Survival Outcomes in Women with Unilateral, Triple-Negative, Breast Cancer Correlated with Contralateral Prophylactic Mastectomy.

BACKGROUND: Despite increased utilization of contralateral prophylactic mastectomy (CPM), there is insufficient evidence that it improves survival in average-risk women with unilateral breast cancer. CPM may be of heightened interest to patients with triple negative breast cancer (TNBC) because these patients are more likely to have BRCA1 mutation-associated disease and are not candidates for the chemoprevention benefits of adjuvant endocrine therapy. METHODS: Survival and recurrence outcomes were evaluated for all TNBC patients from a multi-institutional database (1999-2018) at two academic cancer programs in two metropolitan cities of the Northeast and Midwest. Median follow-up time was 3.7 years. RESULTS: Seven hundred and nighty six TNBC patients were evaluated and 15.45% underwent CPM. Women undergoing CPM were more likely to be white (p < 0.001), younger (p < 0.001), and underwent genetic testing (p < 0.001). A borderline survival benefit was observed for TNBC patients undergoing CPM (5-year overall survival 95.1% vs. 85.0%; p = 0.05). There was no difference in survival when BRCA mutation carriers were excluded (5-year overall survival 94.1% vs. 85.2%; p = 0.12). For BRCA mutation carriers, a numeric trend was observed for improved survival for patients undergoing CPM (5-year overall survival 97.2% vs. 84.1%; p = 0.35). Among patients not undergoing CPM, the rate of developing a new primary breast cancer was 2.2% (15/673). Among these 15 patients, 20% (3/15) were known BRCA mutation carriers. CONCLUSIONS: Our data demonstrate no survival benefit for TNBC patients without BRCA1/2 mutations undergoing CPM.

African Ancestry-Associated Gene Expression Profiles in Triple-Negative Breast Cancer Underlie Altered Tumor Biology and Clinical Outcome in Women of African Descent.

Women of sub-Saharan African descent have disproportionately higher incidence of triple-negative breast cancer (TNBC) and TNBC-specific mortality across all populations. Population studies show racial differences in TNBC biology, including higher prevalence of basal-like and quadruple-negative subtypes in African Americans (AA). However, previous investigations relied on self-reported race (SRR) of primarily U.S. populations. Due to heterogeneous genetic admixture and biological consequences of social determinants, the true association of African ancestry with TNBC biology is unclear. To address this, we conducted RNA sequencing on an international cohort of AAs, as well as West and East Africans with TNBC. Using comprehensive genetic ancestry estimation in this African-enriched cohort, we found expression of 613 genes associated with African ancestry and 2,000+ associated with regional African ancestry. A subset of African-associated genes also showed differences in normal breast tissue. Pathway enrichment and deconvolution of tumor cellular composition revealed that tumor-associated immunologic profiles are distinct in patients of African descent. SIGNIFICANCE: Our comprehensive ancestry quantification process revealed that ancestry-associated gene expression profiles in TNBC include population-level distinctions in immunologic landscapes. These differences may explain some differences in race-group clinical outcomes. This study shows the first definitive link between African ancestry and the TNBC immunologic landscape, from an African-enriched international multiethnic cohort. See related commentary by Hamilton et al., p. 2496. This article is highlighted in the In This Issue feature, p. 2483.

Benefit of adjuvant chemotherapy in node-negative T1a versus T1b and T1c triple-negative breast cancer.

