A population-based study of lung cancer and benign intrathoracic tumors
1University of Oulu, Faculty of Medicine, Department of Internal Medicine
|Online Access:||PDF Full Text (PDF, 1.6 MB)|
|Persistent link:|| http://urn.fi/urn:isbn:9514252845
|Publish Date:|| 1999-06-04
|Thesis type:||Doctoral Dissertation
|Defence Note:||Academic Dissertation to be presented with the assent of the Faculty of Medicine, University of Oulu, for public discussion in Auditorium 10 of the University Hospital of Oulu, on June 23rd, 1999, at 12 noon.
Docent Kari Liippo
Professor Hannu Tukiainen
A prospective population-based study was conducted to assess the incidence, diagnosis, histology, treatment and survival of lung cancer in northern Finland. The results were compared with those obtained in a similar survey 20 years earlier.
In a population of 440,000, altogether 602 lung cancer patients, 510 men and 92 women, were diagnosed during the years 1990 - 92, the annual incidence per 100,000 being 63 for males and 9.5 for females. Lung cancer was confirmed histologically in 381 cases (63%) and in addition, cytologically in 135 cases (23%). Squamous cell carcinoma was the most common histologic type (40%), the proportion of adenocarcinomas being 26%, small-cell carcinomas 24% and large cell carcinomas 4%. The age-standardized incidence of lung cancer had decreased significantly among males (from 87 to 63 per 100 000) compared to the situation 20 years earlier but increased among females (from 4.1 to 9.5), mainly due to adenocarcinoma.
The 5-year survival rate had improved during 20 years from 4% to 12% (p < 0.001). The differences in survival between the histological types (χ2logrank = 59.2, p < 0.0001), TNM stages (χ2logrank = 199.6, p < 0.001), symptomatic stages (χ2logrank = 120, p < 0.001) and treatments (χ2logrank = 277, p < 0.001) were also significant. A total of 20% of the patients were operated on in the newer series of patients, the corresponding percentage in the earlier series being 16%. The 5-year survival of the patients who had been operated on had increased from 23% to 48%. The survival of patients with non-small-cell lung carcinoma had increased significantly, even though the patients were older now than earlier.In seventy operated lung cancer patients, the histological tumor types and grades were compared with the etiological factors of lung carcinoma, including cigarette smoking and asbestos exposure. A majority of the patients (93%) were smokers. The incidence of adenocarcinoma among non-smokers had remained the same, 50%. The accumulation of the p53 protein in lung carcinoma was associated with heavy smoking. Exposure to asbestos fibers either by a positive history or by a number of asbestos bodies (AB) in the histological sections of lung tissue was also associated with p53 accumulation.
Benign intrathoracic tumors are uncommon, and their occurrence in unselected populations is poorly defined. Thirty-six benign intrathoracic tumors were found. A histologic diagnosis was available for 24 (67%). Hamartoma was the most common benign lung tumor.
Acta Universitatis Ouluensis. D, Medica
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