Physician-level variation in axillary surgery in older adults with T1N0 hormone receptor-positive breast cancer: A retrospective population-based cohort study.

INTRODUCTION: We sought to determine how considerations specific to older adults impact between- and within-surgeon variation in axillary surgery use in women ≥70 years with T1N0 HR+ breast cancer. MATERIALS AND METHODS: Females ≥70 years with T1N0 HR+/HER2-negative breast cancer diagnosed from 2013 to 2015 in SEER-Medicare were identified and linked to the American Medical Association Masterfile. The outcome of interest was axillary surgery. Key patient-level variables included the Charlson Comorbidity Index (CCI) score, frailty (based on a claims-based frailty index score), and age (≥75 vs <75). Multilevel mixed models with surgeon clusters were used to estimate the intracluster correlation coefficient (ICC) (between-surgeon variance), with 1-ICC representing within-surgeon variance. RESULTS: Of the 4410 participants included, 6.1% had a CCI score of ≥3, 20.7% were frail, and 58.3% were ≥ 75 years; 86.1% underwent axillary surgery. No surgeon omitted axillary surgery in all patients, but 42.3% of surgeons performed axillary surgery in all patients. In the null model, 10.5% of the variance in the axillary evaluation was attributable to between-surgeon differences. After adjusting for CCI score, frailty, and age in mixed models, between-surgeon variance increased to 13.0%. DISCUSSION: In this population, axillary surgery varies more within surgeons than between surgeons, suggesting that surgeons are not taking an "all-or-nothing" approach. Comorbidities, frailty, and age accounted for a small proportion of the variation, suggesting nuanced decision-making may include additional, unmeasured factors such as differences in surgeon-patient communication.

Avoiding Locoregional Overtreatment in Older Adults With Early-Stage Breast Cancer.

Advances in the treatment of older women with early-stage breast cancer, particularly opportunities for de-escalation of therapy, have afforded patients and providers opportunity to individualize care. As the majority of women ≥65 have estrogen receptor-positive, HER2-negative disease, locoregional therapy (surgery and/or radiation) may be tailored based on a patient's physiologic age to avoid either over- or undertreatment. To determine who would derive benefit from more or less intensive therapy, an accurate assessment of an older patient's physiologic age and incorporation of patient-specific values are paramount. While there now exist well-validated geriatric assessment tools whose use is encouraged by the American Society of Clinical Oncology when considering systemic therapy, these instruments have not been widely integrated into the locoregional breast cancer care model. This review aims to highlight the importance of assessing frailty and the concepts of and over- and undertreatment, in the context of trial data supporting opportunities for safe deescalation of locoregional therapy, when treating older women with early-stage breast cancer.

Trends in Locoregional Therapy in Older Women with Early-Stage Hormone Receptor-Positive Breast Cancer by Frailty and Life Expectancy.

BACKGROUND: In women ≥ 70 years of age with T1N0 hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer, breast surgery type and omission of axillary surgery or radiation therapy (RT) do not impact overall survival. Although frailty and life expectancy ideally factor into therapy decisions, their impact on therapy receipt is unclear. We sought to identify trends in and factors associated with locoregional therapy type by frailty and life expectancy. METHODS: Women ≥ 70 years of age with T1N0 HR+/HER2- breast cancer diagnosed in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database between 2010 and 2015 were stratified by validated claims-based frailty and life expectancy measures. Therapy trends over time by regimen intensity ('high intensity': lumpectomy + axillary surgery + RT, or mastectomy + axillary surgery; 'moderate intensity': lumpectomy + RT, lumpectomy + axillary surgery, or mastectomy only; or 'low intensity': lumpectomy only) were analyzed. Factors associated with therapy type were identified using generalized linear mixed models. RESULTS: Of 16,188 women, 21.8% were frail, 22.2% had a life expectancy < 5 years, and only 12.3% fulfilled both criteria. In frail women with a life expectancy < 5 years, high-intensity regimens decreased significantly (48.8-31.2%; p < 0.001) over the study period, although in 2015, 30% still received a high-intensity regimen. In adjusted analyses, frailty and life expectancy < 5 years were not associated with breast surgery type but were associated with a lower likelihood of axillary surgery (frailty: odds ratio [OR] 0.86, 95% confidence interval [CI] 0.76-0.96; life expectancy < 5 years: OR 0.22, 95% CI 0.20-0.25). Life expectancy < 5 years was also associated with a lower likelihood of RT receipt in breast-conserving surgery patients (OR 0.30, 95% CI 0.27-0.34). CONCLUSIONS: Rates of high-intensity therapy are decreasing but overtreatment persists in this population. Continued efforts aimed at appropriate de-escalation of locoregional therapy are needed.

