International Prognostic Index
Encyclopedia
The International Prognostic Index (IPI) is a clinical tool developed by oncologists to aid in predicting the prognosis
of patients with aggressive non-Hodgkin's lymphoma. Prior to 1993, when the IPI was developed, the primary consideration in assessing prognosis was the Ann Arbor stage
alone, but this was increasingly found to be an inadequate means of predicting survival outcomes, and so other factors were studied.
A retrospective analysis was performed on 2031 patients with aggressive non-Hodgkin's lymphoma, of all ages, treated with a doxorubicin
-based chemotherapy regimen such as CHOP
between 1982 and 1987. Several patient characteristics were analyzed to determine whether they were associated with differences in survival, and the factors that emerged as significant were, in addition to the Ann Arbor stage: age, elevated serum lactate dehydrogenase
(LDH), performance status
, and number of extranodal sites of disease.
The sum of the points allotted correlates with the following risk groups:
The sum of the points allotted correlates with the following risk groups:
Although the IPI has shown itself to be a useful clinical tool, widely used by oncologists and a mainstay of risk stratification in clinical trials for lymphoma, it should be kept in mind that it was developed prior to the use of rituximab
, which is now included with anthracycline-based combination chemotherapy as of the standard of care in B-cell lymphomas (the majority of non-Hodgkin's lymphomas). Rituximab has dramatically improved the outcomes of lymphoma patients, and its effect on the prognostic value of the IPI is uncertain.
. The prognostic factors that emerged from this were: age, stage, number of lymph node areas involved, serum hemoglobin
level, and serum LDH.
One point is assigned for each of the following adverse prognostic factors:
The sum of the points allotted correlates with the following risk groups:
The point values are assigned as follows:
The sum of the allotted points correlates with the following risk groups:
Prognosis
Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...
of patients with aggressive non-Hodgkin's lymphoma. Prior to 1993, when the IPI was developed, the primary consideration in assessing prognosis was the Ann Arbor stage
Ann Arbor staging
Ann Arbor staging is the staging system for lymphomas, both in Hodgkin's lymphoma and Non-Hodgkin lymphoma . It was initially developed for Hodgkin's, but has some use in NHL...
alone, but this was increasingly found to be an inadequate means of predicting survival outcomes, and so other factors were studied.
A retrospective analysis was performed on 2031 patients with aggressive non-Hodgkin's lymphoma, of all ages, treated with a doxorubicin
Doxorubicin
Doxorubicin INN is a drug used in cancer chemotherapy. It is an anthracycline antibiotic, closely related to the natural product daunomycin, and like all anthracyclines, it works by intercalating DNA....
-based chemotherapy regimen such as CHOP
CHOP
CHOP is the acronym for a chemotherapy regimen used in the treatment of non-Hodgkin lymphoma. CHOP consists of:* Cyclophosphamide, an alkylating agent which damages DNA by binding to it and causing cross-links...
between 1982 and 1987. Several patient characteristics were analyzed to determine whether they were associated with differences in survival, and the factors that emerged as significant were, in addition to the Ann Arbor stage: age, elevated serum lactate dehydrogenase
Lactate dehydrogenase
Lactate dehydrogenase is an enzyme present in a wide variety of organisms, including plants and animals.Lactate dehydrogenases exist in four distinct enzyme classes. Two of them are cytochrome c-dependent enzymes, each acting on either D-lactate or L-lactate...
(LDH), performance status
Performance status
In medicine , performance status is an attempt to quantify cancer patients' general well-being and activities of daily life. This measure is used to determine whether they can receive chemotherapy, whether dose adjustment is necessary, and as a measure for the required intensity of palliative care...
, and number of extranodal sites of disease.
International Prognostic Index
One point is assigned for each of the following risk factors:- Age greater than 60 years
- StageCancer stagingThe stage of a cancer is a description of the extent the cancer has spread. The stage often takes into account the size of a tumor, how deeply it has penetrated, whether it has invaded adjacent organs, how many lymph nodes it has metastasized to , and whether it has spread to distant organs...
