Survival outcomes after breast-conserving therapy compared with mastectomy for patients with early-stage metaplastic breast cancer: a population-based study of 2412 patients

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.

Therapeutic strategies and landscape of metaplastic breast cancer

Metaplastic breast cancer is a rare and heterogeneous subtype of breast cancer, associated with a poor prognosis. Its distinct biological behavior and morphological features contribute to resistance to standard treatment regimens. Hitherto, the optimal therapeutic strategy for metaplastic breast cancer remains underexplored. Herein, we review the literature on the treatment of metaplastic breast cancer, summarizing current local and systemic therapies, and discuss potential therapeutic targets and novel strategies based on its pathological and molecular characteristics. Targeted therapy and immunotherapy may provide more personalized treatment options, with the potential to improve the prognosis of this disease.

Higher 10-Year Survival with Breast-Conserving Therapy over Mastectomy for Women with Early-Stage (I-II) Breast Cancer: Analysis of the CDC Patterns of Care Data Base

Background

Studies in the United States are scarce that assess the survival differences between breast-conserving surgery plus radiation (Breast-Conserving Therapy; BCT) and mastectomy groups using population-based data while accounting for sociodemographic and clinical factors that affect the survival of women with early-stage breast cancer (ESBC).

Objective

To assess whether BCT provides superior long-term overall survival (OS) and breast cancer-specific survival (BCSS) compared with mastectomy in women with ESBC, while considering key factors that impact survival.

Design

Cohort study.

Methods

We analyzed data on women aged 20 years and older diagnosed with stage I-II breast cancer (BC) in 2004 who received either BCT or mastectomy. The data were collected by 5 state cancer registries through the Centers for Disease Control and Prevention-funded Patterns of Care study. Multivariable Cox proportional hazard models, accounting for sociodemographic and clinical factors, were used to calculate hazard ratios (HRs) with 95% confidence intervals (CI). Sensitivity analysis involved optimal caliper propensity score (PS) matching to address residual confounding.

Results

Of the 3495 women, 41.5% underwent mastectomy. The 10-year OS and BCSS were 82.7% and 91.1% for BCT and 72.3% and 85.7% for mastectomy, respectively. Adjusted models showed that mastectomy recipients had a 22% higher risk of all-cause deaths (ACD) (HR = 1.22, 95% CI = [1.06, 1.41]) and a 26% higher risk of breast cancer-specific deaths (BCD) (HR = 1.26, 95% CI = [1.02, 1.55]) than BCT recipients. Sensitivity analysis demonstrated that mastectomy was associated with a higher risk of ACD (P < .05) but did not exhibit a statistically significant risk for BCD. Women with HR+/HER2+ (luminal B) or invasive ductal carcinoma BC who underwent mastectomy had higher risks of ACD and BCD compared with BCT recipients, while the hazards for ACD in triple-negative BC did not remain significant after adjusting for covariates.

Conclusion

ESBC BCT recipients demonstrate superior OS and BCSS compared with mastectomy recipients.

Three-dimensional surgical margin positioning technique versus palpation-guided method for breast-conserving surgery: Feasibility, advantages, and quality of life

BACKGROUND

The accurate evaluation of surgical margins holds crucial importance in determining the success of breast-conserving surgery (BCS). The aim of this study was to introduce a novel technique for the positioning of surgical margins in BCS while highlighting its advantages.

METHODS

This study included a cohort of breast cancer patients who underwent BCS. The patients were categorized into two groups: one group underwent BCS with the traditional palpation-guided method, and the other with the 3D-MPT technique. The study assessed and compared the feasibility, advantages, and outcomes in terms of quality of life between the two groups.

RESULTS

A total of 80 patients were successfully enrolled in the study. No significant differences in clinicopathological features were observed between the two groups. The 3D-MPT technique was found to be feasible and offered several advantages over the palpation-guided method. The utilization of guide wires by experienced radiologists to position the margins before surgery enabled precise and swift specimen removal, resulting in the conservation of valuable time and a reduction in the need for re-excision. Furthermore, the 3D-MPT technique exhibited the potential to enhance cosmetic outcomes and elevate patient satisfaction, particularly in cases with uncertain tumor boundaries detectable by palpation.

CONCLUSION

The 3D-MPT technique proves to be an effective and safe approach for reducing tumor positivity rates in initial surgical margins, thereby improving the quality of life for patients undergoing breast-conserving surgery in comparison to the conventional method.

