Effect of hospital volume on processes of breast cancer care: A National Cancer Data Base study.

BACKGROUND: The purpose of this study was to examine variations in delivery of several breast cancer processes of care that are correlated with lower mortality and disease recurrence, and to determine the extent to which hospital volume explains this variation. METHODS: Women who were diagnosed with stage I-III unilateral breast cancer between 2007 and 2011 were identified within the National Cancer Data Base. Multiple logistic regression models were developed to determine whether hospital volume was independently associated with each of 10 individual process of care measures addressing diagnosis and treatment, and 2 composite measures assessing appropriateness of systemic treatment (chemotherapy and hormonal therapy) and locoregional treatment (margin status and radiation therapy). RESULTS: Among 573,571 women treated at 1755 different hospitals, 38%, 51%, and 10% were treated at high-, medium-, and low-volume hospitals, respectively. On multivariate analysis controlling for patient sociodemographic characteristics, treatment year and geographic location, hospital volume was a significant predictor for cancer diagnosis by initial biopsy (medium volume: odds ratio [OR] = 1.15, 95% confidence interval [CI] = 1.05-1.25; high volume: OR = 1.30, 95% CI = 1.14-1.49), negative surgical margins (medium volume: OR = 1.15, 95% CI = 1.06-1.24; high volume: OR = 1.28, 95% CI = 1.13-1.44), and appropriate locoregional treatment (medium volume: OR = 1.12, 95% CI = 1.07-1.17; high volume: OR = 1.16, 95% CI = 1.09-1.24). CONCLUSIONS: Diagnosis of breast cancer before initial surgery, negative surgical margins and appropriate use of radiation therapy may partially explain the volume-survival relationship. Dissemination of these processes of care to a broader group of hospitals could potentially improve the overall quality of care and outcomes of breast cancer survivors. Cancer 2017;123:957-66. © 2016 American Cancer Society.

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.

An algorithm to identify the development of lymphedema after breast cancer treatment.

PURPOSE: Large, population-based studies are needed to better understand lymphedema, a major source of morbidity among breast cancer survivors. One challenge is identifying lymphedema in a consistent fashion. We sought to develop and validate an algorithm using Medicare claims to identify lymphedema after breast cancer surgery. METHODS: From a population-based cohort of 2,597 elderly (65+) women who underwent incident breast cancer surgery in 2003 and completed annual telephone surveys through 2008, two algorithms were developed using Medicare claims from half of the cohort and validated in the remaining half. A lymphedema-positive case was defined by patient report. RESULTS: A simple two ICD-9 code algorithm had 69 % sensitivity, 96 % specificity, positive predictive value >75 % if prevalence of lymphedema is >16 %, negative predictive value >90 %, and area under receiver operating characteristic curve (AUC) of 0.82 (95 % CI 0.80-0.85). A more sophisticated, multi-step algorithm utilizing diagnostic and treatment codes, logistic regression methods, and a reclassification step performed similarly to the two-code algorithm. CONCLUSIONS: Given the similar performance of the two validated algorithms, the ease of implementing the simple algorithm and the fact that the simple algorithm does not include treatment codes, we recommend that this two-code algorithm be validated in and applied to other population-based breast cancer cohorts. IMPLICATIONS FOR CANCER SURVIVORS: This validated lymphedema algorithm will facilitate the conduct of large, population-based studies in key areas (incidence rates, risk factors, prevention measures, treatment, and cost/economic analyses) that are critical to advancing our understanding and management of this challenging and debilitating chronic disease.

Surgeon specialization and use of sentinel lymph node biopsy for breast cancer.

IMPORTANCE: Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging in patients with clinically node-negative breast cancer. It is not known whether SLNB rates differ by surgeon expertise. If surgeons with less breast cancer expertise are less likely to offer SLNB to these patients, this practice pattern could lead to unnecessary axillary lymph node dissections and lymphedema. OBJECTIVE: To explore potential measures of surgical expertise (including a novel objective specialization measure: percentage of a surgeon's operations performed for breast cancer determined from Medicare claims) on the use of SLNB for invasive breast cancer. DESIGN, SETTING, AND POPULATION: A population-based prospective cohort study was conducted in California, Florida, and Illinois. Participants included elderly (65-89 years) women identified from Medicare claims as having had incident invasive breast cancer surgery in 2003. Patient, tumor, treatment, and surgeon characteristics were examined. MAIN OUTCOME AND MEASURE: Type of axillary surgery performed. RESULTS: Of 1703 women who received treatment by 863 surgeons, 56.4% underwent an initial SLNB, 37.2% initial axillary lymph node dissection, and 6.3% no axillary surgery. The median annual surgeon Medicare volume of breast cancer cases was 6.0 (range, 1.5-57.0); the median surgeon percentage of breast cancer cases was 4.5% (range, 0.4%-100.0%). After multivariable adjustment of patient and surgeon factors, women operated on by surgeons with higher volumes and percentages of breast cancer cases had a higher likelihood of undergoing SLNB. Specifically, women were most likely to undergo SLNB if the operation was performed by high-volume surgeons (regardless of percentage) or by lower-volume surgeons with a high percentage of breast cancer cases. In addition, membership in the American Society of Breast Surgeons (odds ratio, 1.98; 95% CI, 1.51-2.60) and Society of Surgical Oncology (1.59; 1.09-2.30) were independent predictors of women undergoing an initial SLNB. CONCLUSIONS AND RELEVANCE: Patients who receive treatment from surgeons with more experience with and focus on breast cancer are significantly more likely to undergo SLNB, highlighting the importance of receiving initial treatment by specialized providers. Factors relating to specialization in a particular area, including our novel surgeon percentage measure, require further investigation as potential indicators of quality of care.

A contemporary, population-based study of lymphedema risk factors in older women with breast cancer.

BACKGROUND: We studied potential risk factors for lymphedema in a contemporary population of older breast cancer patients. METHODS: Telephone surveys were conducted among women (65-89 years) identified from Medicare claims as having initial breast cancer surgery in 2003. Lymphedema was classified by self-report. Surgery and pathology information was obtained from Medicare claims and the state cancer registries. RESULTS: Of 1,338 patients treated by 707 surgeons, 24% underwent sentinel lymph node biopsy (SLNB) and 57% axillary lymph node dissection (ALND). At a median of 48 months postoperatively, 193 (14.4%) had lymphedema. Lymphedema developed in 7% of the 319 patients who underwent SLNB and in 21% of the 759 patients who underwent ALND. When controlling for patient age, tumor size, type of breast cancer, type of breast and axillary surgery, receipt of radiation, chemotherapy, and hormonal therapy, and surgeon case volume, the independent predictors of lymphedema were removal of more than five lymph nodes [odds ratio (OR) 4.68-5.61, 95% confidence interval (CI) 1.36-19.74 for 6-15 nodes; OR 10.50, 95% CI 2.88-38.32 for >15 nodes] and presence of lymph node metastases (OR 1.98, 95% CI 1.21-3.24). CONCLUSIONS: Four years postoperatively, 14% of a contemporary, population-based cohort of elderly breast cancer survivors had self-reported lymphedema. In this group of predominantly community-based surgeons, the number of lymph nodes removed is more predictive of lymphedema rather than whether SLNB or ALND was performed. As more women with breast cancer undergo only SLNB, it is essential that they still be counseled on their risk for lymphedema.