Erratum: Multidisciplinary Management of Breast Cancer During Pregnancy.

[This corrects the article DOI: 10.1634/theoncologist.2016-0208.].

LCCC 1025: a phase II study of everolimus, trastuzumab, and vinorelbine to treat progressive HER2-positive breast cancer brain metastases.

PURPOSE: HER2 + breast cancer (BC) is an aggressive subtype with high rates of brain metastases (BCBM). Two-thirds of HER2 + BCBM demonstrate activation of the PI3K/mTOR pathway driving resistance to anti-HER2 therapy. This phase II study evaluated everolimus (E), a brain-permeable mTOR inhibitor, trastuzumab (T), and vinorelbine (V) in patients with HER2 + BCBM. PATIENTS AND METHODS: Eligible patients had progressive HER2 + BCBM. The primary endpoint was intracranial response rate (RR); secondary objectives were CNS clinical benefit rate (CBR), extracranial RR, time to progression (TTP), overall survival (OS), and targeted sequencing of tumors from enrolled patients. A two-stage design distinguished intracranial RR of 5% versus 20%. RESULTS: 32 patients were evaluable for toxicity, 26 for efficacy. Intracranial RR was 4% (1 PR). CNS CBR at 6 mos was 27%; at 3 mos 65%. Median intracranial TTP was 3.9 mos (95% CI 2.2-5). OS was 12.2 mos (95% CI 0.6-20.2). Grade 3-4 toxicities included neutropenia (41%), anemia (16%), and stomatitis (16%). Mutations in TP53 and PIK3CA were common in BCBM. Mutations in the PI3K/mTOR pathway were not associated with response. ERBB2 amplification was higher in BCBM compared to primary BC; ERBB2 amplification in the primary BC trended toward worse OS. CONCLUSION: While intracranial RR to ETV was low in HER2 + BCBM patients, one-third achieved CNS CBR; TTP/OS was similar to historical control. No new toxicity signals were observed. Further analysis of the genomic underpinnings of BCBM to identify tractable prognostic and/or predictive biomarkers is warranted. CLINICAL TRIAL: (NCT01305941).

Multidisciplinary Management of Breast Cancer During Pregnancy.

BACKGROUND: Although breast cancer during pregnancy (BCDP) is rare (occurring with only 0.4% of all BC diagnoses in female patients aged 16-49 years), management decisions are challenging to both the patient and the multidisciplinary team. MATERIALS AND METHODS: Experts in breast cancer at the University of North Carolina conducted a targeted literature search regarding the multidisciplinary treatment approaches to BCDP: medical, surgical, and radiation oncology. Supportive care, including antiemetic agents, and imaging approaches were also reviewed. RESULTS: Review of the literature revealed key points in the management of BCDP. Surgical management is similar to that in nonpregnant patients; pregnant patients may safely undergo breast-conserving surgery. Recommendations should be tailored to the individual according to the clinical stage, tumor biology, genetic status, gestational age, and personal preferences. Anthracycline-based chemotherapy can be safely initiated only in the second and third trimesters. The rate of congenital abnormalities in children exposed to chemotherapy is similar to the national average (approximately 3%). Dosing of chemotherapy should be similar to that in the nonpregnant patient (i.e., actual body surface area). Antihuman epidermal growth factor receptor 2 therapy, radiation, and endocrine treatment are contraindicated in pregnancy and lactation. Care should include partnership with obstetricians. The literature regarding prognosis of BCDP is mixed. CONCLUSION: To maximize benefit and minimize risk to the mother and fetus, an informed discussion with the patient and her medical team should result in an individualized treatment plan, taking into account the timing of the pregnancy and the stage and subtype of the breast cancer. Because BCDP is rare, it is essential to collect patient data in international registries. The Oncologist 2017;22:324-334 IMPLICATIONS FOR PRACTICE: Breast cancer during pregnancy is a major ethical and professional challenge for both the patient and the multidisciplinary treatment team. Although the oncologic care is based on that of the non-pregnant breast cancer patient, there are many challenges from regarding the medical, surgical and radiation oncology and obstetrical aspects of care that need to be considered to deliver the safest and best treatment plan to both the mother and developing fetus.

Early cardiac perfusion defects after left-sided radiation therapy for breast cancer: is there a volume response?