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.

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.

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.

Breast-conserving surgery versus mastectomy for treatment of breast cancer after neoadjuvant chemotherapy

Background

To compare recurrence and survival outcomes between breast-conserving surgery (BCS) and mastectomy after neoadjuvant chemotherapy (NACT).

Methods

The data of 730 patients who underwent NACT between 2000 and 2014 were retrospectively reviewed. A total of 104 (14.2%) patients received BCS and 626 (85.8%) received mastectomy. Locoregional recurrence (LRR), distant metastases (DM), disease-free survival (DFS), breast cancer-specific survival (BCSS), and overall survival (OS) were analyzed using the Kaplan-Meier method. The impact of BCS versus mastectomy on outcomes was assessed by multivariate Cox models. Inverse probability of treatment weighting (IPTW) was used to balance covariates between the two groups.

Results

The median follow-up of BCS and mastectomy groups were 86.5 and 87.4 months, respectively. There were significant differences in distribution of most baseline characteristics between two groups. Compared with those who underwent mastectomy, the patients with BCS had similar 5-year LRR, DM, and DFS rates, but had significantly higher 5-year BCSS (98.9% vs. 90.4%, P = 0.005) and OS (98.9% vs. 90.1%, P = 0.003) rates. Multivariate analysis also showed that BCS significantly improved BCSS (HR = 0.27, 95% CI: 0.08-0.85, P = 0.025) and OS (HR = 0.25, 95% CI: 0.08-0.79, P = 0.018). After IPTW adjustment, the LRR, DM, DFS, BCSS and OS between two groups had no significant differences.

Conclusions

The recurrence and survival outcomes are comparable with BCS and mastectomy. Thus, BCS is a safe treatment option for selected breast cancer patients after NACT.

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.

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.

Fall in Ki67 Index After Short-Term Preoperative Letrozole: a Gateway to Assess the Response in Hormone-Positive Early Breast Cancers

Endocrine treatment for breast cancer acts largely by inhibiting tumor cell proliferation. The study aimed to explore the fall in proliferative marker Ki67 in patients receiving preoperative endocrine therapy and the factors associated with it. A prospective series of hormone receptor-positive postmenopausal women with early N0/N1 breast cancer were enrolled. Patients were requested to take letrozole OD while they await surgery. The fall in Ki67 after the endocrine therapy was defined as the percentage of the difference between the pre-and postoperative Ki67 value with the preoperative Ki67. Sixty cases matched the criteria of which 41 (68.3%) of women showed a good response to preoperative letrozole (fall in Ki67 > 50%; p-value < 0.001). The average mean fall in Ki67 was 57.083 ± 37.97. Postoperative Ki67 after the therapy was less than 10% in 39 (65%) patients. Ten patients (16.6%) had a low Ki67 index at baseline, which continued to remain low after preoperative endocrine therapy. The duration of the therapy did not affect the percentage of Ki67 fall in our study. Short-term changes in the Ki67 index in the neoadjuvant settings may predict outcomes during adjuvant use of the same treatment. Proliferation index on residual tumor holds prognostic importance, and our results reflect that greater attention should be given to the percentage of reduction of Ki67, rather than focusing purely on a fixed value. This could help predict patients who respond well to endocrine therapy, while those who respond poorly may require further adjuvant treatment.

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.

Breast-Conserving Surgery or Mastectomy?: Impact on Survival

The early randomized controlled trials revealed no differences in survival between breast-conserving surgery (BCS) and mastectomy. However, breast cancer treatment has undergone changes, and the results of recent population-based registry studies suggest superior long-term survival after BCS. To explore the current evidence, a systematic review and meta-ana lysis of population-based observational studies from 2010 and onward was conducted.

Methods

A literature search was conducted in the PubMed, Embase, and Cochrane databases to identify relevant literature. Keywords included "mastectomy," "breast conserving surgery," and "survival." The identified studies were narratively reviewed and effect sizes (hazard ratios [HRs]) for overall (OS) and breast cancer-specific survival (BCSS) were combined with random-effects models.

