Cancer Mortality Patterns by Birthplace and Generation Status of Mexican Latinos: The Multiethnic Cohort

Abstract

Background: Latinos are the largest minority group in the United States. We assessed cancer mortality by birthplace and generation status of Mexican Latinos in the Multiethnic Cohort.

Methods: We included 26 751 Latinos of Mexican origin and 6093 non-Latino Whites aged 45-74 years at cohort entry (1993-1996) from the California Multiethnic Cohort component. The Mexican Latinos comprised 42% first-generation Mexico-born immigrants, 42% second-generation (28% US-born with both parents Mexico-born and 14% US-born with 1 parent US-born and 1 parent Mexico-born), and 16% third-generation or more who were US-born with both parents US-born. Multivariable Cox models were used to calculate covariate adjusted hazard ratios and 95% confidence intervals for overall and site-specific cancer mortality by birthplace and generation status. All statistical tests were 2-sided.

Results: Cancer death rate was highest among the US-born with 1 parent US-born and 1 parent Mexico-born (age-adjusted rate = 471.0 per 100 000 person-years) and US-born with both parents US-born (age-adjusted rate = 469.0 per 100 000 person-years) groups. The US-born with both parents Mexico-born group had a 30% (hazard ratio = 1.30, 95% confidence interval = 1.18 to 1.44) higher risk of cancer death than the first-generation Mexico-born immigrants group, showing US birthplace was associated with an elevated cancer mortality. For cancer-specific mortality, US birthplace was positively associated with colorectal, liver and lung, and ovarian cancer (P values ranged from .04 to .005). Among US-born Mexican Latinos, generation status was not statistically significantly associated with overall cancer or site-specific cancer mortality.

Conclusions: Our findings suggest that US birthplace is a risk factor for cancer death in Mexican Americans. Identification of the contributing factors is important to curtail patterns of increasing cancer mortality in US-born Mexican Latinos.

Figure 1.

Age-standardized overall cancer mortality rate in the study population. Birthplace and generation status of Latinos was based on the birthplace information of the study participants and their parents, collected from the baseline questionnaire. Study participants were categorized into 5 groups: Mexico-born Latinos with both parents Mexico-born (MX/MXMX); US-born Latinos with both parents Mexico-born (US/MXMX); US-born Latinos with 1 parent US-born and 1 parent Mexico-born (US/MXUS); US-born Latinos with both parents US-born (US/USUS); and non-Latino Whites (NLWs). Age-standardized cancer mortality rate (using the 2000 US standard population, per 100 000 person-years [PYs]) in female (dark grey), male (light grey), and total (white) population was shown separately, with mortality rate and corresponding 95% confidence interval (using the error bar) annotated.