Outcome Prediction of Pulmonary Metastasectomy Can Be Evaluated Using Metastatic Lesion in Osteosarcoma Patients

Background We investigated whether molecular prognostic factors should be evaluated in specimens of the primary or the metastatic lesion and if the prognosis after initial pulmonary metastasectomy can be predicted based on evaluation of metastatic lesion specimens in osteosarcoma patients. Methods This retrospective study included 29 osteosarcoma patients with pulmonary metastases (19 males, 10 females; age 21 ± 10 years). Molecular prognostic factors were the levels of vascular endothelial growth factor type A (VEGF-A), VEGF type C (VEGF-C), and Ki67. Primary and pulmonary metastatic lesions could be compared in 18 patients regarding the values of marker expressions and the prognosis after initial pulmonary resection. Finally, the prognosis of all 29 cases was compared according to the molecular markers of the metastatic lesions. Results Evaluation of the metastatic lesions reflected the prognosis after pulmonary metastasectomy more than that of the primary lesions. In the metastatic lesions, positive expression of VEGF-A ( n = 15), VEGF-C ( n = 2), and Ki67 ( n = 15) was associated with a significantly poorer prognosis ( p = 0.0013, 0.0001, and 0.037, respectively). No patients with positive expression of both VEGF-A and Ki67 ( n = 7) survived more than 5 years after the initial pulmonary resection. All patients who had negative reactions to both VEGF-A and Ki67 ( n = 6) were alive at the end of the study. Conclusions Molecular prognostic factors should be investigated in specimens of the metastatic lesion. Combined evaluation of VEGF-A and Ki67 and of VEGF-C using pulmonary metastatic lesion specimens in osteosarcoma patients effectively reflects survival after pulmonary metastasectomy.