Autopsy studies have shown that a sizeable portion of lung cancers are never diagnosed and thus not entered into any cancer registry.
In 1997, we decided to make all available efforts to find all patients with lung cancer who had not been registered previously.
The local hospitals in the county of Gävleborg, Sweden.
All patients with lung cancer diagnosed in the county from 1997 to 2000.
In meetings with all the general practitioners of the county, these were asked to refer all suspected cases as early as possible, including those with a seemingly dismal prognosis. This initiative was also covered by the newspapers and the local television station.
Measurements and results:
From 1997 onwards, the incidence of lung cancer in the county was found to be 40–50 per 100 000 inhabitants compared with an incidence of about 30 during the ten preceding years. This difference is significant in time (P<0.0001) and is compared with the incidence of lung cancers in four neighboring counties (P=0.002).
There can be a considerable number of patients with lung cancer who are never diagnosed. This can explain differences in survival between various countries and this will also affect the results of screening programs, since the control groups will also include a number of lung cancer cases which will never be recognized.
2002. Vol. 37, no 2, 137-142 p.