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The following is a summary of “Mitotic rate as a prognostic biomarker after preoperative radiotherapy for high-grade limb/trunk soft tissue sarcoma,” published in the August 2024 issue of Oncology by Ouyang et al.
There is no universally accepted standardized method for the pathological assessment of soft tissue sarcoma (STS) following preoperative radiotherapy (PORT). This study evaluated the prognostic significance of pathological features observed after PORT in patients with high-grade limb or trunk STS. Researchers examined a cohort of 116 patients treated with PORT followed by surgical resection. Key variables were systematically reviewed and reassessed, including patient demographics, imaging characteristics (tumor size and volume), and pathological parameters (mitotic rate, necrosis rate, viable cell count, and hyalinization/fibrosis)d. Survival outcomes, including disease-free survival (DFS) and overall survival (OS), were calculated using the Kaplan-Meier method, and hazard ratios were determined through Cox proportional hazards models.
Two predictive nomograms were constructed based on significant prognostic factors. The 5-year DFS and OS rates were 52.9% and 70.3%, respectively. Multivariate analysis identified several independent risk factors: tumor size before (HR: 1.07, 95% CI: 1.01–1.14) and after PORT (HR: 1.08, 95% CI: 1.01–1.14), tumor volume (HR: 1.06, 95% CI: 1.01–1.12), mitotic rate after PORT (HR: 1.06, 95% CI: 1.02–1.11), and the change in mitotic rate following PORT (HR: 1.04, 95% CI: 1.00–1.09) were all significant predictors of DFS. Similarly, for OS, independent risk factors included tumor size before (HR: 1.08, 95% CI: 1.03–1.14) and after PORT (HR: 1.09, 95% CI: 1.04–1.15), tumor volume (HR: 1.05, 95% CI: 1.01–1.09), mitotic rate after PORT (HR: 1.09, 95% CI: 1.04–1.13), and the change in mitotic rate post-PORT (HR: 1.05, 95% CI: 1.01–1.09). The predictive nomogram incorporating mitotic rate demonstrated C-index values of 0.67 for DFS and 0.73 for OS, while the nomogram integrating morphological and pathological data achieved a C-index of 0.79 for OS.
These findings underscore that tumor size, volume, and mitotic rate before and after PORT are critical factors influencing prognosis. Specifically, the mitotic rate, irrespective of tumor morphology, shows promise as a robust prognostic biomarker for evaluating high-grade STS after PORT.
Source: sciencedirect.com/science/article/abs/pii/S0167814024007527
