Perioperative magnetic resonance imaging in breast cancer care: Distinct adoption trajectories among physician patient-sharing networks.

BACKGROUND: Despite no proven benefit in clinical outcomes, perioperative magnetic resonance imaging (MRI) was rapidly adopted into breast cancer care in the 2000's, offering a prime opportunity for assessing factors influencing overutilization of unproven technology. OBJECTIVES: To examine variation among physician patient-sharing networks in their trajectory of adopting perioperative MRI for breast cancer surgery and compare the characteristics of patients, providers, and mastectomy use in physician networks that had different adoption trajectories. METHODS AND FINDINGS: Using the Surveillance, Epidemiology, and End Results-Medicare database in 2004-2009, we identified 147 physician patient-sharing networks (caring for 26,886 patients with stage I-III breast cancer). After adjusting for patient clinical risk factors, we calculated risk-adjusted rate of perioperative MRI use for each physician network in 2004-2005, 2006-2007, and 2008-2009, respectively. Based on the risk-adjusted rate, we identified three distinct trajectories of adopting perioperative MRI among physician networks: 1) low adoption (risk-adjusted rate of perioperative MRI increased from 2.8% in 2004-2005 to 14.8% in 2008-2009), 2) medium adoption (8.8% to 45.1%), and 3) high adoption (33.0% to 71.7%). Physician networks in the higher adoption trajectory tended to have a larger proportion of cancer specialists, more patients with high income, and fewer patients who were Black. After adjusting for patients' clinical risk factors, the proportion of patients undergoing mastectomy decreased from 41.1% in 2004-2005 to 38.5% in 2008-2009 among those in physician networks with low MRI adoption, but increased from 27.0% to 31.4% among those in physician networks with high MRI adoption (p = 0.03 for the interaction term between trajectory group and time). CONCLUSIONS: Physician patient-sharing networks varied in their trajectory of adopting perioperative MRI. These distinct trajectories were associated with the composition of patients and providers in the networks, and had important implications for patterns of mastectomy use.

Characteristics and Long-Term Risk of Breast Angiosarcoma.

BACKGROUND: Angiosarcoma of the breast is rare and aggressive. It can occur as a de novo tumor or secondary to breast cancer treatment. The purpose of this study is to analyze differences between patients with primary and secondary angiosarcoma of the breast and investigate potential risk factors for its development. PATIENTS AND METHODS: The Surveillance, Epidemiology, and End Results program of the National Cancer Institute database was queried to identify patients with angiosarcoma of the breast, trunk, shoulder, and upper arm. The population-based incidence was analyzed. Primary and secondary angiosarcoma cases were identified and compared. Breast cancer characteristics of secondary angiosarcoma patients were compared with all breast cancer patients in the database who did not develop angiosarcoma. RESULTS: Overall, 904 patients were included, and 65.4% were secondary angiosarcomas. These patients had worse survival, were older, more likely to be White, more likely to have regionally advanced disease, and had angiosarcoma tumors of higher pathologic grade. Independent factors associated with development of secondary angiosarcoma among breast cancer patients included White race, older age, invasive tumor, lymph node removal, lumpectomy, radiation treatment, and left-sided tumor. Although the mean time to develop angiosarcoma after breast cancer diagnosis was 8.2 years, the risk continues to increase up to 30 years after breast cancer treatment. CONCLUSION: Angiosarcoma is rare but increasing in incidence. Secondary angiosarcomas are more common and exhibit more aggressive behavior. Several factors for angiosarcoma after breast cancer treatment could be identified, which may help us counsel and identify patients at risk.

Surgical Outcomes of Mastectomy with Immediate Autologous Reconstruction Followed by Radiation.

