Postmastectomy Radiation Therapy Is Associated With Improved Survival in Node-Positive Male Breast Cancer: A Population Analysis

Male breast cancer: a multicenter study to provide a guide for proper management

INTRODUCTION

To offer an extensive retrospective experience on the management of male breast cancer.

METHODS

A multicenter retrospective observational cohort study was conducted, including male patients diagnosed with breast cancer (invasive or in situ) in 12 Italian breast units from January 1975 to December 2019. Patients aged 18 years or older were assessed for eligibility. Exclusion criteria were metastatic cancer at diagnosis, previous cancer(s), received neoadjuvant treatment, incomplete data on (neo) adjuvant treatment(s), and/or follow-up data. Data on radiological examinations, demographic characteristics, risk factors, histological features, receptor status, treatments, and follow-up were collected.

RESULTS

In a series of 671 male patients with breast cancer assessed for eligibility, 403 (28 in situ and 375 invasive neoplasms) were included in the study. All included patients underwent surgery. The median age at surgery was 63.8 years (IQR 56.1-72.1). In 68% of cases, patients underwent echography, and in 55.1%, a mammography. Most patients were ER and PR positive (63.8%), HER2 negative (80.4%), with high (≥ 20%) Ki67 values (61.3%), and luminal B subtype (51.1%). The 10-year overall survival was 73.6% (95% CI 67.0-79.1) for invasive breast cancer and 90% (95% CI 65.6-97.4) for in situ breast cancer. In patients with invasive breast cancer, at univariable analysis, having a G3 tumor (vs. G1), pT2/3/4 (vs. pT1), pN2/3 (vs. pN0), luminal B subtype with Ki67 ≥ 20% (vs. Luminal A), were significantly associated with a higher risk of death. In multivariable analyses, pT2/3/4 (vs. pT1) remained significantly associated with a higher risk of death (HR 3.14, 95% CI 1.83-5.39), and having a HER2 positive or a triple-negative subtype (vs. Luminal A) was also significantly associated with a higher risk of mortality (HR 4.76, 95% CI 1.26-18.1).

CONCLUSION

Male breast cancer is a rare disease, the better understanding of which is necessary for a more effective diagnostic and therapeutic approach.

Nationwide Analysis of Locoregional Management for Ductal Carcinoma In Situ in Males: An NCDB Analysis of the Surgical Approach to DCIS in Males

BACKGROUND

Limited data exist regarding the optimal locoregional approach for males with ductal carcinoma in situ (DCIS). This study examined trends in management and survival for males with DCIS.

METHODS

The National Cancer Database (NCDB) was queried for males with a diagnosis of DCIS from 2006 to 2017. Patients were categorized by locoregional management. Continuous variables were evaluated by Kruskal-Wallis and categorical variables by chi-square or Fisher's exact test. Univariable and multivariable logistic regressions were performed to evaluate for predictors of patients receiving partial mastectomy (PM) with radiation. Survival was analyzed by Kaplan-Meier.

RESULTS

Between 2006 and 2017, 711 males with DCIS were identified. Most received mastectomy alone (57.1%). No change was observed in management approach from 2006 to 2017. Patients who underwent mastectomy alone were mostly hormone-positive (95.9% were estrogen-positive, 90.9% were progesterone-positive), although this cohort was least likely to receive hormone therapy (17.2%). Among those who underwent PM with radiation, only 61% of those who were hormone-positive received hormone therapy. Univariable analysis demonstrated that those of black race had lower odds of receiving PM with radiation (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.36-0.84), which persisted in the multivariable analysis with control for age and tumor size (OR, 0.32; 95% CI, 0.15-0.67). Overall survival did not differ significantly between the four treatment methods (p = 0.08).

CONCLUSIONS

The management approach to male DCIS did not change from 2006 to 2017. Survival did not differ between treatment methods. Demographic and clinicopathologic features, including race, may influence locoregional treatments received, and further studies are needed to further understand this.

Establishment of Prognostic Nomogram for Male Breast Cancer Patients: A Surveillance, Epidemiology and End Results Database Analysis

BACKGROUND

Male breast cancer (MBC) represents a rare subtype of breast cancer, with limited prognostic factor studies available. The purpose of this research was to develop a unique nomogram for predicting MBC patient overall survival (OS) and breast cancer-specific survival (BCSS).