PURPOSE: National comprehensive cancer network guidelines recommend delivery of adjuvant chemotherapy in node-negative triple-negative breast cancer (TNBC) if the tumor is > 1 cm and consideration of adjuvant chemotherapy for T1b but not T1a disease. These recommendations are based upon sparse data on the role of adjuvant chemotherapy in T1a and T1b node-negative TNBC. Our objective was to clarify the benefits of chemotherapy for patients with T1N0 TNBC, stratified by tumor size. METHODS: We performed a retrospective analysis of survival outcomes of TNBC patients at two academic institutions in the United States from 1999 to 2018. Primary tumor size, histology, and nodal status were based upon surgical pathology. The Kaplan-Meier plot and 5-year unadjusted survival probability were evaluated. RESULTS: Among 282 T1N0 TNBC cases, the status of adjuvant chemotherapy was known for 258. Mean follow-up was 5.3 years. Adjuvant chemotherapy was delivered to 30.5% of T1a, 64.7% T1b, and 83.9% T1c (p < 0.0001). On multivariable analysis, factors associated with delivery of adjuvant chemotherapy were tumor size and grade 3 disease. Improved overall survival was associated with use of chemotherapy in patients with T1c disease (93.2% vs. 75.2% p = 0.008) but not T1a (100% vs. 100% p = 0.3778) or T1b (100% vs. 95.8% p = 0.2362) disease. CONCLUSION: Our data support current guidelines indicating benefit from adjuvant chemotherapy in node-negative TNBC associated with T1c tumors but excellent outcomes were observed in the cases of T1a and T1b disease, regardless of whether adjuvant chemotherapy was delivered.

Screening mammography mitigates breast cancer disparities through early detection of triple negative breast cancer.

PURPOSE: Screening mammography improves breast cancer survival through early detection, but Triple Negative Breast Cancer (TNBC) is more difficult to detect on mammography and has lower survival compared to non-TNBC, even when detected at early stages. TNBC is twice as common among African American (AA) compared to White American (WA) women, thereby contributing to the 40% higher breast cancer mortality rates observed in AA women. The role of screening mammography in addressing breast cancer disparities is therefore worthy of study. METHODS: Outcomes were evaluated for TNBC patients treated in the prospectively-maintained databases of academic cancer programs in two metropolitan cities of the Northeast and Midwest, 1998-2018. RESULTS: Of 756 TNBC cases, 301 (39.8%) were mammographically screen-detected. 46% of 189 AA and 38.5% of 460 WA patients had screen-detected TNBC (p = 0.16). 25.3% of 257 TNBC cases ≤50 years old had screen-detected disease compared to 47.3% of 499 TNBC cases >50 years old (p < 0.0001). 220/301 (73.1%) screen-detected TNBC cases were T1 lesions versus 118/359 (32.9%) non-screen-detected cases (p < 0.0001). Screen-detected TNBC was more likely to be node-negative (51.9% v. 40.4%; p < 0.0001). Five-year overall survival was better in screen-detected TNBC compared to nonscreen-detected TNBC (92.8% v. 81.5%; p < 0.0001) in the entire cohort. The magnitude of this effect was most significant among AA patients (Fig. 1). Screening-related survival patterns were similar among AA and WA patients in both cities. CONCLUSION: Data from two different cities demonstrates the value of screening mammography to mitigate breast cancer disparities in AA women through the early detection of TNBC.

Investigation of triple-negative breast cancer risk alleles in an International African-enriched cohort.

Large-scale efforts to identify breast cancer (BC) risk alleles have historically taken place among women of European ancestry. Recently, there are new efforts to verify if these alleles increase risk in African American (AA) women as well. We investigated the effect of previously reported AA breast cancer and triple-negative breast cancer (TNBC) risk alleles in our African-enriched International Center for the Study of Breast Cancer Subtypes (ICSBCS) cohort. Using case-control, case-series and race-nested approaches, we report that the Duffy-null allele (rs2814778) is associated with TNBC risk (OR = 3.814, p = 0.001), specifically among AA individuals, after adjusting for self-indicated race and west African ancestry (OR = 3.368, p = 0.007). We have also validated the protective effect of the minor allele of the ANKLE1 missense variant rs2363956 among AA for TNBC (OR = 0.420, p = 0.005). Our results suggest that an ancestry-specific Duffy-null allele and differential prevalence of a polymorphic gene variant of ANKLE1 may play a role in TNBC breast cancer outcomes. These findings present opportunities for therapeutic potential and future studies to address race-specific differences in TNBC risk and disease outcome.