PURPOSE: Cardiac single-photon emission computed tomography (SPECT) is often used to identify defects in myocardial perfusion due to atherosclerotic coronary artery disease. It was also used in studies to evaluate radiation therapy (RT)-associated cardiac abnormalities. In the current review, we aim to evaluate the rates of post-RT cardiac SPECT early perfusion abnormalities and relate this to the irradiated left ventricular volume. METHODS: The studies cited in this systematic review were identified using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. RESULTS: Six studies between 1996 and 2016 fulfilled the inclusion criteria. The reported perfusion defects in these studies were seen in the apical and anterolateral aspects of the left ventricle. Three studies show correlation between the percent of the left ventricle within the RT-field and percent of patients with early perfusion defects on cardiac SPECT. In two studies that used cardiac sparing techniques (such as deep inspiration), that resulted in a low mean heart dose, no perfusion defects were noted. CONCLUSIONS: Data suggest that incidental irradiation of the heart in cases of left breast/chest wall RT can result in early post-RT perfusion defects on cardiac SPECT. There appears to be strong dose/volume dependence to the risk, and hence techniques to reduce cardiac exposure are recommended.

The incidence of radiation necrosis following stereotactic radiotherapy for melanoma brain metastases: the potential impact of immunotherapy.

Stereotactic radiotherapy (SRT) is the standard treatment for patients with limited number of brain metastases. In the past few years, newer immunotherapies (immune checkpoint inhibitors) have been proven to prolong survival in patients with metastatic melanoma. The safety of the combination of SRT and immunotherapy for brain metastases is unknown. We retrospectively identified patients with melanoma brain metastases treated with SRT between 2007 and 2015. Patients who did not have at least 3 months of follow-up with imaging after SRT were excluded from the analysis. Outcomes were compared between patients who were treated with or without immunotherapy. A total of 58 patients were included; of these, 29 were treated with SRT and immunotherapy. MAPK inhibitors (BRAF, MEK inhibitors) were used more often in the immunotherapy group (nine vs. two patients). There was a higher incidence of intracranial complications in patients treated with immunotherapy and SRT. Eight patients had radiation necrosis; all occurred in patients who were treated with immunotherapy. Nine patients had hemorrhage, of which seven occurred in patients who were treated with immunotherapy (P=0.08). However, patients treated with immunotherapy and SRT had a significant overall survival advantage compared with SRT without immunotherapy (15 vs. 6 months, P=0.0013). Patients treated with SRT and immunotherapy have a higher incidence/risk of intracranial complications, but a longer overall survival.

The prognostic value of pre-diagnosis health-related quality of life on survival: a prospective cohort study of older Americans with lung cancer.

PURPOSE: Health-related quality of life (HRQOL) after cancer diagnosis is prognostic for overall survival (OS). However, no studies have assessed if HRQOL before diagnosis is predictive for OS. The objective of this study was to determine the association between pre-lung cancer diagnosis HRQOL and OS. METHODS: Our prospective cohort study used surveillance, epidemiology, and end results linked to the Medicare Health Outcomes Survey. We included 6290 individuals 65 years or older diagnosed with incident lung cancer from 1998 to 2013. We assessed the prognostic value of (1) short-form 36 summary component and domain-specific scores, (2) activities of daily living (ADL), and (3) two global HRQOL questions. Cox-proportional hazards models were used to examine associations between HRQOL and OS, adjusting for demographics, comorbid conditions, and clinical characteristics. RESULTS: Worse pre-diagnosis HRQOL was significantly associated with greater risk of death across HRQOL measures. An above average physical or mental component summary score was associated with 16 and 24% decreases in the hazard of death, respectively (p < 0.0001). Being unable to perform ADLs, such as bathing oneself, was associated with an 89% increased hazard of death (p < 0.0001). Reporting "poor" versus "excellent" health was associated with a 74% increase in the hazard of death (p < 0.0001). CONCLUSION: This population-based study reinforces the importance of self-reported health status as a predictor for OS. Routine HRQOL screening may identify patients who could benefit from early interventions to improve HRQOL. Future studies should explore associations between changes in HRQOL before and after cancer diagnosis and OS.

A Multidisciplinary Breast Cancer Brain Metastases Clinic: The University of North Carolina Experience.