METHODS

From 2010 to 2020, clinical characteristics of male breast cancer patients were obtained from the Surveillance, Epidemiology and End Results (SEER) database. Following univariate and multivariate analyses, nomograms for OS and BCSS were created. Kaplan-Meier plots were further generated to illustrate the relationship between independent risk variables and survival. The nomogram's ability to discriminate was measured by employing the area under a time-dependent receiver operating characteristic curve (AUC) and calibration curves. Additionally, when the nomogram was used to direct clinical practice, we also used decision curve analysis (DCA) to evaluate the clinical usefulness and net clinical benefits.

RESULTS

A total of 2143 patients were included in this research. Univariate and multivariate analysis showed that age, grade, surgery, chemotherapy status, brain metastasis status, subtype, marital status, race, and AJCC-T, AJCC-N, and AJCC-M stages were significantly correlated with OS. Lung metastasis, age, marital status, grade, surgery, and AJCC-T, AJCC-N, and AJCC-M stages were significantly correlated with BCSS. By comprising these variables, a predictive nomogram was constructed in the SEER cohort. Then, it could be validated well in the validation cohort by receiver operating characteristics (ROCs) curve and calibration plot. Furthermore, the nomogram demonstrated better decision curve analysis (DCA) results, indicating the ability to forecast survival probability with greater accuracy.

CONCLUSION

We created and validated a unique nomogram that can assist clinicians in identifying MBC patients at high risk and forecasting their OS/BCSS.

The role of postoperative radiation therapy in stage I–III male breast cancer: A population-based study from the surveillance, epidemiology, and End Results database

Background

This study aimed to investigate the role of postoperative radiation therapy in a large population-based cohort of patients with stage I–III male breast cancer (MaBC).

Methods

Patients with stage I–III breast cancer treated with surgery were selected from the Surveillance, Epidemiology, and End Results cancer database from 2010 to 2015. Multivariate logistic regression identified the predictors of radiation therapy administration. Multivariate Cox regression model was used to evaluate the predictors of survival.

Results

We identified 1321 patients. Age, stage, positive regional nodes, surgical procedure, and HER2 status were strong predictors of radiation therapy administration. There was no difference between patients who received radiation therapy and those who did not (P = 0.46); however, after propensity score matching, it was associated with improved OS (P = 0.04). In the multivariate analysis of the unmatched cohort, the factors associated with better OS were administration of radiation therapy and chemotherapy. In the subset analysis of the unmatched cohort, postoperative radiation therapy was associated with improved OS in men undergoing breast-conserving surgery (BCS), with four or more node-positive or larger primary tumours (T3/T4). Furthermore, we found no benefit of radiation therapy, regardless of the type of axillary surgery in mastectomy (MS). In older MaBC patients with T1-2N1 who underwent MS, radiation therapy showed no significant effects, regardless of chemotherapy.

Conclusion

Postoperative radiation therapy could improve the survival of MaBC patients undergoing BCS, with four or more node-positive or larger primary tumours. Moreover, it should be carefully considered in patients undergoing MS and older T1-2N1 patients.

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Postoperative radiation therapy may improve survival of some male breast cancer patients.

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Patients undergoing breast-conserving surgery or with large tumours may benefit.

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Radiation therapy had no benefits in mastectomy regardless of axillary surgery type.

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Radiation therapy was not effective in older T1-2N1 patients with receiving mastectomy.

Case Series Analysis of Male Breast Cancer

Male breast cancer is a rare disease, accounting for less than 1% of all cases of breast cancer. However, the incidence of male breast cancer is increasing. In this study, we systematically analyzed the cases of male breast cancer and evaluated the management of operable male breast cancer in daily clinical practice according to the international clinical guidelines. Data of male breast cancer characteristics and management were recorded from our electronic database. We present a case series of male breast cancer patients treated at our institution between 2013 and 2021 and summarize the recommendations on management of male patients with breast cancer. Twenty-six patients met the search criteria. The majority of tumors were hormone-receptor positive and human epidermal growth factor receptor 2 negative. Two tumors were derived from axillary accessory breast. All patients underwent mastectomy. Fifteen patients received adjuvant chemotherapy containing anthracycline or taxane. Ten patients received adjuvant radiotherapy for lymph node metastasis. Twenty-five patients received adjuvant endocrine therapy. None of patients received anti-human epidermal growth factor receptor 2 therapy. During the median follow-up period of 37 months, one patient died of previous lung cancer recurrence and one patient developed lung metastases 2 years after breast surgery. No recurrence or distant metastasis occurred in the other twenty-four patients. The incidence of male breast cancer is low. In this study, we present twenty-six cases of male patients with operable breast cancer in our department. All of them received surgery and adjuvant treatment. Early diagnosis and combined therapy benefit male patients with breast cancer. Surgery together with adjuvant treatment can bring a good prognosis.

