Abstract
For the past 13 years (from May, 1969 to December, 1975), the cases of lung cancer and laryngeal cancer treated in National Cancer Center Hospital are 1451 and 463 respectively. We have studied 15 complication cases of the lung and laryngeal cancers, and have set up our original standard for the definition of multiple cancer cases according to the Warren and Gates standard. The expected occurrence rate of multiple cancers was computed with the person-year-method, and as the result, it was revealed statistically that the lung cancer is frequently originated from the laryngeal cancer. The patient having the history of laryngeal cancer was diagnosed as lung cancer with the sputum cytology, and the definitive diagnosis was obtained by bronchofiberscopy, and thus the detection of early lung cancer has become possible. The cigarette smoking is one of the most important environmental factors for the multiple cancer cases of the lung and larynx, and, therefore, the etiological study of such environmental factors concerning the multiple case of laryngeal and lung cancer would not be so significant in the future, if the cigarette smoking' factor should be excluded.
