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

Successful regression of metaplastic triple-negative breast cancer with neoadjuvant chemotherapy and surgical intervention: A case report

RATIONALE

Metaplastic breast carcinoma (MBC) is a rare, aggressive subtype of triple-negative breast cancer, accounting for 0.2% to 5% of all breast cancers. It is associated with poor prognosis, twice the recurrence rate, and resistance to chemotherapy. This case report presents the treatment and outcome of a 39-year-old female with locally advanced stage III MBC.

PATIENT CONCERNS

The patient presented with a right breast mass, which had increased in size despite prior incomplete excision. She also had a contralateral breast mass, which was later confirmed as a benign neoplasm.

DIAGNOSES

The patient was diagnosed with metaplastic carcinoma of the right breast, classified as triple-negative breast cancer due to the absence of estrogen, progesterone, and human epidermal growth factor receptor 2 receptors. A biopsy revealed mesenchymal differentiation with a Nottingham grade 3 tumor measuring 35 mm, with high mitotic index and positive surgical margins.

INTERVENTIONS

The patient underwent neoadjuvant chemotherapy with taxane/carboplatin, followed by modified radical mastectomy and axillary lymph node dissection on the right, and subcutaneous mastectomy with sentinel lymph node dissection on the left. Post-surgery, she received adjuvant chemotherapy and radiotherapy.

OUTCOMES

Following neoadjuvant chemotherapy, significant morpho-metabolic tumor regression was observed. Postoperative imaging demonstrated near-complete resolution of the tumor and metastases. The patient's quality of life improved significantly, despite the emotional and physical challenges of the treatment.

LESSONS

This case highlights the potential efficacy of combining neoadjuvant chemotherapy, surgery, and adjuvant therapy in the management of MBC, emphasizing the need for careful monitoring of clinical, histological, and imaging data to guide treatment decisions for this rare cancer subtype.

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.

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.

Treatment outcomes and prognostic factors in nonmetastatic metaplastic breast cancer patients: a multicenter retrospective cohort study

BACKGROUND AND PURPOSE

Metaplastic breast carcinoma (BC-Mp) is an uncommon subtype that poses unique challenges. The limited information on patient prognosis and therapeutic strategies motivated our research initiative. We aimed to assess disease-free survival (DFS), overall survival (OS), and influential factors in patients with nonmetastatic BC-Mp.

MATERIALS AND METHODS

In this multicenter retrospective cohort study, clinicopathological data for nonmetastatic BC-Mp patients treated at four oncology units in Poland (2012-2022) were gathered.

RESULTS

Among 115 women (median age 61, range: 28-91), the median tumor size was 40 mm (range 20-130); 30% of patients exhibited positive local lymph nodes. The majority of patients presented with stage II (46%) and triple-negative breast cancer (TNBC) (84%). Radiotherapy was administered to 61% of patients. Surgical procedures included breast-conserving surgery in 31% of patients and mastectomy in 68%. Eighty-three per cent of patients received chemotherapy. The median estimated DFS and OS were 59 and 68 months, respectively. Multivariable analysis revealed that tumor size influenced DFS and OS (Hazard ratios [HR] = 1.02, 95%CI 0.01-0.03 for both endpoints) and taxanes application improved DFS (HR = 0.47, 95%CI 0.24-0.93), but other factors did not. For patients receiving neoadjuvant systemic therapy (N = 51), taxanes improved DFS and OS according to univariable analysis.

INTERPRETATION

Our findings highlight poor DFS and OS regardless of receiving optimal treatment, emphasizing the need for tailored therapeutic strategies for BC-Mp patients. Taxanes appear promising in a neoadjuvant setting, particularly within the current standard of care for the TNBC subtype.

Overall survival after mastectomy versus breast-conserving surgery with adjuvant radiotherapy for early-stage breast cancer: meta-analysis

BACKGROUND

Breast-conserving surgery with adjuvant radiotherapy and mastectomy are currently offered as equivalent surgical options for early-stage breast cancer based on RCTs from the 1970s and 1980s. However, the treatment of breast cancer has evolved and recent observational studies suggest a survival advantage for breast-conserving surgery with adjuvant radiotherapy. A systematic review and meta-analysis was undertaken to summarize the contemporary evidence regarding survival after breast-conserving surgery with adjuvant radiotherapy versus mastectomy for women with early-stage breast cancer.

METHODS

A systematic search of MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL), and Embase that identified studies published between 1 January 2000 and 18 December 2023 comparing overall survival after breast-conserving surgery with adjuvant radiotherapy versus mastectomy for patients with unilateral stage 1-3 breast cancer was undertaken. The main exclusion criteria were studies evaluating neoadjuvant chemotherapy, rare breast cancer subtypes, and specific breast cancer populations. The ROBINS-I tool was used to assess risk of bias, with the overall certainty of evidence assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool. Studies without critical risk of bias were included in a quantitative meta-analysis.

