Sinonasal cancer incidence in Lombardy, Italy, 2008-20.

Background: Epithelial sinonasal cancers (SNC) are rare tumours with recognized associations with known/suspected occupational carcinogens (wood/leather dust, nickel/chromium compounds and formaldehyde). In Italy, a national SNC registry organized as a network of regional registries was established by law in 2008.

Aims: To describe SNC time trends, occupational exposures and geographical distribution in Lombardy, North-West Italy, based on population registry data (2008-20).

Methods: The Lombardy SNC Registry records epithelial SNCs using various sources. Interviews to collect occupational history are performed using a standardized questionnaire. Using several standard populations, we calculated yearly crude and age-standardized rates (ASRs per 100,000 person-years). Standardized incidence ratios (SIR) at municipality level were calculated, and Bayesian models were fitted to produce smoothed SIR maps.

Results: We recorded 827 cases (553 men, 274 women). Crude (world standardized) ASRs were 0.9 (0.4) in men and 0.4 (0.2) in women, with no time trends. Interviews were obtained for 485 (88%) men and 223 (81%) women. Among men, 217 (45%) had been exposed to occupational carcinogens (wood/leather dust: 150/65 cases, 31%/13%), while only 36 women (16%) were exposed. Among 201 men with adenocarcinoma, exposure to wood/leather dust occurred in 103/50 cases (75%/50%). Areas with elevated SIRs associated with leather dust were found in the Western areas. Exposure to wood dust was more widespread.

Conclusions: This study found a high frequency of occupational exposures (wood and leather dust), particularly in men with SNC. Employment in shoe industries clustered in the Western part, while work in furniture industries was less spatially structured.