Metaplastic breast cancer: Treatment and prognosis by molecular subtype

Survival trends of patients with metaplastic breast carcinoma with different hormone receptor statuses: a SEER-based retrospective cohort study

BACKGROUND

Metaplastic breast carcinoma (MpBC) is a rare histological subtype of breast cancer, and its prognosis is relatively poor. The survival trend of MpBC with different hormone receptor statuses has remained unclear over the past two decades.

METHODS

MpBC patient data were collected from the Surveillance, Epidemiology, and End Results database from 2000 to 2019. Patients were divided into two groups according to their hormone receptor status (negative and positive). The survival probabilities were calculated via Kaplan‒Meier curves. Logistic regression analysis was used to obtain odds ratios for treatment and demographic characteristics. Multivariate Cox regression was used to identify prognostic factors.

RESULTS

A total of 3,076 patients were enrolled, and a significant improvement in survival was observed over the last 10 years. For HR-negative MpBC patients, both overall survival and breast cancer-specific survival improved, whereas no survival improvement was observed for HR-positive patients. Compared with those in the time period from 2000 to 2009, the proportion of negative nodes and the likelihood of receiving chemotherapy increased for HR-negative patients from 2010 to 2019. In the HR-negative subgroup, the survival of Whites improved significantly, whereas the survival of Blacks improved in the HR-positive subgroup.

CONCLUSIONS

The survival of HR-negative MpBC patients has improved significantly in the past 20 years, which may be related to early diagnosis, increased adjuvant therapy and medical development, but no trend towards improvement has been observed in HR-positive patients. Racial disparities in different HR statuses also need to be addressed.

A comprehensive overview of metaplastic breast cancer: Features and treatments

Metaplastic breast cancer is a rare, aggressive, and chemotherapy-resistant subtype of breast cancers, accounting for less than 1% of invasive breast cancers, characterized by adenocarcinoma with spindle cells, squamous epithelium, and/or mesenchymal tissue differentiation. The majority of metaplastic breast cancers exhibit the characteristics of triple-negative breast cancer and have unfavorable prognoses with a lower survival rate. This subtype often displays gene alterations in the PI3K/AKT pathway, Wnt/β-catenin pathway, and cell cycle dysregulation and demonstrates epithelial-mesenchymal transition, immune response changes, TP53 mutation, EGFR amplification, and so on. Currently, the optimal treatment of metaplastic breast cancer remains uncertain. This article provides a comprehensive review on the clinical features, molecular characteristics, invasion and metastasis patterns, and prognosis of metaplastic breast cancer, as well as recent advancements in treatment strategies.

Validation and clinical discovery demonstration of breast cancer data from a real-world data extraction platform

Objective

To validate and demonstrate the clinical discovery utility of a novel patient-mediated, medical record collection and data extraction platform developed to improve access and utilization of real-world clinical data.

Materials and Methods

Clinical variables were extracted from the medical records of 1011 consented patients with breast cancer. To validate the extracted data, case report forms completed using the structured data output of the platform were compared to manual chart review for 50 randomly-selected patients with metastatic breast cancer. To demonstrate the platform's clinical discovery utility, we identified 194 patients with early-stage clinical data who went on to develop distant metastases and utilized the platform-extracted data to assess associations between time to distant metastasis (TDM) and early-stage tumor histology, molecular type, and germline BRCA status.

Results

The platform-extracted data for the validation cohort had 97.6% precision (91.98%-100% by variable type) and 81.48% recall (58.15%-95.00% by variable type) compared to manual chart review. In our discovery cohort, the shortest TDM was significantly associated with metaplastic (739.0 days) and inflammatory histologies (1005.8 days), HR-/HER2- molecular types (1187.4 days), and positive BRCA status (1042.5 days) as compared to other histologies, molecular types, and negative BRCA status, respectively. Multivariable analyses did not produce statistically significant results.

Discussion

The precision and recall of platform-extracted clinical data are reported, although specificity could not be assessed. The data can generate clinically-relevant insights.

Conclusion

The structured real-world data produced by a novel patient-mediated, medical record-extraction platform are reliable and can power clinical discovery.

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.

Significance of Estrogen/Progesterone Receptor Expression in Metaplastic Breast Carcinoma

Introduction

Metaplastic breast carcinoma (MBC) is a rare subgroup of breast neoplasms associated with adverse outcomes because of its aggressive nature. Typically, MBCs show triple-negative hormone receptor (HR) status. Determining the HR status of breast cancer is an integral part because it is an important prognostic factor and helps in the treatment course of the disease. This study aimed to determine the HR status of MBC, its significance, and its association with various clinicopathological parameters.

