Liver metastasis at the time of initial diagnosis of lung cancer.

In order to evaluate clinicopathological features associated with liver metastases from lung cancer, we reviewed our experience of lung cancer patients seen in our division. Of the 1073 lung cancer patients diagnosed between October 1976 and May 2002, 62 (5.8%) patients had liver metastasis. The incidence of liver metastasis was 17.5% in small-cell lung cancer (SCLC) patients, whereas the incidence in non-small-cell lung cancer patients was 3.8%. Of the 62 patients, 17 had sole liver metastasis, and the remaining 45 had synchronous spread to the liver and one or more other organs. Six of 12 squamous cell carcinoma patients and 10 of 28 SCLC patients had sole liver metastasis. However, 19 of 20 adenocarcinoma patients showed liver metastasis with one or more other organs. In morphological liver metastasis, 26 of the 28 SCLC patients had multiple nodules, whereas 16 of the 34 non-small-cell lung cancer patients had a solitary liver nodule (p = 0.0006). Liver is a possible site of extrathoracic spread of disease for some patients with lung cancer, especially with SCLC. When the histological types are squamous cell carcinoma or SCLC, it would also be considered likely that an isolated liver mass represents a metastasis even though there is no metastatic disease elsewhere.