Standardized incidence ratios of malignant neoplasms among patients with pneumoconiosis

BACKGROUND: Patients with pneumoconiosis, such as silicosis and asbestosis, have a high risk of lung cancer. However, whether these patients are at high risk for neoplasms other than lung cancer and mesothelioma remains inconclusive. AIMS: To examine whether patients with pneumoconiosis have a higher incidence of malignant neoplasms other than lung cancer. METHODS: We conducted a cohort study using the medical records of patients with pneumoconiosis who visited our two hospitals from 1 January 1991 through 31 December 2017. We identified the occurrence of malignant neoplasms and calculated the incidences and standardized incidence ratios (SIRs) compared with those of the general population. RESULTS: One hundred and seventy patients with pneumoconiosis (163 men, 7 women) including 142 patients with silicosis, 24 with asbestosis and 4 with pneumoconiosis were identified. The mean age was 66.8 years. The proportion of smokers was 79%. Forty-seven malignant neoplasms occurred. Most malignant neoplasms were lung cancer (n = 22), while some were digestive cancers such as gastric cancer (n = 9), oesophageal cancer (n = 3) and colorectal cancer (n = 3). Participants presented increased risks for lung cancer (SIR: 10.86, 95% confidence interval [CI]: 7.15-16.49), gastric cancer (SIR: 2.55, 95% CI: 1.22-5.35) and oesophageal cancer (SIR: 5.78, 95% CI: 1.86-17.92). CONCLUSIONS: Compared with the general population, patients with pneumoconiosis had an increased risk of malignant neoplasms of the digestive system in addition to lung cancer. Clinicians should consider testing for digestive system cancers as well as for lung cancers in these patients.