with HER2-negative status can benefit from PMRT, but not those with HER2-positive status. After PSM, on multivariate Cox analysis, the prognosis was related to HER2 status and PMRT. In the Kaplan-Meier analysis, PMRT was related to a better prognosis for HER2-negative patients.

CONCLUSIONS

Our findings supported that PMRT and HER2-positive status were associated with a better prognosis after PSM. However, HER2-negative, but not HER2-positive patients could benefit from PMRT.

Presentation and survival by hormonal receptor status in metaplastic breast cancer: A propensity score-matched analysis

Background

Metaplastic breast cancer (MBC) is a rare and aggressive form of breast cancer. The effectiveness of chemotherapy (CT) for MBC remains controversial. The present study aimed to evaluate the efficacy of CT combined hormone receptor (HR) status on MBC patients with high risk (T1-4N2-3M0 and T4N0-1M0) by propensity-score matching (PSM).

Methods

A retrospective study was performed to analyze MBC from the SEER database. Breast cancer-specific survival (BCSS) was analyzed using the Kaplan–Meier curve. Cox proportional hazard models were used to assess BCSS. PSM was used to make 1:1 case-control matching.

Results

This study identified 3116 patients. The median follow-up time was 44 months (range, 1–321 months). About 62.5 % of patients received CT. 23.0 % of patients were HR-positive. Recurrence risk had a significant difference between the HR-negative and HR-positive groups. In the multivariable Cox regression model, CT had no benefit for MBC patients. HR status was not associated with a better prognosis. In subgroup analysis, the Kaplan–Meier analysis showed that HR-negative MBC with intermediate-risk benefited from CT. For HR-positive MBC, patients with intermediate and high risk also benefited from CT. After PSM, neither CT nor HR status was not related to better BCSS. Moreover, the use of CT could only improve the survival of HR-positive MBC patients with high risk.

Conclusion

PSM analysis showed that HR status was not associated with a better prognosis. CT was not a significant prognostic factor for prognosis. However, HR-positive MBC patients with high risk might benefit from CT.

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Metaplastic breast cancer (MBC) is a rare and aggressive form of breast cancer.

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Hormone receptor (HR) status was not associated with a better prognosis.

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Chemotherapy (CT) was not a significant prognostic factor for prognosis.

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HR-positive MBC patients with high risk might benefit from CT.

Long non-coding RNAs as the critical regulators of doxorubicin resistance in tumor cells

Resistance against conventional chemotherapeutic agents is one of the main reasons for tumor relapse and poor clinical outcomes in cancer patients. Various mechanisms are associated with drug resistance, including drug efflux, cell cycle, DNA repair and apoptosis. Doxorubicin (DOX) is a widely used first-line anti-cancer drug that functions as a DNA topoisomerase II inhibitor. However, DOX resistance has emerged as a large hurdle in efficient tumor therapy. Furthermore, despite its wide clinical application, DOX is a double-edged sword: it can damage normal tissues and affect the quality of patients’ lives during and after treatment. It is essential to clarify the molecular basis of DOX resistance to support the development of novel therapeutic modalities with fewer and/or lower-impact side effects in cancer patients. Long non-coding RNAs (lncRNAs) have critical roles in the drug resistance of various tumors. In this review, we summarize the state of knowledge on all the lncRNAs associated with DOX resistance. The majority are involved in promoting DOX resistance. This review paves the way to introducing an lncRNA panel marker for the prediction of the DOX response and clinical outcomes for cancer patients.

Metaplastic carcinoma of the breast: Clinicopathological features and treatment outcomes with long-term follow up

Metaplastic breast carcinoma is an uncommon subtype of invasive ductal carcinoma with a tendency towards poorer clinical outcomes. Following ethical approval, the current study reviewed the institutional records of ~2,500 women with breast cancer. A total of 14 cases of metaplastic breast cancer were reviewed for management and treatment outcomes. The results demonstrated that patients had median follow up of 30 months, a 5-year disease-free survival of 57.1% and 5-year overall survival of 57.1%. The majority of patients had at least T2 disease and all tumours were high grade. Additionally, most patients were triple negative and nodal metastases were uncommon. Metaplastic breast cancer is an aggressive variant of invasive breast cancer. Most patients can be treated with breast conservation and survival parameters tend to be worse than more common breast cancer subtypes.