RESULTS

From 11 750 abstracts, 108 eligible articles were identified, with one article including two studies; 29 studies were excluded from the meta-analysis due to an overall critical risk of bias, 42 studies were excluded due to overlapping study populations, and three studies were excluded due to reporting incompatible results. A total of 35 observational studies reported survival outcomes for 909 077 patients (362 390 patients undergoing mastectomy and 546 687 patients undergoing breast-conserving surgery with adjuvant radiotherapy). The pooled HR was 0.72 (95% c.i. 0.68 to 0.75, P < 0.001), demonstrating improved overall survival for patients undergoing breast-conserving surgery with adjuvant radiotherapy. The overall certainty of the evidence was very low.

CONCLUSION

This meta-analysis provides evidence suggesting a survival advantage for women undergoing breast-conserving surgery with adjuvant radiotherapy for early-stage breast cancer compared with mastectomy. Although these results should be interpreted with caution, they should be shared with patients to support informed surgical decision-making.

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 cancer: an all-round multidisciplinary consensus

Metaplastic breast cancer (MpBC) is a rare and aggressive histologic subtype of breast cancer (BC) characterized by the presence of at least two cellular types, commonly epithelial and mesenchymal components. Despite growing evidence that MpBC is a unique entity, it has long been treated as a variant of nonspecial type (NST) BC. MpBC typically shows the phenotype of triple-negative breast cancer (TNBC), but compared to NST-TNBC, it is a relatively chemorefractory tumor associated with worse outcomes. Therefore, there is an urgent need to develop management guidelines specifically for MpBC to improve the prognosis of patients with early MpBC. This expert consensus aims to guide diagnosis and standardize clinical management of early MpBC among treating physicians. We provide guidance on the challenging radiological and pathological diagnosis of MpBC. Evidence on the involvement of genetic predisposition in the development of MpBC is also explored. We emphasize the importance of a multidisciplinary approach for the treatment of patients with early MpBC. The optimal surgery and radiotherapy approach is presented, as well as the opportunity offered by novel therapeutic approaches to increase treatment response in this chemoresistant subtype. Appropriate management of patients with MpBC is critical to reduce the high risk of local and distant recurrence that characterizes this disease.

The conundrum of metaplastic breast cancer: a single Egyptian institution retrospective 10-year experience (2011-2020)

BACKGROUND

Metaplastic breast cancer (MetBC) still represents a conundrum owing to its peculiar histogenesis and molecular drivers that render it extremely resistant to standard chemotherapy with ultimate dismal survival.

AIM

Describe the Egyptian National Cancer Institute's (NCI-E) experience with MetBC regarding its clinicopathologic features, treatment, and survival outcomes.

PATIENTS AND METHODS

Between 2011 and 2020, all MetBC patients presented to NCI-E were retrospectively evaluated. Original clinicopathologic data, therapeutic modalities, pathologic response to neoadjuvant chemotherapy (NACT), recurrence, and date of last follow-up/death were obtained from archived charts.

RESULTS

A cohort of 135 females, the median age was 52 years, and median follow-up period was 40 months (range: 2.6-130.8). Two-thirds were triple negative (TN). Squamous carcinoma was prevalent in 74.8% followed by carcinoma with osseous/chondroid differentiation, spindle cell, and low-grade adenosquamous carcinoma encountered in 13.3, 7.4, and 4.5%, respectively. Modified radical mastectomy was done in 59.3%, and positive nodes (pN+) were depicted in 37.7%. Median Ki-67 was 45% (range: 10-88); grade III and lymphovascular invasion (LVI) were observed in 83.7 and 43.7%, respectively. Stage II was the most common (49%), whereas initial stage IV was encountered in 8.1%. Anthracyclines/taxane combinations were rampant in adjuvant/neoadjuvant settings. The latter was employed in 41 patients, with only 3 cases (7.3%) achieving pathologic complete response (pCR), while moderate/significant residual tumor burden was found in 83%. The 5-year DFS and OS were 56.4 and 57.6%, respectively. Spindle cell carcinoma showed the worst survival parameters in univariate analysis. On the multivariate level, higher tumor stage (pT3 & 4), Ki-67 ≥ 45%, and TN subtype were independent variables for worse DFS and OS; age ≥ 52 years and the presence of LVI were independent features for worse DFS, whereas pN+ was an independent parameter for worse OS.

CONCLUSIONS

This study further solidifies the dreadful response of MetBC to conventional chemotherapy regimens employed in common non-metaplastic pathologies. A radical shift in treatment standards tailored to combat the molecular landscape of this distinctive tumor is urgently needed. Immunotherapy and molecularly targeted agents demonstrated promising results in phase I and II trials with hopeful sooner implementation in phase III studies.

Recurrent Metaplastic Breast Cancer with Subtype Converted from Triple-Negative to HER2-Positive: A Case Report and Literature Review

Background

Metaplastic breast cancer (MBC) is an extremely rare malignant breast disease that has rarely been reported. The molecular subtype of MBC is mostly triple-negative, with a high recurrence rate and a worse prognosis. Due to its low HR- and HER2-positive rate, reports on endocrine and targeted therapy are very limited.

