Abstract LB-418: Factors associated with colorectal cancer survival vary by gender
Authors: Vogtmann Emily J. , Shanmugam Chandrakumar , Waterbor John , Bumpers Harvey , Manne Upender 
Published: February 2011

Introduction: Some studies have found that women have longer survival after colorectal cancer (CRC) surgery than men. The present study investigated whether CRC-specific and overall survival after surgery were different for males and females.

Methods: The study population consisted of patients who underwent curative or palliative resection for CRC at the University of Alabama at Birmingham Hospital between 1981 and 2002. Follow-up ended in August 2009. Tumor characteristics [differentiation, histologic type, staging components (TNM), size, and site within the colorectum] were extracted from pathology and radiology reports. Demographic characteristics were obtained from physician charts and medical records. Pathologic and demographic characteristics were initially compared between genders using Pearson chi-square and/or two-sample t-test statistics. Median follow-up times were compared using the Wilcoxon Rank Sum test. Univariate Kaplan-Meier analyses were used to compare the overall (all-cause) and CRC-specific survival for males and females. Multivariate Cox proportional hazards models were used to assess factors associated with survival. All analyses were conducted with SAS 9.2.

Results: Demographic and pathological data were available for 599 males and 494 females. The racial (non-Hispanic Caucasian and African-Americans) distribution was different for males and females: 69.6% of males were white, compared to 61.0% of females (p = 0.003). The distribution of tumor site (proximal colon, distal colon, or rectum) differed by gender (p = 0.007). Tumor stage, size, differentiation, and type, however, were not statistically different. Kaplan-Meier curves did not show differences in overall or CRC-specific survival for men and women. When stratified by tumor stage, overall survival for females with Stage II cancer was higher than for males (logrank, p = 0.03); however, such a difference was not statistically significant for CRC-specific mortality. In multivariate analyses, factors significantly associated with overall survival for males were age, race; and tumor location, size, stage, and differentiation. For females, only age and tumor stage were significantly associated with overall survival. For CRC-specific survival in males, significant factors were age; and tumor location, size, and stage. For females, only tumor stage was significantly associated with CRC-specific survival.

Discussion: Factors associated with overall and CRC-specific survival differ by gender. For males, several demographic and pathologic factors, in addition to tumor stage, were associated with survival; for females, only tumor stage was an important prognostic factor. Other unmeasured covariates, including socioeconomic status and tumor molecular characteristics, may influence patient survival; their effects should be studied in the future.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-418.