Conclusion
Our study reinforces the reproducibility of the CNS-IPI, specifically apart from clinical trials, and suggests the CNS-IPI score as a tool to guide therapy.
Methods
Primary DLBCL patients were eligible for this study, between January 2007 and January 2017. All patients were treated with rituximab-based chemotherapy, mostly R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone). The CNSi was diagnosed by liquor (positive cytology and/or immunophenotype), computerized tomography, magnetic resonance image and/or fluorodeoxy-glucose-positron emission tomography, requested only in symptomatic patients when the CNSi was clinically suspected. The CNS-IPI was assessed by graphical comparison and calibration.
Results
After applying the inclusion/exclusion criteria, 322 patients were available for the analysis. The median follow-up was 60 months and the median age was 58 years. Seven patients experienced CNSi, characterizing an incidence of 2.17% (7/322). Comparing groups of patients with and without CNSi, we observed that the lactate dehydrogenase (LDH), number of extranodal sites, IPI, kidney/adrenal and absence of complete response were statistically different. The CNS-IPI model stratified patients in a three-risk group model as low-, intermediate- and high-risk. In our cohort, using the same stratification, we obtained an equivalent the 2-year rate of CNS relapse of 0.0%, 0.8% and 13.8%, respectively.