Assessing environmental exposure and socioeconomic history prior to cancer diagnosis

BACKGROUND AND AIM Exposure assessment solely based on the address at cancer diagnosis assumes fixed exposure over time, while ignoring exposures from other addresses prior to cancer diagnosis. We aim to examine excess exposure risks of non-asbestos air toxics and socioeconomic status (SES) estimated over available residential history for mesothelioma patients. METHODS Patients’ residential histories were obtained by linking mesothelioma cases (n=1,015) diagnosed during 2011-2015 from the New York State Cancer Registry to LexisNexis administrative data and inpatient claims data. Percentile ranking of lifetime cancer risk from inhalation of non-asbestos air toxics was based on the National Air Toxic Assessment. SES was measured by Yost index, which is a percentile ranking derived from U.S. Census data. Excess exposure risk was calculated by dividing exposures at individual census tracts by the state-level average and subtracting one. We used a generalized linear regression model with the generalized estimating equation to compare the excess exposure risk in years prior to and at cancer diagnosis. RESULTS Approximately 43% of the study sample had a residential history prior to the cancer diagnosis for up to 30 years, and 94% up to 5 years. The excess exposure risks at the cancer-diagnosis tracts were below the state average, with means ranging from -0.22 to -0.11 for air toxics, and from -0.23 to -0.18 for SES. Excess exposure risks for both air toxics and SES tended to be higher in earlier addresses than addresses at cancer diagnosis, though the effect size was relatively small (1%-6.2%). CONCLUSIONS We demonstrated the feasibility of including residential history in cancer research and revealed differences between multiple approaches of estimating residence-related exposure risks over time. As the findings may be unique to the mesothelioma patients studied, future examinations using different exposure indicators and among different patient populations and other cancer types are needed.