Cancer incidence among Armenians in California.

Introduction: California is home to the largest population of Armenians in the United States. The historical categorization of Armenians as 'White' or 'Some Other Race' in population databases has likely masked cancer incidence patterns in this population. This is the first study considering cancer incidence among Armenians in California.

Methods: We used the Armenian Surname List and birthplace information in the California Cancer Registry to identify Armenians with cancer diagnosed during 1988-2019. We calculated proportional incidence ratios (PIR) among Armenians compared with non-Hispanic Whites (NHWs). As an exploratory analysis, we calculated incidence rate ratios (IRR) during 2006-2015 using Armenian population denominators from the American Community Survey (ACS). We selected PIR as our primary method given uncertainty regarding the use of ACS population estimates for rate calculations.

Results: There were 27,212 cancer diagnoses among Armenians in California, 13,754 among males and 13,458 among females. Armenian males had notably higher proportions of stomach (PIR = 2.39), thyroid (PIR = 1.45), and tobacco-related cancers including bladder (PIR = 1.53), colorectal (PIR = 1.29), and lung (PIR = 1.16) cancers. Higher proportional incidence of cancers including stomach (PIR = 3.24), thyroid (PIR = 1.47), and colorectal (PIR = 1.29) were observed among Armenian females. Exploratory IRR analyses showed higher stomach (IRR = 1.78), bladder (IRR = 1.13), and colorectal (IRR = 1.12) cancers among Armenian males and higher stomach (IRR = 2.54) cancer among Armenian females.

Conclusion: We observed higher stomach, colorectal and thyroid cancer incidence among males and females, and tobacco-related cancers among males. Further research is needed to refine Armenian population estimates and understand and address risk factors associated with specific cancers among Armenians in California.