Wood Workers and Sino-nasal Cancers
An occupational exposure to wood dust results in an aggressive cancer of the nose and associated air sinuses – sinonasal cancer. Sinonasal cancer develops in an occupation that involves working in or about a building where wooden goods are manufactured or repaired. There is increasing evidence that the carpenter and other employed earners carry a markedly higher risk to develop sinonasal cancer following occupational exposure to wood dust in the machine processing of wood. On the basis of the marked increase in the occurrence of sinonasal cancer among woodworkers, the International Agency for Research on Cancer (IARC) classified wood dust as a ‘definite’ human carcinogen and assigned it to the group 1 of carcinogens to humans.
Sinonasal cancer occurs with the highest occupational exposures to wood dust in furniture and cabinet manufacture, especially during machine sanding and similar procedures. Many groups, including carpenters and joiners, wood machinists, sawmill, forestry, and timber workers, boat pattern makers, woodcarvers, makers of wooden shoes, vats and boards, finishing departments of plywood mills, where wood is sawn and sanded, and in the areas of sawmills near chippers, saws and planers are exposed to fine particles of wood. The risk appears notably higher among workers from the furniture industry.
Sinonasal cancer affects the nasal cavity (the space inside the nose) and/or para-sinuses, which are small air cavities in the bones around the nose. This cancer is rare, 1 per 100,000 in most developed countries and represents less than 1% of all cancers and less than 4% of those arising in the head and neck region. It is more common in men than women. A Belgian study was able to conclude that men’s occupational history of being a carpenter, joiner, furniture worker, or other woodworker, resulted as risk factor of developing cancer of the maxillary sinus.
The occurrence of sino-nasal cancer varies as per anatomic site – almost half of sinonasal cancers are localized to the nasal cavity (43.9%), while most others originate in the air cavity behind the cheek-maxilla (35.9%) or above the nose-ethmoid (9.5%) sinus. Histologically, they are mainly squamous cell carcinoma (a tumor developing from lining cells) and adenocarcinoma (a tumor developing from glandular cells). Some 60% of cancers in the nasal cavity and paranasal sinuses are squamous cell carcinoma, while about 10% are adenocarcinomas. Rarely, esthesioneuroblastoma (from the cells that perceive smell) and adenoid cystic carcinoma forms are also seen.
Imaging studies include X-ray, CT and MRI, all of which provide vital clues of the lesion itself and the possible involvement of close by areas including bony involvement. Nasal endoscopy permits us to see the extent and site of the tumor under direct vision as well allows removal of tissue from the tumor (biopsy) that can provide a final diagnosis.
The management depends on the extent of tumor and the histological type. Usually a combination of surgery, radiotherapy and chemotherapy are needed.
The average overall 5-year survival rates have improved dramatically, ranging from less than 30% in the 1960s to over 70% in the 2000s.