The 'reservoir' of undetected bronchial carcinomas in the general population.
OBJECTIVE
Autopsy studies have shown that a sizeable portion of lung cancers are never diagnosed and thus not entered into any cancer registry.


METHODS
In 1997, we decided to make all available efforts to find all patients with lung cancer who had not been registered previously.


METHODS
The local hospitals in the county of Gävleborg, Sweden.


METHODS
All patients with lung cancer diagnosed in the county from 1997 to 2000.


METHODS
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.


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).


CONCLUSIONS
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.
Koyi
Hirsh
H
Department of Respiratory Medicine, Gävleborg County Hospital, 801-87 Gävle, Sweden. hirsh.koyi@lg.se
Hillerdal
Gunnar
G
Brandén
Eva
E
Nordesjö
Lars-Olof
LO
D002283:Carcinoma, Bronchogenic / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D008403:Mass Screening; D011446:Prospective Studies; D013548:Sweden / Q000453:epidemiology