International Prognostic Index (IPI)

The International Non-Hodgkin's Lymphoma Prognostic Factors Project. A predictive model for aggressive non-Hodgkin's lymphoma. Five pretreatment factors (age > 60, raised LDH, ECOG ≥ 2, Ann Arbor III–IV, > 1 extranodal site) defined four risk groups with 5-year overall survival of 73%, 51%, 43% and 26%.

Sehn LH, Berry B, Chhanabhai M, et al. The revised International Prognostic Index (R-IPI) is a better predictor of outcome than the standard IPI for patients with diffuse large B-cell lymphoma treated with R-CHOP. Regroups the score into very good (0), good (1–2) and poor (3–5), with 4-year progression-free survival of 94%, 80% and 53%.

The IPI (and disease-specific variants: R-IPI, NCCN-IPI, and for follicular lymphoma the FLIPI) is a prognostic tool used for counselling and trial stratification, not a treatment selector. Age-adjusted IPI (stage, LDH, performance status) is used for patients ≤ 60 years.