Colorectal cancer in the United States and a review of its heterogeneity among Asian American subgroups.

Colorectal cancer is the third most common cancer in the United States. Established risk factors include older age, unhealthy lifestyle (high consumptions of red/preserved meat, low consumptions of fruit and vegetables, smoking, high alcohol consumption, and lack of physical activities), personal and family medical histories and low socioeconomic status (low insurance coverage, education and income). Asian American subgroups vary significantly in terms of culture, socioeconomic status, and health behaviors, yet most registries and researches aggregate all Asian Americans as one group. In this review, we summarized and compared colorectal cancer incidence among different Asian American subgroups, and to explore the reasons behind the heterogeneity. Based on limited literatures, we found that Japanese Americans have the highest colorectal cancer incidence among all Asian Americans. The incidence is decreasing among most Asian American subgroups except for Korean Americans. Such heterogeneity is influenced by lifestyle factors related to the country of origin and the United States, as well as colorectal cancer screening.