Pulmonary tumours in the Netherlands: focus on temporal trends in histology and stage and on rare tumours.

Background: Recent temporal trends in histology and stage of pulmonary tumours in the Netherlands were studied. The incidence of rare pulmonary tumours was determined.
Methods: All tumours originating from the trachea, bronchus and lung recorded in the Netherlands Cancer Registry were included. Based on ICD-O morphology codes, five major subgroups were constructed: squamous carcinoma (SC), adenocarcinoma (AC), large cell (undifferentiated) carcinoma (LC), small cell lung cancer (SCLC) and other (including uncommon tumours).
Results: Between 1989 and 2003, 134,894 tumours were diagnosed. In men the age-adjusted incidence of SC and SCLC decreased, AC remained stable and LC increased. In women the incidence of all subgroups increased. Since 1996, a stage shift was observed with fewer patients in stage I and more patients in stage IV at diagnosis. This stage shift occurred equally in SC, AC and LC. In SC, fewer patients presented with stage IV disease than in AC and LC (25% vs 44% and 49% in 2003, respectively). The incidence of adenosquamous carcinoma decreased from 0.6 to 0.29/100 000 (p<0.001). The incidence of carcinoid tumours, sarcomatoid carcinomas and primary pulmonary sarcomas remained stable (0.44, 0.17 and 0.08/100 000, respectively).
Conclusion: The incidence of smoking-related tumours decreased in men (especially SC and SCLC) and increased in women (all subgroups). More patients presented with stage IV disease. The incidence of non-smoking-related uncommon tumours remained constant.