Case report

We report a case of infrequent triple-negative MBC, which, although at an early stage, quickly developed multiple recurrent lesions in the chest wall. The tumor relapsed repeatedly after comprehensive treatment, including surgery, chemotherapy and radiotherapy. However, pathological results after the third surgery suggested that the molecular subtype had changed from triple-negative to HER2-positive. The previous comprehensive treatment had not been able to effectively control the disease, but the patient achieved a long progression-free survival time through chemotherapy and trastuzumab targeted therapy after the subtype change. To date, there has been no recurrence for over eight years.

Conclusion

Among repeatedly relapsed MBC patients, further investigation should be taken into consideration. As in the case presented in our study, it is possible that the HER2 status can convert from negative to overexpression. Moreover, for HER2-positive MBC patients, anti-HER2 therapy is recommended. The decision-making process requires multidisciplinary involvement.

Clinical characteristics and overall survival prognostic nomogram for metaplastic breast cancer

Background

Metaplastic breast cancer (MBC) is a rare breast tumor and the prognostic factors for survival in patients still remain controversial. This study aims to develop and validate a nomogram to predict the overall survival (OS) of patients with MBC.

Methods

We searched the Surveillance, Epidemiology, and End Results (SEER) database for data about patients including metaplastic breast cancer and infiltrating ductal carcinoma (IDC) from 2010 to 2018. The survival outcomes of patients between MBC and IDC were analyzed and compared with the Kaplan-Meier (KM) method. MBC patients were randomly allocated to the training set and validation I set by a ratio of eight to two. Meanwhile, the performance of this model was validated again by the validation II set, which consisted of MBC patients from the Union Hospital of Fujian Medical University between 2010 and 2018. The independent prognostic factors were selected by univariate and multivariate Cox regression analyses. The nomogram was constructed to predict individual survival outcomes for MBC patients. The discriminative power, calibration, and clinical effectiveness of the nomogram were evaluated by the concordance index (C-index), the receiver operating characteristic (ROC) curve, and the decision curve analysis (DCA).

Results

MBC had a significantly higher T stage (T2 and above accounting for 75.1% vs 39.9%), fewer infiltrated lymph nodes (N0 accounted for 76.2% vs 67.7%), a lower proportion of ER (22.2% vs 81.2%), PR (13.6% vs 71.4%), and HER-2(6.7% vs 17.7%) positive, radiotherapy(51.6% vs 58.0%) but more chemotherapy(67.5% vs 44.7%), and a higher rate of mastectomy(53.2% vs 36.8%), which was discovered when comparing the clinical baseline data between MBC and IDC. Age at diagnosis, T, N, and M stage, as well as surgery and radiation treatment, were all significant independent prognostic factors for overall survival (OS). In the validation I cohort, the nomogram's C-index (0.769 95% CI 0.710 -0.828) was indicated to be considerably higher than the standard AJCC model's (0.700 95% CI 0.644 -0.756). Nomogram's great predictive capability capacity further was supported by the comparatively high C-index of the validation II sets (0.728 95%CI 0.588-0.869).

Conclusions

Metaplastic breast cancer is more aggressive, with a worse clinical prognosis than IDC. This nomogram is recommended for patients with MBC, both American and Chinese, which can help clinicians make more accurate individualized survival analyses.

Does Breast-Conserving Surgery with Radiotherapy have a Better Survival than Mastectomy? A Meta-Analysis of More than 1,500,000 Patients

BACKGROUND

There have been conflicting studies reporting on survival advantages between breast-conserving surgery with radiotherapy (BCS) in comparison with mastectomy. Our aim was to compare the efficacy of BCS and mastectomy in terms of overall survival (OS) comparing all past published studies.

METHODS

We performed a comprehensive review of literature through October 2021 in PubMed, Scopus, and EMBASE. The studies included were randomized controlled trials (RCTs) and cohorts that compare BCS versus mastectomy. We excluded studies that included male sex, stage 0, distant metastasis at diagnosis, bilateral synchronous cancer, neoadjuvant radiation/chemotherapy, and articles with incomplete data. We performed a meta-analysis following the random-effect model with the inverse variance method.

RESULTS

From 18,997 publications, a total of 30 studies were included in the final analysis: 6 studies were randomized trials, and 24 were retrospective cohorts. A total of 1,802,128 patients with a follow-up ranging from 4 to 20 years were included, and 1,075,563 and 744,565 underwent BCS and mastectomy, respectively. Among the population, BCS is associated with improved OS compared with mastectomy [relative risk (RR) 0.64, 95% confidence interval (CI) 0.55-0.74]. This effect was similar when analysis was performed in cohorts and multi-institutional databases (RR 0.57, 95% CI 0.49-0.67). Furthermore, the benefit of BCS was stronger in patients who had less than 10 years of follow-up (RR 0.54, 95% CI 0.46-0.64).

CONCLUSIONS

Patients who underwent BCS had better OS compared with mastectomy. Such results depicting survival advantage, especially using such a large sample of patients, may need to be included in the shared surgical decision making when discussing breast cancer treatment with patients.