Not Too Little, Not Too Much: Optimizing More Versus Less Locoregional Treatment for Older Patients With Breast Cancer.

Although undertreatment of older women with aggressive breast cancers has been a concern for years, there is increasing recognition that some older women are overtreated, receiving therapies unlikely to improve survival or reduce morbidity. De-escalation of surgery may include breast-conserving surgery over mastectomy for appropriate candidates and omitting or reducing extent of axillary surgery. Appropriate patients to de-escalate surgery are those with early-stage breast cancer, favorable tumor characteristics, are clinically node-negative, and who may have other major health issues. De-escalation of radiation includes reducing treatment course length through hypofractionation and ultrahypofractionation regimens, reducing treatment volumes through partial breast irradiation, omission of radiation for select patients, and reducing radiation dose to normal tissues. Shared decision making, which aims to facilitate patients making decisions concordant with their values, can guide health care providers and patients through complicated decisions optimizing breast cancer care.

Association of Surgery With Frailty Status in Older Women With Early-Stage Breast Cancer.

This cohort study examines associations between type of breast cancer surgery and changes in frailty status among US women aged 70 years or older with early-stage breast cancer.

Assessment of Oncologists' Perspectives on Omission of Sentinel Lymph Node Biopsy in Women 70 Years and Older With Early-Stage Hormone Receptor-Positive Breast Cancer.

Importance: Randomized clinical trial data have demonstrated that omission of surgical axillary evaluation does not affect overall survival in women 70 years and older with early-stage (clinical tumor category 1 [cT1] with node-negative [N0] disease) hormone receptor (HR)-positive and erb-B2 receptor tyrosine kinase 2 (ERBB2; formerly HER2)-negative breast cancer. Therefore, the Choosing Wisely initiative has recommended against routine use of sentinel lymph node biopsy (SLNB) in this population; however, retrospective data have revealed that more than 80% of patients eligible for SLNB omission still undergo the procedure. Multidisciplinary factors involved in these patterns remain unclear. Objective: To describe surgical, medical, and radiation oncologists' perspectives on omission of SLNB in women 70 years and older with cT1N0 HR-positive, ERBB2-negative breast cancer. Design, Setting, and Participants: This qualitative study used in-depth semi-structured interviews to explore the factors involved in oncologists' perspectives on providing care to older women who were eligible for SLNB omission. Purposive snowball sampling was used to recruit a sample of surgical, medical, and radiation oncologists representing a wide range of practice types and number of years in practice in the US and Canada. A total of 29 oncologists who finished training and were actively treating patients with breast cancer were interviewed. Interviews were conducted between March 1, 2020, and January 17, 2021. Main Outcomes and Measures: Recordings from semi-structured interviews were transcribed and deidentified. Thematic analysis was used to identify emergent themes. Results: Among 29 physicians (16 women [55.2%] and 13 men [44.8%]) who participated in interviews, 16 were surgical oncologists, 6 were medical oncologists, and 7 were radiation oncologists. Data on race and ethnicity were not collected. Participants had a range of experience (median [range] years in practice, 12.0 [0.5-30.0]) and practice types (14 academic [48.3%], 7 community [24.1%], and 8 hybrid [27.6%]). Interviews revealed that the decision to omit SLNB was based on nuanced patient- and disease-level factors. Wide variation was observed in oncologists' perspectives on SLNB omission recommendations and supporting data. In addition, participants' statements suggested that the multidisciplinary nature of cancer care may increase oncologists' anxiety regarding SLNB omission. Conclusions and Relevance: In this study, findings from interviews revealed that oncologists' perspectives may have implications for the largely unsuccessful deimplementation of SLNB in women 70 years and older with cT1N0 HR-positive, ERBB2-negative breast cancer. Interventions aimed at educating physicians, improving patient-physician communication, and facilitating preoperative multidisciplinary conversations may help to successfully decrease SLNB rates in this patient population.

