Racial Differences in Colorectal Cancer Incidence, Prevalence, and Survival Rates over 10 Years: A Retrospective Single Center Study

Abstract

Introduction: Colorectal cancer (CRC) is the third leading cause of cancer related deaths in the United States. Although, studies have been performed on malignancy behavior in African Americans and Caucasians, very few studies focused on the Hispanic, Arab, and Asian ethnicities. Methods: We present a retrospective single center study that includes analysis of 1,860 patient charts with a diagnosis of CRC from January 1, 2004 to December 31, 2014. Data collected on each patient included age, gender, ethnicity, primary site and histological stage of CRC at the time of diagnosis. Survival time over the course of 5 years was documented for patients between January 1, 2004 to December 31, 2009. Comparisons were made amongst different ethnic groups for above mentioned variables. Results: Study population consisted of 24.6% African Americans, 60.6% Caucasians,4% Hispanic Americans, 0.6% South Asians, 0.9% Arab Americans,0.5% Asian Americans and 0.2% American Indians. Age at presentation: Mean age of presentation for Caucasians was 71, African Americans was 68 and Hispanic Americans was 60 years. All results were statistically significant. (p=0.02) Histological Stage at Diagnosis: African Americans (27.1%) and Hispanic Americans (33.3%) presented predominantly at stage IV as compared to other ethnicities. Caucasians (24.5%) presented predominantly at stage II. Site of Cancer: The rectum was the most common site of cancer across all ethnicities with the exception of Asians where sigmoid colon was the predominant site (30%). Caucasians were found to have significantly higher incidence rate in ascending colon and rectosigmoid junction.Table 1: Table showing mean age of presentation of colorectal cancer for different ethnicitiesTable 2: Table showing comparisons of different ethnicities for age at presentation of colorectal ancerFigure 1Figure 2Figure 3Type of Carcinoma: Adenocarcinoma remained the predominant cancer type in all ethnic groups. Hispanic Americans had relatively higher incidence rate of Carcinoid tumor (12.7%). Survival time: Survival time analysis showed that Caucasians tend to have better survival time over 5 years after initial diagnosis of CRC as compared to African Americans but results were not statistically significant (p=0.69). Conclusion: According to the American Cancer Society, the incidence of CRC in African-American males is 63.8/100,000, as compared to 50.9/100,000 in Caucasian males. There is a lack of research and data performed on other ethnic groups. Our study highlights some important clinical differences of CRC presentation in different ethnic groups. This study can serve as baseline for future multi-center studies in further disease behavior assessment.