Abstract
Twenty-three cases of double primary cancer involving lung cancer were experienced from June, 1969, to November, 1985.
The incidence was 3.8 per cent of all hospitalized cases of primary lung cancer. The patients included 19 males and 4 females, a ratio of 5 to 1. Their ages at the time of detection of the lung cancer ranged from 48 to 74 years with an average age of 62.8 years. Thirteen out of 23 cases of double cancer appeared synchronously. Of 20 patients who had pulmonary excision, 16 had lobectomies, one had a pneumonectomy and 3 had segmentectomies or wedge resections. The counterpart organs involved were the stomach in 7 cases, prostate and larynx in 3 cases each, rectum and uterus in 2 cases each and esophagus and pancreas in 1 case each. There were four multiple lung cancers. In respect to the histological type of lung cancer, 11 were adenocarcinoma, 9 were squamous cell carcinoma, 3 were small cell carcinoma and 3 were large cell carcinoma.
The incidence of double primary cancer tends to increase in time, and the prognosis of double primary cancer involving lung cancer will depend on the clinical course of the lung cancer. Nevertheless, limited resection for lung cancer can occasionally be recommended to conserve pulmonary function as much as possible. The possibility of a second primary cancer should be considered carefully whenever a solitary shadow appears on the chest roentgenogram of a patient who has been treated for another cancer before.
