Receipt Of Sentinel Lymph Node Biopsy Research Articles

Persistent poverty impacts survival and National Comprehensive Cancer Network guideline-concordant care for patients with melanoma.

1598 Background: Based on guidelines from the National Comprehensive Cancer Network (NCCN), sentinel lymph node biopsy (SLNB) should be offered to patients with high-risk stage IB or stage II melanoma and adjuvant systemic therapy is recommended for patients with stage III disease. Persistent poverty census tracts are defined as areas where at least20% of residents were poor as measured by each of the 1980, 1990, 2000 censuses and 2007 American Community Survey 5-year average. The aim of this study was to describe the association between persistent poverty and adherence to NCCN guidelines and cancer-specific survival in patients with cutaneous melanoma. Methods: Patients diagnosed with melanoma from 2006-2018 were identified in Survival, Epidemiology, and End Results (SEER) Program registries. The analytic cohort was restricted to patients with superficial spreading melanoma, nodular melanoma, malignant melanoma with regression, lentigo malignant melanoma, and acral lentiginous melanoma. Patient demographics such as age, race, and ethnicity and tumor characteristics associated with stage at diagnosis were analyzed using adjusted regression analyses for patients of all melanoma stages. Demographics and tumor characteristics associated with receipt of SLNB were analyzed amongst pathologic stage IB and II cases, and demographics and tumor characteristics associated with receipt of adjuvant systemic therapy were analyzed amongst stage III cases. Kaplan-Meier curves and adjusted accelerated failure time models were used to examine disparities in cancer-specific survival. Results: Of 127,308 total patients, 3.13% (n=3994) lived in census tracts with persistent poverty. In adjusted analyses, persistent poverty was an independent predictor of later pathologic stage at diagnosis (OR 1.32 [95% CI 1.21-1.44] p<0.001). Persistent poverty was also associated with lower likelihood of receiving SLNB according to NCCN guidelines (OR 0.717 [SE 0.072] p<0.01) and with worse cancer-specific survival (HR 1.25 [1.06-1.47], p=0.008) when controlling for age, race, ethnicity, pathologic stage at diagnosis, and histology. In univariable models persistent poverty was associated with increased odds of receiving systemic therapy, but this relationship was not significant on multivariable analysis. Conclusions: Patients from areas with persistent poverty had a later pathologic stage at diagnosis, were less likely to receive a SLNB according to NCCN guidelines, and had worse cancer-specific survival. Efforts to better define and resolve disparities in the treatment and survival of patients with melanoma are warranted.

Luminal A Versus B After Choosing Wisely: Does Lymph Node Surgery Affect Oncologic Outcomes?

In 2016, the Choosing Wisely campaign recommended against routine sentinel lymph node biopsy (SLNB) in women ≥ 70 years old diagnosed with early-stage hormone receptor positive (HR+), HER2 negative (HER2-) breast cancer. No distinction is made between luminal A and luminal B phenotypes, despite luminal B being considered more aggressive. This study evaluates the effect of SLNB on oncologic outcomes in HER2- luminal B versus luminal A breast cancer. We performed an IRB-approved, single institution, retrospective cohort study from 2010 to 2020 of women aged ≥ 70 years with clinically node negative, HR+ breast cancer undergoing definitive surgical treatment. Luminal status was defined by gene expression panel testing, Ki67%, and/or pathologic grading. Primary endpoints included locoregional recurrence (LRR), disease free survival (DFS), and overall survival (OS). SLNB did not correlate with significant differences in LRR in luminal A (p = 0.92) or luminal B (p = 0.96) disease. SLNB correlated with improved DFS (p < 0.01) and OS (p < 0.001) in luminal A disease, but not in luminal B disease (DFS p = 0.73; OS p = 0.36). On multivariate analysis, age (HR = 1.17; p < 0.01) and tumor size (HR = 1.03; p < 0.05) were associated with DFS, while SLNB was not (p = 0.71). Luminal status (HR = 0.52, p < 0.05), age (HR = 1.15, p < 0.01), and comorbidities (HR = 1.35, p < 0.05) were associated with OS, but not SLNB (p = 0.71). Our results suggest that SLNB may be safely omitted in patients aged ≥ 70 years with luminal B disease given similar LRR in luminal A disease. Our findings suggest that DFS and OS are driven by tumor biology, patient age, and comorbidities rather than receipt of SLNB.

Axillary surgery efficacy for patients with breast cancer receiving neoadjuvant chemotherapy on NSABP B40 and B41.