III or IV disease - Elevated serum LDH
- ECOG/ZubrodPerformance statusIn medicine , performance status is an attempt to quantify cancer patients' general well-being and activities of daily life. This measure is used to determine whether they can receive chemotherapy, whether dose adjustment is necessary, and as a measure for the required intensity of palliative care...
performance status of 2, 3, or 4 - More than 1 extranodal site
The sum of the points allotted correlates with the following risk groups:
- Low risk (0-1 points) - 5-year survival of 73%
- Low-intermediate risk (2 points) - 5-year survival of 51%
- High-intermediate risk (3 points) - 5-year survival of 43%
- High risk (4-5 points) - 5-year survival of 26%
Age-Adjusted IPI
A simplified index can be used when comparing patients within an age group (i.e. 60 or younger, or over 60) and includes only 3 of the above factors:- Stage
- LDH
- Performance status
The sum of the points allotted correlates with the following risk groups:
- Low risk (0 points) - 5-year survival of 83%
- Low-intermediate risk (1 point) - 5-year survival of 69%
- High-intermediate risk (2 points) - 5-year survival of 46%
- High risk (3 points) - 5-year survival of 32%
Although the IPI has shown itself to be a useful clinical tool, widely used by oncologists and a mainstay of risk stratification in clinical trials for lymphoma, it should be kept in mind that it was developed prior to the use of rituximab
Rituximab
Rituximab, sold under the trade names Rituxan and MabThera, is a chimeric monoclonal antibody against the protein CD20, which is primarily found on the surface of B cells...
, which is now included with anthracycline-based combination chemotherapy as of the standard of care in B-cell lymphomas (the majority of non-Hodgkin's lymphomas). Rituximab has dramatically improved the outcomes of lymphoma patients, and its effect on the prognostic value of the IPI is uncertain.
Follicular Lymphoma International Prognostic Index (FLIPI)
Given the success of the IPI for intermediate grade lymphomas, an effort was undertaken to develop a similar prognostic index for the most common low-grade lymphoma, follicular lymphomaFollicular lymphoma
Follicular lymphoma is the most common of the indolent non-Hodgkin's lymphomas, and the second most common form of non-Hodgkin's lymphomas overall. It is defined as a lymphoma of follicle center B-cells , which has at least a partially follicular pattern...
. The prognostic factors that emerged from this were: age, stage, number of lymph node areas involved, serum hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...
level, and serum LDH.
One point is assigned for each of the following adverse prognostic factors:
- Age greater than 60 years
- Stage III or IV disease
- Greater than 4 lymph node groups involved
- Serum hemoglobin less than 12 g/dL
- Elevated serum LDH
The sum of the points allotted correlates with the following risk groups:
- Low risk (0-1 points) - 5 and 10-year survivals of 91% and 71%, respectively
- Intermediate risk (2 points) - 5 and 10-year survivals of 78% and 51%, respectively
- High risk (3-5 points) - 5 and 10-year survivals of 53% and 36%, respectively
Mantle Cell Lymphoma International Prognostic Index (MIPI)
An effort was more recently undertaken to identify a similar prognostic index predictive of outcome in advanced mantle cell lymphoma. There were four factors found to have independent prognostic relevance: age, performance status, LDH, and white blood cell count (WBC).The point values are assigned as follows:
- 0 points: Age less than 50 years, ECOG performance status of 0-1, LDH less than 0.67 of the upper limit of normal, or WBC of less than 6,700 cells/mcl
- 1 point: Age 50-59, LDH 0.67-0.99 of the upper limit of normal, or WBC 6,700 to 9,999 cells/mcl
- 2 points: Age 60-69, ECOG performance status of 2-4, LDH 1-1.49 times the upper limit of normal, or WBC 10,000-14,000 cells/mcl
- 3 points: Age 70 or greater, LDH 1.5 times the upper limit of normal or greater, and WBC of 15,000 cells/mcl or greater
The sum of the allotted points correlates with the following risk groups:
- Low risk (0-3 points) - median survival not yet reached
- Intermediate risk (4-5 points) - median survival of 51 months
- High risk (6-11 points) - median survival of 29 months