Methods

This was a retrospective study conducted at the Department of Histopathology, Liaquat National Hospital. A total of 140 biopsy-proven cases of MBC were enrolled in the study. Clinical and pathological data were retrieved from the institutes' archives. Immunohistochemical studies were conducted to determine the estrogen receptor (ER) and progesterone receptor (PR) status.

Results

The mean age of MBC in our population was found to be 52.18 ± 12.19 years. The HR positivity rate in our population was found to be 32.9%. A significant association was found between HR status and tumor laterality, tumor size, tumor grade, tumor stage, and recurrence. ER/PR-negative MBCs were most probably associated with higher grade and higher tumor stage and were larger in size (6.62 ± 3.43 cm) than ER/PR-positive MBCs (4.20 ± 1.88 cm). Moreover, ER/PR-positive MBCs showed a higher recurrence rate than ER/PR-negative MBCs (43.5% vs. 25.5%, respectively). No statistically significant relationship was found between HR status and patient age, histological subtype, or survival rate.

Conclusion

MBC is a rare breast neoplasm. MBC was found to be triple negative in most cases, but a significant percentage were HR (ER/PR) positive. Moreover, we found an association between HR status and various clinicopathological features, indicating that HR status is a significant predictor of MBC prognosis.

Comparative expression of trophoblast cell-surface antigen 2 (TROP2) in the different molecular subtypes of invasive breast carcinoma: An immunohistochemical study of 94 therapy-naive primary breast tumors

BACKGROUND

Sacituzumab govitecan, targeting trophoblast cell-surface antigen 2 (TROP2), is approved for the treatment of triple-negative and hormone receptor-positive/HER2-negative breast cancers. However, detailed studies comparing TROP2 protein expression in the different molecular subtypes of breast cancer are limited, and definitive evidence supporting the use of TROP2 as a biomarker for predicting response to this agent in patients with breast cancer is currently lacking.

OBJECTIVE

To compare the expression of TROP2 in the different molecular subtypes of breast cancer.

METHODS

Immunohistochemical staining for TROP2 was performed on 94 therapy-naive primary invasive breast carcinomas, including 25 luminal A-like, 25 luminal B-like, 19 HER2-like, and 25 triple-negative tumors.

RESULTS

Intermediate to high levels of TROP2 expression were observed in the majority of carcinomas of each molecular subtype, with a wide range of expression in each subtype. Occasional tumors with low or absent TROP2 expression were encountered, including two metaplastic carcinomas which were completely negative for TROP2.

CONCLUSIONS

Our observations support the continued investigation of the efficacy of sacituzumab govitecan in all molecular subtypes of breast carcinoma. Furthermore, the observed wide range of expression of TROP2 suggests that TROP2 may have potential utility as a biomarker for predicting responsiveness to sacituzumab govitecan. If this proves to be the case, then immunohistochemical staining for TROP2 would be critical for identifying those patients whose tumors are completely negative for TROP2, since these patients may be least likely or unlikely to respond to this agent, and alternative therapies may be more appropriate in such instances.

Trends of incidence and mortality in metaplastic breast cancer and the effect of contralateral prophylactic mastectomy: A population-based study

INTRODUCTION

Metaplastic breast cancer (MBC) is considered rare and aggressive. We examined the epidemiology of and prognostic factors for MBC and investigated the effect of contralateral prophylactic mastectomy (CPM), because neither had been thoroughly examined previously.

METHODS

We obtained data from the Surveillance, Epidemiology, and End Results (SEER)-18(2000-2018) for epidemiological and survival analysis.

RESULTS

The age-adjusted incidence per 100,000 persons of MBC increased significantly from 0.12 to 0.35 [annual percent change (APC):2.95%, 95% confidence interval [CI], 1.73-4.19]. The incidence-based mortality increased from 0.01 to 0.12 (APC: 5.01%, 95% CI: 2.50-7.58). The incidence of MBC patients who underwent CPM significantly increased from 0.003 to 0.039 with an APC of 10.96% (95%CI, 7.26-14.78). Older patients and those with higher T classification were less likely to receive CPM. The multivariate Cox model showed that CPM was not an independent predictor of good prognosis for both overall survival (OS) and breast cancer-specific survival (BCSS) (pre-propensity score matching (PSM): OS: P = 0.331; BCSS: P = 0.462. post-PSM: OS: P = 0.916; BCSS: P = 0.967). Subgroup analysis showed that CPM still did not provide a survival benefit to any risk groups.

CONCLUSION

In this study, we demonstrated that the incidence and incidence-based mortality of MBC have increased over the past decades. Although the number of MBC patients who underwent CPM has significantly increased recently, CPM did not confer a survival benefit compared with unilateral mastectomy, indicating that the decision to undergo CPM should be considered carefully.