Outcome of African-American compared to White-American patients with early-stage breast cancer, stratified by phenotype.

BACKGROUND: Breast cancer mortality rates are 39% higher in the African-American (AA) women compared to White-American (WA) women despite the advances in overall breast cancer screening and treatments. Several studies have undertaken to identify the factors leading to this disparity in United States with possible effects of lower socioeconomic status and underlying aggressive biology. METHODS: A retrospective analysis was done using a prospectively maintained database of a metropolitan health system. Patients were selected based on diagnosis of early-stage breast cancer between 10/1998 and 02/2017, and included women over age of 18 with clinically node-negative disease. Patients were then stratified by phenotype confirmed by pathology and patient-identified race. RESULTS: A total of 2,298 women were identified in the cohort with 39% AA and 61% WA women. The overall mean age at the time of diagnosis for AA women was slightly younger at 60 years compared to 62 years for WA women (p = 0.003). Follow-up time was longer for the WA women at 95 months vs. 86 months in AA women. The overall 5-year survival was analyzed for the entire cohort, with the lowest survival occurring in patients with triple-negative breast cancer (TNBC). Phenotype distribution revealed a higher incidence of TNBC in AA women compared to WA women (AA 16% vs. WA 10%; p < 0.0001). AA women also had higher incidence of HER2 positive cancers (AA 16.8% vs. WA 15.3%; p < 0.0001). WA women had a significantly higher distribution of Non-TNBC/HER2-negative phenotype (AA 55% vs. WA 65%; p < 0.0001). Furthermore, a subgroup analysis was done for a sentinel lymph node (SLN) negative cohort that showed higher rates of grade 3 tumors in AA (AA 35% vs. WA 23%; p < 0.0001); and higher rates of grade 1 and grade 2 tumors in WA (30% vs. 21% and 44% vs. 40%). Despite higher grade tumors in AA women, five-year overall survival outcomes in SLN-negative cohort did not differ between AA and WA women when stratifying based on tumor subtype. CONCLUSION: Breast cancer survival disparities in AA and WA women with SLN-negative breast cancer are diminished when evaluated at early-stage cancers defined by SLN-negative tumors. Our evaluation suggests that when diagnosed early, phenotype does not contribute to racial survival outcomes. The lower survival rate in AA women with breast cancer may be attributed to later stage biology between the two races, or underlying socioeconomic disparities.

Multiethnic PDX models predict a possible immune signature associated with TNBC of African ancestry.

PURPOSE: Triple-negative breast cancer (TNBC) is an aggressive subtype most prevalent among women of Western Sub-Saharan African ancestry. It accounts for 15-25% of African American (AA) breast cancers (BC) and up to 80% of Ghanaian breast cancers, thus contributing to outcome disparities in BC for black women. The aggressive biology of TNBC has been shown to be regulated partially by breast cancer stem cells (BCSC) which mediate tumor recurrence and metastasis and are more abundant in African breast tumors. METHODS: We studied the biological differences between TNBC in women with African ancestry and those of Caucasian women by comparing the gene expression of the BCSC. From low-passage patient derived xenografts (PDX) from Ghanaian (GH), AA, and Caucasian American (CA) TNBCs, we sorted for and sequenced the stem cell populations and analyzed for differential gene enrichment. RESULTS: In our cohort of TNBC tumors, we observed that the ALDH expressing stem cells display distinct ethnic specific gene expression patterns, with the largest difference existing between the GH and AA ALDH+ cells. Furthermore, the tumors from the women of African ancestry [GH/AA] had ALDH stem cell (SC) enrichment for expression of immune related genes and processes. Among the significantly upregulated genes were CD274 (PD-L1), CXCR9, CXCR10 and IFI27, which could serve as potential drug targets. CONCLUSIONS: Further exploration of the role of immune regulated genes and biological processes in BCSC may offer insight into developing novel approaches to treating TNBC to help ameliorate survival disparities in women with African ancestry.