Male Breast Cancer: An Updated Review of Epidemiology, Clinicopathology, and Treatment

Male breast cancer (MaBC) is a rare clinical entity, which makes up approximately 1% of all breast cancers. However, the incidence of MaBC has been steadily increasing over the past few decades. The risk factors for MaBC include age, black race, family history of breast cancer, genetic mutations, liver cirrhosis, and testicular abnormalities. The majority of patients with MaBC present with painless lumps, and about half of the patients have at least one lymph node involved at the time of diagnosis. The treatment of MaBC models that of female breast cancer (FeBC), but this is mainly due to lack of prospective studies for MaBC patients. The treatment modality includes surgery, adjuvant radiation, endocrine therapy, and chemotherapy. However, there are some distinct features of MaBC, both clinically and molecularly, that may warrant a different clinical approach. Ongoing multinational effort is required, to conduct clinical trials for MaBC, or the inclusion of MaBC patients in FeBC trials, to help clinicians improve care for MaBC patients.

Management of Male Breast Cancer: The Journey so Far and Future Directions

Male breast cancer is now shown to be a unique entity and should be considered as a distinct disease. Given the relatively smaller number of cases, randomized controlled trials for treatment are extremely limited and majority of practices are derived from female breast cancer studies. This paper reviews available literature on surgical, radiation, and systemic therapies for male breast cancer, and discusses current practice recommendations.

Clinicopathologic characteristics and prognosis for male breast cancer compared to female breast cancer

Male breast cancer (MBC) is rare. Due to limited information, MBC has always been understudied. We conducted a retrospective population-based cohort study using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. The clinical and biological features of female breast cancer (FBC) patients were compared with MBC patients. Cox regression models and competing risks analyses were used to identify risk factors associated with cancer-related survival in MBC and FBC groups. Results showed that MBC patients suffered from higher TNM stages, tumor grades, and a higher percentage of hormone receptor-positive tumors, compared with FBC patients (all p < 0.05). In addition, the breast tumor locations varied a lot between males and females (p < 0.05). FBC patients were associated with superior overall survival than MBC patients. Results from multivariate cox regression and competing risks analyses showed age, race, T, N, M-stages, tumor grades, estrogen receptor (ER)/progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2) overexpression were independent prognosis factors in FBC patients (all p < 0.05). MBC patients had similar risk factors to FBC patients, but PR and HER-2 status did not independently influence survival (all p > 0.05). Tumor location was an independent prognostic factor for both gender groups.

Survival Outcomes After Breast-Conserving Therapy Compared With Mastectomy for Patients With Early-Stage Invasive Micropapillary Carcinoma of the Breast: A SEER Population-Based Study

Background

Invasive micropapillary breast carcinoma (IMPC) is a relatively rare pathological type of invasive breast cancer. Little is currently known on the efficacy and safety of breast-conserving treatment (BCT, lumpectomy plus postsurgical radiation) compared with mastectomy in women diagnosed with early-stage IMPC. Accordingly, we sought to investigate the long-term prognostic differences between BCT and mastectomy in patients with T1-3N0-3M0 invasive micropapillary breast carcinoma using data from the Surveillance, Epidemiology, and End Results (SEER) database.

Materials and Methods

We retrospectively analyzed 1,203 female patients diagnosed with early-stage IMPC between 2004 and 2015 from the SEER database. The impact of different surgical approaches on patient prognosis was assessed by the Kaplan-Meier method and Cox proportional risk models.