524 Background: Alliance A011202 is evaluating the efficacy of axillary lymph node dissection (ALND) compared to regional nodal irradiation (RNI) for patients with cN1 breast cancer who receive neoadjuvant chemotherapy (NCTX) that becomes ycN0 but remains pN+. In the absence of its publication, level I guidance does not exist regarding the optimal axillary surgery for patients receiving NCTX. We sought to evaluate outcomes across two national contemporary clinical NCTX trials based on axillary and breast response to NCTX, particularly if more aggressive surgery was associated with more favorable outcomes. Methods: With IRB approval (IRB201802781), we obtained data from NCTX trials NSABP B40 and B41. B40 enrolled women with HER2- disease, and B41 enrolled those with HER2+ disease. RNI and axillary surgery were selected at physician discretion and not protocolled. Patients received sentinel lymph node biopsy (SLNB), SLNB+ALND (S+ALND), or ALND. We examined outcomes of locoregional recurrence (LRR), distant recurrence (DR), disease free survival (DFS), and overall survival (OS). Univariable and multivariable analyses of B40 and B41 data were performed to evaluate the associations of axillary surgery with the outcomes above, adjusting for age, tumor subtype, mastectomy or not, breast pathologic complete response (pCR), axillary pCR, tumor subtype, regional nodal irradiation, and grade. Kaplan-Meier estimation was used for OS and DFS, with cumulative incidence function for LRR and DR. Results: Median follow-up for studies B40 and B41 were 4.5 and 5.1 years, respectively, including 1154 and 504 patients for analysis. A total of 786 (47%) patients were cN+, and of those, 377 had a pcR (48%). 440 (27%), 505 (31%), and 663 (41%) patients had SLNB, S+ALND, and ALND respectively. 855 (52%) and 803 (48%) patients had mastectomy and lumpectomy, respectively. 783 (51%) received RNI. For the 518 ypN+ patients on B40, 7/25 (SLNB), 69/234 (S+ALND), and 107/259 (ALND) experienced an event. DFS at 5 years was 71%, 68%, and 56% for the SLNB, S+ALND, and ALND groups respectively with ypN+ on B40. For the 112 ypN+ patients on B41, 3/6, 15/43, and 27/63 experienced an event. DFS at 5 years was 50%, 64%, and 55% for the SLNB, S+ALND, and ALND groups, respectively, with ypN+ on B41. In multivariable analyses for the combined population of B40 and B41 for LRR, DR, DFS, and OS, SLNB was never associated with a higher chance of relapse or inferior survival (HR &gt; 1) compared to S+ALND or ALND. Conclusions: Among women prospectively treated on national trials with NCTX and axillary surgery and RNI selected at physician discretion, receipt of SLNB alone was not associated with a higher likelihood of recurrence compared to S+ALND or ALND. Anticipated results of A011202 will provide level I guidance on axillary surgery for patients with cN1 disease converting to cN0 post-NCTX.

Utilization of sentinel lymph node biopsy for Merkel cell carcinoma

To the Editor: Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumor with a high incidence of nodal and distant metastases and a high mortality rate.1 Among patients with MCC, 27% to 31% present with clinically apparent nodal disease and another 16% to 38% have occult nodal metastasis determined by sentinel lymph node biopsy (SLNB).2 Although SLNB is recommended for all clinically node-negative patients with MCC, little is known regarding its use for MCC. The purpose of this study was to evaluate the factors associated with the receipt of SLNB in patients with MCC.

26682 Socioeconomic factors associated with receipt of sentinel lymph node biopsy for melanoma

Background: Sentinel lymph node biopsy (SLNB) is an important staging and prognostic tool for melanoma. However, there exists a knowledge gap regarding whether socioeconomic factors influence the type of care that melanoma patients receive. Our aim was to investigate the relationship between socioeconomic factors and receipt of SLNB among melanoma patients.

Outcomes After Sentinel Lymph Node Biopsy and Radiotherapy in Older Women With Early-Stage, Estrogen Receptor–Positive Breast Cancer

