DLBCL Prognosis Calculator – IPI Score & Survival Prediction

Diffuse Large B-Cell Lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma, accounting for approximately 30–35% of all newly diagnosed lymphoma cases worldwide. It is an aggressive B-cell malignancy characterised by rapidly enlarging lymph nodes, frequent extranodal involvement, and constitutional B symptoms. Despite its aggressive nature, DLBCL is potentially curable in a substantial proportion of patients, making accurate initial risk stratification critically important for treatment planning. The International Prognostic Index (IPI) was developed in 1993 by a large international collaborative group and published in the New England Journal of Medicine. The study identified five clinical and laboratory variables — patient age, ECOG performance status, serum lactate dehydrogenase (LDH) level, number of extranodal sites, and Ann Arbor clinical stage — each of which independently predicted overall survival. By assigning one point for each adverse factor present, the IPI creates a 0–5 point score that stratifies patients into four risk groups with dramatically different 5-year overall survival rates in the original anthracycline-based chemotherapy era. The Low risk group (IPI 0–1) had an estimated 5-year overall survival of approximately 73% with historical CHOP-based chemotherapy, rising to over 80% with the addition of rituximab in the R-CHOP era. The Low-Intermediate group (IPI 2) achieved approximately 51% 5-year survival historically, the High-Intermediate group (IPI 3) approximately 43%, and the High risk group (IPI 4–5) approximately 26%. With modern R-CHOP, these figures have improved across all categories, and with salvage CAR-T therapy for relapsed/refractory disease, a further subset of high-risk patients can achieve durable remissions. The Revised IPI (R-IPI), published in 2007 using rituximab-era data, identified three prognostic groups. The Very Good group (R-IPI 0) achieves approximately 94% 4-year overall survival; the Good group (R-IPI 1–2) approximately 79%; and the Poor group (R-IPI 3–5) approximately 55%. The R-IPI better captures the improved outcomes associated with immunochemotherapy and is increasingly used alongside the original IPI in clinical practice. Beyond the classic IPI factors, cell of origin biology substantially modifies prognosis. The germinal centre B-cell (GCB) subtype, identified by immunohistochemistry (Hans algorithm) or gene expression profiling, has a more favourable prognosis than the activated B-cell (ABC) subtype, which exhibits constitutive NF-κB activation and poorer response to R-CHOP. Additionally, double-hit lymphoma — defined by concurrent MYC and BCL2 or BCL6 translocations — has a substantially worse prognosis than the IPI score alone predicts, typically warranting consideration of intensified induction regimens. This calculator integrates the IPI and R-IPI scoring algorithms with supplementary prognostic indicators to provide a comprehensive initial risk assessment. The tool is intended as a clinical decision support resource for oncologists, haematologists, and advanced practitioners managing DLBCL, and all management decisions should be made in the context of multidisciplinary team discussion and in accordance with current treatment guidelines.