A statewide study on cancer and ethnicity hints that cancer rates among immigrant groups may be tied to their degree of assimilation into American culture. The study, released by the University of Southern California's Norris Comprehensive Cancer Center, marks the first statewide look at cancer rates among Vietnamese and South Asians and provides a roadmap for what the nation's cancer landscape could look like in 20 years, researchers say. Findings from the study include: in some cases, immigrants who hold onto their native culture longer reported higher rates of certain types of cancer; and Asians had the highest incidence of stomach cancer, with Koreans experiencing a one and a half-fold increase over Japanese and Vietnamese between 1993 and 2001.