A rare presentation of bilateral, synchronous male breast cancer.

Rarity of male breast cancer limits available clinical research and data for management guidance and screening guidelines for patients at high risk. Here, we report on a patient with bilateral, synchronous male breast cancer with discussion of risk factors and need for possible screening.

Hereditary Susceptibility for Triple Negative Breast Cancer Associated With Western Sub-Saharan African Ancestry: Results From an International Surgical Breast Cancer Collaborative.

OBJECTIVE: To investigate subtype-specific risk of germline alleles associated with triple negative breast cancer (TNBC) in African ancestry populations. BACKGROUND: Breast cancer (BC) mortality is higher in African American (AA) compared to White American (WA) women; this disparity is partly explained by 2-fold higher TNBC incidence. METHODS: We used a surgically maintained biospecimen cohort of 2884 BC cases. Subsets of the total (760 AA; 962 WA; 910 West African/Ghanaian; 252 East African/Ethiopian) were analyzed for genotypes of candidate alleles. A subset of 417 healthy controls were also genotyped, to measure associations with overall BC risk and TNBC. RESULTS: TNBC frequency was highest in Ghanaian and AA cases (49% and 44% respectively; P < 0.0001) and lowest in Ethiopian and WA cases (17% and 24% respectively; P < 0.0001). TNBC cases had higher West African ancestry than non-TNBC (P < 0.0001). Frequency of the Duffy-null allele (rs2814778; an African ancestral variant adopted under selective pressure as protection against malaria) was associated with TNBC-specific risk (P < 0.0001), quantified West African Ancestry (P < 0.0001) and was more common in AA, Ghanaians, and TNBC cases. Additionally, rs4849887 was significantly associated with overall BC risk, and both rs2363956 and rs13000023 were associated with TNBC-specific risk, although none as strongly as the Duffy-null variant. CONCLUSIONS: West African ancestry is strongly correlated with TNBC status, as well as germline variants related to BC risk. The Duffy-null allele was associated with TNBC risk in our cohort.

Distribution and Short-term Prognostic Value of the 21-gene recurrence score in African American compared to White American breast cancer patients.

We evaluated 328 patients (34.8% African American [AA]; 65.2% White American [WA]) with hormone receptor-positive, HER2/neu-negative breast cancer. Mean age (60 years); mean tumor size (1.6 and 1.7 cm for AA and WA, respectively) were similar, and mean BMI was higher for AA (33 vs 29.8; P = 0.001). Recurrence score (RS) distribution was similar- 8.3% AA and 5.9% WA with high RS (≥31). No significant differences were observed in delivery of chemotherapy stratified by score. With median follow-up 27.2 months for AA and 33.4 months for WA, distant recurrence occurred in 1.0% and 1.6%, respectively (P = 1). Our results suggest comparable RS utility in AA and WA patients.

Evaluation of a Multidisciplinary Team Approach for Generating Survivorship Care Plan Treatment Summaries in Patients With Breast Cancer.