Results

A total of 609 and 594 patients underwent mastectomy and BCT, respectively. Compared with patients who underwent a mastectomy, patients in the BCT group were older and had lower tumor diameters, lower rates of lymph nodes metastasis, and higher rates of ER receptor positivity and PR receptor positivity (p < 0.05). Kaplan-Meier plots showed that the overall survival (OS) and breast cancer-specific survival (BCSS) were higher in the BCT group than in the mastectomy group. In subgroup analysis, patients with T2 stage in the BCT group had better OS than the mastectomy group. Multivariate analysis showed no statistical difference in OS and BCSS for patients in the mastectomy group compared with the BCT group (hazard ratio (HR) = 0.727; 95% confidence interval (95% CI) 0.369–1.432, p = 0.357; HR = 0.762; 95% CI 0.302–1.923, p = 0.565; respectively). During the multivariate analysis and stratifying for the T stage, a better OS was found for patients with T2 stage in the BCT group than the mastectomy group (HR = 0.333, 95% CI: 0.149–0.741, p = 0.007). There was no significant difference in OS for patients with T1 and T3 stages between the BCT and mastectomy groups (p > 0.05).

Conclusion

In women with early-stage IMPC, BCT was at least equivalent to mastectomy in terms of survival outcomes. When both procedures are feasible, BCT should be recommended as the standard surgical treatment, especially for patients with T2 disease.

Treatment of male breast cancer: meta-analysis of real-world evidence

BACKGROUND

Breast cancer is rare in men and managed by extrapolating from breast cancer in women. The clinicopathological features of male breast cancer, however, differ from those of female breast cancer. Because clinical trials are rare, the synthesis of real-world data is one method of integrating sufficient evidence on the optimal treatment for this patient population.

METHODS

PubMed, Embase, and Cochrane Library databases were searched. Clinical studies were included if they evaluated the treatments of interest in male breast cancer; these evaluations included breast-conserving surgery (BCS) versus mastectomy, postmastectomy radiation therapy versus no radiation, the accuracy of sentinel lymph node biopsy (SLNB), and a comparison of various endocrine therapies.

RESULTS

Forty studies were retrieved. The pooled estimate of overall survival (OS) revealed no difference between BCS and mastectomy groups. Postmastectomy radiation to the chest wall significantly increased OS relative to no postmastectomy radiation (hazard ratio (HR) 0.67, 95 per cent confidence interval 0.54 to 0.84). The pooled estimates of identification and false-negative rates of SLNB were 97.4 and 7.4 per cent respectively. Tamoxifen treatment was associated with significantly increased OS compared with no tamoxifen intake (HR 0.62, 0.41 to 0.95).

CONCLUSION

Identification and false-negative rates for SLNB were comparable to those in female breast cancer. Breast-conserving surgery can be effective and safe; postmastectomy radiation to the chest wall and 5-year tamoxifen treatment improves survival.

An updated review of epidemiology, risk factors, and management of male breast cancer

Unlike female breast cancer, male breast cancer (MBC) is rare and not very well understood. Prospective data in the management of MBC are lacking and majority of treatment strategies are adopted from the established guidelines for breast cancer in women. The understanding of biology, clinical presentation, genetics, and management of MBC is evolving but there still remains a large knowledge gap due to the rarity of this disease. Older age, high estradiol levels, klinefelter syndrome, radiation exposure, gynecomastia, family history of breast cancer, BRCA2 and BRCA1 mutation are some of the known risk factors for MBC. Routine screening mammography is not recommended for asymptomatic men. Diagnostic mammogram with or without ultrasound should be considered if there is a suspicion for breast mass. Majority of men with early-stage breast cancer undergo mastectomy whereas breast conserving surgery (BCS) with sentinel lymph node biopsy (SLNB) remains an alternative option in selected cases. Since the majority of MBC are hormone receptor positive (HR+), adjuvant hormonal therapy is required. Tamoxifen for a total of 5 to 10 years is the mainstay adjuvant hormonal therapy. The role of neoadjuvant and adjuvant chemotherapy for early-stage breast cancer is uncertain and not commonly used. The role of gene recurrence scores like oncotype Dx and mammaprint is evolving and can be used as an aid for adjuvant chemotherapy. Majority of metastatic MBC are treated with hormonal therapy with either tamoxifen, gonadotropin-releasing hormone agonist (GnRH) with aromatase inhibitors (AI), or fulvestrant. Chemotherapy is reserved for patients with visceral crisis or rapidly growing tumors.

Adjuvant Radiation Therapy for Male Breast Cancer-A Rare Indication?

