Introduction: The survival of patients (pts) with classic Hodgkin Lymphoma (cHL) has been significantly increased due to refinement of therapeutic strategies. International Prognostic Score (IPS-7) is the most used risk stratification tool for patients with advanced-stage cHL but it may have decreased prognostic value in cHL pts treated in the contemporary era. A novel scoring system, IPS-3, comprising three of the seven IPS-7 indicators (age ≥45, stage IV, haemoglobin <105 g/L), was recently proposed to identify high-risk patients but require further validation.
Aim: To validate IPS-3 and evaluate its discriminatory power in advanced stages cHL.
Methods: Single centre retrospective analysis of adult pts with cHL diagnosed between 1990 and 2017 treated with ABVD, ABVD hybrid protocols or escalated BEACOPP. Advanced stage was defined according to the German Hodgkin Study Group classification system. Stratified models for IPS-3 and IPS-7 were compared using Akaike’s information criteria (AIC) and Harrell’s concordance index (C-index).
Results: We included 227 pts, with similar gender proportion; median age was 32.3 (18-80). Nodular sclerosis was the most common histologic subtype (n=176 pts; 77.5%); 90 pts (39.6%) presented stage IV; 13 pts (5.7%) had IPS-3 high risk, 12 pts (5.3%) IPS-7 high risk and 8 pts (3.5%) had both. After a median follow-up of 123 months (m), the median overall survival (OS) was not reached. IPS-7 (HR 2.13 [95%IC 1.49-3.05]; p<0.001) and IPS-3 (HR 3.05 [95%IC 1.98-4.69]; p<0.001) identify different prognosis groups for OS, with IPS-3 (AIC 633; C-index 0.6547) providing best fit for data compared with IPS-7 (AIC 643; C-index 0.6403). Median progression free survival (PFS) was 295.6m. IPS-7 (HR 1.43 [95%IC 1.05-1.96]; p=0.025) and IPS-3 (HR 1.72 [95%IC 1.20-2.46]; p=0.003) identified different prognostic groups for PFS, with IPS-3 (AIC 917; C-index 0.5717) providing best fit for data compared with IPS-7 (AIC 921; C-index 0.5570). IPS-3 remained predictive for OS (HR 3.05; p<0.001) and PFS (HR 1.72; p=0.003) after adjustment for treatment protocol and had a good performance discriminating high vs intermediate/low risk for OS and PFS (HR 2.40; p=0.002 and PFS HR 3.03; p=0.001, respectively).
Conclusion: IPS-3 had better performance predicting OS and PFS compared with IPS-7, allowing a better segregation of patients with worse prognosis, which suggests its value to identify patients that will benefit more aggressive treatment protocol.