Durable Response to PD1 Inhibitor Pembrolizumab in a Metastatic, Metaplastic Breast Cancer

Metaplastic breast cancer (MBC) is a rare and aggressive subtype of breast cancer. Tumor characteristics typically feature estrogen receptor, progesterone receptor, and HER2-negative, triple-negative breast cancer (TNBC), with a poorer prognosis relative to pure invasive ductal or lobular disease. Resistance to chemotherapy often leads to local recurrence and distant metastasis. Genomic profiling has identified multiple molecular abnormalities that may translate to targetable therapies in MBC. These tumors are known to display higher PD-L1 expressivity than other subtypes of breast cancer, and disease control with pembrolizumab and chemotherapy has been documented. We identify a patient with metastatic, metaplastic TNBC, with mesenchymal components and osseous differentiation, who completed 2 years of pembrolizumab treatment and has remained without evidence of disease after 32 months of observation, while maintaining good quality of life. Future efforts should focus on immunotherapy response with respect to the various subtypes of MBC, and treatment should continue to be incorporated in clinical trials to maximize disease response.

A Case Series of Metastatic Metaplastic Breast Carcinoma Treated With Anti-PD-1 Therapy

Metaplastic breast cancer is a rare and often chemo-refractory subtype of breast cancer with poor prognosis and limited treatment options. Recent studies have reported overexpression of programmed death ligand 1 (PD-L1) in metaplastic breast cancers, and there are several reports of anti-PD-1/L1 being potentially active in this disease. In this case series, we present 5 patients with metastatic metaplastic breast cancer treated with anti-PD-1-based therapy at a single center, with 3 of 5 cases demonstrating a response to therapy, and one of the responding cases being a metaplastic lobular carcinoma with low-level hormone receptor expression. Cases were evaluated for PD-L1 expression, tumor infiltrating lymphocytes (TILs), DNA mutations, RNA sequencing, and T-cell receptor sequencing. Duration of the response in these cases was limited, in contrast to the more durable responses noted in other recently published reports.

Single Hormone Receptor-Positive Metaplastic Breast Cancer: Similar Outcome as Triple-Negative Subtype

Background

Metaplastic breast cancer (MBC) is a rare and aggressive subtype of the breast. To understand the characteristics and prognosis of single hormone receptor-positive (HR+) MBC (estrogen receptor-positive [ER+]/progesterone receptor-negative [PR-] and ER-/PR+), we compared these tumors to double HR+ tumors as well as HR- tumors.

Patients and Methods

The Surveillance, Epidemiology, and End Results database was used to analyze MBC between 1975 and 2016. The effect of HR status was evaluated using a multivariate Cox regression model.

Results

We included 3369 patients with a median follow-up time of 42 months (range 0-322 months). In this study, 280 (8.3%) cases were double HR+ tumors, 2597 (77.1%) were double HR- tumors, and 492 (14.6%) cases were single HR+ tumors, of which 159 (4.7%) cases were ER-/PR+ tumors and 333 (9.9%) were ER+/PR- tumors. On multivariate Cox analysis, the prognosis was related to age, race/ethnicity, tumor grade, TNM stage, and surgery. HR status remained no impact on breast cancer-specific survival (BCSS). In the Kaplan-Meier curve, HR status was not associated with better BCSS or overall survival (OS). In patients without HER2 overexpression, the BCSS and OS of ER+/PR- and ER-/PR+ tumors were not significantly different from that of ER-/PR- and ER+/PR+ tumors. The difference remains no significant in patients with HER2 overexpression.

Conclusions

In comparison with both ER-/PR- and ER+/PR+ tumors, we have identified clinically and biologically distinct features of single HR+ tumors. In patients with or without HER2 overexpression, the prognosis of single HR+ tumors was similar to ER-/PR- and ER+/PR+ tumors.

Metaplastic Breast Carcinoma: Experience of a Tertiary Cancer Center in the Middle East

Background:

Metaplastic breast cancer (MetBC) represents a therapeutic challenge. We evaluated the impact of clinicopathological characteristics and treatment modalities on outcomes among MetBC patients treated at our center.

Methods:

Women with stage I-III MetBC were reviewed from our database from 2005-2018. Kaplan-Meier method was used to calculate locoregional-failure-free survival (LRFFS), overall-survival (OS) and distant-metastases-free survival (DMFS). We assessed associations with survival outcomes by log-rank tests. Multivariate Cox proportional-hazards models were used to identify independent predictors of LRFFS, OS and DMFS.