INTRODUCTION: Timing of autologous reconstruction relative to postmastectomy radiation therapy (PMRT) is debated. Benefits of immediate reconstruction must be weighed against a possibly heightened risk of complications from flap irradiation. We reviewed flap outcomes after single operation plus PMRT in a large institutional cohort. METHODS: Medical records were reviewed for women who underwent simultaneous mastectomy-autologous reconstruction with PMRT from 2007 to 2016. Primary endpoints were rates and types of radiation-related flap complications and reoperations, whose predictors were assessed by multivariable analysis. A p value < 0.10 was deemed significant to avoid type II error. Non-parametric logistic regression generated a model of PMRT timing associated with probabilities of complications and reoperations. RESULTS: One-hundred and thirty women underwent 208 mastectomy reconstruction operations, with a median follow up of 35.1 months (interquartile range 23.6-56.5). Forty-seven (36.2%) women experienced radiation-related complications, commonly fat necrosis (44.1%) and chest wall asymmetry (28.8%). Complications were higher among women who received PMRT < 3 months after surgery (46.8% for < 3 months vs. 29.3% for ≥ 3 months; p = 0.06), most of whom received neoadjuvant chemotherapy, and among women treated with internal mammary nodal (IMN) radiation (65.2% vs. 26.4%; p < 0.01); IMN radiation remained strongly associated in multivariable analysis (odds ratio [OR] 5.24; p < 0.01). Thirty-two (24.6%) women underwent 70 reoperations, commonly fat grafting (51.9%) and fat necrosis excision (17.1%). Reoperations were higher among women who received PMRT < 3 months after surgery (48.9 for < 3 months vs. 36.6 for ≥ 3 months; p = 0.19), which was significantly associated in multivariable analysis (OR 0.42; p = 0.08 for ≥ 3 months). The probabilities of complications and reoperations were lowest when PMRT was administered ≥ 3 months after surgery. CONCLUSIONS: Among a large institutional cohort, immediate autologous reconstruction was associated with similar rates of adverse flap outcomes as historically reported alternatively sequenced protocols. IMN radiation increased risk, while PMRT ≥ 3 months after surgery decreased risk. Additional studies are needed to elaborate the impact of IMN radiation and early PMRT in immediate versus delayed autologous reconstruction.

"Radiotherapy for older women (ROW)": A risk calculator for women with early-stage breast cancer.

OBJECTIVE: Among older adult women with early-stage breast cancer who undergo lumpectomy, the benefits of radiotherapy vary according to tumor characteristics and life expectancy. We aimed to develop a risk calculator to predict individualized probability of long-term survival and local recurrence, accounting for these factors. METHODS: We developed a simulation model to estimate an individual patient's risk of local recurrence and all-cause mortality according to age, comorbidities, functional status, tumor characteristics, and radiotherapy status. We integrated two existing prediction models, the Early Breast Cancer Trialist's Collaborative Group prediction model for breast cancer specific outcomes and ePrognosis for life expectancy. An online risk calculator "Radiotherapy for Older Women (ROW)" was developed through an iterative multi-stage process, that included individual consultation and group meetings with an advisory committee (AC) comprised of patients, advocates, clinicians, and researchers. RESULTS: We developed the tool over 40 months and had 15 group meetings. The risk calculator developed as a simulation model with 16 factors (5 tumor-related, 3 demographic, 4 comorbidities, and 4 functional statuses). Across 56,700 simulated scenarios, the benefit of RT in terms of absolute 10-year local recurrence reduction, ranged from 0% to 34%, depending on individual characteristics. Based on feedback from the AC, overall survival and local recurrence were chosen as the output for ROW, with these outcomes displayed numerically (percentages and natural frequencies) and graphically (pictographs). CONCLUSIONS: This tool "ROW" could facilitate shared decision making regarding receipt of radiotherapy for older women with early breast cancer. Additional studies to examine usability testing are underway.

Association between perceived benefits and receipt of radiotherapy among older breast cancer patients.

