The Value of MIPI and Ki-67 in Mantle Cell Lymphoma
Panelists:> Alexey V. Danilov, MD, PhD, Oregon Health & Science University; Andre Goy, MD, Hackensack University Medical Center; John P. Leonard, MD, New York-Presbyterian/Weill Cornell Medical Center; John M. Pagel, MD, PhD, DSc, Swedish Medical Center Seattle and Issaquah>; Stephen J. Schuster, MD, The University of Pennsylvania
John P. Leonard, MD: We have the MIPI, the Mantle Cell Lymphoma International Prognostic Index, that’s come along. I know that’s evolved over time, and there are different versions. I don’t think we want to go through the details of it. The audience can reference it. But in a general sense, what are the key aspects of MIPI, and also Ki-67, which Andre alluded to, that put patients into different risk groups?
Andre Goy, MD: MIPI is a score that is similar to the International Prognostic Index, and FLIPI scores in follicular lymphoma. MIPI essentially evaluates 4 components which include age, leukocytosis, LDH (lactate dehydrogenase), and performance status. There are 3 categories: high risk, intermediate risk, and low risk. In high risk MIPI, the median survival is about 30 months. Intermediate risk, 50 months. And in the original publication, it wasn’t reached for low risk MIPI.
And the Ki-67, as Andre has already mentioned, demonstrates over 30%. If you add that to MIPI, you get biological MIPI, and that further helps stratify patients. However, the molecular prognostic markers are extremely important. Steve has already mentioned p53 aberrations. They have been considered in about 20% of patients. Then, there are CDKN2A abnormalities. The gene encoded for p16, which is an endogenous cyclin-dependent kinase inhibitor, demonstrates another 20%. There was also a recent publication from Europe which demonstrated that those abnormalities negatively impact response to chemotherapy in mantle cell lymphoma.
Interestingly, MYC is also apparent in about 20% of patients. However, it does not seem to carry the same negative prognostic significance as the other 2 genes. MYC translocations are fairly uncommon. They are more common in blastic mantle cell lymphoma, but are still quite rare.