Results:

81 patients were eligible for the study. Median age at diagnosis was 48 years. 90.1% had G-III tumors, 64.2% were pathologically node negative and lympho-vascular invasion (LVI) was absent in 72.8%. 67.8% were triple negative, and 7.4% were HER2-neu positive. Most (66.7%) patients underwent mastectomy. Free margins were achieved in the entire cohort, however, 17.3% had close margin (<2 mm). Almost all patients received chemotherapy. 75.3% received radiotherapy, 23.5% received hormonal therapy and 6.2% received Trastuzumab. With a median follow-up of 54 months, 18.5% developed loco-regional recurrence and 34.6% relapsed distally. Five-year OS was 66.0%. On multivariate analysis: adjuvant radiotherapy correlated with better OS (P < .0001), and tumor size >5 cm, nodal involvement and LVI correlated with worse OS, (P = .019, P = .021, P = .028, respectively). There were no survival differences with respect to age, triple negativity, and morphologic subtype.

Conclusion:

We report the largest single institutional series on MetBC in the Middle East region. MetBC confers worse survival outcomes, and more aggressive local and systemic treatment strategies should be investigated.

An Update on the Molecular Pathology of Metaplastic Breast Cancer

Metaplastic breast cancer (MpBC) is a fascinating morphologic sub-type of breast cancer, characterised by intra-tumoural heterogeneity. By definition, these tumors show regions of metaplasia that can present as spindle, squamous, chondroid or even osseous differentiation. MpBC are typically triple-negative, and are therefore not targetable with hormone therapy or anti-HER2 therapies, leaving only chemotherapeutics for management. MpBC are known for their aggressive course and poor response to chemotherapy. We review herein the pathology and molecular landscape of MpBC and discuss opportunities for targetted therapies as well as immunotherapies.

Research on the Role of Combined Chemotherapy and Radiotherapy in Patients With N+ Non-Metastatic Metaplastic Breast Carcinoma: A Competing Risk Analysis Model Based on the SEER database, 2000 to 2015

Purpose

Due to the rarity of metaplastic breast carcinoma (MpBC), no randomized trials have investigated the role of combined chemotherapy and radiotherapy (CCRP) in this condition. We aimed to explore and identify the effectiveness of CCRP in patients with regional lymph node metastasis (N+) non-metastatic MpBC.

Materials and Methods

Data were obtained from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) Program database. We assessed the effects of CCRP on overall survival (OS), breast cancer-specific survival (BCSS), and breast cancer-specific death (BCSD) using Kaplan-Meier analysis, competing risk model analysis, and competing risk regression mode analysis.

Results

A total of 707 women and 361 death cases were included in the unmatched cohort, of which 76.45% (276/361) were BCSD, and 23.55% (85/361) were non-breast cancer-specific deaths (non-BCSD). Both the ChemT and CCRP groups had better OS (ChemT group: HR: 0.59, 95% CI: 0.45–0.78, P<0.001; CCRP group: HR: 0.31, 95% CI: 0.23–0.41, P<0.001) and BCSS (ChemT group: HR: 0.63, 95% CI: 0.45–0.87, P<0.001; CCRP group: HR: 0.32, 95%CI: 0.22–0.46, P<0.001) than the non-therapy group. Subjects in the CCRP group tended to have significantly lower cumulative BCSD (Gray’s test, P=0.001) and non-BCSD (Gray’s test, P<0.001) than the non-therapy group or ChemT group. In competing risk regression model analysis, subjects in the CCRP group had a better prognosis in BCSD (HR: 0.710, 95% CI: 0.508–0.993, P=0.045) rather than the ChemT group (HR: 1.081, 95% CI: 0.761–1.535, P=0.660) than the non-therapy group.

Conclusion

Our study demonstrated that CCRP could significantly decrease the risk of death for both BCSD and non-BCSD and provided a valid therapeutic strategy for patients with N+ non-metastatic MpBC.

