International Prognostic Index (IPI) for aggressive lymphoma
Five pretreatment factors that stratify survival in diffuse large B-cell and other aggressive lymphomas.
Switch how results are explained
Low risk (IPI 0-1). Five-year overall survival was 73% in the original pre-rituximab cohort.
- Evidence grade
- A
What it is and when to use it
The IPI gives one point to each of five adverse factors present before treatment: age over 60, serum LDH above normal, ECOG performance status of 2 or more, Ann Arbor stage III–IV and more than one extranodal site. The total ranges from 0 to 5.
How to interpret it
0–1 low risk, 2 low-intermediate, 3 high-intermediate, 4–5 high. In the 1993 derivation cohort, treated with doxorubicin-based chemotherapy before rituximab, five-year overall survival was 73%, 51%, 43% and 26% respectively.
Limitations and when not to use it
The survival figures predate rituximab; outcomes with R-CHOP are better in every group, although the index still separates risk. It is assessed at diagnosis, before treatment, and was derived in aggressive lymphoma — it is not the score for follicular lymphoma (FLIPI) or Hodgkin lymphoma. For patients aged 60 or under, the age-adjusted IPI uses only stage, LDH and performance status.
Formulas and cut-offs are from the original authors of each score; see the references.
Last reviewed: June 2026
References
- International Non-Hodgkin's Lymphoma Prognostic Factors Project. A predictive model for aggressive non-Hodgkin's lymphoma. N Engl J Med. 1993;329(14):987-994. PMID:8141877