Prognostic role of serum soluble ST2 of advanced breast cancer patients: a retrospective cohort study

Background

The soluble suppression of tumorigenicity 2 receptor (sST2) binds to interleukin-33 (IL-33) and blocks IL-33 and ST2 binding, suggesting that sST2 acts as a "decoy" receptor for IL-33 and is involved in the malignant progression of breast cancer. This paper aimed to investigate the differences in sST2 expression in patients with different molecular subtypes of breast cancer and assess its clinical value in the prognostic evaluation of advanced breast cancer.

Methods

In this paper, we collected sera from 91 patients firstly diagnosed with advanced breast cancer at the Tianjin Medical University Cancer Institute and Hospital from 2008 to 2021 during their first hospitalization. We detected the expression level of sST2 in the serum of patients with different molecular fractions of breast cancer and analyzed the relationship between serum sST2 levels and breast cancer-related bone metastasis, cardiotoxicity, and overall survival. Bone metastases were detected using the Emission Computed Tomography technique, and chemotherapy drug-induced cardiotoxicity was detected by echocardiography. The Overall Survival was evaluated using the Kaplan-Meier estimator, and multivariate Cox regression analysis was performed to demonstrate the association between variables and sST2 levels.

Results

Serum sST2 levels did not vary among the different pathological types, molecular types, and estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and tumor proliferation marker (Ki-67) subgroups, and only differed significantly in the cardiotoxicity group. There were no statistical differences in tissue polypeptide specific antigen (TPSA), carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA), carbohydrate antigen 153 (CA153), D-dimer, and inflammatory indexes neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) among different molecular subgroups. However, except for triple-negative breast cancer (TNBC), there was no difference in peripheral blood soluble ST2 concentrations among other molecular subtypes. Meanwhile, the survival of the high sST2 level group among advanced breast cancer patients was significantly lower than that of the normal group, and sST2 expression was closely related to cardiotoxicity and clinical stage.

Conclusions

Serum sST2 is not only traditionally applied to the assessment of cardiac injury, but can also be utilized for assessing the prognosis of advanced breast cancer, excluding the influence of clinical stage and cardiotoxicity.

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 Carcinoma of the Breast: Case Series of a Single Institute and Review of the Literature

Metaplastic carcinoma of the breast (MpBC) is a very rare and aggressive type of breast cancer. Data focusing on MpBC are limited. The aim of this study was to describe the clinicopathological features of MpBC and evaluate the prognosis of patients with MpBC. Eligible articles about MpBC were identified by searching CASES SERIES gov and the MEDLINE bibliographic database for the period of 1 January 2010 to 1 June 2021 with the keywords metaplastic breast cancer, mammary gland cancer, neoplasm, tumor, and metaplastic carcinoma. In this study, we also report 46 cases of MpBC stemming from our hospital. Survival rates, clinical behavior, and pathological characteristics were analyzed. Data from 205 patients were included for analysis. The mean age at diagnosis was 55 (14.7) years. The TNM stage at diagnosis was mostly stage II (58.5%) and most tumors were triple negative. The median overall survival was 66 (12-118) months, and the median disease-free survival was 56.8 (11-102) months. Multivariate Cox regression analysis revealed that surgical treatment was associated with decreased risk of death (hazard ratio 0.11, 95% confidence interval 0.02-0.54, p = 0.01) while advanced TNM stage was associated with increased risk of death (hazard ratio 1.5, 95% confidence interval 1.04-2.28, p = 0.03). Our results revealed that surgical treatment and TNM stage were the only independent risk factors related to patients' overall survival.

The mixed subtype has a worse prognosis than other histological subtypes: a retrospective analysis of 217 patients with metaplastic breast cancer

OBJECTIVE

Metaplastic breast cancer (MpBC) is an aggressive subtype of all breast cancer. We aimed to investigate the clinicopathological features, treatments and prognoses of MpBC patients.

METHODS

We collected the data from MpBC patients diagnosed at Tianjin Medical University Cancer Hospital from 2010 to 2017. Kaplan Meier curves and Cox regression model were used to evaluating clinical outcomes and prognostic factors. After removing baseline differences by propensity score matching (PSM), we analyzed the prognosis between MpBC patients and invasive ductal carcinomas of no special type (IDC-NST) patients.

