Among non–small-cell lung carcinoma (NSCLC) patients, foreign-born Hispanics show less cancer-related mortality compared with US-born Hispanics and non-Hispanic whites, in part due to social and cultural environment, according to results published in the Journal of Clinical Oncology.
The so-called “Hispanic paradox” refers to the finding that Hispanics tend to present with more advanced, late-stage lung cancer. They are also less likely to receive treatment for cancer. Both of these observations are thought to be due to the socioeconomic status of many Hispanic patients. Despite the disparity, cancer mortality is cut in half for Hispanics compared with non-Hispanic whites. The reasons behind the paradox have not been fully elucidated, leading a group from Stanford University to question whether social or cultural factors were at play.
In this study, non-Hispanic white and Hispanic NSCLC patient data from 1998 to 2007 were collected from the California Cancer Registry. Data were then analyzed for several criteria to relate to mortality, including individual (age, gender, etc), clinical (treatment, histologic subtype, etc), and neighborhood traits (socioeconomic status and ethnic enclave status). A total of 14,280 Hispanic patients were segregated into foreign-born (n = 7,074) and US-born (n = 7,206).
The results showed that foreign-born Hispanics were more likely to have advanced disease compared with US-born Hispanics (60.1% vs 55.3%), but this did not lead to a survival disadvantage. Foreign-born Hispanics showed a 10% decreased cancer-related mortality rate compared with US-born Hispanics. This advantage was even more pronounced when comparing foreign-born Hispanics to non-Hispanic whites, showing a 15% decreased risk of cancer-related mortality. Interestingly, no significant difference could be found between the mortality rate of US-born Hispanics and non-Hispanic whites.
The findings led the researchers to conclude that socioeconomic status was a major factor in the decreased cancer-related mortality rate of foreign-born Hispanic NSCLC patients. Indeed, when results were analyzed to include only those foreign-born Hispanics in the lowest quartiles of socioeconomic status and the most dense social structure, the survival advantage improved to 14% over US-born Hispanics. Remarked the authors, “…populations retain some cultural and behavioral norms that may be advantageous with respect to the incidence and mortality of some cancers.”
Furthermore, “Our neighborhood enclave variable suggests that coethnic support may play a role in the survival advantage among foreign-born relative to US-born Hispanics with NSCLC in those neighborhoods.”
Overall, these results suggest to the authors that cultural and social behaviors found in foreign-born Hispanics most likely explain the survival advantage in these patients, as opposed to inherent genetic features predisposing this population to survival. The individual factors within the broad context of neighborhood traits have yet to be elucidated and warrant further investigation.