Acceptability of a companion patient guide to support expert consensus guidelines on surveillance mammography in older breast cancer survivors.

PURPOSE: To support shared decision-making, patient-facing resources are needed to complement recently published guidelines on approaches for surveillance mammography in breast cancer survivors aged ≥ 75 or with < 10-year life expectancy. We created a patient guide to facilitate discussions about surveillance mammography in older breast cancer survivors. METHODS: The "Are Mammograms Still Right for Me?" guide estimates future ipsilateral and contralateral breast (in-breast) cancer risks, general health, and the potential benefits/harms of mammography, with prompts for discussion. We conducted in-clinic acceptability testing of the guide by survivors and their clinicians at a National Cancer Institute-designated comprehensive cancer center, including two community practices. Patients and clinicians received the guide ahead of a clinic visit and surveyed patients (pre-/post-visit) and clinicians (post-visit). Acceptability was defined as ≥ 75% of patients and clinicians reporting that the guide (a) should be recommended to others, (b) is clear, (c) is helpful, and (d) contains a suitable amount of information. We also elicited feedback on usability and mammography intentions. RESULTS: We enrolled 45 patients and their 21 clinicians. Among those responding in post-visit surveys, 33/37 (89%) patients and 15/16 (94%) clinicians would recommend the guide to others; 33/37 (89%) patients and 15/16 (94%) clinicians felt everything/most things were clear. All other pre-specified acceptability criteria were met. Most patients reported strong intentions for mammography (100% pre-visit, 98% post-visit). CONCLUSION: Oncology clinicians and older breast cancer survivors found a guide to inform mammography decision-making acceptable and clear. A multisite clinical trial is needed to assess the guide's impact mammography utilization. TRIAL REGISTRATION: ClinicalTrials.gov-NCT03865654, posted March 7, 2019.

Variation in Deescalated Axillary Surgical Practices in Older Women with Early-Stage Breast Cancer.

BACKGROUND: Randomized controlled trials show that certain axillary surgical practices can be safely deescalated in older adults with early-stage breast cancer. Hospital volume is often equated with surgical quality, but it is unclear whether this includes performance of low-value surgeries. We sought to describe how utilization of two low-value axillary surgeries has varied by time and hospital volume. METHODS: Women aged ≥ 70 years diagnosed with breast cancer from 2013 to 2016 were identified in the National Cancer Database. The outcomes of interest were sentinel lymph node biopsy (SLNB) in cT1N0 hormone receptor-positive cancer patients and axillary lymph node dissection (ALND) in cT1-2N0 patients undergoing breast-conserving surgery with ≤ 2 pathologically positive nodes. Time trends in procedure use and multivariable regression with restricted cubic splines were performed, adjusting for patient, disease, and hospital factors. RESULTS: Overall, 83.4% of 44,779 women eligible for omission of SLNB underwent SLNB and 20.0% of 7216 patients eligible for omission of ALND underwent ALND. SLNB rates did not change significantly over time and remained significantly different by age group (70-74 years: 93.5%; 75-79 years: 89.7%, 80-84 years: 76.7%, ≥ 85 years: 48.9%; p < 0.05). ALND rates decreased over the study period across all age groups included (22.5 to 16.9%, p < 0.001). In restricted cubic splines models, lower hospital volume was associated with higher likelihood of undergoing SLNB and ALND. CONCLUSIONS: ALND omission has been more widely adopted than SLNB omission in older adults, but lower hospital volume is associated with higher likelihood of both procedures. Practice-specific deimplementation strategies are needed, especially for lower-volume hospitals.

