Abstract C45: Rural-urban and access to care differences in cervical cancer stage at diagnosis
Authors: Zahnd Whitney , McQueen Amy , Lobb Rebecca , Diaz-Sylvester Paula , Brard Laurent 
Published: March 2017

Abstract
Purpose: Rural women are less likely to have regular Pap smears and often have less access to care than their urban peers, which may lead to more advanced stage at diagnosis of cervical cancer. We sought to evaluate the relationship of rural-urban status and access to care on cervical cancer stage at diagnosis.
Methods: We extracted 2007 to 2013 Surveillance Epidemiology and End Results (SEER) 18 data on cervical cancer cases diagnosed in women aged 21 to 65 (n=19,492), the age recommended for Pap smears. SEER 18 registries include roughly 30% of the U.S. population. Case-level variables included rural-urban status, stage at diagnosis, age, race/ethnicity, insurance status, and marital status. Staging was categorized as I, II, III, IV, or unknown. We also examined county-level socioeconomic factors matched to cases' county of residence (% below poverty, median household income, and % of adults without a high school education) extracted from SEER. Using data from the Area Health Resource File, we calculated the mean density of both primary care physicians and obstetricians/gynecologists per 100,000 women aged 20-65 in each SEER 18 county. We also classified each county by its designation as a health professional shortage area for primary care. We performed chi-square analysis to compare stage at diagnosis, demographic, socioeconomic, and access to care characteristics of cases by rural-urban status. Socioeconomic and access to care variables were categorized by quartiles. We performed multivariable, modified Poisson regression to calculate the relative risk (RR) of Stage I to II (early vs. moderate early) and Stage I to III/IV (early vs. advanced) by rural, demographic, socioeconomic and access to care variables. RRs were also calculated stratified by rural-urban status.
Results: Rural cancer cases were poorer, were more likely to be on Medicaid or be uninsured, and had less access to primary care physicians and obstetricians/gynecologists than urban cases, but there was no rural-urban difference in stage or age at diagnosis. Age, black race, insurance status, being single/divorced/widowed, and county-level poverty were associated with more advanced stage at diagnosis. For example, compared to privately insured cases, women with Medicaid or who were uninsured were more likely to be diagnosed at an advanced stage (RR= 1.45; 95% confidence interval (CI)1.39-1.51 and RR=1.47; 95% CI 1.36-1.57, respectively). Among urban cervical cancer cases, age, black race, and being single/divorced/widowed were associated with both moderate early and advanced stage. The highest quartile of poverty and the lowest density of primary care physicians also was associated with advanced stage at diagnosis. Among rural cervical cancer cases, age and insurance status were associated with both moderate early and advanced stage at diagnosis. The effect of age on advanced staging was of greater magnitude in rural cases than in urban cases. In urban women, compared to women aged 20-29, cases aged 30-39 and 40-65 were at greater risk for advanced stage cancer (RR=1.37; 95% CI 1.23-1.54 and RR=2.24, 95% CI 2.00-2.51, respectively). In rural women, cases aged 30-39 (RR=2.31, 95% CI 1.49-3.59) and 40-65 (RR=3.51, 95% CI 2.27-5.43) had more than two to three times the risk, respectively, of advanced staged cervical cancer than their younger peers.
Conclusions: We did not find rural-urban or access to care disparities in stage at diagnosis. However, other socio-demographic factors were associated with more advanced stage, and the magnitude of such factors differed by rural-urban status. Future research should be performed to elucidate the relationship between these factors and staging, and interventions should be targeted by rural-urban specific factors.
Citation Format: Whitney Zahnd, Amy McQueen, Rebecca Lobb, Paula Diaz-Sylvester, Laurent Brard. Rural-urban and access to care differences in cervical cancer stage at diagnosis. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr C45.