Recent Discoveries of Macromolecule- and Cell-Based Biomarkers and Therapeutic Implications in Breast Cancer

Breast cancer is the most commonly diagnosed cancer type and the leading cause of cancer-related mortality in women worldwide. Breast cancer is fairly heterogeneous and reveals six molecular subtypes: luminal A, luminal B, HER2+, basal-like subtype (ER−, PR−, and HER2−), normal breast-like, and claudin-low. Breast cancer screening and early diagnosis play critical roles in improving therapeutic outcomes and prognosis. Mammography is currently the main commercially available detection method for breast cancer; however, it has numerous limitations. Therefore, reliable noninvasive diagnostic and prognostic biomarkers are required. Biomarkers used in cancer range from macromolecules, such as DNA, RNA, and proteins, to whole cells. Biomarkers for cancer risk, diagnosis, proliferation, metastasis, drug resistance, and prognosis have been identified in breast cancer. In addition, there is currently a greater demand for personalized or precise treatments; moreover, the identification of novel biomarkers to further the development of new drugs is urgently needed. In this review, we summarize and focus on the recent discoveries of promising macromolecules and cell-based biomarkers for the diagnosis and prognosis of breast cancer and provide implications for therapeutic strategies.

The longitudinal risk of mortality between invasive ductal carcinoma and metaplastic breast carcinoma

The management of metaplastic breast carcinoma (MBC) has largely paralleled the paradigms used for invasive ductal carcinoma (IDC) in the current National Comprehensive Cancer Network guidelines of breast cancer. However, patients with IDC and MBC have been shown to have a different prognosis, and there are significant differences in risk and failure patterns after treatment. The purpose of this study was to compare breast cancer specific survival (BCSS) and hazard function between IDC and MBC. We included patients from the Surveillance, Epidemiology, and End Results program with stage I-III IDC and MBC between 2000 and 2012. Statistical analyses were including chi-square analysis, life-table methods, multivariate Cox proportional hazards models, and propensity score matching (PSM). We identified 294,719 patients; 293,199 patients with IDC and 1520 patients with MBC. Multivariate analyses showed that the MBC subtype had significantly lower BCSS than the IDC subtype before and after PSM (p < 0.001). There were significant differences in the hazard curve between IDC and MBC. The hazard curve for breast cancer mortality in the IDC cohort peaked at 3 years (2%), and then changed to a slowly decreasing plateau after prolonged follow up. However, the hazard curve for breast cancer mortality in the MBC cohort peaked at 2 years (7%), then declined sharply between 3 and 6 years, and changed to a low death rate after a follow-up time exceeding 6 years. Subgroup analyses revealed that the hazard curves significantly differed between IDC and MBC after stratifying by tumor stage and hormone receptor status. Our study suggests that patients with MBC should receive more effective systemic agents and intensive follow-up because of their significantly augmented risk of death compared to IDC patients.

Characteristics and prognosis of 17 special histologic subtypes of invasive breast cancers according to World Health Organization classification: comparative analysis to invasive carcinoma of no special type

BACKGROUND

Breast cancer is a heterogeneous disease with various histopathologic subtypes. Except for invasive carcinoma of no special type (NST), other subtypes are rare with limited data. The purpose of this study was to analyze the characteristics and prognosis of special histopathologic subtypes of breast cancer compared to NST.

METHODS

A total of 136,140 patients were analyzed using the Korean Breast Cancer Society Registry database between January 1996 and March 2019. The clinicopathologic features and survival outcomes of special type breast carcinoma were compared with those of NST.

RESULTS

The prevalence of special subtypes other than NST was 13.7% (n = 18,633). Compared to NST, patients with lobular, medullary, metaplastic, and micropapillary carcinoma had larger tumors (p < 0.001). Patients with mucinous, tubular, medullary, metaplastic, and cribriform carcinoma presented with less node metastasis (p < 0.001), contrary to patients with micropapillary carcinoma. Patients with lobular, mucinous, tubular, papillary, and cribriform carcinoma presented as luminal A subtype much more often (p < 0.001). Micropapillary carcinoma included more luminal B subtype (p < 0.001). Typically, medullary and metaplastic carcinoma included more triple-negative subtypes (p < 0.001). In survival analysis, only medullary (Hazard Ratio (HzR) 0.542, 95% CI 0.345 to 0.852, p = 0.008) and metaplastic carcinoma (HzR 1.655, 95% CI 1.317 to 2.080, p < 0.001) showed significantly different overall survival from NST by multivariate analysis.

CONCLUSION

Breast cancer had distinct clinicopathologic features according to histopathologic subtype. However, special types of breast cancer had similar survival outcomes compared to NST when adjusting for other prognostic factors, except for metaplastic carcinoma and medullary carcinoma.