INTRODUCTION: The optimal structure for survivorship care plan (SCP) programs and methodology for generating treatment summaries (TSs) has not yet been defined, but the Commission on Cancer and the National Accreditation Program for Breast Centers both mandate that participating oncology programs implement SCP-TS processes for patients that have completed treatment. METHODS: We used the Institute for Healthcare Improvement's Plan-Do-Study-Act model for conducting a quality improvement project evaluating two different SCP-TS programs implemented at the Henry Ford Health System/Henry Ford Cancer Institute's Breast Oncology Program in Detroit, Michigan. System I involved TSs drafted by nonspecialist breast clinic staff; System II involved TSs vetted through a multidisciplinary breast specialist conference approach. Accuracy of basic documentation entries related to dates and components of treatment were compared for the two approaches. RESULTS: Seventy-one System I and 93 System II documents were reviewed. Documentation was accurate in at least 90% of documents for both systems regarding delivery of chemotherapy and/or endocrine therapy and for documenting the identity of the various members of the cancer treatment team. Both systems had notable inaccuracies in documenting type of surgery performed, but System II had fewer inaccuracies than System I (33.78% v 51.67%, respectively; P = .05). System II, compared with System I, had fewer inaccuracies in documenting date of diagnosis (9.68% v 25.35%, respectively; P = .01) and had less missing information for dose of radiation delivered (9.33% v 33.9%, respectively; P < .01). CONCLUSION: A multidisciplinary team approach to drafting and reviewing SCP-TS documents improved content accuracy for our program, but ongoing education regarding documentation of various surgical procedures is warranted.

Breast Cancer Knowledge and Decisions Made for Contralateral Prophylactic Mastectomy: A Survey of Surgeons and Women in the General Population.

BACKGROUND: Decisions made to undergo contralateral prophylactic mastectomy, in women at low risk for bilateral disease, are often attributed to a lack of knowledge. This study examines the role knowledge plays in determining surgical treatment for unilateral breast cancer made by laywomen and surgeons for themselves or loved ones. METHODS: The study cohort had three groups: (1) laywomen in the general population, (2) breast surgeons, and (3) plastic surgeons. Laywomen were recruited using Amazon Mechanical Turk Crowd Sourcing. Breast and plastic surgeons from nine states were sent electronic surveys. Demographic and contralateral prophylactic mastectomy-specific data on decisions and knowledge were collected and analyzed. RESULTS: Surveys from 1333 laywomen, 198 plastic surgeons, and 142 breast surgeons were analyzed. A significantly greater proportion of laywomen in the general population favored contralateral prophylactic mastectomy (67 percent) relative to plastic (50 percent) and breast surgeons (26 percent) (p < 0.0001). Breast surgeons who chose contralateral prophylactic mastectomy were younger (p = 0.044) and female (0.012). On assessment of knowledge, 78 percent of laywomen had a low level of breast cancer knowledge. Laywomen with higher levels of breast cancer knowledge had lower odds of choosing contralateral prophylactic mastectomy (OR, 0.37; 95 percent CI, 0.28 to 0.49). CONCLUSIONS: Fewer women are likely to make decisions in favor of contralateral prophylactic mastectomy with better breast cancer-specific education. A knowledge gap likely explains the lower rates with which surgeons choose contralateral prophylactic mastectomy for themselves or loved ones; however, some surgeons who were predominantly young and female favor contralateral prophylactic mastectomy. Improving patient education on surgical options for breast cancer treatment is critical, with well-informed decisions as the goal.

Effects of Implementing a Breast Surgery Rotation on ABSITE Scores and Surgical Case Volume.

BACKGROUND: Little is known about general surgery trainees' education regarding management of breast problems. We sought to measure the impact of a dedicated breast surgery rotation on American Board of Surgery In-Service Examination (ABSITE) scores and operative volumes. METHODS: A breast surgery rotation was implemented at our program in July 2016. We obtained the January 2017 ABSITE scores for postgraduate year (PGY) 1-3 residents, and obtained the case volumes for PGY 1-3 residents during the years 2015-2016 and 2016-2017. RESULTS: We compared the performance on total questions and skin, soft tissue, and breast questions between the residents who had the breast rotation before the ABSITE to those that had it after. There was no difference in the average overall percentage (70.2% versus 71.7%, P = 0.55) or in the average skin, soft tissue, and breast percentage (70% versus 71.4%, P = 0.72). A postgraduate year-to-year comparison showed an increase in average total major cases among the PGY-1 residents (93.8 versus 166.8, P = 0.02), and an increase in average breast cases among the PGY-1 (17.8 versus 27 cases, P < 0.01) and PGY-2 (27.3 versus 47.7 cases, P = 0.02) years. There was an increase in the proportion of complex breast cases performed by PGY-3 residents (23.2% versus 33.1%, P = 0.01). CONCLUSIONS: A dedicated breast surgery rotation did not detract from the nonbreast general surgery educational experience of junior residents (as measured by ABSITE scores), and it increased the case volume of breast as well as total major cases among junior residents. A breast surgery rotation is valuable for strengthening surgical case volumes.

