A study found that the central nervous system international prognostic index (CNS-IPI), which is widely used for the identification of patients with diffuse large B cell lymphoma (DLBCL) with a high risk of CNS relapse, has its benefits, but exposes young patients to unnecessary prophylaxis.
The researchers of this study aimed to confirm the value of the CNS-IPI in predicting CNS relapse in a young study population and to evaluate its impact on the selection of patients for CNS prophylaxis.
In this retrospective study, researchers assessed 354 patients (median age, 46 years) diagnosed with DLBCL who were treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) from January 2010 till December 2018. Correlation between CNS-IPI and cumulative incidence of CNS relapse and time to CNS relapse was examined through Kaplan-Meier plots. Median time to CNS relapse and median overall survival after CNS relapse were also estimated using the Kaplan-Meier plots.
Overall, 5% of the patient population developed CNS relapse, and survived for an average of seven months following reoccurrence. Two-year CNS relapse rates according to CNS-IPI were 0.7%, 5.1%, and 26% for low, intermediate, and high-risk groups, respectively. Multivariate analysis demonstrated a significant association between CNS relapse and poor performance status (P = 0.045), involvement of two or more extranodal sites (P = 0.021), involvement of bone marrow (P = 0.029), and renal or adrenal glands (P = 0.006).
“Although CNS-IPI helps in better selection of DLBCL patients for CNS prophylaxis, it can possibly increase the number of patients exposed to unnecessary prophylaxis. More investigational biomarkers are needed to better refine high-risk patients,” the researchers concluded.