[Pulmonary metastasis from primary lung cancer and its treatment]

In this paper, we reviewed the mechanisms, pathways and patterns of pulmonary metastasis from lung cancer. For seven years from 1975 to 1981, 1,158 patients with primary lung cancer were admitted to our hospital. On admission, pulmonary metastases were radiographically found in 44 of 529 patients with adenocarcinoma (8.3%), 8 of 427 patients with squamous cell carcinoma (1.9%) and 2 of 150 patients with small cell carcinoma (1.3%). In adenocarcinoma, the radiographical patterns of pulmonary metastasis were divided into 2 types, that is, "cannon ball" type and "snowstorm" type. Of 24 patients with "cannon ball" type, there were 17 bilateral, 4 contralateral and 3 ipsilateral pulmonary metastases. Of 20 patients with "snowstorm" type, 19 patients had bilateral and one patient contralateral metastasis. In squamous cell carcinoma, there were 3 bilateral, 4 contralateral and 1 ipsilateral metastasis. In small cell carcinoma, 1 bilateral and 1 contralateral metastasis. In extensive disease which had pulmonary metastases etc., response to chemotherapy did not directly lead to the prolongation of survival, the causes of which were discussed.