A prognostic index, called the geriatric prognostic index (GPI), was developed for older patients with diffuse large B-cell lymphoma (DLBCL) who are candidates for treatment with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).
The new GPI outperformed the most widely used clinical prediction models, including the international prognostic index (IPI), the revised IPI (R-IPI), and the National Comprehensive Cancer Network IPI (NCCN-IPI), according to the study published in Haematologica.
Read more about DLBCL prognosis
The GPI combines scores for activities of daily living, the Charlson comorbidity index (CCI), age, sex, albumin levels, stage, Eastern Cooperative Oncology Group (ECOG) performance status, and lactate dehydrogenase levels to predict survival in patients with DLBCL aged 70 years and above.
“The model outperformed IPI, R-IPI, and NCCN-IPI and could be a tool for informed treatment decisions and for stratifying older DLBCL patients for clinical trials,” the authors wrote.
Using the prognostic factors and objective cutoff values at the 30th and 80th percentiles, the GPI was able to stratify patients into 3 risk groups (low, intermediate, and high) with significantly different 2-year overall survival (OS), 2-year progression-free survival (PFS), and 5-year OS rates. In the training dataset, the 2-year OS values were 94%, 65%, and 25% (P <.001) for the low-, intermediate-, and high-risk groups, respectively. The 2-year PFS values were 92%, 60%, and 23%, and the 5-year OS values were 84%, 49%, and 18% for the 3 groups, respectively.
In an external validation using a test set of patients, the GPI showed significantly different 2-year OS values for the 3 risk groups, with values of 95%, 65%, and 44%, respectively (P <.001). The 5-year OS values were 75%, 49%, and 32%, while the 2-year PFS values were 91%, 59%, and 41%, respectively. The GPI showed better discrimination than the IPI, R-IPI, and NCCN-IPI on the test set with C-index values of 0.621, 0.583, and 0.670, respectively.
The researchers identified 365 patients with DLBCL who were at least 70 years of age and who were treated with R-CHOP using the Cancer Registry of Norway (CRN). These patients were then included in the training dataset. The test set included 193 Norwegian patients.
Isaksen KT, Galleberg R, Mastroianni MA, et al. The geriatric prognostic index: a clinical prediction model for survival of older diffuse large B-cell lymphoma patients treated with standard immunochemotherapy. Haematologica. Published online March 2, 2023. doi:10.3324/haematol.2022.282289