While radiotherapy can be safely omitted in many older women with early-stage breast cancer after lumpectomy, approximately two-thirds of eligible women still undergo this treatment. We surveyed 63 older women with stage I (T1N0M0), estrogen-receptor-positive breast cancer who underwent lumpectomy, and were considering/receiving radiotherapy. Participants perceived that radiotherapy would reduce their 10-year risk of local recurrence by an average of 18.7%, which is significantly higher than the 8% risk reduction reported in literature. Multivariate analyses demonstrated that participants who reported a large perceived benefit were significantly more likely to undergo radiotherapy treatment (odds ratio 10.34; 95% confidence interval: 1.66-66.35).

Income disparities in needle biopsy patients prior to breast cancer surgery across physician peer groups.

OBJECTIVE: Evaluate income disparities in receipt of needle biopsy among Medicare beneficiaries and describe the magnitude of this variation across physician peer groups. METHODS: The Surveillance, Epidemiology and End Results (SEER)-Medicare database was queried from 2007-2009. Physician peer groups were constructed. The magnitude of income disparities and the patient-level and physician peer group-level effects were assessed. RESULTS: Among 9770 patients, 65.4% received needle biopsy. Patients with low income (median area-level household income < $33K) were less likely to receive needle biopsy (58.5%) compared to patients with high income (≥ $50K) (68.6%; adjusted odds ratio 0.77; 95% confidence interval (CI) 0.65-0.91). Needle biopsy varied substantially across physician peer groups (interquartile range 43.4-81.9%). The magnitude of the disparity ranged from an odds ratio (OR) of 0.50 (95% CI 0.23-1.07) for low vs. high income patients to 1.27 (95% CI 0.60-2.68). The effect of being treated by a physician peer group that treated mostly low-income patients on receipt of needle biopsy was nearly three times the effect of being a low-income patient. CONCLUSIONS: Needle biopsy continues to be underused and disparities by income exist. The magnitude of this disparity varies substantially across physician peer groups, suggesting that further work is needed to improve quality and reduce inequities.

The effect of modifiable risk factors on breast cancer aggressiveness among black and white women.

INTRODUCTION: Although breast cancer incidence is higher among white women, black women are more likely to have aggressive tumors with less favorable histology, and to have a worse prognosis. Obesity and alcohol consumption have been identified as two modifiable risk factors for breast cancer, while physical activity may offer protection. Little however is known about the association of these factors with race on the severity of breast cancer. METHODS: Data collected as part of a large prospective study looking at insulin resistance and race among women with breast cancer was queried for patient characteristics, lifestyle factors and tumor characteristics. The association with Nottingham Prognostic Index (NPI) was assessed with different models using univariate and multivariate linear regression. RESULTS: Among 746 women in our cohort, 82% (n = 615) were white and 18% (n = 131) were black, mean age 58 years. Black patients were more likely to have high BMI (31.0 vs. 26.7, p < 0.0001), comorbidities (69% vs 55%, p = 0.01), self-reported poor diet (70% vs 42%, p < 0.001), be sedentary (56% vs 46%, p = 0.03) and were less likely to consume alcohol (8% vs 32%, p < 0.0001) compared to white patients. Overall, 137 (18%) of the patients had poorer prognosis (NPI > 4.4), which was significantly associated with younger age (55.6 vs 58.5 years, p = 0.02), black race (27% vs 15%, p = 0.001), triple negative cancer (15% vs 6%, p = 0.003), and poor diet (54% vs 45%, p = 0.046) compared to patients with better prognosis (NPI ≤ 4.4). On multivariate analysis, (model R2 = 0.12; p < 0.001), age (ß = -0.011 per year, p = 0.002), healthy diet (ß = -0.195, p = 0.02), and exercise (ß = -0.004, p = 0.02) were associated with better prognosis, while black race (ß = 0.247, p = 0.02) and triple negative cancer (ß = 0.908, p < 0.0001) were associated with poor prognosis. Neither alcohol use nor BMI was significantly associated with NPI. CONCLUSION: Among modifiable risk factors, diet and exercise are associated with NPI. Unmodifiable factors including race and biologic subtype remain the most important determinants of prognosis.

