Abstract 22P
Background
The new ESGO-ESTRO-ESP 2020 risk classification system (molecular classification unknown) has allocated fewer patients to the high-risk group compared to the previous risk stratification system in 2016. The study aims to clinically validate the new system in predicting the outcome compared to the previous one.
Methods
We retrospectively analyzed the data of 684 patients treated between 2009 and 2013 for carcinoma endometrium in a tertiary care oncology center. The three years overall survival (OS) and disease-free survival (DFS) estimates were generated independently using the Kaplan Meier method for the new and previous classification system. Akaike information criterion and concordance index was calculated between both staging systems to identify better predictive model.
Results
After re-classification, 43% of patients in the high-risk group based on the 2016 system are shifted to the high-intermediate group and 93% of patients migrated from the high-intermediate to intermediate-risk group (Table). The 3-year OS for low risk, intermediate risk, high intermediate risk, high risk, and advanced patients according to the 2016 risk stratification system was 98.3%,95.7%,98%,90.1%, and 64.2% respectively and was 98.3%, 96.6%,92.9%,88.9% and 61.3% respectively according to the 2020 system. The 3-year DFS was 97.9%,79.3%,88.9%,77.3% and 57.2% according to the 2016 system and 97.9%,83%,85.3%,72.2% and 53.8% respectively with the 2020 system. The survival rate decreased from low to advanced risk groups and the newer high-risk group has a lower survival rate than the previous one. The Akaike Information Criterion was lower (0.685 versus 0.702) and Concordance Index values were better (1566.661 versus1545.505) for ESGO 2020 system for DFS, indicating that the newer edition gives a better predictive model Table: 22P
ESGO 2016 and ESGO-2020 cross-tabulation
| ESGO-2020 | Total | ||||||
| Low | Intermediate | High- Intermediate | High | Advanced | |||
| ESGO 2016 | Low | 216 | 0 | 0 | 0 | 0 | 216 |
| Intermediate | 0 | 81 | 0 | 0 | 0 | 81 | |
| High-Intermediate | 0 | 54 | 4 | 0 | 0 | 58 | |
| High | 0 | 1 | 124 | 158 | 0 | 283 | |
| Advanced | 0 | 0 | 0 | 2 | 44 | 46 | |
| Total | 216 | 136 | 128 | 160 | 44 | 684 |
Conclusions
The new 2020 risk stratification appears better predictive of survival events.
Legal entity responsible for the study
Institutional Review Board, Regional Cancer Centre, Thiruvananthapuram.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.