Race and Site of Care Impact Treatment Delays in Older Women with Non-Metastatic Breast Cancer.

BACKGROUND: Women ≥ 65 years of age are less likely to receive guideline-concordant breast cancer care. Given existing racial/ethnic disparities, older minority breast cancer patients may be especially prone to inequalities in care. How site of care impacts older breast cancer patients is not well defined. We sought to evaluate the association between race/ethnicity and breast cancer treatment delays in older women treated at minority-serving hospitals (MSHs) versus non-MSHs. METHODS: Women ≥ 65 years of age treated for non-metastatic breast cancer were identified in the National Cancer Database (2010-2017). Treatment delay was defined as > 90 days from diagnosis to initial treatment. MSHs were defined as the top decile of hospitals serving predominantly Black or Hispanic patients. Multivariable logistic regression models adjusted for patient, tumor, and hospital characteristics were used to determine the odds of treatment delay for women at MSHs versus non-MSHs across racial/ethnic groups. RESULTS: Overall, 557,816 women were identified among 41 MSHs and 1146 non-MSHs. Average time to treatment was 33.71 days (standard deviation 26.92 days). Older women at MSHs were more likely to experience treatment delays than those at non-MSHs (odds ratio 1.28, 95% confidence interval 1.21-1.36). Regardless of where they received care, minorities were more likely to experience treatment delays than non-Hispanic White women. CONCLUSIONS: Although 97% of older women treated at Commission on Cancer-accredited hospitals received timely breast cancer care, minorities and those treated at MSHs were more likely to experience treatment delays. Interventions addressing barriers to timely breast cancer care at MSHs may be an effective approach to reducing racial/ethnic disparities.

Acceptability of a patient decision aid for women aged 70 and older with stage I, estrogen receptor-positive, HER2-negative breast cancer.

OBJECTIVES: A comprehensive decision aid (DA) for women ≥70 years with Stage I ER+/HER2-negative breast cancer was developed to support locoregional and systemic treatment decision-making. We aimed to test the acceptability of this novel DA in women newly-diagnosed with breast cancer. MATERIALS AND METHODS: Women ≥70 diagnosed with Stage I, ER+/HER2- breast cancer were recruited from three Boston-area hospitals. They underwent baseline interviews after initial surgical consultation, reviewed the DA, and were surveyed <2 weeks later to determine DA acceptability (e.g., was it helpful?), changes in decisional conflict, stage of decision-making, and knowledge. Participants could optionally complete a three-month follow-up. Paired t-tests and McNemar's tests were used for statistical comparisons, and thematic analyses were conducted to identify themes in participants' open-ended comments. RESULTS: Thirty-three of 56 eligible patients approached completed the baseline and acceptability surveys, and 25 completed the three-month follow-up. Participants' mean age was 74.7 years (±3.8). Nearly all participants (n = 31, 94%) strongly agreed that the DA was helpful and felt that the DA prepared them for treatment decision-making, with a mean decision preparation score of 4.1 (out of 5.0); 6% (n = 2) found it very anxiety provoking. Knowledge improved with a mean of 9.0 out of 14 questions correct at baseline to 10.6 correct on the acceptability survey (p < 0.0001). CONCLUSIONS: A DA tailored to women ≥70 with Stage I, ER+, HER2- breast cancer increased knowledge and was perceived to be helpful by older women. A randomized controlled trial is needed to evaluate its efficacy.

Individualizing Surveillance Mammography for Older Patients After Treatment for Early-Stage Breast Cancer: Multidisciplinary Expert Panel and International Society of Geriatric Oncology Consensus Statement.

