Gender Differences in Hepatocellular Carcinoma in the United States

Abstract

Purpose: Hepatocellular carcinoma is the sixth most common cancer in the world. Hepatocellular carcinoma is more common in men as compared to women. Higher incidence of hepatocellular carcinoma in men may be due to differences in hormonal characteristics. Previous studies of gender differences in hepatocellular carcinoma were done in single institutions and outside the United States. The primary objective of our study is to compare stage-specific survival of men and women with hepatocellular carcinoma in the United States. Methods: We studied a retrospective cohort of hepatocellular carcinoma patients in National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database. Seventeen registries are currently enrolled in SEER database and cover approximately 28% of U.S. population. SEER database has information about demographic characteristics of patients, presenting features and survival of patients with hepatocellular carcinoma. We included all patients aged 65 years or older with hepatocellular carcinoma in SEER database from 1973-2009. Patients with unknown stage were excluded from the study. The survival curves were compared using the Mantel-Haenszel log-rank test. A multivariate Cox-proportional hazards regression model was used to compare survival between men and women after adjusting for variables that are statistically significant different between those groups in univariate analysis. We performed statistical analysis using SPSS software (version 19.0). Results: We included 10,497 adult patients age greater than 65 years with hepatocellular carcinoma in SEER database from1973-2009. We excluded 2,962 patients who did not have documented staging. There were predominantly men 7,194 (68.5%). Mean age (SD) of women was 76 (6.8) years compared to men 74 (6.2) years (P<0.001). A higher proportion of men were Caucasian compared to women (68% vs. 65%, respectively). The median survival of women and men for localized, regional and distant stage of disease in years was 1.33 vs.1.33, 0.33 vs. 0.41, 0.17 vs. 0.17, respectively. Univariate survival analysis showed women and men had similar stage-specific survival (P = 0.24). Women had similar survival time compared to men even after adjusting for age, stage of the disease, and race in multi-variate analysis (hazard ratio (95%CI) 1.01 (0.96-1.04). Conclusion: Hepatocellular carcinoma is more common in men but stage-specific survival was similar in women and men even after adjusting for differences in age, stage and race.