DLBCL IPI Calculator (International Prognostic Index for diffuse large B-cell lymphoma)

Understanding the DLBCL IPI calculator — concept and principle

The International Prognostic Index (IPI) sorts adults with diffuse large B-cell lymphoma (DLBCL) and other aggressive non-Hodgkin lymphomas into four risk groups using five simple facts available at diagnosis. Doctors use it to describe prognosis, compare patients in trials and discuss treatment intensity.

IPI: one point per factor: with the default inputs the result is IPI 3 (high-intermediate · 43% / 65%).

How it is calculated

IPI score = one point for each of the following:

Age over 60 years
Ann Arbor stage III or IV
Serum LDH above the upper limit of normal
ECOG performance status 2, 3 or 4
More than one extranodal site

Score 0–1 = low risk, 2 = low-intermediate, 3 = high-intermediate, 4–5 = high risk. For each group the calculator shows the 5-year overall survival reported in the original 1993 cohort (73%, 51%, 43%, 26%) and the 3-year overall survival reported in a later cohort treated with rituximab plus CHOP (91%, 81%, 65%, 59%).

The principle

The index was built from 2,031 patients. Researchers tested many factors and kept the five that independently predicted survival. Each reflects a different part of the disease: age and performance status show how well the body tolerates treatment, while stage, LDH and extranodal spread reflect how much lymphoma there is and how fast it grows. Giving each factor one point keeps the score easy to use at the bedside.

Worked example

Default inputs: age 66, stage III or IV, LDH above normal, ECOG 1, one extranodal site.

Age over 60 → 1 point.
Stage III or IV → 1 point.
LDH above normal → 1 point.
ECOG 1 is below 2 → 0 points.
One extranodal site is not more than one → 0 points.
Total 3 → High-intermediate risk, 5-year survival 43% (1993 cohort), 3-year survival 65% (R-CHOP era).

How to read the result

Where does your result fall?

The percentages are averages for large groups in past trials. Survival has improved since 1993, so the R-CHOP figures are closer to current practice. A higher score means a higher chance that standard treatment will not control the lymphoma, which may lead doctors to consider trials or other options.

Common mistakes

Counting age 60 itself as a point. Only age over 60 scores.
Counting a single extranodal site. The point needs more than one.
Reading the percentage as one person's chance.

Keep in mind: This is not a diagnosis or a personal prognosis. Treatment decisions belong to the haematology or oncology team, who use many more details than these five factors.

Frequently asked questions

What is a normal LDH?

The upper limit of normal depends on the laboratory. Your report shows the reference range next to the result.

What does ECOG performance status mean?

It is a 0–4 scale of daily activity: 0 fully active, 1 light work possible, 2 up and about more than half the day but unable to work, 3 in bed or chair more than half the day, 4 completely disabled.

What is the difference between IPI and R-IPI?

The R-IPI uses the same five factors but regroups the scores into three groups based on patients treated with rituximab.

Sources: The 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 · MSD Manual Professional calculator, "International Prognostic Index for non-Hodgkin lymphoma"

Checked 9 Nov 2026. The 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; risk groups and survival figures (1993 cohort and rituximab-CHOP cohort of 1,063 patients) as tabulated in the MSD Manual calculator “International Prognostic Index for non-Hodgkin lymphoma”.

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