IMPORTANCE: There is currently no guidance on how to approach surveillance mammography for older breast cancer survivors, particularly when life expectancy is limited. OBJECTIVE: To develop expert consensus guidelines that facilitate tailored decision-making for routine surveillance mammography for breast cancer survivors 75 years or older. EVIDENCE: After a literature review of the risk of ipsilateral and contralateral breast cancer events among breast cancer survivors and the harms and benefits associated with mammography, a multidisciplinary expert panel was convened to develop consensus guidelines on surveillance mammography for breast cancer survivors 75 years or older. Using an iterative consensus-based approach, input from clinician focus groups, and critical review by the International Society for Geriatric Oncology, the guidelines were refined and finalized. FINDINGS: The literature review established a low risk for ipsilateral and contralateral breast cancer events in most older breast cancer survivors and summarized the benefits and harms associated with mammography. Draft mammography guidelines were iteratively evaluated by the expert panel and clinician focus groups, emphasizing a patient's risk for in-breast cancer events, age, life expectancy, and personal preferences. The final consensus guidelines recommend discontinuation of routine mammography for all breast cancer survivors when life expectancy is less than 5 years, including those with a history of high-risk cancers; consideration to discontinue mammography when life expectancy is 5 to 10 years; and continuation of mammography when life expectancy is more than 10 years. Individualized, shared decision-making is encouraged to optimally tailor recommendations after weighing the benefits and harms associated with surveillance mammography and patient preferences. The panel also recommends ongoing clinical breast examinations and diagnostic mammography to evaluate clinical findings and symptoms, with reassurance for patients that these practices will continue. CONCLUSIONS AND RELEVANCE: It is anticipated that these expert guidelines will enhance clinical practice by providing a framework for individualized discussions, facilitating shared decision-making regarding surveillance mammography for breast cancer survivors 75 years or older.

The Frailty Syndrome: A Critical Issue in Geriatric Oncology.

The number of older adults with cancer is growing in the United States, and there is a relative paucity of data relating the presence of frailty with its outcomes of interest. The authors present the surgical oncology, radiation oncology, and medical oncology literature with respect to the presence of frailty in older adults with cancer. More research is needed to understand how the presence of frailty should be used by surgical, radiation, and medical oncologists to guide patient counseling and treatment planning.

Assessment of Time-to-Treatment Initiation and Survival in a Cohort of Patients With Common Cancers.

Importance: Resource limitations because of pandemic or other stresses on infrastructure necessitate the triage of time-sensitive care, including cancer treatments. Optimal time to treatment is underexplored, so recommendations for which cancer treatments can be deferred are often based on expert opinion. Objective: To evaluate the association between increased time to definitive therapy and mortality as a function of cancer type and stage for the 4 most prevalent cancers in the US. Design, Setting, and Participants: This cohort study assessed treatment and outcome information from patients with nonmetastatic breast, prostate, non-small cell lung (NSCLC), and colon cancers from 2004 to 2015, with data analyzed January to March 2020. Data on outcomes associated with appropriate curative-intent surgical, radiation, or medical therapy were gathered from the National Cancer Database. Exposures: Time-to-treatment initiation (TTI), the interval between diagnosis and therapy, using intervals of 8 to 60, 61 to 120, 121 to 180, and greater than 180 days. Main Outcomes and Measures: 5-year and 10-year predicted all-cause mortality. Results: This study included 2 241 706 patients (mean [SD] age 63 [11.9] years, 1 268 794 [56.6%] women, 1 880 317 [83.9%] White): 1 165 585 (52.0%) with breast cancer, 853 030 (38.1%) with prostate cancer, 130 597 (5.8%) with NSCLC, and 92 494 (4.1%) with colon cancer. Median (interquartile range) TTI by cancer was 32 (21-48) days for breast, 79 (55-117) days for prostate, 41 (27-62) days for NSCLC, and 26 (16-40) days for colon. Across all cancers, a general increase in the 5-year and 10-year predicted mortality was associated with increasing TTI. The most pronounced mortality association was for colon cancer (eg, 5 y predicted mortality, stage III: TTI 61-120 d, 38.9% vs. 181-365 d, 47.8%), followed by stage I NSCLC (5 y predicted mortality: TTI 61-120 d, 47.4% vs 181-365 d, 47.6%), while survival for prostate cancer was least associated (eg, 5 y predicted mortality, high risk: TTI 61-120 d, 12.8% vs 181-365 d, 14.1%), followed by breast cancer (eg, 5 y predicted mortality, stage I: TTI 61-120 d, 11.0% vs. 181-365 d, 15.2%). A nonsignificant difference in treatment delays and worsened survival was observed for stage II lung cancer patients-who had the highest all-cause mortality for any TTI regardless of treatment timing. Conclusions and Relevance: In this cohort study, for all studied cancers there was evidence that shorter TTI was associated with lower mortality, suggesting an indirect association between treatment deferral and mortality that may not become evident for years. In contrast to current pandemic-related guidelines, these findings support more timely definitive treatment for intermediate-risk and high-risk prostate cancer.