The 2018 Compensation Survey of the American Society of Breast Surgeons.

BACKGROUND: There is limited compensation data for breast surgery benchmarking. In 2018, the American Society of Breast Surgeons conducted its second membership survey to obtain updated compensation data as well as information on practice type and setting. METHODS: In October 2018, a survey was emailed to 2676 active members. Detailed information on compensation was collected, as well as data on gender, training, years in and type of practice, percent devoted to breast surgery, workload, and location. Descriptive statistics and multivariate analyses were performed to analyze the impact of various factors on compensation. RESULTS: The response rate was 38.2% (n = 1022, of which 73% were female). Among the respondents, 61% practiced breast surgery exclusively and 54% were fellowship trained. The majority of fellowship-trained surgeons within 5 years of completion of training (n = 126) were female (91%). Overall, mean annual compensation was $370,555. On univariate analysis, gender, years of practice, practice type, academic position, ownership, percent breast practice, and clinical productivity were associated with compensation, whereas fellowship training, region, and practice setting were not. On multivariate analysis, higher compensation was significantly associated with male gender, years in practice, number of cancers treated per year, and wRVUs. Compensation was lower among surgeons who practiced 100% breast compared with those who did a combination of breast and other surgery. CONCLUSIONS: Differences in compensation among breast surgeons were identified by practice type, academic position, ownership, years of practice, percent breast practice, workload, and gender. Overall, mean annual compensation increased by $40,000 since 2014.

Why Has Breast Cancer Screening Failed to Decrease the Incidence of de Novo Stage IV Disease?

: Background: Despite screening mammography, the incidence of Stage IV breast cancer (BC) at diagnosis has not decreased over the past four decades. We previously found that many BCs are small due to favorable biology rather than early detection. This study compared the biology of Stage IV cancers with that of small cancers typically found by screening. Methods: Trends in the incidence of localized, regional, and distant female BC were compared using SEER*Stat. The National Cancer Database (NCDB) was then queried for invasive cancers from 2010 to 2015, and patient/disease variables were compared across stages. Biological variables including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (Her2), grade, and lymphovascular invasion were sorted into 48 combinations, from which three biological subtypes emerged: indolent, intermediate, and aggressive. The distributions of the subtypes were compared across disease stages. Multivariable regression assessed the association between Stage IV disease and biology. Results: SEER*Stat confirmed that the incidence of distant BC increased between 1973 and 2015 (annual percent change [APC] = 0.46). NCDB data on roughly 993,000 individuals showed that Stage IV disease at presentation is more common in young, black, uninsured women with low income/education and large, biologically aggressive tumors. The distribution of tumor biology varied by stage, with Stage IV disease including 37.6% aggressive and 6.0% indolent tumors, versus sub-centimeter Stage I disease that included 5.1% aggressive and 40.6% indolent tumors (p < 0.001). The odds of Stage IV disease presentation more than tripled for patients with aggressive tumors (OR3.2, 95% CI 3.0⁻3.5). Conclusions: Stage I and Stage IV breast cancers represent very different populations of biologic tumor types. This may explain why the incidence of Stage IV cancer has not decreased with screening.

Long-Term Outcomes of Sentinel Lymph Node Biopsy for Ductal Carcinoma in Situ.

The use of sentinel lymph node biopsy (SLNB) for ductal carcinoma in situ (DCIS) is controversial. Using population-cohort data, we examined whether SLNB improves long-term outcomes among patients with DCIS who underwent breast-conserving surgery. We identified 12 776 women aged 67-94 years diagnosed during 2001-2013 with DCIS who underwent breast-conserving surgery from the US Surveillance, Epidemiology, and End Results-Medicare dataset, 1992 (15.6%) of whom underwent SLNB (median follow-up: 69 months). Tests of statistical significance are two-sided. Patients with and without SLNB did not differ statistically significantly regarding treated recurrence (3.9% vs 3.7%; P = .62), ipsilateral invasive occurrence (1.4% vs 1.7%, P = .33), or breast cancer mortality (1.0% vs 0.9%, P = .86). With Mahalanobis-matching and competing-risks survival analyses, SLNB was not statistically significantly associated with treated recurrence, ipsilateral invasive occurrence, or breast cancer mortality (P ≥ .27). Our findings do not support the routine performance of SLNB for older patients with DCIS amenable to breast conservation.