Overtreatment of early-stage breast cancer with favorable tumor biology in older patients may be harmful without affecting recurrence and survival. Guidelines that recommend deimplementation of sentinel lymph node biopsy (SLNB) (Choosing Wisely) and radiotherapy (RT) (National Comprehensive Cancer Network) have been published. To describe the use rates and association with disease recurrence of SLNB and RT in older women with breast cancer. This cohort study obtained patient and clinical data from an integrated cancer registry and electronic health record of a single health care system in Pennsylvania. The cohort was composed of consecutive female patients 70 years or older who were diagnosed with early-stage, estrogen receptor-positive, ERBB2 (formerly HER2)-negative, clinically node-negative breast cancer from January 1, 2010, to December 31, 2018, who were treated at 15 community and academic hospitals within the health system. Sentinel lymph node biopsy and adjuvant RT. Primary outcomes were 5-year locoregional recurrence-free survival (LRFS) rate and disease-free survival (DFS) rate after SLNB and after RT. Secondary outcomes included recurrence rate, subgroups that may benefit from SLNB or RT, and use rate of SLNB and RT over time. Propensity scores were used to create 2 cohorts to separately evaluate the association of SLNB and RT with recurrence outcomes. Cox proportional hazards regression model was used to estimate hazard ratios (HRs). From 2010 to 2018, a total of 3361 women 70 years or older (median [interquartile range {IQR}] age, 77.0 [73.0-82.0] years) with estrogen receptor-positive, ERBB2-negative, clinically node-negative breast cancer were included in the study. Of these women, 2195 (65.3%) received SLNB and 1828 (54.4%) received adjuvant RT. Rates of SLNB steadily increased (1.0% per year), a trend that persisted after the 2016 adoption of the Choosing Wisely guideline. Rates of RT decreased slightly (3.4% per year). To examine patient outcomes and maximize follow-up time, the analysis was limited to cases from 2010 to 2014, identifying 2109 patients with a median (IQR) follow-up time of 4.1 (2.5-5.7) years. In the propensity score-matched cohorts, no association was found between SLNB and either LRFS (HR, 1.26; 95% CI, 0.37-4.30; P = .71) or DFS (HR, 1.92; 95% CI, 0.86-4.32; P = .11). In addition, RT was not associated with LRFS (HR, 0.33; 95% CI, 0.09-1.24; P = .10) or DFS (HR, 0.99; 95% CI, 0.46-2.10; P = .97). Subgroup analysis showed that stratification by tumor grade or comorbidity was not associated with LRFS or DFS. Low absolute rates of recurrence were observed when comparing the groups that received SLNB (3.5%) and those that did not (4.5%) as well as the groups that received RT (2.7%) and those that did not (5.5%). This study found that receipt of SLNB or RT was not associated with improved LRFS or DFS in older patients with ER-positive, clinically node-negative breast cancer. Despite limited follow-up time and wide 95% CIs, this study supports the continued deimplementation of both SLNB and RT in accordance with the Choosing Wisely and National Comprehensive Cancer Network guidelines.

Abstract PS1-10: Outcomes after sentinel lymph node biopsy and radiation therapy in women over 70 years old with ER+, HER2-, clinically node negative breast cancer

Abstract Overtreatment of early-stage breast cancer with favorable tumor biology in elderly patients can result in higher rates of complications and morbidities without impacting survival. Guidelines directed towards deimplementation of sentinel lymph node biopsy (SLNB) (Choosing Wisely) and radiation therapy (RT) (National Comprehensive Cancer Network) have been recommended. We sought to describe rates and impact on disease recurrence and survival of SLNB and RT in elderly patients with early breast cancer. Patient data were obtained from the cancer registry and electronic health record from University of Pittsburgh Medical Center, multicenter, single health care system. Consecutive female patients aged ≥ 70 with ER+, HER2- clinically node-negative breast cancer within a health care system from 2010 to 2018 were identified. Rates and patient characteristics associated with receipt of SLNB and RT, as well as local recurrence free survival (LRFS) and disease-free survival (DFS) were compared for patients that were diagnosed between 2010 and 2014 to allow for adequate follow up time. Cox proportional hazards regression was used to estimate hazard ratios (HRs) of mortality. Among 3,361 identified women, 2,195 (65.3%) received SLNB and 1,828 (54.4%) received RT. Rates of SLNB steadily increased (1.0% per year); this trend persisted in 2017 and 2018, even after the Society of Surgical Oncology adopted the Choosing Wisely Guidelines in 2016. During the same time period, rates of RT declined (3.4% per year). To examine outcomes, we limited the analysis to 2109 cases from 2010-2014; median (IQR) follow up time was 4.1 (2.5-5.7) years. Median (IQR) age was 77 (73-82) years. 1373 (65.1%) received SLNB and 1,219 (57.8%) received RT. Patients receiving SLNB were younger (P &amp;lt; 0.001) with smaller (P &amp;lt; 0.0001) and lower stage (P &amp;lt; 0.0001) tumors. They had fewer comorbidities (P &amp;lt; 0.001), longer follow-up times (P &amp;lt; 0.001), were less likely on Medicaid/Medicare (P = 0.0091), and were more often seen at an academic center (P &amp;lt; 0.0001). There was no difference in grade between those that did and did not receive SLNB (P = 0.31) and those that did and did not receive RT (P = 0.13). Multivariate cox proportional hazard analysis showed no effect of SLNB on LRFS (HR = 1.17, 95% CI 0.29-4.75, P = 0.83) or DFS (HR = 0.90, 95% CI 0.44-1.83, P = 0.77). Log rank test showed no difference in 5-year LRFS (P = 0.78) between patients who received (98.5%, 95% CI 97.7%-99.7%) and did not receive (98.1%, 95% CI 96.7%-99.5%) SLNB, but an increase was seen with 5-year DFS (P = 0.023), with 96.2% (95% CI 95.0%-97.4%) of patients disease-free among those who did receive SLNB vs. 93.0% (95% CI 90.6%-95.4%) with no SLNB. Multivariate cox proportional hazard analysis showed that RT was associated with improved LRFS (HR = 0.13, 95% CI 0.03-0.51, P &amp;lt; 0.01) and DFS (HR = 0.32, 95% CI 0.15-0.68, P &amp;lt; 0.01). Log rank test showed a difference in 5-year LRFS (P &amp;lt; 0.0001) for those who received RT (99.4%, 95% CI 98.8%-100%) against those who did not (96.5%, 95% CI 95.0%-98.1%), and a similar difference in 5-year DFS (P &amp;lt; 0.0001) in patients who did (97.0%, 95% CI 95.8%-98.1%) and did not (92.4%, 95% CI 90.2%-94.7%) receive RT. Lower age (OR = 0.89, 95% CI 0.87-0.92) and comorbidities (OR = 0.79, 95% CI 0.66-0.94) were associated with receipt of SLNB, while only age (OR = 0.91, 95% CI 0.88-0.94) was associated with receipt of RT. We conclude that receipt of SLNB has no impact upon DFS or LRFS. This data supports deimplementation of SLNB for this patient population. Receipt of RT is important for controlling locoregional recurrence, supporting use of RT in this patient cohort. Citation Format: Priscilla F McAuliffe, Neil M Carleton, Jian Zou, Yusi Fang, Stephen E Koscumb, Osama Shah, Fangyuan Chen, Sushil Beriwal, Emilia J Diego, Adam M Brufsky, Steffi Oesterreich, Steve D Shapiro, Robert Ferris, Leisha A Emens, George Tseng, Oscar C Marroquin, Adrian V Lee. Outcomes after sentinel lymph node biopsy and radiation therapy in women over 70 years old with ER+, HER2-, clinically node negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-10.