Association Between Time to Operation and Pathologic Stage in Ductal Carcinoma in Situ and Early-Stage Hormone Receptor-Positive Breast Cancer.

BACKGROUND: During the COVID-19 pandemic, surgical delays have been common for patients with ductal carcinoma in situ (DCIS) and early-stage estrogen receptor-positive (ER+) breast cancer, often in favor of neoadjuvant endocrine therapy (NET). To understand possible ramifications of these delays, we examined the association between time to operation and pathologic staging and overall survival (OS). STUDY DESIGN: Patients with DCIS or ER+ cT1-2N0 breast cancer treated from 2010 through 2016 were identified in the National Cancer Database. Time to operation was recorded. Factors associated with pathologic upstaging were examined using logistic regression analyses. Cox proportional hazard models were used to analyze OS. Analyses were stratified by disease stage and initial treatment strategy. RESULTS: There were 378,839 patients identified. Among those undergoing primary surgical procedure, time to operation was within 120 days in > 98% in all groups. Among cT1-2N0 patients selected for NET, operations were performed within 120 days in 59.6% of cT1N0 and 30.9% of cT2N0 patients. Increased time to operation was associated with increased odds of pathologic upstaging in DCIS patients (ER+: 60 to 120 days: odds ratio 1.15; 95% CI, 1.08 to 1.22; more than 120 days: odds ratio 1.44; 95% CI, 1.24 to 1.68; ER-: 60 to 120 days: NS; more than 120 days: odds ratio 1.36; 95% CI, 1.01 to 1.82; 60 days or less: reference), but not in patients with invasive cancer, irrespective of initial treatment strategy. No difference in OS was seen by time to operation in DCIS or NET patients. CONCLUSIONS: Increased time to operation was associated with a small increase in pathologic upstaging in DCIS patients, but did not impact OS. In patients with cT1-2N0 disease, NET use did not impact stage or OS, supporting the safety of delay strategies in ER+ breast cancer patients during the pandemic.

Patient preferences for locoregional therapy in early-stage breast cancer.

PURPOSE: With an increasing emphasis on patient-centered care, clinicians in subspecialties such as breast surgery and radiation oncology that offer multiple therapeutic options with equivalent outcomes are under increasing pressure to aid patients with the decision-making process. The aim of this review is to summarize existing studies that either evaluated factors in patient's decision-making regarding locoregional therapy in early-stage breast cancer or evaluated benefit thresholds required to change therapy decisions. METHODS: A PubMed search to identify prospective or retrospective studies written in English reporting factors in patient decision-making regarding locoregional therapy in early-stage breast cancer was conducted. No restriction was placed on publication date. Studies that focused on breast reconstruction decisions or on patient preferences for decision-making involvement were excluded. RESULTS: A total of 39 studies were identified; 19 examining patient preferences for breast-conserving surgery versus mastectomy, 7 on preferences for contralateral prophylactic mastectomy, 2 on non-surgical options, 2 on the extent of axillary surgery, and 9 on radiation therapy decisions. Themes such as fear of recurrence, desire to avoid additional invasive therapy, and the importance of physician preference were common, but many studies also highlighted factors important to specific subpopulations of women. CONCLUSIONS: Patient preference is difficult to define and measure, and heterogeneity across studies renders direct comparison difficult. Future work is needed to define women's risk-thresholds for certain treatments, delve into the psychological factors that direct their decisions, and understand how patients' valuations of risk interact with society's.

