# Development and Validation of a Site-Specific Tumor Burden Score for Predicting Surgical Outcomes in Advanced Ovarian Cancer

## TL;DR

This study introduces a new score to predict surgical outcomes in advanced ovarian cancer by assessing tumor burden at specific metastatic sites, improving preoperative evaluation.

## Contribution

The novel predictive score based on site-specific tumor burden outperforms existing methods for predicting surgical outcomes in ovarian cancer.

## Key findings

- MRI is more accurate than CT for assessing metastatic site-specific tumor burden.
- A predictive score incorporating tumor burden and clinical factors achieved an AUC of 0.873 for suboptimal cytoreduction.
- Lower predictive scores (<11) correlate with longer progression-free survival and higher R0 resection rates.

## Abstract

The goal of ovarian cancer (OC) preoperative evaluation is to assess surgical feasibility for achieving optimal cytoreduction. In this study, we systematically explored the role of site-specific tumor burden in the preoperative evaluation of OC and had several key findings: First, MRI was superior to CT for metastatic site-specific tumor burden assessment. Second, the tumor burden integrated suboptimal cytoreduction predictive score (AUC = 0.873) outperforms the metastatic site-integrated scores. Third, R0 resection was inversely linked to the predictive score and the tumor burden integrated predictive score <11 correlated with longer progression-free survival. We comprehensively delineate the role of site-specific tumor burdens in OC preoperative evaluation, which provides novel insights for refining preoperative assessment of ovarian cancer, marking a shift from evaluating metastatic sites to assessing metastatic site-specific tumor burden.

Objective: The relationship between surgical outcomes and metastatic sites in ovarian cancer (OC) is known, but the role of metastatic site-specific tumor burden remains unclear. Methods: We prospectively analyzed data from 202 OC patients. We developed a preoperative protocol evaluating tumor burden in 30 metastatic sites and created a predictive score for suboptimal cytoreduction, which was externally validated. Results: MRI-assessed tumor burdens demonstrated superior consistency with surgical findings compared to CT (κ = 0.4–1.0). Three site-specific tumor burdens (diaphragmatic spleen surface, hepatorenal recess, mesentery), upper abdominal tumor burden, and two clinical factors were identified as predictors of suboptimal cytoreduction. The predictive score incorporating these factors achieved an AUC of 0.873 (0.815 externally validated), outperforming metastatic site-integrated scores including the simulated Fagotti score (AUC: 0.656) and Suidan score (AUC: 0.8308). R0 resection rates were inversely correlated with predictive scores: 94.87% for scores of 0–3 versus 8.57% for scores >14. The peak of Youden’s index reached 11, and patients with predictive scores <11 had longer median progression-free survival. Conclusions: We demonstrated that site-specific tumor burden is correlated with surgical outcomes in OC. Incorporating tumor burden into preoperative assessment enhances prediction performance. We developed a clinically applicable tool, marking a shift from evaluating metastatic sites to assessing metastatic site-specific tumor burden.