Surgical Management of the Axilla in Clinically Node-Positive Patients Receiving Neoadjuvant Chemotherapy: A National Cancer Database Analysis.

The feasibility of sentinel lymph node biopsy (SLNB) in patients with clinically node-positive (cN+) disease who convert to clinically node-negative (cN0) disease following neoadjuvant chemotherapy (NAC) has been evaluated in several large clinical trials, but it remains unclear whether the approach has been broadly adopted in the United States. The National Cancer Database was used to identify women diagnosed with cN+ breast cancer who received NAC followed by surgery between 2012 and 2015. Trends in axillary surgery were evaluated and multivariable logistic regression analyses performed to determine factors associated with receipt of SLNB. Of 12,965 women cN+ at baseline, the use of SLNB increased from 31.8% in 2012 to 49% in 2015 (p < 0.001). Using axillary pCR as a surrogate for patients who convert to cN0 following NAC, among 5127 (39.5%) ypN0 patients, SLNB increased from 38.2 to 58.4% over the study period (p < 0.001), resulting in avoidance of axillary dissection in 42.2% of ypN0 patients by 2015. In adjusted analyses, factors significantly associated with SLNB attempt included cN1 disease, age < 45years, treatment facility type, triple-negative and HER2-positive subtypes, and year of diagnosis. In women with residual isolated tumor cells (ITCs), micrometastases, and ypN1 disease, SLNB was the only axillary procedure performed in 36.9%, 23.6%, and 13.0% of cases. The use of SLNB in cN+ patients receiving NAC increased significantly between 2012 and 2015. SLNB alone was performed in more than 10% of patients with ypN1 disease, 20% with micrometastases, and 35% with ITCs; the oncologic safety of omitting axillary dissection in these patients requires further evaluation.

The interplay between hospital and surgeon factors and the use of sentinel lymph node biopsy for breast cancer.

