A simplified geriatric prognostic index to survival in older Asian patients with diffuse large B-Cell lymphoma treated with standard chemo-immunotherapy

While there are many proposed clinical prediction models for diffuse large B-cell lymphoma, like the International Prognostic Index (IPI), revised IPI and the National Comprehensive Cancer Network IPI, there is no widely used model for older patients. A recent study proposed a Geriatric Prognostic Index (GPI) validated in a Norwegian cohort, using independent predictors involving demographic, biochemical and functional parameters. This study aims to validate the GPI in an Asian cohort and simplify the GPI for ease of clinical application. Older patients (age ≥ 70) treated with R-CHOP-like regimens were identified through the Singapore Lymphoma Study. In a retrospective Asian cohort comprising 268 patients, a simplified GPI (sGPI) was created using variables of predictive significance advanced age > 80 years, Eastern Cooperative Oncology Group performance score ≥ 2, serum lactate dehydrogenase level > 3-times upper limit of normal, and stage 3-4, stratifying patients into Low (0), Intermediate (1-2) and High risk (3-4). Cox regression analysis demonstrated a statistically significant difference between risk groups in terms of overall survival (p < 0.00010), with hazard ratios of 1.50 (95% CI: 0.93-2.42), and 4.86 (95% CI: 1.63-14.48), for intermediate and high-risk groups respectively, when compared to the low-risk group. Similar findings were noted for progression free survival (p = 0.00010), with hazard ratios of 1.49 (95% CI: 0.93-2.39) and 4.92 (95% CI: 1.64-14.77) for intermediate and high-risk groups respectively. The sGPI was found to have a C-index of 0.65 (95% CI: 0.60-0.70), which was superior to existing models. In conclusion, we have validated the GPI in an Asian cohort. The sGPI demonstrates good predictive value in an Asian cohort as compared to existing prognostic models.