Due to its rarity, there are no randomized trials investigating the outcome of adjuvant radiotherapy in MBC. This study reports on patient and tumor characteristics of 41 consecutive MBC patients treated between 1990 and 2018 and on clinical outcomes after surgical resection of tumors and adjuvant radiotherapy of the chest wall or breast. Local control (LC), locoregional control (LRC), overall survival (OS), disease-free survival (DFS), and toxicity were evaluated. After a median follow-up of 80 months (95% CI: 14.6-213.8 months) there was only one recurrence, in a patient's locoregional lymph nodes 17 months after start of radiotherapy, resulting in an LC rate of 100% at 5 years and a 5-year LRC rate of 97.4% (standard deviation (SD): 0.025). Five-year DFS and OS rates were 64.6% (SD: 0.085) and 57.2% (SD: 0.082), respectively. Adjuvant radiotherapy was tolerated well without high-grade (CTCAE grade > II) adverse events. After tumor resection and adjuvant radiotherapy, LC and LRC rates in MBC patients are excellent and comparable to results found for female breast cancer (FBC) patients. However, as patients are often diagnosed with locally advanced, higher-risk tumors, distant recurrences remain the major failure pattern.

Male Breast Cancer: 13-Year Single Institution Experience

Due to the low incidence of male breast cancer (BC), there are few studies evaluating outcomes. We evaluated the clinicopathologic features and outcomes of male BC. Male patients with BC from January 2006 to December 2018 were identified. Of 49 patients, mean age was 64 (range 33-94) years. Of the 27 (55.1%) patients who had genetic testing, 9 (33.3%) had a Breast Cancer gene (BRCA) 1 or 2 mutation. The majority of patients had a mastectomy (n = 43/49, 87.8%) and had invasive ductal carcinoma (n = 47/49, 95.9%). 20 patients (n = 20/43, 46.5%) had positive lymph nodes. 41 (n = 41/47, 87.2%) patients had estrogen receptor positive disease. The majority of patients were pathologic stage 2 (n = 21/46, 45.7%), followed by stage 1 (n = 15/46, 32.6%), stage 3 (n = 6/46, 13.0%), and stage 4 (n = 4/46, 8.7%). Eight patients had the 21-gene recurrence score performed. Of patients with stage 1-3 BC, 10 (n = 10/43, 23.3%) patients had recurrence. With median follow-up of 4.1 (range .6-10.6) years, 5-year overall survival was 82.9% and 5-year disease-free survival was 65.9%. In conclusion, our cohort of patients with male BC had a high incidence of BRCA mutations and most commonly had high-grade estrogen positive stage 2 tumors. Breast conserving surgery was utilized in 4% of patients and genomic testing utilized in 55% of patients.

Pharmacological management of male breast cancer

INTRODUCTION

Despite its rarity, male breast cancer shows a steadily rising incidence. Given the absence of ad hoc prospective randomized clinical trials, treatment strategies are based on extrapolation from female breast cancer recommendations or solely on population-based data.

AREAS COVERED

This review discusses the current treatment landscape for male breast cancer in the adjuvant and in the metastatic setting. The authors also discuss the biology and genomic landscape of male breast cancer. Original research and review articles, relative to the period 2010-2019, were included in the review of the literature.

EXPERT OPINION

There is a major medical need to include male patients with breast cancer in prospective clinical trials. The call to equality in breast cancer care can be pursued via two divergent paths: (i) a gender-neutral delivery of breast cancer information and (ii) the creation of separate sections, for the more common female breast cancer and for the rare male ones. We propose to differentiate male breast cancer care, acknowledging unique onco-sexual and social needs that can be only partially shared.

Impact of Adjuvant Radiation Therapy in Patients With Male Breast Cancer: A Multicenter International Analysis

Purpose

Breast cancer in men accounts for approximately 1% of all breast cancers. Breast cancer trials have routinely excluded men. The aim of this analysis was to determine the effect of different treatment factors, in particular, postoperative radiation therapy (RT) on long-term outcomes.

Methods and Materials

Seventy-one patients with male breast cancer treated in 5 closely cooperating institutions between 2003 and 2019 were analyzed.