Utilization of the 21-Gene Recurrence Score in a Diverse Breast Cancer Patient Population: Development of a Clinicopathologic Model to Predict High-Risk Scores and Response to Neoadjuvant Chemotherapy.

INTRODUCTION: The 21-gene expression profile [Oncotype DX Recurrence Score (RS)] stratifies benefit from adjuvant chemotherapy in hormone receptor (HR)-positive, HER2/neu-negative, node-negative breast cancer. It is not routinely applied to predict neoadjuvant chemotherapy (NACT) response; data in diverse patient populations also are limited. We developed a statistical model based on standard clinicopathologic features to identify high-risk cases (RS > 30) and then evaluated ability of predicted high RS to predict for NACT downstaging. METHODS: Primary surgery patients with Oncotype DX RS testing 2012-2016 were identified from a prospectively-maintained database. A RS predictive model was created and applied to a dataset of comparable NACT patients. Response was defined as tumor size decrease ≥ 1 cm. RESULTS: Of 394 primary surgery patients-60.4% white American; 31.0% African American-RS distribution was similar for both groups. No single feature reliably identified high RS patients; however, a model accounting for age, HR expression, proliferative index (MIB1/Ki67), histology, and tumor size was generated, with receiver operator area under the curve 0.909. Fifty-six NACT patients were identified (25 African American). Of 21 cases with all relevant clinicopathology, 14 responded to NACT and the model generated high-risk RS in 14 (100%); conversely, of 16 cases generating high-risk RS, only 2 did not respond. CONCLUSIONS: Predictive modelling can identify high RS patients; this model also can identify patients likely to experience primary tumor downstaging with NACT. Until this model is validated in other datasets, we recommend that Oncotype-eligible patients undergo primary surgery with decisions regarding chemotherapy made in the adjuvant setting.

Association Between Benign Breast Disease in African American and White American Women and Subsequent Triple-Negative Breast Cancer.

IMPORTANCE: Compared with white American (WA) women, African American (AA) women have a 2-fold higher incidence of breast cancers that are negative for estrogen receptor, progesterone receptor, and ERBB2 (triple-negative breast cancer [TNBC]). Triple-negative breast cancer, compared with non-TNBC, likely arises from different pathogenetic pathways, and benign breast disease (BBD) predicts future non-TNBC. OBJECTIVE: To determine whether AA identity remains associated with TNBC for women with a prior diagnosis of BBD. DESIGN, SETTING, AND PARTICIPANTS: This study is a retrospective analysis of data of a cohort of 2588 AA and 3566 WA women aged between 40 and 70 years with a biopsy-proven BBD diagnosis. The data-obtained from the Pathology Information System of Henry Ford Health System (HFHS), an integrated multihospital and multispecialty health care system headquartered in Detroit, Michigan-include specimens of biopsies performed between January 1, 1994, and December 31, 2005. Data analysis was performed from November 1, 2015, to June 15, 2016. MAIN OUTCOMES AND MEASURES: Subsequent breast cancer was stratified on the basis of combinations of hormone receptor and ERBB2 expression. RESULTS: Case management, follow-up, and outcomes received or obtained by our cohort of 2588 AA and 3566 WA patients were similar, demonstrating that HFHS delivered care equitably. Subsequent breast cancers developed in 103 (4.1%) of AA patients (mean follow-up interval of 6.8 years) and 143 (4.0%) of WA patients (mean follow-up interval of 6.1 years). More than three-quarters of subsequent breast cancers in each subset were ductal carcinoma in situ or stage I. The 10-year probability estimate for developing TNBC was 0.56% (95% CI, 0.32%-1.0%) for AA patients and 0.25% (95% CI, 0.12%-0.53%) for WA patients. Among the 66 AA patients who developed subsequent invasive breast cancer, 16 (24.2%) developed TNBC compared with 7 (7.4%) of the 94 WA patients who developed subsequent invasive breast cancers and had complete biomarker data (P = .01). CONCLUSIONS AND RELEVANCE: This study is the largest analysis to date of TNBC in the context of racial/ethnic identity and BBD as risk factors. The study found that AA identity persisted as a significant risk factor for TNBC. This finding suggests that AA identity is associated with inherent susceptibility for TNBC pathogenetic pathways.