BACKGROUND: Breast cancer brain metastasis (BCBM) confers a poor prognosis and is unusual in requiring multidisciplinary care in the metastatic setting. The University of North Carolina at Chapel Hill (UNC-CH) has created a BCBM clinic to provide medical and radiation oncology, neurosurgical, and supportive services to this complex patient population. We describe organization and design of the clinic as well as characteristics, treatments, and outcomes of the patients seen in its first 3 years. METHODS: Clinical and demographic data were collected from patients in a prospectively maintained database. Descriptive statistics are reported as percentages and means. The Kaplan-Meier method was used to estimate time-to-event outcomes. RESULTS: Sixty-five patients were seen between January 2012 and January 2015. At the time of presentation to the BCBM clinic, most patients (74%) had multiple (≥2) brain metastases and had received prior systemic (77%) and whole-brain radiation therapy and/or central nervous system stereotactic radiosurgery (65%) in the metastatic setting. Seventy-eight percent returned for a follow-up visit; 32% were enrolled in a clinical trial. Median time from diagnosis of brain metastasis to death was 2.11 years (95% confidence interval [CI] 1.31-2.47) for all patients, 1.15 years (95% CI 0.4-2.43) for triple-negative breast cancer, 1.31 years (95% CI 0.51-2.52) for hormone receptor-positive/HER2- breast cancer, and 3.03 years (95% CI lower limit 1.94, upper limit not estimable) for HER2+ breast cancer (p = .0037). CONCLUSION: Patients with BCBM have unique and complex needs that require input from several oncologic disciplines. The development of the UNC-CH multidisciplinary BCBM clinic is a model that can be adapted at other centers to provide coordinated care for patients with a challenging and complex disease. IMPLICATIONS FOR PRACTICE: Patients with breast cancer brain metastases often require unique multidisciplinary care to meet the numerous and uncommon challenges associated with their conditions. Here, the development and characteristics of a clinic designed specifically to provide for the multidisciplinary needs of patients with breast cancer brain metastases are described. This clinic may serve as a model for other institutions interested in creating specialty clinics with similar objectives.

Multidisciplinary Management of Breast Cancer Brain Metastases.

This review summarizes the most up-to-date approach to the multidisciplinary management of patients with breast cancer brain metastases. A brief overview of the epidemiology and biology of breast cancer brain metastasis is provided. The perspectives of radiation oncology, neurosurgery, and medical oncology-and landmark studies from each discipline-are all discussed. We also offer practical tips to help guide the treating physician, including data on antiseizure medications. Finally, we introduce the concept of a multidisciplinary clinic that combines input from medical and radiation oncology, neurosurgery, and support services, which we developed at the University of North Carolina as a coordinated and optimal approach to the management of patients with this complex disease.

Two phase I dose-escalation/pharmacokinetics studies of low temperature liposomal doxorubicin (LTLD) and mild local hyperthermia in heavily pretreated patients with local regionally recurrent breast cancer.

PURPOSE: Unresectable chest wall recurrences of breast cancer (CWR) in heavily pretreated patients are especially difficult to treat. We hypothesised that thermally enhanced drug delivery using low temperature liposomal doxorubicin (LTLD), given with mild local hyperthermia (MLHT), will be safe and effective in this population. PATIENTS AND METHODS: This paper combines the results of two similarly designed phase I trials. Eligible CWR patients had progressed on the chest wall after prior hormone therapy, chemotherapy, and radiotherapy. Patients were to get six cycles of LTLD every 21-35 days, followed immediately by chest wall MLHT for 1 hour at 40-42 °C. In the first trial 18 subjects received LTLD at 20, 30, or 40 mg/m2; in the second trial, 11 subjects received LTLD at 40 or 50 mg/m2. RESULTS: The median age of all 29 patients enrolled was 57 years. Thirteen patients (45%) had distant metastases on enrolment. Patients had received a median dose of 256 mg/m2 of prior anthracyclines and a median dose of 61 Gy of prior radiation. The median number of study treatments that subjects completed was four. The maximum tolerated dose was 50 mg/m2, with seven subjects (24%) developing reversible grade 3-4 neutropenia and four (14%) reversible grade 3-4 leucopenia. The rate of overall local response was 48% (14/29, 95% CI: 30-66%), with. five patients (17%) achieving complete local responses and nine patients (31%) having partial local responses. CONCLUSION: LTLD at 50 mg/m2 and MLHT is safe. This combined therapy produces objective responses in heavily pretreated CWR patients. Future work should test thermally enhanced LTLD delivery in a less advanced patient population.

A case report of stereotactic radiosurgery in a patient with Ehlers-Danlos syndrome.

