Currently there is no national unified cancer database for incidence, mortality, and risk factors for Japanese Americans as most previous data were combined with that of other Asian Americans and Pacific Islanders. Present information is derived from published studies, the California Cancer Registry, and the Surveillance, Epidemiology, and End Results (SEER) program among others. With the adaptation to Western diets and a trend to be overweight as elucidated by the California Health Interview Survey, a telephone survey of health risk behaviors, colorectal cancer in Japanese Americans appears to be increasing.
The 2000 to 2002 California Cancer Registry data showed the incidence of this cancer to be higher than that of other Asian ethnic groups and non Hispanic Whites. The colorectal cancer mortality in Japanese American men was also noted to be higher than that of other Asian ethnic groups and non Hispanic Whites. With the exception of fecal occult blood testing, colorectal cancer screening patterns in the Japanese Americans were similar to that of non Hispanic Whites (McCracken et al, 2007).
Japanese Americans also have a high incidence of stomach cancer. In the California Cancer Registry data of 2000 to 2002, the incidence was higher than non Hispanic Whites, Filipinos and Chinese. The consumption of nitrite/nitrate rich and salty foods such as cured meats is thought to increase the risk for this cancer. One Hawaii study of Japanese Americans found an inverse association between fresh fruits and raw vegetable consumption and the risk of stomach cancer, however, no significant relationship was found between stomach cancer incidence and intake of processed meats. (Galantis et al., 1998)
The incidence of breast cancer in the California Cancer Registry of 2000 to 2002 was lower than that of non Hispanic Whites but was higher than that of other Asian ethnic groups. Acculturation and western lifestyle risks such as late childbearing, fewer children, and hormonal use, which are breast cancer risks, are thought to have influenced the high incidence of breast cancer in the Japanese Americans. One study using the National Health Interview Survey found that the percentage of Japanese American women who never had a mammogram and who never had a Papanicolau (Pap) screening test did not differ much from that of White women (Kagawa-Singer et al, 2000). Of interest, uterine cancer incidence but not cervical cancer was also high in Japanese Americans compared to other Asian ethnic groups (Kwong et al, 2005; Kagawa-Singer et al, 2000).
The incidence of prostate cancer for Japanese Americans was second highest next to Filipino Americans when compared with other Asian ethnic groups but lower compared to non Hispanic Whites (McCracken, 2007). The incidence of prostate cancer in Japan compared to that of Japanese Americans in the United States is low. Studies into dietary influences are ongoing (Marks et al, 2008; Masumori et al, 2008).