RETROSPECTIVE ANALYSIS OF PROGNOSTIC FACTORS IN SOFT TISSUE SARCOMA

Abstract

SUMMARY D espite major advances in the knowledge of STS during the last decades, no significant improvement in survival has been observed. Detailed data on the prognosis of STS are crucial in order to identify patients who might benefit from more aggressive treatment. Such data can be obtained from properly designed databases; however, the validation of data is crucial in order to obtain valid, reliable results. Furthermore, the majority of prognostic studies in STS have been limited by potential selection bias and low power due to rarity and heterogeneity of the disease. We investigated the prognostic impact of patient-, tumor, and treatment-related factors on OS and EFS and established that age, tumor size, grade, resection margin and local recurrence, as well as adjuvant radiotherapy and surgery were important prognostic factors. Expression of the Ki-67 antigen in tumor nuclei in our cohort showed high Ki-67 proliferative index to be a significantly correlated with OS and EFS. The cutoff value in our study was 20% as suggested by the previous reports. High Ki-67 proliferative index is an independent prognostic marker for high-risk soft tissue sarcomas that identifies patients with an especially aggressive tumor phenotype who cannot be identified based on well-established clinical parameters alone. On the basis of our data and previous reports, high Ki-67 proliferative index may have potential for predicting the prognosis of patients with high-risk STS in a clinical routine setting and may be a useful addition to AJCC staging criteria for STS. However, this needs to be prospectively confirmed on the basis of clinical trials. Beyond the current TNM staging system, multiple prognostic factors for STS will continue to be discovered and ultimately incorporated into future revisions of the staging system. Molecular staging, through discovery of new oncogenic mutations and genetic profiling, will strongly impact STS prognosis and, ultimately, treatment recommendations and outcomes. The goal is for discovery of molecular markers in STS that can be directly tested for in patients with known clinical outcomes, thereby determining whether any of these can be incorporated into future STS systems.