Stomach Cancer and Exposure to Talc Powder without Asbestos via Chinese Herbal Medicine: A Population-Based Cohort Study.

The present investigation was designed to explore the risk of stomach cancer by oral intake of talc powder without asbestos. We conducted a population-based cohort study on a randomly sampled cohort from Taiwan's health insurance database, with population of 1,000,000. The study participants were followed up through 2013. The outcome event of interest was the diagnosis of stomach cancer. The exposure of interest was the prescription of talc powder. Cox regression analyses were performed respectively. There were 584,077 persons without talc exposure and 21,575 talc users, 1849 diagnosed with stomach cancer. Persons with exposure of talc had a higher hazard ratio of stomach cancer (adjusted hazard ratio, 2.13; 95% confidence interval (CI), 1.54⁻2.94; < 0.001). Classification by cumulative exposure of talc yielded adjusted hazard ratios of stomach cancer of 1.58 (95% CI, 0.79⁻3.17; = 0.19) and 2.30 (95% CI, 1.48⁻3.57; < 0.001) among persons with high (>21 g) and medium (6⁻21 g) exposure of talc, as compared to the low-exposure counterparts. Our data demonstrated positive association between increased risk of stomach cancer and oral intake of talc without asbestos. Despite the absence of dose-response effect, there might be a link between stomach cancer and talc.