The oncological outcomes of isolated limb perfusion and neo-adjuvant radiotherapy in soft tissue sarcoma patients - A nationwide multicenter study.

INTRODUCTION: Patients with locally extensive high-grade extremity soft tissue sarcomas (eSTS) are often presented in multidisciplinary teams to decide between ablative surgery (amputation) or limb-salvage surgery supplemented with either neo-adjuvant radiotherapy (RT) or induction isolated limb perfusion (ILP). In The Netherlands, ILP typically aims to reduce the size of tumors that would otherwise be considered irresectable, whereas neo-adjuvant RT aims mainly at improving local control and reducing morbidity of required marginal margins. This study presents a 15-year nationwide cohort to describe the oncological outcomes of both pre-operative treatment strategies. METHODS: All consecutive patients with locally extensive primary high-grade eSTS surgically treated between 2000 and 2015 at five tertiary sarcoma centers that received neo-adjuvant ILP or RT were included. 169 patients met the inclusion criteria (89 ILP, 80 RT). Median follow-up was 7.3 years. RESULTS: Limb salvage was achieved in 84% of cases in the ILP group (80% for patients with amputation indication) and 96% of cases in the RT group. 5-Year overall survival was 47% in the ILP group, 69% in the RT group. 5-Year local recurrence rate was 14% in the ILP group, 10% in the RT group. Distant metastasis rate was 55% in the ILP group, 36% in the RT group. CONCLUSION: We find oncological outcomes and limb salvage rates in line with existing literature for both treatment modalities. Whether the tumor was locally advanced with an indication for induction therapy to prevent amputation or morbid surgery appeared to be the main determinant in choosing between neo-adjuvant ILP or RT.

Dynamic prediction of overall survival for patients with high-grade extremity soft tissue sarcoma.

PURPOSE: There is increasing interest in personalized prediction of disease progression for soft tissue sarcoma patients. Currently, available prediction models are limited to predictions from time of surgery or diagnosis. This study updates predictions of overall survival at different times during follow-up by using the concept of dynamic prediction. PATIENTS AND METHODS: Information from 2232 patients with high-grade extremity soft tissue sarcoma, who underwent surgery at 14 specialized sarcoma centers, was used to develop a dynamic prediction model. The model provides updated 5-year survival probabilities from different prediction time points during follow-up. Baseline covariates as well as time-dependent covariates, such as status of local recurrence and distant metastases, were included in the model. In addition, the effect of covariates over time was investigated and modelled accordingly in the prediction model. RESULTS: Surgical margin and tumor histology show a significant time-varying effect on overall survival. The effect of margin is strongest shortly after surgery and diminishes slightly over time. Development of local recurrence and distant metastases during follow-up have a strong effect on overall survival and updated predictions must account for their occurrence. CONCLUSION: The presence of time-varying effects, as well as the effect of local recurrence and distant metastases on survival, suggest the importance of updating predictions during follow-up. This newly developed dynamic prediction model which updates survival probabilities over time can be used to make better individualized treatment decisions based on a dynamic assessment of a patient's prognosis.

Hydrogen sulfide restores a normal morphological phenotype in Werner syndrome fibroblasts, attenuates oxidative damage and modulates mTOR pathway.

Werner syndrome (WS) protein is involved in DNA repair and its truncation causes Werner syndrome, an autosomal recessive genetic disorder with a premature aging phenotype. WRN protein mutation is currently known as the primary cause of WS. In cultured WS fibroblasts, we found an increase in cytosolic aggregates and hypothesized that the phenotype is indirectly related to an excess activation of the mTOR (mammalian target of rapamycin) pathway, leading to the formation of protein aggregates in the cytosol with increasing levels of oxidative stress. As we found that the expression levels of the two main H2S producing enzymes, cystathionine ß synthase and cystathionine γ lyase, were lower in WS cells compared to normal, we investigated the effect of administration of H2S as NaHS (50µM). NaHS treatment blocked mTOR activity, abrogated protein aggregation and normalized the phenotype of WS cells. Similar results were obtained by treatment with the mTOR inhibitor rapamycin. This is the first report suggesting that hydrogen sulfide administered as NaHS restores proteostasis and cellular morphological phenotype of WS cells and hints to the importance of transsulfuration pathway in WS.