Surgeon peer network characteristics and adoption of new imaging techniques in breast cancer: A study of perioperative MRI.

BACKGROUND: Perioperative MRI has disseminated into breast cancer practice despite equivocal evidence. We used a novel social network approach to assess the relationship between the characteristics of surgeons' patient-sharing networks and subsequent use of MRI. METHODS: We identified a cohort of female patients with stage 0-III breast cancer from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. We used claims data from these patients and non-cancer patients from the 5% Medicare sample to identify peer groups of physicians who shared patients during 2004-2006 (T1). We used a multivariable hierarchical model to identify peer group characteristics associated with uptake of MRI in T2 (2007-2009) by surgeons who had not used MRI in T1. RESULTS: Our T1 sample included 15 149 patients with breast cancer, treated by 2439 surgeons in 390 physician groups. During T1, 9.1% of patients received an MRI; the use of MRI varied from 0% to 100% (IQR 0%, 8.5%) across peer groups. After adjusting for clinical characteristics, patients treated by surgeons in groups with a higher proportion of primary care physicians (PCPs) in T1 were less likely to receive MRI in T2 (OR = 0.81 for 10% increase in PCPs, 95% CI = 0.71, 0.93). Surgeon transitivity (ie, clustering of surgeons) was significantly associated with MRI receipt (P = 0.013); patients whose surgeons were in groups with higher transitivity in T1 were more likely to receive MRI in T2 (OR = 1.29 for 10% increase in clustering, 95% CI = 1.06, 1.58). CONCLUSION: The characteristics of a surgeon's peer network are associated with their patients' subsequent receipt of perioperative MRI.

Breast cancer histopathology is predictive of low-risk Oncotype Dx recurrence score.

BACKGROUND: Oncotype Dx is a genetic test that has been incorporated into the 2017 AJCC breast cancer staging system for ER positive, HER2-negative, lymph node-negative patients to predict the risk of recurrence. Recent data suggest that immunohistochemistry (ER, PR, HER2, and Ki-67) and histologic subtype may identify patients that will not benefit from Oncotype Dx testing. METHODS: A total of 371 patients underwent Oncotype Dx testing at our institution from 2012 to 2016. Oncotype recurrence score was categorized as low- (ORS = 0-10), intermediate- (11-25), or high risk (26-100). Invasive carcinomas were categorized based on histologic subtype as "favorable" (mucinous, tubular, cribriform, tubulolobular, and lobular) and "unfavorable" (ductal, mixed ductal and lobular, and micropapillary carcinoma). All cases were estrogen receptor positive and HER2-negative. Clinical and histologic predictors of low-risk ORS were assessed in univariate and multivariate logistic regression. RESULTS: A total of 371 patients were categorized by ORS as low risk (n = 85, 22.9%), intermediate risk (n = 244, 65.8%), and high risk (n = 42, 11.3%). The histologic subtypes with the highest percentage of high-risk ORS were invasive micropapillary (n = 4/17, 23.5%), pleomorphic lobular (n = 2/10, 20%), and ductal carcinoma (n = 28/235, 11.9%). Low-grade invasive carcinomas with favorable histology rarely had a high-risk ORS (n = 1/97, 1%). In a simple multivariable model, favorable histologic subtype (OR = 2.39, 95% CI: 1.10 to 5.15, P = 0.026), and histologic grade (OR = 1.76, 95% CI: 1.07 to 2.90, P = 0.025) were the only significant predictors of an ORS less than 11 in estrogen receptor positive, HER2-negative, and lymph node-negative patients. CONCLUSION: We question the utility of performing Oncotype Dx in subtypes of invasive carcinoma that are associated with excellent prognosis. We propose that immunohistochemistry for ER, PR, and HER2 is sufficient for patients with low-grade invasive carcinomas and can be used as a surrogate for Oncotype Dx.