Postmastectomy Radiation Therapy and Two-Stage Implant-Based Breast Reconstruction: Is There a Better Time to Irradiate?

BACKGROUND: The ideal timing of postmastectomy radiation therapy (PMRT) in the setting of two-stage implant-based breast reconstruction remains unclear. In this cohort study, the authors sought to determine whether complication rates differed between patients who received PMRT following tissue expander placement (TE-XRT) and those who received PMRT after exchange for permanent implants (Implant-XRT) utilizing using prospective, multicenter data. METHODS: Eligible patients in the Mastectomy Reconstruction Outcomes Consortium study from 11 institutions across North America were included in the analysis. All patients had at least 6-month follow-up after their last intervention (i.e., implant exchange for TE-XRT patients, and radiation for Implant-XRT patients). Complications including seroma, hematoma, infection, wound dehiscence, capsular contracture, and implant loss were recorded. RESULTS: The authors identified a total of 150 patients who underwent immediate, two-stage implant-based breast reconstruction and received PMRT. Of these, there were TE-XRT 104 patients (69.3 percent) and 46 (30.7 percent) Implant-XRT patients. There were no differences in the incidence of any complications or complications leading to reconstructive failure between the two cohorts. After adjusting for patient characteristics and site effect, the timing of PMRT (i.e., TE-XRT versus Implant-XRT) was not a significant predictor in the development of any complication, a major complication, or reconstructive failure. CONCLUSION: In the setting of PMRT and two-stage implant-based reconstruction, patients who received PMRT after expander placement (TE-XRT) did not have a higher incidence or increased odds of developing complications than those who received PMRT after exchange for a permanent implant (Implant-XRT). CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Differences between Breast Conservation-Eligible Patients and Unilateral Mastectomy Patients in Choosing Contralateral Prophylactic Mastectomies.

There has been an increasing use of bilateral mastectomy (BM) for breast cancer. We sought to examine our trends among breast conservation (BCT) candidates and women recommended for unilateral mastectomy (UM). Our prospective breast cancer database was queried for women with a first-time, unilateral breast cancer. Patient and histologic factors and surgical treatment, including reconstruction, were evaluated. A detailed chart review was performed among patients from two representative time periods as to the reasons the patient underwent mastectomy. We identified 3,892 women between 2000 and 2012 of whom 60% underwent BCT, 1092 (28%) had UM and 12% underwent BM. BM rose from 4% in 2000 to a high of 19% in 2011, increasing around 2002 for women <40. BCT was less likely with decreasing age (p < 0.0001), lobular histology (p < 0.0001), higher stage (p < 0.0001) and decreasing BMI (p < 0.0001). Among mastectomy patients, contralateral mastectomy was associated with decreasing age (p < 0.0001), Caucasian race (p < 0.0001), and lower stage (p = 0.005). Over time, indications for mastectomy decreased while patients deemed BCT-eligible opting for UM or BM increased dramatically. Increases in the use of BM are in large part among women who were otherwise BCT-eligible. Factors associated with BM use are different for BCT-eligible patients and those recommended for UM. A better understanding of the factors driving individual patient choices is needed.