Skip to Navigation Skip to Search Skip to Content
Search All Centers

What Is Prefibrotic Primary Myelofibrosis?

Read Transcript

Published on May 3, 2021

The Difference Between a Prefibrotic Myelofibrosis and Essential Thrombocythemia Diagnosis

In 2016, a distinct classification of myeloproliferative neoplasm was identified: prefibrotic primary myelofibrosis (Pre-PMF). Keep watching to hear Dr. Ruben Mesa, MD, Executive Director of the Mays Cancer Center at UT Health in San Antonio, explain what prefibrotic myelofibrosis is, the similarities it shares with essential thrombocythemia (ET), and what research has found about disease progression.

Support for this series has been provided by Incyte. Patient Power maintains complete editorial control and is solely responsible for program content.

Recommended Programs:


Transcript | What Is Prefibrotic Primary Myelofibrosis?

Dr. Mesa: Hello. My name is Ruben Mesa and I'm the Executive Director of the Mays Cancer Center at UT Health, San Antonio, MD Anderson.

Let me attempt to demystify what we mean by prefibrotic myelofibrosis. This sometimes creates confusion and anxiety. Overt myelofibrosis, whether it be primary myelofibrosis or others, is enlargement of the spleen, significant scarring in the bone marrow, typically low blood counts, significant symptoms such as weight loss, and a life-threatening, potentially life-threatening, phase of the disease.

What Is Prefibrotic Myelofibrosis?

Prefibrotic myelofibrosis is a much earlier form of the disease that, over time, we largely have treated and understood to behave closer to essential thrombocythemia (ET). If you go back 20 to 30 years, the diagnosis of essential thrombocythemia was basically not having myelofibrosis, and having a high platelet count, and not having the criteria for polycythemia vera (PV) by having too many red blood cells. So, at that time it included both individuals that we now call ET and those with prefibrotic myelofibrosis.

How Is Prefibrotic Myelofibrosis Similar to Essential Thrombocythemia?

I think the name has created confusion, in that more accurately, it is like a cousin of ET that has a higher risk of progression. Those that have ET by current criteria have a lower risk of progression to myelofibrosis. And that is fairly uncommon. Individuals that have prefibrotic myelofibrosis, for all intents and purposes, are very much like the experience that ET patients have. The platelets are high. They may have a slightly higher white count. They might have a slightly enlarged spleen. They may have some characteristic changes in the bone marrow in terms of its appearance.

The important part is this. One, it is not the same as having overt myelofibrosis. It's not as severe. It's not as life-threatening. Two, the treatment is much more like ET, where using medicines like Hydrea (hydroxyurea), interferon or others to try to control the counts and decrease the risk of blood clots or bleeding, and control symptoms. Three, the risk of progression to overt myelofibrosis is higher, but it is still not a guarantee. It's probably less than 20% at 10 years. So a very important distinction, and be certain, if you hear this term, to really discuss it with your healthcare provider to truly understand where you stand on that spectrum.