Synchronous metaplastic breast carcinoma and lung adenocarcinoma: a rare case and review of the literature

Synchronous primary cancers occur in 1.7% of breast cancer cases and metaplastic breast cancer (MBC) occurs in less than 1% of breast cancer cases. We present a previously healthy 66-year-old woman diagnosed with MBC after surgical resection of a presumed cyst. A second primary cancer, multifocal lung adenocarcinoma, was discovered during the staging process for her MBC. Remarkably she had not experienced pulmonary or constitutional symptoms at the time of diagnosis. She received chemotherapy with paclitaxel and carboplatin, followed by immunotherapy with nivolumab. At 24 months of follow-up after her initial diagnosis, she was breast cancer-free with stable pulmonary nodules. This case highlights that rather than assuming multifocal lesions represent metastasis, biopsies should be considered as clinical management could be significantly altered in the presence of a synchronous cancer. Furthermore, platinum-based chemotherapy agents have potential to be considered in the treatment of MBC.

Controversies of radiation therapy omission in elderly women with early stage invasive breast cancer

Early stage invasive breast cancer is a disease that is prevalent in the elderly population. Data regarding radiation omission for elderly population is based on patients’ age. Given the increased life expectancy, data on individualizing treatment decisions based on multiple tumor and patient related factors other than age only is emerging. This review aims to analyze published data to provide clinicians with a general oversight on approaching this question.

miR-137 alleviates doxorubicin resistance in breast cancer through inhibition of epithelial-mesenchymal transition by targeting DUSP4

Acquired resistance to chemotherapy is a major obstacle in breast cancer (BC) treatment. Accumulated evidence has uncovered that microRNAs (miRNAs) are vital regulators of chemoresistance in cancer. Growing studies reveal that miR-137 acts as a suppressor in tumor progression. However, it remains obscure the role of miR-137 in modulating the sensitivity of BC cells to doxorubicin (DOX). In this study, we demonstrate that miR-137 exerts a significant effect on repressing the development of chemoresistance of BC cells in response to DOX via attenuating epithelial-mesenchymal transition (EMT) of tumor cells in vitro and in vivo. MiR-137 overexpression dramatically elevated the sensitivity of BC cells to DOX as well as impaired the DOX-promoted EMT of tumor cells. Mechanistically, miR-137 directly targeted dual-specificity phosphatase 4 (DUSP4) to impact on the EMT and chemoresistance of BC cells upon DOX treatment. Consistently, decreased DUSP4 efficiently enhanced the sensitivity of BC cells to DOX while overexpressed DUSP4 significantly diminished the beneficial effect of miR-137 on BC cells chemoresistance. Moreover, the increased miR-137 heightened the sensitivity of BC cells-derived tumors to DOX through targeting DUSP4 in vivo. Together, our results provide a novel insight into the DOX resistance of BC cells and miR-137 may serve as a new promising therapeutic target for overcoming chemoresistance in BC.

Comparison of outcomes between metaplastic and triple-negative breast cancer patients

Purpose

Metaplastic breast cancer (MBC) is a rare, aggressive variant of breast cancer that has been associated with poor clinical outcomes, as has triple-negative breast (TNBC) cancer. Limited studies compare the clinical characteristics and prognosis of MBC to TNBC. This study uses a large, contemporary US cancer database to compare clinical characteristics and survival outcomes for patients with MBC to those with TNBC.

Methods

The National Cancer Database was queried for women with cT1-4N1-3M0 MBC or TNBC diagnosed between 2004 and 2013 and treated with definitive surgery. Chi-squared analysis was performed to determine differences between the cohorts. Kaplan-Meier curves compared overall survival (OS), and Cox regression determined patient factors associated with OS.

Results

Altogether, 55,847 patients met the inclusion criteria; 50,705 (90.8%) had TNBC and 5,142 (9.2%) had MBC. Most patients had no comorbid conditions (82%), N0 disease (71%), poorly differentiated histology (77%), received chemotherapy (87%), and received radiation therapy (60%). Amongst all patients, patients with TNBC disease were observed to have greater OS than those with MBC (5-year OS 72.0% vs 55.8%, p < 0.001). The greater observed OS for patients with TNBC persisted when controlling for stage and when comparing propensity score matched cohorts. On Cox regression, lower age, T1 status, N0 status, chemotherapy, TNBC disease, and radiation therapy (RT) were associated with improved OS.

Conclusions

MBC had an association with poorer OS compared to TNBC, while RT and chemotherapy receipt were associated with improved OS for patients regardless of stage. Further studies are needed to corroborate the conclusions herein.

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Metaplastic breast cancer is associated with poor clinical outcomes.

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Metaplastic breast cancer associated with worse survival than patients with triple negative invasive ductal carcinoma.

