Background: An accurate estimate of the nationwide prevalence of asbestos-related lung cancer (ARLC) is necessary to adequately operate a compensation subsidy program for patients with ARLC. Our study aimed to estimate the proportion of patients with ARLC among patients with primary lung cancer, and describe the characteristics and distribution of ARLC. Methods: All facilities that treated patients diagnosed with lung cancer in 2016 were requested to submit computed tomography images of 10 patients randomly selected from the national databases of hospital-based cancer registries. ARLC was defined as pleural plaques (PPs) extending over one-quarter of the inner lateral chest wall or existing PPs accompanied by obvious lung fibrosis. We estimated the proportion and distribution of ARLC among primary lung cancer cases and compared the characteristics of ARLC with those of primary lung cancer. Results: Of 772 facilities that treated at least one patient with lung cancer, 370 provided 3,565 sets of CT images. Of these, 216 (6.1%) had PPs, and 86 (2.4%) met the compensation criteria. After sample weighting, 2.0% of all primary lung cancers were classified as ARLC in Japan. A higher percentage of patients with ARLC were male (94.2% vs. 68.6%; P < .01) and had more advanced-stage disease (stage III: 22.1% vs. 16.0%; stage IV: 44.2% vs. 39.8%; P =.05) than other primary lung cancers. A majority (53.5%) of patients with ARLC were diagnosed at designated cancer hospitals. The proportion of squamous cell carcinoma was higher in ARLC than in those with primary lung cancer (25.6% vs. 18.6%; P < .01). COnCLUSION: The estimated number of patients with ARLC was larger than expected from the number of applicants in the compensation system for asbestos-related health damages (AHDRS). Consequently, countermeasures are required to accurately identify eligible compensation recipients.

The authors have declared no competing interest.

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the Institutional Review Board of the National Cancer Center, Japan

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