Abstract 1923: Association between socioeconomic status and p53 abnormalities among colorectal cancer patients
Authors: Vogtmann Emily , Shanmugam Chandrakumar , Katkoori Venkat , Waterbor John , Manne Upender 
Published: August 2014

Introduction: For some cancers, low socioeconomic status (SES) is associated with abnormal expression of p53, which contributes to a poor prognosis for colorectal cancer (CRC) patients. This investigation examined proxies of SES, including insurance and employment status, to determine if they were associated with abnormal p53 expression.

Methods: The study population consisted of 253 patients who underwent curative or palliative resection for CRC at the University of Alabama at Birmingham Hospital between 1981 and 2002. Patients were followed until February 2010. Proxies for SES, abstracted from physician charts and medical records, included employment status, Medicaid, Medicare and private insurance coverage. All patients had at least one type of health insurance coverage. Abnormal p53 was determined by immunohistochemistry. Tumor stage at diagnosis was abstracted from pathology reports, and demographic characteristics were obtained from physician charts and medical records. Multivariate logistic regression was used to adjust the SES measures for the possible confounding influences of age, sex, race, and tumor stage at diagnosis.

Results: Medicaid patients had a higher prevalence of abnormal p53 (62.0%) than patients with other insurance coverage (56.3%). Patients with Medicaid coverage were older (mean age, 70 versus 66 years), more likely to be female (83% versus 56%), more likely to be African American (76% versus 45%), and more likely to have advanced (Stage III/IV) disease (48% versus 46%) than patients having other coverage. After adjustment for age, sex, race, and tumor stage, the odds ratio (OR) for abnormal p53 was 1.22 (95% CI 0.52, 2.82) for Medicaid patients compared to patients having other insurance. There was no significant association between unemployment (OR 0.90, 95% CI 0.55, 1.49) or private insurance coverage (OR 1.06, 95% CI 0.62, 1.79) with prevalence of abnormal p53. Having Medicare due to disability was protective from abnormal p53 (OR 0.77, 95% CI 0.24, 2.51).

Conclusions: Although there was increased prevalence of abnormal p53 in CRC patients with Medicaid coverage, this study was underpowered to detect such a weak association with significance. These preliminary findings of an association between Medicaid status and p53 abnormalities in CRC patients provides initial evidence of a molecular basis for the diagnosis of advanced stage disease in economically deprived patients. Because data obtained from medical records may not accurately assess the true SES of patients, a larger patient cohort with SES measured at the community level by use of block-level census data is currently being analyzed. These studies were supported by grants from NIH (2U54-CA118948-03, R01-CA98932-01, R03-CA139629, and 5R25-CA047888-22).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1923. doi:10.1158/1538-7445.AM2011-1923