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Radiation therapy and chemotherapy associated with improved survival for patients with metaplastic breast cancer.

Investigating the regulation mechanism of baicalin on triple negative breast cancer's biological network by a systematic biological strategy

OBJECTIVE

To investigate the regulation mechanism of baicalin on triple negative breast cancer (TNBC)'s biological network by a systematic biological strategy and cytology experiment.

METHODS

A systematic biological methodology is utilized to predict the potential targets of baicalin, collect the genes of TNBC, and analyze the TNBC and baicalin's network. After the systematic biological analysis is performed, the cytology experiment, real-time quantitative PCR (qPCR) is used to validate the key biological processes and signaling pathways.

RESULTS

After systematic biological analysis, two networks were constructed and analyzed: (1) TNBC network; (2) Baicalin-TNBC protein-protein interaction (PPI) network. Several TNBC-related, treatment-related targets, clusters, signaling pathways and biological processes were found. Cytology experiment shows that baicalin can inhibit the proliferation, migration and invasion of breast cancer MDA-MB-231 cells in vitro (P < 0.05). The results of qPCR showed that baicalin increase the expression of E-cadherin mRNA, and decrease the expression of vimentin, β-catenin, c-Myc and MMP-7 mRNA in LPS-induced breast cancer MDA-MB-231 cells (P < 0.05).

CONCLUSION

Baicalin may achieve anti-tumor effects through regulating the targets, biological processes and pathways found in this research.

Rare epithelial breast cancer: surgery and adjuvant therapy

Breast cancer is a heterogenous disease, exhibiting a wide range of morphological phenotypes shaping its prognosis and clinical course. However, optimal management of rarer breast cancer subtypes is often undefined and controversial in literature due to the lack of large studies and randomised trials. This review aims to discuss the treatment of 13 rare epithelial subtypes, focussing on surgery and adjuvant therapies.

The role of radiotherapy in metaplastic breast cancer: a propensity score-matched analysis of the SEER database

BACKGROUND

Only few studies, with small patient cohorts, have evaluated the effect of radiotherapy (RT) for metaplastic breast cancer (MBC). Hence, it is important to investigate the role of RT in MBC survival using a large population-database.

METHODS

A retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER) from 1973 to 2015 was performed. We compared MBC patients with or without RT for overall survival (OS) and breast cancer-specific survival (BCSS) using univariate and multivariate Cox proportional hazard regressions before and after propensity score matching (PSM).

RESULTS

From a total of 2267 patients diagnosed with MBC between 1998 and 2015, 1086 (47.9%) received RT. In the multivariate analysis before PSM, RT provided a better OS (HR 0.73; 95% CI 0.61-0.88; p = 0.001) and BCSS (HR 0.71; 95% CI 0.58-0.88; p = 0.002). Multivariate analyses after PSM (n = 1066) confirmed that patients receiving RT (n = 506) survived longer than those without RT (OS, HR 0.64; 95% CI 0.51-0.80; p < 0.001 and BCSS, HR 0.64; 95% CI 0.50-0.83; p = 0.001). A longer OS was observed when RT was given to older patients (p = 0.001) and in case of large tumor size (p = 0.002). Intriguingly, patients with N0 stage showed better OS after RT (HR 0.69, P = 0.012).

CONCLUSIONS

Our findings support the beneficial effect of RT for MBC patients. In particular, older patients or with large tumor size have a greater survival benefit from RT. In conclusion, we have assessed the importance of the use of RT in MBC as survival factor and this could lead to the development of guidelines for this rare sub-type of tumors.

Therapeutic landscape of metaplastic breast cancer

Metaplastic breast carcinomas (MPBC) are rare, aggressive and relatively chemorefractory tumors with a high unmet need. While most are "triple negative" and lack expression of estrogen, progesterone and HER2 receptors, MPBC are associated with worse outcomes compared to conventional triple negative invasive tumors. MPBCs are genetically heterogeneous and harbor somatic mutations, most frequently in TP53, PIK3CA and PTEN, with emerging studies suggesting a role for novel targeted therapies. These tumors have also been associated with overexpression of PD-L1 and tumor-infiltrating lymphocytes suggesting an endogenous immune response and therefore a rationale for treatment with immunotherapies. Here, we focus on therapeutic options for this difficult to treat breast cancer subtype and encourage physicians to consider targeted therapies/immunotherapies as part of ongoing clinical trials.