Environmental factors affecting the risk of urothelial carcinoma
PATIENTS WHO LIVE in geospatial hotspots of urothelial carcinoma (UC) prevalence are less likely to be white, higher income or tobacco users, and more likely to reside near sources of under- industrial products and environmental pollutants (IBP/EP), according to researchers from Charlotte, NC, and Wynnewood, PA. The results of their study were presented during a session on “Optimizing Personalized Management of Non-Muscle Invasive Bladder Cancer” at the 2021 ASCO Symposium on Genital Cancers.
“Risk factors for UC are well documented, with up to 65% of UC incidence attributable to smoking,” said study presenter Dr. Daniel C. Edwards (Levine Cancer Institute at Atrium Health, Charlotte). “Additionally, industrial and occupational exposure, such as coal mining, petroleum refining, tire manufacturers, painters, dyers, etc., can be attributed to up to 7% of the incidence of UC.” Cancer has been linked to environmental exposures, but research on the effects of non-occupational environmental risk factors has been limited, he explained.
Dr. Edwards and his co-investigators searched a multi-institutional database to identify patients diagnosed with UC between 2008 and 2018 in five southeastern Pennsylvania counties (population approximately 4 million, annual incidence of UC around 1,000). Using geocoded addresses and ArcGIS software, they determined the Getis-Ord-Gi* statistic and performed census block-level hotspot analysis to identify UC hotspots. Pearson’s chi-square and Student’s t-test were used to compare demographics, clinicopathologic disease characteristics, and proximity to IBP/PE sources. The correlation between patient and census block level factors and living in a UC hotspot was tested with adjusted univariate analyzes and multivariate, multilevel random intercept logistic regression models.
A total of 5080 patients were identified, of which 148 were correlated with one of the 3 identified UC hotspots. Univariate analyzes revealed that hotspot patients were less likely to be tobacco users (odds ratio [OR], 0.24; P=0.004), be white (OR, 0.10; P
Multivariate analysis confirmed that patients residing in UC hotspots were less likely to use tobacco (OR, 0.11; P=0.045) and less likely to be white (OR, 0.02; P=0.004).
“In terms of exposure to polycyclic aromatic hydrocarbons, hotspot patients were 40 times more likely to live near a source of release. And hotspot patients were much more likely to reside near high-density traffic hotspots,” Dr Edwards added.
“Ultimately, spatially related clusters of UC may be associated with local or regional environmental exposures. And patients residing in UC hotspots may be more likely to be less educated, earn less, women or non-Caucasian. Socioeconomic disparities may be associated with an increased likelihood of living in risky environments,” Dr. Edwards concluded. “In terms of clinical correlation, research such as this current study and future studies may help identify patients at risk for environmental exposure, allowing interventions to be undertaken, including patient and primary care education, that could improve screening, early diagnosis and treatment outcomes.
Edwards DC, Yankelevich GR, Dreher PC, et al. Socio-environmental conditions associated with geospatial clusters of urothelial carcinoma: a multi-institutional analysis. J Clin Oncol. 2021;39(6, suppl):99. Abstract 392. doi: 10.1200/JCO.2021.39.6_suppl.392