Successful xenotransplantation of human lung cancer correlates with the metastatic phenotype.

Background: Occult micrometastases could explain deaths from stage I non-small cell lung cancer (NSCLC) after complete resections. If patients who have occult metastases could be identified, systemic therapy might be beneficial.

Methods: Non-small cell lung cancers from 81 patients in stages I, II, and III were transplanted to nude beige mice. Mean follow-up was 22.5 months (2 to 61 months).

Results: Twenty-one xenotransplants successfully took, and seven metastasized in the nude mice. Neither the predominant cell type nor the incidence of lymph node metastases correlated with the results of xenotransplantation. Of the 21 patients whose NSCLCs took in xenotransplantation, 13 (61.9%) have had development of metastases, and 9 (42.9%) have died of the cancer. Among the 57 patients whose NSCLCs did not take, 14 (24.6%) have had development of metastases, and 9 (15.8%) have died of their cancer. The higher incidence of metastases in association with xenotransplant take is significant (p = 0.0032).

Conclusions: Patients whose NSCLCs take in xenotransplantation are at high risk for metastases. The xenotransplantation model is a step toward facilitating precise cellular biologic definition of the metastatic propensity of human NSCLC: