Cell type specificity of lung cancer associated with nitric oxide Original Research Article

We aimed to explore whether lung cancer associated with air pollutants, specifically nitric oxide (NO), has cell type specificity. Both Spearman correlation and multiple linear regression between the air quality indices (SO2, CO, O3, NO, and NO2) and age-standardized incidence rate (ASR) of lung cancer by two major pathological types were calculated for both genders. We conducted 4 levels of analyses based on different NO concentrations. We also used Poisson regression to estimate the relative risk of lung cancer. Regardless of gender, the influences of SO2, CO, O3, and NO2 were not statistically significant. There was a dose–response relationship between NO concentrations and adenocarcinoma (AC) incidence rates. On the other hand, none of the air pollutants had a significant impact on the squamous cell carcinoma (SCC) incidence rates for both males and females. The Poisson regression results showed that with the NO concentration ≤ 5.59 ppb as the baseline, the risk for AC among males at 5.59 < NO ≤ 8.55 ppb was 1.32 times of that at the baseline level (95% CI, 1.11–1.59), 1.33 times at 8.55 < NO ≤ 13.54 ppb (95% CI, 1.11–1.61), 1.66 times when NO > 13.54 ppb (95% CI, 1.36–2.01). The test for trend was statistically significant at P < 0.001. Similar results were observed among females. On the contrary, for SCC, we found NO did not pose any significant danger to males and females. Conclusion: Our results showed that there was a dose–response relationship between gaseous NO concentrations and lung AC incidence rates.