In this report, we outline the case of a patient who has Ehlers-Danlos Syndrome (EDS) who received two courses of CyberKnife stereotactic radiosurgery (SRS) for metastatic non-small cell lung cancer. Patients with EDS have increased blood vessel fragility, and therefore are subject to increased risk of bleeding. There are no published data regarding the risks of hemorrhage associated with SRS for intracranial metastases in this patient population. The patient described in this case report had two courses of SRS for two sites of brain metastases. She tolerated treatment well, with no acute toxicity and good local control to date. We have also included a discussion of published literature regarding toxicity of intracranial radiation in patients with EDS.

Intensity-modulated radiation therapy for anal cancer: toxicity versus outcomes.

The treatment of cancer of the anal canal has changed significantly over the past several decades. Although the abdominoperineal resection (APR) was the historical standard of care, a therapeutic paradigm shift occurred with the seminal work of Nigro, who reported that anal canal cancer could be treated with definitive chemoradiation, with APR reserved for salvage therapy only. This remains an attractive approach for patients and physicians alike and the standard of care in this disease. Now, nearly four decades later, a similar approach continues to be utilized, albeit with higher radiation doses; however, this strategy remains fraught with considerable treatment-related morbidities. With the advent of intensity-modulated radiation therapy (IMRT), many oncologists are beginning to utilize this technology in the treatment of anal cancer in order to decrease these toxicities while maintaining similar treatment efficacy. This article reviews the relevant literature leading up to the modern treatment of anal canal cancer, and discusses IMRT-related toxicity and disease-related outcomes in the context of outcomes of conventionally treated anal cancer.

Hyperthermia combined with radiation therapy for superficial breast cancer and chest wall recurrence: a review of the randomised data.

Hyperthermia has long been used in combination with radiation for the treatment of superficial malignancies, in part due to its radiosensitising capabilities. Patients who suffer superficial recurrences of breast cancer, be it in their chest wall following mastectomy, or in their breast after breast conservation, typically have poor clinical outcomes. They often develop distant metastatic disease, but one must not overlook the problems associated with an uncontrolled local failure. Morbidity is enormous, and can significantly impair quality of life. There is no accepted standard of care in treating superficial recurrences of breast cancer, particularly in patients that have previously been irradiated. There is a substantial literature regarding the combined use of hyperthermia and radiotherapy for these superficial recurrences. Most of it is retrospective in nature, but there are several larger phase III randomised trials that show an improved rate of clinical complete response in patients treated with both modalities. In this review article, we will highlight the important prospective data that has been published regarding the combined use of hyperthermia and radiation.

Hyperthermia for locally advanced breast cancer.

Hyperthermia (HT) has a proven benefit for treating superficial malignancies, particularly chest wall recurrences of breast cancer. There has been less research utilising HT in patients with locally advanced breast cancer (LABC), but available data are promising. HT has been combined with chemotherapy and/or radiotherapy in the neoadjuvant, definitive and adjuvant setting, albeit in series with small numbers of patients. There is only one phase III trial that examines hyperthermia in LABC, also with relatively small numbers of patients. The goal of this review is to highlight important research utilising HT in patients with LABC as well as to suggest future directions for its use.

Assessment of Risk of Xerostomia After Whole-Brain Radiation Therapy and Association With Parotid Dose.