Background:Several surgeon characteristics are associated with the use of sentinel lymph node biopsy (SLNB) for breast cancer. No studies have systematically examined the relative contribution of both surgeon and hospital factors on receipt of SLNB.Objective:To evaluate the relationship between surgeon and hospital characteristics, including a novel claims-based classification of hospital commitment to cancer care (HC), and receipt of SLNB for breast cancer, a marker of quality care.Data Sources/Study Design:Observational prospective survey study was performed in a population-based cohort of Medicare beneficiaries who underwent incident invasive breast cancer surgery, linked to Medicare claims, state tumor registries, American Hospital Association Annual Survey Database, and American Medical Association Physician Masterfile. Multiple logistic regression models determined surgeon and hospital characteristics that were predictors of SLNB.Results:Of the 1703 women treated at 471 different hospitals by 947 different surgeons, 65% underwent an initial SLNB. Eleven percent of hospitals were high-volume and 58% had a high commitment to cancer care. In separate adjusted models, both high HC (odds ratio [OR] 1.53, 95% confidence interval [CI] 1.12–2.10) and high hospital volume (HV, OR 1.90, 95% CI 1.28–2.79) were associated with SLNB. Adding surgeon factors to a model including both HV and HC minimally modified the effect of high HC (OR 1.34, 95% CI 0.95–1.88) but significantly weakened the effect of high HV (OR 1.25, 95% CI 0.82–1.90). Surgeon characteristics (higher volume and percentage of breast cancer cases) remained strong independent predictors of SLNB, even when controlling for various hospital characteristics.Conclusions:Hospital factors are associated with receipt of SLNB but surgeon factors have a stronger association. Since regionalization of breast cancer care in the U.S. is unlikely to occur, efforts to improve the surgical care and outcomes of breast cancer patients must focus on optimizing patient access to SLNB by ensuring hospitals have the necessary resources and training to perform SLNB, staffing hospitals with surgeons who specialize/focus in breast cancer and referring patients who do not have access to SLNB to an experienced center.

Abstract C31: Exploring disparities in sentinel lymph node biopsy within the Breast Cancer Care in Chicago study

Abstract Background: Lymph node biopsy is a critical component of a diagnostic work-up for patients with invasive breast cancer and is necessary for evaluating the extent and stage of disease so that appropriate treatment can be recommended. The standard procedure prior to the advent of sentinel lymph node biopsy (SLNB) procedures was axillary lymph node dissection (ALND), which is associated with debilitating side effects such as lymphedema. SLNB diffused into practice during the early 2000s and is associated with fewer side effects; for this reason, SLNB has become the standard of care for women diagnosed with invasive breast cancer without clinically palpable lymph node involvement. Using data from the Breast Cancer Care in Chicago study (BCCC), we investigated racial/ethnic disparities in the receipt of SLNB vs. ALND and whether certain tumor, patient, or facility characteristics might help to explain the likelihood of receiving a SLNB. Methods: A total of 989 female patients newly diagnosed with breast cancer were recruited and interviewed for the study. Eligible patients were female, resided in Chicago, had a first primary in situ or invasive breast cancer; were diagnosed between 2005 and 2008 between the ages of 30 and 79 at diagnosis; and self-identified as either non-Latina (nL) White, nL Black or Latina. Of these, 74% (N=731) consented to medical record abstraction and had complete information on receipt of either ALND or SLNB. The racial/ethnic disparity in receipt of SLNB was estimated as a prevalence difference (PD) using logistic regression with marginal based standardization. Mediation analyses were conducted using the method of rescaled coefficients (Karlson, Holm, and Breen). All models were adjusted for age at diagnosis. Results: Roughly half of patients (57%) received a SLNB; nL White women were more likely to receive a SLNB as compared to nL Black and Hispanic women (67% vs 50% and 50%; p=&amp;lt;.001). The prevalence of SNLB was 33%, 75%, 70%, 38% and 20% for stage 0, 1, 2, 3 and 4 breast cancer (p&amp;lt;0.0001) and was higher for ER/PR positive versus negative tumors (p&amp;lt;0.0001) and decreased with increasing tumor grade (p=0.007). SLNB did not vary appreciably for patients who were uninsured, publicly insured or privately insured and SLNB was more common for patients diagnosed at facilities with accreditations from the National Accreditation Program for Breast Centers (NAPBC) and the Commission on Cancer (COC) and less common for patients diagnosed at disproportionate share facilities (p&amp;lt;0.05 for all). After adjusting for age, stage at diagnosis, and tumor characteristics, the disparity in receipt of SLNB was 24 percentage points. In mediation analysis, facility accreditation and disproportionate share status explained 43% of the disparity (p=0.030). Conclusion: During the mid to late 2000s when the practice of SLNB as an alternative to ALND was reaching about half of eligible patients in Chicago, ethnic minority patients were less likely than their nL White counterparts to receive SLNB. Facility accreditation explained a substantial portion of this disparity. Better access and opportunities to go to highly accredited facilities may decrease this disparity. Citation Format: Bethliz Irizarry, Keith Dookeran, Garth Rauscher. Exploring disparities in sentinel lymph node biopsy within the Breast Cancer Care in Chicago study. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C31.