RESULTS

A total of 217 MpBC patients were subsumed. Of all histological subtypes, 45.1% were mixed subtypes, followed by with mesenchymal differentiation (27.2%), pure squamous (15.2%) and pure spindle (12.4%) subtypes. 69.6% of MpBC were triple-negative, 25.3% and 6.5% were HR-positive and HER2-positive. MpBC patients had worse survival compared to IDC-NST patients, with 5-year RFS of 73.8 and 83.6% (HR = 1.177 95%CI (1.171-2.676) P = 0.0068), and 5-year BCSS of 79.0% and 89.7% (HR = 2.187 95%CI (1.357-3.523) P = 0.0013). In the multivariate COX model, AJCC stage, mixed subtype and chemotherapy were independent prognostic factors. Mixed MpBC is more aggressive than pure and with heterologous mesenchymal differentiation subtypes. And whether squamous or spindle MpBC, mixed forms have shorter outcomes than pure forms.

CONCLUSIONS

MpBCs are associated with poorer prognoses than IDC-NSTs. They are heterogeneous with different clinicopathological features and clinical outcomes between histological subtypes. Pure and with heterologous mesenchymal differentiation subtypes have more survival benefits than the mixed subtype.

Presentation and treatment of aggressive, Triple-Negative carcinosarcoma of the breast

An extremely rare form of breast cancer, breast carcinosarcoma accounts for less than a percent of all breast malignancies and is highly aggressive. Composed of both cancerous epithelial and mesenchymal cell types, breast carcinosarcoma is associated with a poor prognosis compared to more common breast cancers, and typically lack the receptors typical of other breast carcinomas, which minimize potential targets for treatment. In this case report, we discuss a 56-year-old patient affected by carcinosarcoma of the breast at a T2N1 stage, and the decision-making process that factored into her treatment plan.

Metaplastic Breast Carcinoma Presenting as a Mixed Solid and Cystic Lesion

The objective of this paper is to report a rare presentation of metaplastic breast carcinoma (MBC) as a mixed solid/cystic mass and emphasize the possibility of having a different biopsy report and final diagnosis.

MBC is a rare type of breast cancer consisting of mesenchymal or mixed mesenchymal and epithelial components. It is believed to result from the conversion of glandular cells into non-glandular cells through various forms of mutations. It is common in females and more frequent in older women. MBC is a triple-negative breast cancer (progestin receptor, estrogen receptor, and human epidermal growth factor receptor 2) with a very poor prognosis when compared with other types of breast cancers.

This is a case of an 84-year-old woman presenting with rapidly growing mixed solid and cystic breast mass with a final diagnosis of MBC. The initial biopsy report was high-grade ductal carcinoma in situ. This is an unusual presentation of MBC.

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.

[Effect of postmastectomy radiotherapy on survival outcomes of patients with metaplastic breast cancer]

OBJECTIVE

To evaluate the effect of postmastectomy radiotherapy (PMRT) on the overall survival (OS) and breast cancer-specific survival (BCSS) of patients with metaplastic breast cancer (MpBC) in comparison with those of patients with invasive ductal breast carcinoma (IDC).

METHODS

We selected the patients with pathologically confirmed MpBC and IDC who either received PMRT or not from the archived cases (from January, 1998 to December, 2016) in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database. In total, 31 982 patients were selected, including 308 patients with MpBC and PMRT, 629 with MpBC and PMRT, and 31 045 with IDC and PMRT. All the included patients were above 18 years of age without distant metastases or a second primary cancer and underwent radical surgery. Baseline characteristics of the patients were compared among the 3 subgroups, and multivariate Cox regression and Kaplan-Meier analyses were performed for analyzing the prognostic factors of MpBC, OS, and BCSS.

RESULTS

The majority (81.2%) of patients with MpBC were older than 50 years, had pathological grade III (68%), and were negative for ER (75.9%) and PR (79.8%) and in stage T2-3 (71.3%) and N0-1 (85.6%). Multivariate Cox regression analysis showed that age, T stage, N stage, PMRT, and chemotherapy were significantly associated with the prognosis of patients with MpBC (P < 0.05), while pathological grade, ER status, or PR status did not significantly affect the prognosis (P>0.05). Kaplan-Meier analysis showed that the patients with MpBC and PMRT had better OS (HR=1.394, 95% CI: 1.125-1.727; P < 0.05) and BCSS (HR=1.390, 95% CI: 1.074-1.800; P < 0.05) than those with MpBC who did not receive PMRT; but after PMRT, the patients with MpBC had worse OS (HR=1.626, 95%CI: 1.386-1.908; P < 0.001) and BCSS (HR=1.710, 95% CI: 1.418-2.062; P < 0.001) as compared with those with IDC.

CONCLUSION

MpBC has unique clinicopathological features. In patients with MpBC, age, T stage, N stage, radiotherapy and chemotherapy are all the prognostic factors affecting the survival outcomes, and PMRT can improve the OS and BCSS of the patients.