Importance: Whole-brain radiation therapy (WBRT) delivers a substantial radiation dose to the parotid glands, but the parotid glands are not delineated for avoidance and xerostomia has never been reported as an adverse effect. Minimizing the toxic effects in patients receiving palliative treatments, such as WBRT, is crucial. Objective: To assess whether xerostomia is a toxic effect of WBRT. Design, Setting, and Participants: This observational cohort study enrolled patients from November 2, 2015, to March 20, 2018, at 1 academic center (University of North Carolina Hospitals) and 2 affiliated community hospitals (High Point Regional Hospital and University of North Carolina Rex Hospital). Adult patients (n = 100) receiving WBRT for the treatment or prophylaxis of brain metastases were enrolled. Patients who had substantial baseline xerostomia or did not complete WBRT or at least 1 postbaseline questionnaire were prospectively excluded from analysis and follow-up. Patients received 3-dimensional WBRT using opposed lateral fields covering the skull and the C1 or C2 vertebra. Per standard practice, the parotid glands were not prospectively delineated. Main Outcomes and Measures: Patients completed the University of Michigan Xerostomia Questionnaire and a 4-point bother score at baseline, immediately after WBRT, at 1 month, at 3 months, and at 6 months. The primary end point was the 1-month xerostomia score, with a hypothesized worsening score of 10 points from baseline. Results: Of the 100 patients enrolled, 73 (73%) were eligible for analysis and 55 (55%) were evaluable at 1 month. The 73 patients included 43 women (59%) and 30 men (41%) with a median (range) age of 61 (23-88) years. The median volume of parotid receiving at least 20 Gy (V20Gy) was 47%. The mean xerostomia score was 7 points at baseline and was statistically significantly higher at each assessment period, including 21 points immediately after WBRT (95% CI, 16-26; P < .001), 23 points (95% CI, 16-30; P < .001) at 1 month, 21 points (95% CI, 13-28; P < .001) at 3 months, and 14 points (95% CI, 7-21; P = .03) at 6 months. At 1 month, the xerostomia score increased by 20 points or more in 19 patients (35%). The xerostomia score at 1 month was associated with parotid dose as a continuous variable and was 35 points in patients with parotid V20Gy of 47% or greater, compared with only 9 points in patients with parotid V20Gy less than 47% (P < .001). The proportion of patients who self-reported to be bothered quite a bit or bothered very much by xerostomia at 1 month was 50% in those with parotid V20Gy of 47% or greater, compared with only 4% in those with parotid V20Gy less than 47% (P < .001). At 3 months, this difference was 50% vs 0% (P = .001). Xerostomia was not associated with medication use. Conclusions and Relevance: Clinically significant xerostomia occurred by the end of WBRT, appeared to be persistent, and appeared to be associated with parotid dose. The findings from this study suggest that the parotid glands should be delineated for avoidance to minimize these toxic effects in patients who undergo WBRT and often do not survive long enough for salivary recovery.

Prospective Assessment of Patient-Reported Dry Eye Syndrome After Whole Brain Radiation.

PURPOSE: Dry eye is not typically considered a toxicity of whole brain radiation therapy (WBRT). We analyzed dry eye syndrome as part of a prospective study of patient-reported outcomes after WBRT. METHODS AND MATERIALS: Patients receiving WBRT to 25 to 40 Gy were enrolled on a study with dry mouth as the primary endpoint and dry eye syndrome as a secondary endpoint. Patients received 3-dimensional WBRT using opposed lateral fields. Per standard practice, lacrimal glands were not prospectively delineated. Patients completed the Subjective Evaluation of Symptom of Dryness (SESoD, scored 0-4, with higher scores representing worse dry eye symptoms) at baseline, immediately after WBRT (EndRT), and at 1 month (1M), 3 months, and 6 months. Patients with baseline SESoD ≥3 (moderate dry eye) were excluded. The endpoints analyzed were ≥1-point and ≥2-point increase in SESoD score at 1M. Lacrimal glands were retrospectively delineated with fused magnetic resonance imaging scans. RESULTS: One hundred patients were enrolled, 70 were eligible for analysis, and 54 were evaluable at 1M. Median bilateral lacrimal V20Gy was 79%. At 1M, 17 patients (32%) had a ≥1-point increase in SESoD score, and 13 (24%) a ≥2-point increase. Lacrimal doses appeared to be associated with an increase in SESoD score of both ≥1 point (V10Gy: P = .042, odds ratio [OR] 1.09/%; V20Gy: P = .071, OR 1.03/%) and ≥2 points (V10Gy: P = .038, OR 1.15/%; V20Gy: P = .063, OR 1.04/%). The proportion with increase in dry eye symptoms at 1M for lacrimal V20Gy ≥79% versus <79% was 46% versus 15%, respectively, for ≥1 point SESoD increase (P = .02) and 36% versus 12%, respectively, for ≥2 point SESoD increase (P = .056). CONCLUSIONS: Dry eye appears to be a relatively common, dose/volume-dependent acute toxicity of WBRT. Minimization of lacrimal gland dose may reduce this toxicity, and patients should be counseled regarding the existence of this potential side effect and treatments for dry eye.

Assessment of postbrachytherapy sexual function: a comparison of the IIEF-5 and the MSEFS.

