The Burden of Infection-Associated and Common Cancers Among South Asians and Other Asian Subpopulations in the United States, 1999-2009

Abstract

Cancer surveillance systems often do not provide detailed estimates of disease among racial/ethnic minorities due to the use of combined racial groups such as Asian/Pacific Islander. The current cancer burden in the South Asian population in the U.S. is largely unknown due to the lack of studies that examine this group separately from other Asian/Pacific Islander populations. We utilized SEER data to examine differences in stage at diagnosis and survival of infection-associated (liver, stomach, and cervical) and common (breast) cancers among South Asians compared to other Asian subpopulations in the U.S. SEER-Medicare data were used to assess the association between primary care physician visits and these cancer outcomes among these groups. In our study of infection-associated cancers, it was found that South Asians had the highest proportion (48%) of late stage liver cancer cases compared to the other Asian subpopulations examined. When examining breast cancer outcomes among the Asian subpopulations, the highest risk for late stage diagnosis when compared to non-Hispanic whites was found among South Asians, with 3% (OR=0.97; 95% CI 0.81, 1.16) reduced risk for late stage diagnosis for this group. When examining those diagnosed at early-stage disease, South Asians had 39% significant reduced risk (95% CI 0.44, 0.84) of death when compared to non-Hispanic whites. Among those diagnosed with late-stage disease, this group had 20% reduced risk (95% CI 0.59, 1.09) of death when compared to non-Hispanic whites. Primary care visits were associated with decreased risk of late stage diagnosis of breast cancer among both Asians and non-Hispanic whites. Asians in the highest quartile of total physician visits had 57% (OR=0.43; 95% CI 0.27, 0.70) decreased risk of late stage diagnosis compared to those in the lowest quartile. Our findings provide evidence for the need to examine Asian subpopulations as individual groups rather than using the aggregate racial/ethnic category known as Asian/PI. True heterogeneity in cancer outcomes exists within these separate groups and requires targeted interventions for specific subpopulations.%%%%Ph.D., Public Health – Drexel University, 2014