JAK2 Mutation - Effects and Questions

It is hard to understand I was told I have Essential Thrombocytosis with a JAK 2 mutation. I take 500MG of
hydrea every other day. I still don't understand exactly what I have. I was told that without the hydrea and asprin I could have a stroke or heart attack. However I don't understand the cancer diagnosis.
I get very confused, but I just go along with what my doctor tells me to do.

Hi @remo1110 Blood conditions and blood cancers can be confusing. You’ve been diagnosed with Essential Thrombocytosis which is a condition in which your body produces too many platelets. Platetes are crucial in helping your blood to clot if you’re injured. However, if you have too many it can cause clotting to form where you don’t want it to happen such as deep within leg veins, lungs, etc.
You have an acquired gene mutation which is allowing the normal production of cells to not shut off in a timely fashion so the platelets are in an over production mode.
The medication your doctor has you taking will help get that back under control and the aspirin will keep your blood thinner so that you don’t clot as easily.

I’ve found some good reading literature for you that will really help explain what’s happening.
These two articles are a good overview of thrombocytosis:
https://www.mayoclinic.org/diseases-conditions/thrombocytosis/symptoms-causes/syc-20378315
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https://www.verywellhealth.com/thrombocytosis-overview-and-more-5187124
This article goes into more detail about the JAK2 mutation which is part of your diagnosis.
https://www.verywellhealth.com/jak2-mutation-5217909
I hope this is helpful. Are you having any side effects from the Hydroxurea?

You have elevate number of thrombocytes, also known as platelets, due to a cancer gene mutation (JAK2). Platelets are one of the many components made in your bone marrow and released to your blood stream as needed. JAK2 interferes with the proper production of these blood components such as white cell, red cells, platelets. The roll of mature platelets is to stick to injured tissue to stop the bleeding. You do have other blood clotting factors, but platelets tend to plug the hole.
Aspirin has been known for years to make platelets less sticky. So it is your best defense against blood clots. You may find that cuts or nose bleeds take longer to stop when on aspirin.
I too have a JAK2 mutation with elevated platelets and white count. A bone marrow study revealed that I have Primary Myelofibrosis. My marrow is filling in with scar tissue. There is no simple fix, but I continue to take aspirin to avoid blood clots or stroke because of the elevated platelets.
In case you are wondering, I’m a retired clinical scientist. I worked in hematology and in cancer genetics for over 40 years. Talk about irony.

So I have a quick question for you, knowing your background. I was diagnosed with polycythemia vera in June. I had increased red blood cells for almost a year before be diagnosed. my red blood cells when diagnosed was 23/68. I went through 7 weeks of weekly blood letting to get levels back to normal, and just went two months without having to have phlebotomy. Need to have 1 yesterday because my hematocrit was 48. The hematologist I have, was a intern doctor and didn't really take the time to explain best course of action. He really just asked what I wanted to do, said I could be put on medication or just continue blood letting if I tolerated it ok. My question is, what is the best route of action for longevity. I hate taking medication, but if it turns off the mutation so I don't cause more damage to my bone marrow and cause scarring, is that a better route then just removing blood? He basically just told me to take 325 mg aspirin and continue cbc every month. I had to ask him if I should be taking an aspirin after joining this forum. Surprised he said 325 and not the 81 mg (baby aspirin). Any suggestions/info is appreciated.

I have the same situation and my oncologist put me on hydroxyurea 500 mg a day. Within 2 weeks, my platelets dropped from 337 to 57. He has taken me off hydroxyurea and new blood tests in 2 weeks. I asked him your question and he told me that I am at high risk of blood clots because I have the Jak 2 and the drug helps protect me from that. Does anyone have any other information?

Good questions. I’m not a medical doctor. My career was at the diagnostic end (lab). Therefore, I can’t comment on treatment except from my own experience.
I initially was misdiagnosed as having Polycythemia Vera based on having a JAK2 mutation. At the time I was in denial because I was anemic. Finally, I challenged my heme/onc doctor. Told her if this was PV with anemia that the two of us should publish it because I haven’t found any articles supporting this. She laughed and agreed. To get the correct diagnosis I had to have a bone marrow biopsy. Many other gene mutations in the myeloid series were studied, but the defining diagnosis came from the pathology lab. I had Primary myelofibrosis. Sometimes that is the only way to get an accurate diagnosis.
As to hydroxyurea, when I took it for my elevated platelets and white count; it did not lower my platelets. It dropped my white count and lowered my red count making me anemic. So no more hydroxyurea. There are other drugs approved to inhibit the JAK2. Once symptoms elevate I will consider them. As for now low dose aspirin is all I’m on.
As I understand, even with meds blood letting will still be necessary. Hang in there. At least we are aware. Be sure to let all of your other doctors know.

Thank you for responding. Most days are great and I feel fine. The probable I’m having is not knowing whether symptoms are related to PV or perimenopause. My most frequent issues are achy joints. I’ve only been doing the blood letting and aspirin. I’ve have also experienced anemia throughout my life. When I was first diagnosed my ferritin was only 8.

My brother and I have the JAK 2 mutation. I take 500 mg of Hydrea but my brother had more servere side effects from Hydrea so his medication was switched. My blood platelet count is in the high normal range but my brother's is still a bit too high.
My hematologist at University of Chicago Cancer and Blood Institue in Hinsdale, IL, kept repeating to me, "This is not cancer" over and over and over. Guess she knew how concerned I happened to be. I will take her word regarding essential thrombocythosis due to her vast experience. Yes, I was told I could have a heart attack or a stroke also so the Hydrea I will take for life, I suppose. I am thankful for that medication.

Thank you so much for your response. I plan on reading the articles you provided.
I appreciate your taking the time to respond to me.

Good luck

An oncology nurse told me that blood withdrawn from people with blood disorders/cancers is discarded.

And the Red Cross, to which I had regularly donated for years, told me my ET diagnosis means I can no longer do so.