Results

A total of 30 reports were included in the review, and results from 25 studies were included in the meta-analyses. Compared with mastectomy, BCS was associated with better OS (HR = 1.34 [1.20-1.51]; N = 1,311,600) and BCSS (HR = 1.38 [1.29-1.47]; N = 494,267). Selected subgroups of patients, based on lymph node status, age (<50 years/≥50 years), and radiation therapy after mastectomy (±), all showed better overall survival after BCS. The number (range 4-12) and type of prognostic variables adjusted for in the survival analyses of the studies did not statistically significantly moderate the differences in survival between BCS and mastectomy.

Conclusions

The combined findings from large population-based studies indicate that BCS is associated with survival benefit compared with mastectomy, suggesting that BCS be the recommended treatment of early breast cancer (T1-2N0-1M0) if a radical lumpectomy can be performed.

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.

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

Background

Metaplastic breast cancer (MBC) are rare. The survival outcomes of MBC patients after breast conserving surgery plus radiotherapy (BCS+RT) or mastectomy have not been established. The study aimed to compare survival outcomes of MBC patients subjected to BCS+RT or mastectomy therapeutic options.

Methods

Patients who were subjected to BCS+RT or mastectomy between 2004 and 2014 were enrolled in this study through the Surveillance, Epidemiology and End Results (SEER) database. Breast cancer-specific survival (BCSS) and the overall survival (OS) of the participants were determined. Cox proportional hazard model and the Kaplan Meier method were used to determine the correlation between the two surgical methods and survival outcomes.

Results

A total of 1197 patients were enrolled in this study. Among them, 439 patients were subjected to BCS+RT, while 758 patients were subjected to mastectomy. After propensity score matching (PSM), the BCS+RT and mastectomy groups consisted of 321 patients, respectively. The univariate and multivariate analysis with a 6-month landmark all indicate that patients receiving BCS+RT has higher OS than patients receiving mastectomy (HR = 0.701,95% CI = 0.496–0.990, P = 0.044; HR = 0.684,95% CI = 0.479–0.977, P = 0.037) while the BCSS was no difference between the two groups (HR = 0.739,95% CI = 0.474–1.153, P = 0.183; HR = 0.741,95% CI = 0.468–1.173, P = 0.200).

Conclusion

The BCS+RT therapeutic option exhibits a higher OS in MBC patients compared to the mastectomy approach.

Improved Survival after Breast-Conserving Therapy Compared with Mastectomy in Stage I-IIA Breast Cancer

Simple Summary

The majority of patients with breast cancer are suitable for either breast-conserving therapy, consisting of breast-conserving surgery and radiation therapy, or mastectomy alone. In the present study, we compared survival outcomes in 1360 patients affected with early-stage breast cancer (stage I-IIA) according to the type of local treatment. We confirmed that patients treated with breast-conserving therapy had a lower rate of local, regional, and distant disease recurrences, and at least equivalent overall survival compared to those treated with mastectomy alone. Our results add to previous research showing a potential benefit of breast-conserving therapy when compared to mastectomy in patients suitable for both treatments at baseline.

Abstract

In the current study, we sought to compare survival outcomes after breast-conserving therapy (BCT) or mastectomy alone in patients with stage I-IIA breast cancer, whose tumors are typically suitable for both locoregional treatments. The study cohort consisted of 1360 patients with stage I-IIA (T1–2N0 or T0–1N1) breast cancer diagnosed between 2001 and 2013 and treated with either BCT (n = 1021, 75.1%) or mastectomy alone (n = 339, 24.9%). Median follow-ups for disease-free survival (DFS) and overall survival (OS) were 6.9 years (range, 0.3–15.9) and 7.5 years (range, 0.2–25.9), respectively. Fifteen (1.1%), 14 (1.0%) and 48 (3.5%) patients experienced local, regional, and distant relapse, respectively. For the whole cohort of patients, the estimated 5-year DFS and OS were 96% and 97%, respectively. After stratification based on the type of local treatment, the estimated 5-year DFS for BCT was 97%, while it was 91% (p < 0.001) for mastectomy-only treatment. Inverse probability of treatment weighting matching based on confounding confirmed that mastectomy was associated with worse DFS (HR 2.839, 95% CI 1.760–4.579, p < 0.0001), but not with OS (HR 1.455, 95% CI 0.844–2.511, p = 0.177). In our study, BCT was shown to have improved disease-specific outcomes compared to mastectomy alone, emphasizing the important role of adjuvant treatments, including postoperative radiation therapy, in patients with early-stage breast cancer at diagnosis.