International Prognostic Index

Mantle Cell Lymphoma (MCL) is a distinct subtype of Non-Hodgkin Lymphoma (NHL). It is one of the rarest, comprising only around 6% of NHL cases. MCL responds to a variety of initial therapies; however, conventional chemotherapy regimens achieve relatively short-term remissions. Moreover, there is a wide heterogeneity in clinical outcomes; some patients have a very aggressive presentation and others a very indolent clinical course.¹ 

The MCL International Prognostic Index (MIPI) was formulated by the European MCL Network to address the unmet need for a prognostic index particularly applicable to patients with advanced MCL.^1,2 Outcome data from 455 patients with advanced MCL taking part in several clinical trials between 1996 and 2004 were subject to multivariate analysis to determine which variables can be viewed as predictive of patient prognosis following treatment. Age, Eastern Cooperative Oncology Group (ECOG) performance status (2–4 vs 0–1), B-symptoms, spleen involvement, maximal lymph node size, White Blood Cell (WBC) counts, Lactate Dehydrogenase (LDH), hemoglobin and β₂-microglobulin (β₂M) had significant prognostic relevance for Overall Survival (OS). Age, ECOG performance status, LDH as a ratio to the Upper Limit of Normal (ULN), and WBC count were statistically identified as independent variables and then included in the derivation of a mathematical formula for the prognostic index:

           MIPI score                      = (0.03535 x age [years])

                                                          + 0.6978 (if ECOG>1)

                                                          + (1.367 x log₁₀ [LDH/ULN])

                                                          + (0.9393 x log₁₀ [WBC count per 10^-6 L])

 The use of these parameters led to the emergence of three groups:

• MIPI low risk with median OS not reached (5-year OS 60%)
• MIPI intermediate risk with median OS of 51 months
• MIPI high risk with median OS of 29 months

 In 236 of the 455 patients, the percentage of cells positive for the proliferation index, Ki-67, was available. This parameter also proved to have strong univariate prognostic relevance for OS. A modification of the MIPI was therefore made to include a biological component (addition of 0.02142 x Ki-67 [%] to produce a biological MIPI score, MIPIb).^1,2

As an alternative to the formula-based MIPI above, a simplified, score-based MIPI was proposed with points allocated as follows:

Points	Age	ECOG	LDH/ULN	WBC (109/L)
0	<50	0–1	<0.67	<6.700
1	50–59	—	0.67–0.99	6.700–9.999
2	60–69	2–4	1.000–1.49	10.00–14.999
3	>70	—	≥1.5000	≥15.000

 The MIPI has gained a level of acceptance in the medical community and there are now websites available which enable quick calculation of the MIPI score. For example, the website below enables the MIPI value to be calculated from a patient’s age, ECOG score, LDH, LDH/ULN for the testing laboratory, and WBC count. In addition to these four independent prognostic factors included in the model, the cell proliferation index (Ki-67) is a factor that has been shown to have additional prognostic value.³ If the percentage of Ki-67 positive cells is known, the MIPIb can also be calculated.

http://www.qxmd.com/calculate-online/hematology/prognosis-mantle-cell-lymphoma-mipi