Abstract 138: Disparities in lymph node evaluation among women with breast cancer.
Authors: Kong Weihong , Hillemeier Marianne M. 
Published: August 2014

Breast cancer is the second leading cause of death in U.S. women, representing one out of every three cancer cases diagnosed annually in this population. While breast cancer death rates have declined to 22.2 deaths per 100,000 women in 2009 from 33.2 deaths per 100,000 in 1990, disparities persist by race and socioeconomic status in stage at diagnosis and guideline-concordance of treatment. In 2005, NICCQ (National Initiative for Cancer Care Quality) proposed that women with a new diagnosis of stage I-III breast cancer undergo axillary node sampling or at minimum be informed that this is recommended procedure. In this study, we examined disparities in performance of regional lymph node evaluation among primary breast carcinoma patients diagnosed in the period 2004 to 2009. We seek to understand race-specific frequencies of recommended lymph node evaluation and relationship of lymph node evaluation rates with breast cancer mortality. Methods: Using data from the Surveillance, Epidemiology, and End Results (SEER), we identified 37,204 female primary breast cancer patients who were diagnosed from 2004 to 2009 with in situ/local/regional disease including stages 0, 1, 2, and 3. Patients who were diagnosed at stage 4 breast cancer were excluded from this study, since they were not included in the NICCQ recommendation. We estimated three logistic regression models to investigate the relationships between lymph nodes evaluation and overall or cause-specific death rates controlling for age, race, stage, grade, marital status, radiation, surgery, and relevant county attributes. All analysis was carried out using SAS 9.3 software. Results: We identified 36,462 patients diagnosed with stage I-III primary breast carcinoma during 2004 to 2009. Overall, 12.13 percent (N=4,423) did not undergo lymph nodes evaluation. Multivariate logistic models were estimated and odds ratios (ORs) were calculated from model coefficients. The odds of being evaluated with regional lymph nodes significantly increased for patients who were white, younger than 65, and married. The same is true for those who lived in nonmetropolitan counties and counties that had a higher mammography rate within the previous 2 years. The odds of surviving cancer were significantly decreased if regional lymph nodes were not evaluated. For example, there was a 63% decrease in the odds of overall survival for unevaluated patients, holding other predictors constant. The percentage of patients with unexamined lymph nodes remained similar (11.97%-12.38%) over the years observed. Conclusions: Study findings support the need for quality improvement in cancer care, and the relevance of evaluating regional lymph nodes for disparities in cancer mortality. No significant improvement in rates of regional lymph node evaluation occurred after the NICCQ recommendation, suggesting additional policy interventions may be needed.

Citation Format: Weihong Kong, Marianne M. Hillemeier. Disparities in lymph node evaluation among women with breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 138. doi:10.1158/1538-7445.AM2013-138