Abstract P5-12-09: Clinical stage, not race, predicts receipt of sentinel lymph node biopsy in medically-underserved patients

Abstract Background: Sentinel lymph node biopsy (SLNB) has replaced axillary node dissection for staging clinically node negative breast cancer patients. Previously, other investigators have found disparities in the rate of SLNB in African Americans. Therefore, we hypothesized that African Americans and Hispanics are offered SLNB less frequently than Caucasians in a large safety-net hospital. Methods: A retrospective review of female patients who underwent breast cancer surgery from 2002-2011 at a safety-net hospital was completed. Data was collected from the institutional cancer registry and medical record for: age at diagnosis, patient demographics, pathologic and clinical stage at presentation, and receipt of SLNB. Patients with clinically negative nodes (N0) were determined to be appropriate for SLNB. Patients with clinically positive nodes, biopsy proven nodal involvement, or stages IIIC or IV were deemed not appropriate for SLNB. Results: Of 566 patients, the mean age at diagnosis was 53 years (range: 28-79); 46% (n = 269) were Hispanic, 31% African American (n = 174), 17% Caucasian (n = 95) and 5% Asian/Other (n = 28). Based on clinical stage, which was available for 561 patients, 64% were eligible for SLNB. Of those, 95% received appropriate SLNB. Race was not a predictor of eligibility for or receipt of appropriate SLNB. TotalCaucasianAfrican AmericanHispanicOtherp-value %(n = 566)%(n = 95)%(n = 95)%(n = 269)%(n = 28) Clinical Stage 0.70010.4 (59)7.4 (7)10.9 (19)11.2 (30)10.7 (3) 123.5 (133)25.3 (24)24.7 (43)22.7 (61)17.9 (5) 2A28.3 (160)29.5 (28)24.7 (43)11.5 (31)35.7 (10) 2B15.4 (87)18.9 (18)19.0 (33)7.1 (19)17.9 (5) 3A6.0 (34)5.3 (5)5.7 (10)7.8 (21)0 3B7.6 (43)8.4 (8)6.9 (12)7.8 (21)7.1 (2) 3C3.4 (19)1.1 (1)1.7 (3)5.2 (14)3.6 (1) 44.6 (26)3.2 (3)5.7 (10)4.5 (12)3.6 (1) Unknown0.9 (5)1.1 (1)5.7 (10)0.7 (2)3.6 (1) Appropriate for SLNB64.0 (362)67.4 (64)61.5 (107)63.2 (170)75.0 (21)0.48Received appropriate SLNB94.7 (343)93.8 (60)92.5 (99)95.9 (163)100.0 (21)0.28 Conclusions: There was no difference in the rate of SLNB between racial and ethnic minority patients at a large safety-net hospital. The previously reported disparity likely resulted from more advanced presentation of disease rather than lack of appropriate care. Efforts to improve disparities seen in medically underserved patients should be focused on earlier detection and treatment of breast cancer. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-12-09.

Differential receipt of sentinel lymph node biopsy within practice-based research networks.

102 Background: Sentinel lymph node biopsy (SLNB) is a quality indicator for breast cancer care. Provider-based research networks (PBRNs) promote diffusion of innovations like SLNB into clinical practice; however, evidence is limited. We examined the diffusion of SLNB for early-stage breast cancer through the Community Clinical Oncology Program (CCOP), a community-based PBRN and its interaction with medical school affiliation. Methods: We identified women undergoing breast conserving surgery with axillary staging for stage I or II breast cancer between January 2000 and December 2003 using Surveillance Epidemiology and End Results-Medicare data (n=6,226). The primary outcome was receipt of SLNB vs. ALND. Exposure was constructed by combining information on the CCOP affiliation of the preforming physician with the medical school affiliation of the hospital. Covariates included race, age, marital status, education, Medicaid eligibility, comorbidity, tumor grade, stage, estrogen receptor status, year of diagnosis, SEER region, and NCI cancer center designation. Multivariable generalized linear modeling with generalized estimating equations was used to measure association between CCOP exposure and receipt of SLNB. Results: Women who saw a CCOP physician at a hospital affiliated with a medical school had a three-fold increase in odds of receiving SLNB compared to non-CCOP women. In contrast, the odds of SLNB were equivalent when looking in women who were seen by a CCOP physician but differed only by their hospital affiliation. Conclusions: Women seen by CCOP-affiliated physicians were more likely to receive SLNB; while medical school affiliation did appear to significantly impact receipt. Innovative, high-quality cancer care can be facilitated PBRNs such as the NCI CCOP program. There must be mechanisms by which providers are exposed to advances in clinical practice outside of organizational affiliations. [Table: see text]

Differential receipt of sentinel lymph node biopsy within practice-based research networks.