Results

Almost all patients (95%) underwent surgical resection. Forty-two patients (59%) received chemotherapy, and 59 (83%) received adjuvant hormonal therapy. Of the 71 patients, 52 (73%) were treated with RT. The rate of recurrence was 20% in the whole cohort, with a locoregional recurrence rate of 3%. In the entire group, the 5-year local control (LC) was 95%, whereas 5-year progression-free survival (PFS) and 5-year overall survival (OS) were 62% and 96%, respectively. There was a lower rate of relapses after adjuvant RT (19% vs 32%, P = .05) without in-field relapse after postoperative RT (0%) versus 10% in patients without RT (P = .02). In the multivariate analysis performed, hormonal therapy administration was found to have a possible significant effect on LC and PFS. Administration of adjuvant RT and stage affect PFS. In patients who received RT, there were no grade 3 or 4 acute toxicities.

Conclusions

Adjuvant RT is an effective and safe treatment for male breast cancer patients with no infield relapses and better PFS. Hormonal therapy administration was found to have a possible effect on LC and PFS.

Male breast cancer in the United States: Treatment patterns and prognostic factors in the 21st century

BACKGROUND

Male breast cancer (MBC) is a rare disease for which there is limited understanding of treatment patterns and prognostic factors.

METHODS

Men with TNM stage I to stage III breast cancer diagnosed between 2004 and 2014 in the National Cancer Data Base were included. Trends in treatment modalities were described using the average annual percentage change (AAPC) and estimated using Joinpoint software for the analysis of trends. Kaplan-Meier curves and the multivariate Cox proportional hazards regression model were used to compare survival between subgroups and to identify prognostic factors.

RESULTS

A total of 10,873 MBC cases were included, with a median age at diagnosis of 64 years. Breast-conserving surgery was performed in 24% of patients, and 70% of patients undergoing breast conservation received radiotherapy. Approximately 44% of patients received chemotherapy, and 62% of patients with estrogen receptor-positive disease received endocrine therapy. Oncotype DX was ordered in 35% of patients with lymph node-negative, estrogen receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative tumors. During the study period, there was a significant increase in the rates of total mastectomy, contralateral prophylactic mastectomy, radiotherapy after breast conservation, ordering of Oncotype DX, and the use of endocrine therapy (P < .05). On multivariate analysis, factors found to be associated with worse overall survival were older age, black race, higher Charlson Comorbidity Index, high tumor grade and stage of disease, and undergoing total mastectomy. Residing in a higher income area; having progesterone receptor-positive tumors; and receipt of chemotherapy, radiotherapy, and endocrine therapy were associated with better overall survival.

CONCLUSIONS

Despite the lack of prospective randomized trials in patients with MBC, the results of the current study demonstrated that the treatment of this disease has evolved over the years. These findings further the understanding of the modern treatment and prognosis of MBC, and identify several areas for further research.

Metastasis pattern and prognosis of male breast cancer patients in US: a population-based study from SEER database

Background

The aims of this study were to analyze the metastasis pattern and prognosis of male breast cancer (MBC) and compare it with female breast cancer (FBC), and to determine the independent factors affecting the prognosis of MBC patients.

Methods

Metastatic MBC diagnosed in the Surveillance, Epidemiology and End results (SEER) database from 2010 to 2015 were selected. Chi-squared test was used to compare clinicopathological characteristics. Survival differences were compared by Kaplan-Meier analysis. Cox proportional hazard model was used to determine the prognostic factors affecting overall survival.

Results

A total of 2754 MBC patients were identified, of which 196 had distant metastasis. Compared with nonmetastatic MBC, metastatic MBC patients had a higher proportion of <60 years old and grade III-IV, and were more likely to receive chemotherapy and radiotherapy, while the proportion of surgery, central portion of the breast, and Her2-/HR+ was lower. Compared with metastatic FBC, metastatic MBC patients had a higher proportion of ⩾60 years old, central portion of the breast, surgery, simultaneous bone and lung metastasis, while the proportion of Her2+/HR-, triple negative, liver metastasis only, and simultaneous bone and liver metastasis was lower. MBC patients with lung alone, bone alone, and simultaneous lung and bone metastasis had a higher hazard ratio (2.41; 3.06; 2.52; p < 0.0001) compared with nonmetastatic patients.

Conclusions

Compared with nonmetastatic MBC patients, metastatic MBC patients had unique clinicopathological features, and were also different from metastatic FBC patients. However, there was no difference in prognosis between metastatic MBC and FBC patients. Distant metastasis was an independent risk factor for the prognosis of MBC patients.

