R. Makitaro et al., An epidemiological study of lung cancer: history and histological types ina general population in northern Finland, EUR RESP J, 13(2), 1999, pp. 436-440
A prospective epidemiological study was conducted to assess the incidence,
diagnosis, histology and surgical treatment of lung cancer in northern Finl
and, The results were compared with those obtained in a similar survey 20 y
rs earlier.
Most of the patients with a suspected lung tumour were interviewed (72% ) a
nd the information was combined with that obtained from the national cancer
registry, All pathological specimens were re-evaluated by a pathologist.
A total of 602 new lung cancer cases (85% male, 15% female) were diagnosed
during the years 1990-1992, the annual incidence per 100,000 being 63 for m
ales and 9.5 for females,The number not reported to the Finnish Cancer Regi
stry was low (<1%). Lung cancer was confirmed histologically in 381 cases (
63%) and in addition cytologically in 135 cases (23%), Squamous cell carcin
oma was the most common histological type (40 %), the proportion of adenoca
rcinoma being 26%, small cell carcinoma 24% and large cell carcinoma 4%. Th
e incidence of lung cancer had decreased significantly among males (from 87
to 63 per 100,000) compared with 20 yrs earlier but had increased among fe
males (from 4.1 to 9.5), chiefly on account of adenocarcinoma.
The findings of this prospective study show an increase in the incidence of
lung adenocarcinoma among females, a histological type which is less close
ly related to smoking than the other cancers. This suggests that other risk
factors may play an increasing role in the aetiology of lung cancer.