[Risk factors influencing lymph nodes metastasis in lung cancer with stage I, II or IIIA]

The purpose of this study was to assess the risk factors involved in the intrapulmonary, hilar and mediastinal lymph nodes metastases in seventy-eight patients with stage I, II or IIIA lung cancer postoperatively, which were resected from 1978 to 1988. In the histological type, the incidence of the mediastinal lymph nodes metastases in adenocarcinoma was higher than that in other types, such as squamous cell carcinoma and large cel carcinoma. In addition, the incidence of mediastinal lymph nodes metastases in the papillary type was significantly higher than that in the tubular type (p less than 0.05). The incidence of mediastinal lymph nodes metastases increased as invasion into the lymphatic duct and/or vessel was demonstrated (p less than 0.01, p less than 0.05). The proximal type, in which the cancer spread to the secondary segmental bronchus, metastasized to the hilar lymph nodes more frequently than the distal type, in which the cancer was located in the bronchus distal to the third segmental one. Although there was no significant relationship between the site of the cancer and the incidence of the metastatic lymph nodes, the hilar and superior mediastinal lymph nodes (#1-4, 3a, 3p) metastases were demonstrated regardless of the lobe in which the cancer was located. The primary tumor located in the left lower lobe of the lung tended to metastasize to the inferior mediastinal lymph nodes (#8, 9). Twenty-five out of 33 patients with the lymph nodes metastases had hilar metastatic lymph nodes. However, the mediastinal lymph nodes metastases were proved in 5 patients without any intrapulmonary and hilar lymph nodes metastases. No relationship between the histological differentiation, size of tumor, pT factor and the incidence of lymph nodes metastases was found.