Do Body Mass Index and Breast Density Impact Cancer Risk Among Women with Lobular Carcinoma In Situ?

PURPOSE: Both body mass index (BMI) and breast density impact breast cancer risk in the general population. Whether obesity and density represent additive risk factors in women with lobular carcinoma in situ (LCIS) is unknown. METHODS: Patients diagnosed with LCIS from 1988 to 2017 were identified from a prospectively maintained database. BMI was categorized by World Health Organization classification. Density was captured as the mammographic Breast Imaging Reporting and Data System (BIRADS) value. Other covariates included age at LCIS diagnosis, menopausal status, family history, chemoprevention, and prophylactic mastectomy. Cancer-free probability was estimated using the Kaplan-Meier method, and Cox regression models were used for univariable and multivariable analyses. RESULTS: A total of 1222 women with LCIS were identified. At a median follow-up of 7 years, 179 women developed breast cancer (121 invasive, 58 ductal carcinoma in situ); 5- and 10-year cumulative incidences of breast cancer were 10% and 17%, respectively. In multivariable analysis, increased breast density (BIRADS C/D vs. A/B) was significantly associated with increased hazard of breast cancer (hazard ratio [HR] 2.42, 95% confidence interval [CI] 1.52-3.88), whereas BMI was not. On multivariable analysis, chemoprevention use was associated with a significantly decreased hazard of breast cancer (HR 0.49, 95% CI 0.29-0.84). Exploratory analyses did not demonstrate significant interaction between BMI and menopausal status, BMI and breast density, BMI and chemoprevention use, or breast density and chemoprevention. CONCLUSIONS: Breast cancer risk among women with LCIS is impacted by breast density. These results aid in personalizing risk assessment among women with LCIS and highlight the importance of chemoprevention counseling for risk reduction.

Assessment of hospital-level adjusted breast cancer sentinel lymph node positivity rates.

BACKGROUND/OBJECTIVES: Proficiency of performing sentinel lymph node biopsy (SLNB) for breast cancer varies among hospitals and may be reflected in the hospital's SLNB positivity rate. Our objectives were to examine whether hospital characteristics are associated with variation in SLNB positivity rates and whether hospitals with lower-than-expected SLNB positivity rates have worse patient survival. METHODS: Using the National Cancer Data Base, stage I to III breast cancer patients were identified (2004-2012). Hospital-level SLNB positivity rates were adjusted for tumor and patient factors. Hospitals were divided into terciles of SLNB positivity rates (lower-, higher-, as-expected). Hospital characteristics and survival were examined across terciles. RESULTS: Of 438 610 SLNB patients (from 1357 hospitals), 78 104 had one or more positive SLN (21.3%). Hospitals in the low and high terciles were more likely to be low volume (low: RRR, 4.40; 95% CI, 2.89-6.57; P < 0.001; and high: RRR, 1.79; 95% CI, 1.21-2.64; P < 0.001) compared to hospitals with as-expected (middle tercile) SLNB positivity rates. Stage I patients at low- and high-tercile hospitals had statistically worse survival. CONCLUSIONS: There is a wide variation in hospital SLNB positivity rates. Hospitals with lower- or higher-than-expected SLNB positivity rates were associated with survival differences. Hospital SLNB positivity rates may be a novel 'process measure' to report to hospitals for internal quality assessment.