6104 Background: Sentinel lymph node biopsy (SLNB) for breast cancer was introduced into clinical practice in the late 1990s as an alternative to axillary lymph node dissection (ALND). Provider-based research networks (PBRNs) are believed to promote diffusion of innovations like SLNB into clinical practice; however, evidence of this association is limited. This study examines the diffusion of SLNB for early-stage breast cancer through the Community Clinical Oncology Program (CCOP), a community-based PBRN. Methods: We identified women undergoing breast conserving surgery with axillary staging for stage I or II breast cancer between January 2000 and December 2003 using Surveillance Epidemiology and End Results-Medicare data (n=6,226). The primary outcome was receipt of SLNB vs. ALND, and exposure was care received from CCOP physicians or institutions between diagnosis and surgery. Exposure was quantified as both a binary measure of ever seeing a CCOP, and as a proportion of all their claims associated with a CCOP. Covariates included race, age, marital status, education, Medicaid eligibility, comorbidity, tumor grade, stage, estrogen receptor status, year of diagnosis, SEER region, and other institutional characteristics such as NCI center designation, cooperative group, and medical school affiliation. Multivariable generalized linear modeling with generalized estimating equations was used to measure association between CCOP exposure and receipt of SLNB. Results: Women who received a higher proportion of their care from a CCOP-affiliated physician or hospital were more likely to receive SLNB. A 10% increase in the proportion of CCOP-affiliated claims was associated with a greater odds of receiving SLNB (OR 1.14; 95% CI 1.08, 1.20), after controlling for covariates. Similarly, sensitivity analysis of the binary indicator of CCOP exposure also showed greater odds of receiving SLNB (OR 1.32; 95%CI 1.01, 1.74). Conclusions: The quality of cancer care delivered in community settings can be influenced by provider-based research networks. Our findings contribute to the growing body of evidence that community-based PBRNs can facilitate adoption of cancer innovations outside of academic medical centers.

Overuse of sentinel lymph node biopsy with breast conserving surgery for clinical DCIS.

1125 Background: The National Comprehensive Cancer Network (NCCN) guidelines recommend against sentinel lymph node biopsy (SLNB) for ductal carcinoma in-situ (DCIS) treated with breast conservation surgery (BCS). SLNB is appropriate with mastectomy because it precludes subsequent SLNB if invasive cancer is identified. However, SLNB is commonly performed with BCS for DCIS. We hypothesize SLNB use in the setting of BCS for DCIS varies and may be over used in some cancer centers. Methods: We examined 6,070 cases with initial biopsy showing DCIS presenting to 13 institutions participating in the NCCN Breast Outcomes Database from 1998-2009. Receipt of SLNB was defined as SLNB performed at any point in primary treatment for those with a final diagnosis of DCIS or at the first surgical procedure for those upstaged to invasive cancer. Characteristics of patients who did and did not have SLNB were compared using Chi-square tests. Logistic models adjusting for clinical and pathologic variables were performed to assess factors associated with use of SLNB. Results: Of 3,725 treated with BCS, 778 (20.9%) had SLNB. Among 2,345 treated with mastectomy, 1,484 (63.3%) had SLNB. Within BCS, patients presenting with clinical symptoms (vs. screening detected) were more likely to have SLNB (p=0.0006, OR: 1.76; 95% CI 1.31-2.36). For both groups, presence of comedo necrosis, year of diagnosis, and treating institution were predictors of SLNB (p&lt;0.0001). 1,171 (19.3%) were upstaged from DCIS at initial biopsy to invasive cancer on final pathology. 212 (18.1% invasive cancer group) had positive nodes. Use of SLNB increased over time from 1998-2009 in mastectomy group. Among BCS group, SNLB use decreased over the first half of the study period and then remained stable at approximately 15% across all centers. Conclusions: Although use of SNLB has decreased over time, a substantial percentage of patients undergoing BCS for DCIS receive SNLB. Practices vary considerably across centers. SLNB can be performed as a second procedure for those treated with BCS and identified with invasive cancer, thereby avoiding unnecessary risk of significant morbidity. Breast programs should review their practices to curtail the use of unnecessary surgery for women with DCIS.

Race and age disparities in receipt of sentinel lymph node biopsy for early-stage breast cancer

To evaluate differences in use of sentinel lymph node biopsy (SLNB) by age and race in Medicare recipients with early-stage breast cancer, we examined Surveillance, Epidemiology and End Results-Medicare linked data for women undergoing breast conserving surgery for stage I or II breast cancer, including axillary staging, between January 2000 and December 2002. Multivariable generalized linear modeling with generalized estimating equations was used to identify predictors of receiving SLNB versus standard axillary lymph node dissection as the primary axillary staging modality. Women were significantly less likely to receive SLNB as their primary staging procedure if they were African American (OR 0.65), greater than 80years of age (OR 0.71 vs. age <70), or dually eligible for Medicare and Medicaid (OR 0.61). Tumor characteristics, including well-differentiated histology and stage I disease, were associated with increased likelihood of SLNB, but estrogen receptor status was not a significant predictor. Women treated at an institution affiliated with an NCI cooperative research group had significantly greater likelihood of receiving SLNB (OR 2.31). Likelihood of receiving SLNB increased for women diagnosed in 2001 and 2002 compared with 2000. Significant disparities exist in receipt of SLNB in the Medicare population, with African Americans, the elderly, and economically disadvantaged patients being less likely to receive this innovative and morbidity-sparing procedure. These findings continue a previously observed pattern of reduced access to state of the art breast cancer care among underserved populations.

