Prevalence of Cancer & Cancer Subtypes and Association with Benzene, Toluene, Ethylbenzene, and Xylene - a Study from the National Health and Nutrition Survey

BACKGROUND: BTEX (benzene, toluene, ethylbenzene, and xylene) is a lipid soluble volatile organic compound (VOC). Its toxicity is exhibited through absorption and accumulation in high concentrations in the brain, liver, and adipose tissue. The literature about its carcinogenic effects is limited. Hence, we aim to study its prevalence and association with different types of cancer.

METHOD: A retrospective cross-sectional study using the NHANES database (2013 to 2018) was conducted. Questionnaires of individuals with complete data on exposure to BTEX and cancer were included in the study. Univariate (chi-square test and unpaired t-test) and multivariate analyses (survey logistic regression model) were conducted to evaluate the prevalences of cancer subtypes and the association of cancer with BTEX exposure compared to no BTEX exposure. The p-value of <0.05 was considered statistically significant.

RESULTS: 124,162 participants with BTEX exposure were identified. Univariate analysis showed higher total prevalence of cancer in BTEX (9.3% vs. 1.3%;p<0.0001) compared to no BTEX. Individuals with BTEX exposure had higher prevalence of blood cancer (0.47% vs 0.00%; p<0.0001), leukemia (0.56% vs 0.00%; p<0.001), and lymphoma (1.72% vs 0.39%; p<0.0001), lung (2.06% vs 0.11%; p<0.0001), melanoma (13.33% vs 1.37; p<0.0001), Skin(non-melnoma) (14.97% vs 1.93; p<0.0001), Thyroid (2.02% vs 0.21%; p<0.0001), Uterus (3.44% vs 0.23%; p<0.0001), Breast (10.80% vs 2.82%; p<0.0001), Cervix (5.60% vs 0.42%; p<0.0001), Colon (5.26% vs 0.71%; p<0.0001), Kidney (1.15% vs 0.72%; p<0.0001), and Others (3.67% vs 0.81%; p<0.0001) in comparison with no exposure. Multivariate analysis showed participants with BTEX exposure had 11% higher risk of cancer (OR: 1.10; 95%CI: 1.10-1.10; p=<0.0001) compared to no BTEX exposure. Additionally, exposure to individual components of benzene (OR: 1.24; 95%CI: 1.24; p=<0.0001), ethylbenzene (OR: 1.08; 95%CI: 1.08-1.08; p=<0.0001), and o-xylene (OR: 1.19; 95%CI: 1.19-1.19; p=<0.0001) had higher risk of cancer compared to no exposure participants.

CONCLUSION: There is a higher risk of cancer in participants with BTEX exposure and also an increased cancer risk among participants with exposure to benzene, ethylbenzene, and o-xylene. Future studies are warranted to evaluate the association of various types of cancer in BTEX exposure and its individual components.

No relevant conflicts of interest to declare.