PURPOSE: This study is to compare the Mount Sinai Erectile Function Score (MSEFS), our brachytherapy program's physician-assigned scale, with patients' independently completed International Index of Erectile Function-5 (IIEF-5). METHODS AND MATERIALS: A total of 1202 patients with T1-T3 prostate cancer were treated with ultrasound-guided radioactive seed implantation +/- EBRT with at least one visit where both MSEFS and IIEF-5 were completed. Spearman rho correlations were performed. RESULTS: The MSEFS significantly correlated with the total IIEF-5 scores on all comparisons. The coefficient was 0.65 for comparisons at initial consultation and 0.76 for all visits. The correlations remained strong, averaging to 0.76 for visits 1 through 10. CONCLUSIONS: In assessing erectile dysfunction after radiation, the MSEFS correlates well with, but cannot be replaced by, the IIEF-5, which is weighted toward one's degree of sexual desire. More insight into patients' erectile function after brachytherapy may be gotten if the IIEF-15 is used instead of the IIEF-5 with our MSEFS.

Adoption of Stereotactic Body Radiotherapy for Stage IA Non-Small Cell Lung Cancer Across the United States.

BACKGROUND: Stereotactic body radiotherapy (SBRT) is a treatment option for stage I non-small cell lung cancer (NSCLC), providing a potentially curative therapy for patients who are nonsurgical candidates. This study describes the adoption of SBRT vs other treatment options across the United States, as well as commonly used dose-fractionation regimens. METHODS: We analyzed patients in the National Cancer Data Base. A total of 107 233 stage IA NSCLC patients diagnosed from 2008 to 2013 were included. We described the proportions of patients who received different surgical and radiation treatment options by year. A multivariable model was constructed to assess factors associated with patients receiving SBRT. In patients who received SBRT, we described the proportion of patients who received common dose/fractionation regimens. RESULTS: Use of SBRT increased from 6.7% to 16.3% from 2008 to 2013, with a corresponding decrease in lobectomy/pneumonectomy (49.5% to 43.7%). The rates of wedge resection, conventional radiotherapy, and no treatment remained relatively constant. Adoption of SBRT was lowest in small community centers (8.6% of patients by 2013). On multivariable analysis, older age and treatment at larger centers were associated with higher SBRT receipt, and black race and higher comorbidity were associated with lower SBRT receipt. There was statistically significant geographic variation. Common SBRT schemes were 10 Gy × 5 (19%), 18-20 Gy × 3 (31%), and 12 Gy × 4 (16%). CONCLUSIONS: SBRT adoption has been modest over time and has not substantially replaced less curative treatments. Lack of access to this technology in smaller cancer centers may have partly contributed to the slow adoption.

Evaluating the Effectiveness of Neoadjuvant Chemotherapy in Reducing Mastectomy for Women With Breast Cancer.

BACKGROUND: Neoadjuvant chemotherapy in breast cancer reduced mastectomy rates by 7% to 13% in randomized trials. However, the differential effects for women with different stages, receptor subtypes, and ages are unknown. We compared mastectomy rates in women who did vs did not receive neoadjuvant chemotherapy in 18 patient subgroups. The main objective was to quantify the potential benefit from neoadjuvant chemotherapy in reducing mastectomy rates for each subgroup. METHODS: Our retrospective analysis used data from the National Cancer Data Base, which includes approximately 70% of incident cancers across the United States. Absolute risk reductions for mastectomy were determined for 18 subgroups of clinical stage, receptor subtype, and age group. In each subgroup, propensity score weighting balanced measured covariates between women treated with vs without neoadjuvant chemotherapy. RESULTS: A total of 55 709 patients were analyzed. In clinical stage IIA disease, only patients with human epidermal growth factor receptor 2 (HER2)-positive tumors had reduced mastectomy rates associated with neoadjuvant chemotherapy (age < 60 years, 12%; age ≥ 60 years, 12.6%). For stage IIB cancers, neoadjuvant chemotherapy was associated with an absolute reduction in mastectomy rates of 5.9% in women younger than age 60 years with hormone receptor-positive/HER2- disease, 8.2% to 10.7% for triple-negative disease, and 11.7% to 17.4% for HER2+ disease. For stage IIIA, the reductions in mastectomy rates ranged from 6.6% to 15.9%. CONCLUSIONS: In an analysis of patients treated across the United States, we found that neoadjuvant chemotherapy was associated with a reduction in mastectomy rates to a similar magnitude overall as shown in randomized trials, but this benefit varied widely by patient subgroup. This study provides novel information to help women make informed decisions regarding treatment.