Enhanced expression levels of NG2 proteoglycan in presurgical original lesions of soft-tissue sarcoma (STS) patients defines with 55% probability the immediate (i.e., within 12 months postsurgery) risk in these individuals to develop postsurgical secondary lesions, independently of any other clinical trait. It, therefore, provides a molecular factor that alone prospects a particularly unfavorable clinical outcome in such patients. Evaluation of the timing of metastasis formation in patients with high and low levels of NG2 in their primitive lesions further stratified the patients in subsets with diverse lag phases in the occurrence of metastatic disease. In our cohort of high-grade STS cases, transcription of NG2 also showed a 81-fold amplification in metastatic lesions, when compared to primitive ones, and this gene overexpression was accompanied by an abundant but nonuniform in situ expression of its product. In a similar manner as seen in primitive lesions, patients with higher levels of metastatic NG2 encountered a significantly more dismal clinical course. Multivariate analysis asserted that in these individuals upregulation of NG2 represented an absolute independent prognostic parameter. Therefore, minimally invasive assessment of the transcription levels of the NG2 gene represents a parameter capable of predicting the arising of metastatic disease within a definite postsurgery time interval, and affords in adjunct in the definition of life expectance in STS patients.