Associations of preoperative breast magnetic resonance imaging with subsequent mastectomy and breast cancer mortality.

PURPOSE: To examine associations between pre-operative magnetic resonance imaging (MRI) use and clinical outcomes among women undergoing breast-conserving surgery (BCS) with or without radiotherapy for early-stage breast cancer. METHODS: We identified women from the Surveillance, Epidemiology, and End Results-Medicare dataset aged 67-94 diagnosed during 2004-2010 with stage I/II breast cancer who received BCS. We compared subsequent mastectomy and breast cancer mortality with versus without pre-operative MRI, using Cox regression and competing risks models. We further stratified by receipt of radiotherapy for subgroup analyses. RESULTS: Our sample consisted of 24,379 beneficiaries, 4691 (19.2%) of whom received pre-operative MRI. Adjusted rates of subsequent mastectomy and breast cancer mortality were not significantly different with and without MRI: 3.2 versus 4.1 per 1000 person-years [adjusted hazard ratio (AHR) 0.92; 95% confidence interval (CI) 0.70-1.19] and 5.3 versus 8.7 per 1000 person-years (AHR 0.89; 95% CI 0.73-1.08), respectively. In subgroup analyses, women receiving BCS plus radiotherapy had similar rates of subsequent mastectomy (AHR 1.17; 95% CI 0.84-1.61) and breast cancer mortality (AHR 1.00; 95% CI 0.80-1.24) with versus without MRI. However, among women receiving BCS alone, MRI use was associated with lower risks of subsequent mastectomy (AHR 0.60; 95% CI 0.37-0.98) and breast cancer mortality (AHR 0.57; 95% CI 0.36-0.92). CONCLUSIONS: Pre-operative MRI was associated with improved outcomes among older women with breast cancer receiving BCS alone, but not among those receiving BCS plus radiotherapy. Further research is needed to identify appropriate settings for which MRI may be helpful.

Associations Between Sentinel Lymph Node Biopsy and Complications for Patients with Ductal Carcinoma In Situ.

PURPOSE: To examine the associations between sentinel lymph node biopsy (SLNB) and complications among older patients who underwent breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS). METHODS: We identified women from the Surveillance, Epidemiology, and End Results-Medicare dataset aged 67-94 years diagnosed during 1998-2011 with DCIS who underwent BCS as initial treatment. We assessed incidence of complications, including lymphedema, wound infection, seroma, or pain, within 9 months of diagnosis. We used Mahalanobis matching and generalized linear models to estimate the associations between SLNB and complications. RESULTS: Our sample consisted of 15,515 beneficiaries, 2409 (15.5%) of whom received SLNB. Overall, 16.8% of women who received SLNB had complications, compared with 11.3% of women who did not receive SLNB (p < 0.001). Use of SLNB was associated with subsequent mastectomy but not radiotherapy. Multivariate analyses of the matched sample showed that, compared with no SLNB, SLNB use was significantly associated with incidence of any complication [adjusted odds ratio (AOR) 1.39; 99% confidence interval (CI) 1.18-1.63], lymphedema (AOR 4.45; 99% CI 2.27-8.75), wound infection (AOR 1.24; 99% CI 1.00-1.54), seroma (AOR 1.40; 99% CI 1.03-1.91), and pain (AOR 1.31; 99% CI 1.04-1.65). Sensitivity analyses excluding patients who underwent mastectomy yielded qualitatively similar results regarding the associations between SLNB and complications. CONCLUSIONS: Among older women with DCIS who received BCS, SLNB use was associated with higher risks of short-term complications. These findings support consensus guidelines recommending against SLNB for this population and provide empirical information for patients.