Regional Differences in the Use of Sentinel Lymph Node Biopsy for Melanoma: A Potential Quality Measure

Sentinel lymph node biopsy (SLNB) provides accurate nodal staging in patients with melanoma. However, its prevalence across geographic regions is unknown. Our aim was to determine if SLNB for melanoma has been widely adopted throughout the United States. All patients in the Surveillance, Epidemiology and End Results (SEER) cancer registry for 2004 with melanoma were evaluated. Data were collected for demographics, depth of melanoma, and type of nodal evaluation (regional lymph node dissection vs SLNB). Registry sites were categorized into West, Midwest, Northeast, and Southeast. Chi2 analysis was performed to identify regional differences in receipt of SLNB. Overall, the West region (n = 2352) had a higher use of SLNB compared with the Midwest (n = 497), Northeast (n = 630), and Southeast (n = 268) regions (82.1% vs 77.9%, 65.4%, and 60.1%, respectively; P < 0.001). Intermediate-thickness (1 to 4 mm) melanomas had differences in SLNB use between the West and Midwest (83.6% and 81.4%) versus the Northeast and Southeast (66.3% and 60.2%) (P < 0.05). This population-based analysis shows low use of SLNB for melanoma in some U.S. regions. Further studies need to address the reasons for these differences and target ways to improve rates. Results suggest that SLNB may be considered as a potential quality measure.

Disparities and Trends in Sentinel Lymph Node Biopsy Among Early-Stage Breast Cancer Patients (1998-2005)

Sentinel lymph node biopsy (SLNB), an acceptable alternative to axillary lymph node dissection for staging patients with breast cancer, was introduced to clinical practice in the late 1990s. We assessed demographic, clinical, and facility-related factors associated with SLNB in women with early-stage breast cancer and evaluated trends in these factors over time. Data on early-stage breast cancers (T1a, T1b, T1c, and T2N0) diagnosed between January 1, 1998, and December 31, 2005, were extracted from the National Cancer Database, a hospital-based registry. Patient demographics, tumor stage, type of lymph node surgery, type of breast cancer surgery, health insurance, treatment facility type, and area-level education and income variables were collected. Multivariable logistic regression analyses were performed to assess predictive factors associated with SLNB, temporal differences in factors associated with SLNB, and differences in rates of SLNB by facility type, race/ethnicity, and type of health insurance over time. The total analytic study population included 490,899 women. The use of SLNB increased from 26.8% in 1998 to 65.5% in 2005. Factors associated with lower likelihood of SLNB over the study period included being older (odds ratio [OR] = 0.80, 95% confidence interval [CI] = 0.78 to 0.92 for those aged 72 or older compared with those aged 51 or younger), being of racial/ethnic minority (OR = 0.76, 95% CI = 0.74 to 0.78 for African Americans compared with whites), having no health insurance (OR = 0.77, 95% CI = 0.73 to 0.80 for uninsured compared with having private insurance), having certain government insurance plans (for Medicaid, OR = 0.81, 95% CI = 0.78 to 0.84, and for Medicare at age <65 years, OR = 0.83, 95% CI = 0.80 to 0.87, both compared with private insurance), residing in zip codes with lower proportion of high school graduates (OR = 0.88, 95% CI = 0.86 to 0.89) or with lower median income (OR = 0.79, 95% CI = 0.77 to 0.81), and receiving treatment in facility types other than a teaching or research hospital (for community hospital, OR = 0.84, 95% CI = 0.82 to 0.86; for community cancer center, OR = 0.86, 95% CI = 0.84 to 0.87). The associations with insurance status and sociodemographic characteristics were more pronounced in 2005 than in 1998. For example, the adjusted annual rates of SLNB in 1998 were 0.29 in whites, 0.26 in African Americans, and 0.35 in Hispanics; in 2005 the respective rates were 0.70, 0.64, and 0.67. Although use of SLNB increased from 1998 to 2005, disparities persisted in receipt of SLNB that are based on nonclinical factors, including sociodemographic characteristics and insurance status.