A contemporary review of male breast cancer: current evidence and unanswered questions

Male breast cancer is rare, accounting for 1% of all breast cancer diagnoses in the USA. Because of its rarity, most major breast cancer trials have included only female patients. This has resulted in limited prospective data to guide the clinical management of men with breast cancer. As a result, treatment decisions are typically extrapolated from data generated in female patients. This approach may be suboptimal, particularly considering the differing hormonal milieus between men and women with respect to both breast cancer development and treatment. Herein, we summarize current knowledge of the biology and clinicopathology of male breast cancer and review current approaches to locoregional and systemic management of this rare disease.

Is Breast-Conserving Therapy Appropriate for Male Breast Cancer Patients? A National Cancer Database Analysis

BACKGROUND

Current treatment guidelines for male breast cancer are predominantly guided by female-only clinical trials. With scarce research, it is unclear whether breast-conserving therapy (BCT) is equivalent to mastectomy in men. We sought to compare overall survival (OS) among male breast cancer patients who underwent BCT versus mastectomy.

METHODS

We performed a retrospective analysis of 8445 stage I-II (T1-2 N0-1 M0) male breast cancer patients from the National Cancer Database (2004-2014). Patients were grouped according to surgical and radiation therapy (RT). BCT was defined as partial mastectomy followed by RT. Multivariable and inverse probability of treatment-weighted (IPTW) Cox proportional hazards models were used to compare OS between treatment groups, controlling for demographic and clinicopathologic characteristics.

RESULTS

Most patients underwent total mastectomy (61.2%), whereas 18.2% underwent BCT, 12.4% underwent total mastectomy with RT, and 8.2% underwent partial mastectomy alone. In multivariable and IPTW models, partial mastectomy alone, total mastectomy alone, and total mastectomy with RT were associated with worse OS compared with BCT (p < 0.001 all). Ten-year OS was 73.8% for BCT and 56.3, 58.0 and 56.3% for other treatment approaches. Older age, higher T/N stage, histological grade, and triple-negative receptor status were associated with poorer OS (p < 0.05). Subgroup analysis by stage demonstrated similar results.

CONCLUSIONS

In this national sample of male breast cancer patients, BCT was associated with greater survival. The underlying mechanisms of this association warrant further study, because more routine adoption of BCT in male breast cancer appears to translate into clinically meaningful improvements in survival.

Pattern of care of adjuvant radiotherapy in male breast cancer patients in clinical practice: an observational study

BACKGROUND AND PURPOSE

Due to the rarity of male breast cancer (male BC), no consensus has been reached regarding the most appropriate curative treatment strategy. The objective of the present observational study was to identify patient and tumor characteristics and assess the role of radiotherapy (RT) in clinical practice.

METHODS

Between 1998 and 2014, data of male BC patients treated at two breast centers were consecutively collected and retrospectively analyzed. Patients were stratified based on the addition of adjuvant RT. Data on overall survival (OS) and local recurrence-free survival (LRFS) were estimated with the Kaplan-Meier method and compared by the log-rank test.

RESULTS

A consecutive cohort of 58 male BC patients was evaluated. Median follow-up was 56 months. Twenty-one patients (36.2%) received adjuvant RT. Overall, patients undergoing postoperative RT were characterized by more high-risk features. Patients receiving postoperative RT had significantly more frequently a high UICC stage (50 vs. 9.7% UICC III, p = 0.018) and positive lymph nodes as compared to patients undergoing surgery alone (65 vs. 34.4% pN+, p = 0.046). Accordingly, there was a higher proportion of patients receiving axillary lymph node dissection in the RT group (71.4 vs. 35.6%). Mastectomy was performed in 31/37 (86.1%) in the surgery group as compared to 14/21 (66.7%) in patients receiving postoperative RT. In addition, RT patients were more likely to receive endocrine therapy (78.9 vs. 39.3%, p = 0.016). Outcome was not significantly different between the groups (5-year LRFS: 89.8 vs. 80.0%, p = 0.471 and 5‑year OS 88.4 vs. 88.9%, p = 0.819).

CONCLUSION

The present observational study evaluated the pattern of care in male BC patients treated in clinical practice. Due to its rarity, randomized clinical trials are unlikely and male BC remains an entity with a poor evidence base. Nevertheless, RT remains a crucial component of the multidisciplinary treatment strategy in male BC.