by David Wallace
Let’s Define the term “Rare Disease”
** January 2022 update: Because of the direct impact of this article, some organizations referenced herein have either removed their links or updated / changed their data. **
Now that all of the hoopla of “Rare Disease Day” has passed, it is time to peel away the layers of misconception, myths and false belief to uncover the truth. First of all, let’s define the term “rare disease.” In the United States, a rare disease is defined as a condition that affects fewer than 200,000 people…while our friends in Europe define a disease as rare when it affects fewer than 1 in 2000 people. Isn’t that an eye opener?…..What a huge disparity in just the definition. For the purpose of this article (and clarity), we are focused on the United States only.
According to NORD (National Organization for Rare Disorders), Polycythemia Vera (PV) affects approximately 2 people per 100,000 in the general population. Their statistics on Essential Thrombocythemia (ET) state “fewer than 1 in 100,000 people are diagnosed with ET in any year.” The key item here is the way the statistics are presented, very confusing and murky. PV affects about 2 people per 100,000 (that assumes a total figure), while the ET figure 1 in 100,000 is a yearly figure. The fact is the number of PV and ET patients is approximately the same.
The MPN Landmark survey – “The Untold Story”
The survey (whose lead author is Dr. Ruben Mesa) talks about Quality of Life (QOL) issues, which is really no surprise. Those of us living with a MPN know first hand the toll it takes on a patient’s QOL. While the MPN Landmark study is an important, detailed survey looking at disease burden and & QOL on MPN patients, the “Untold Story” as I see it, is the number of patients reported per 100,000. Click here for the link to the study.
“The Philadelphia chromosome−negative myeloproliferative neoplasms (MPN) myelofibrosis (MF), polycythemia vera (PV), and essential thrombocythemia (ET) negatively affect patient quality of life (QOL) and are associated with increased risk of mortality. The MPN Landmark survey was conducted from May to July 2014 in patients with MF, PV, or ET under active management in the United States.…”
The BIG story is here, just look at the numbers:
“Out of every 100,000 people in the United States, an estimated 44 to 57 people have PV, and a similar number have ET. Myelofibrosis is less common, affecting 4 to 6 people per 100,000.” Common belief (and frequently published) is 1 – 2 in 100,000 have PV or ET and less for MF.
I have been saying for years, our numbers are WAY under-reported. Why does this huge discrepancy exists? Here is your proof, we are not even a rare disease and frankly, don’t belong in that category (that requires 1 in 200,000).
Debunking the Rare Disease Myth
Those numbers are confirmed in the full version of the MPN Landmark Study and here in Epidemiology of MPNs in the United States. Either I missed the boat or there is some reason for the hush-hush on the True Number of MPN Patients (perhaps a lack of consensus or…??). The Orphan Drug Act does provide incentives for “rare diseases,” again defined as less than 200,000 patients in the U.S. – but that’s not us, we are not even close. I am here to report the truth and not to prolong a myth that has no basis for reality.
The U.S. population in 2016 was 322,761,807 on January 1st, according to the US Census Bureau (309 million in 2010).
On the MPN Research Foundation website (MPN Prevalence in the U.S.), they reference Marketscan database estimates from 2010, the projected prevalence for MPNs in the U.S. on December 31, 2010 were:
- MF – 12,812
- PV – 148,363
- ET – 134,534
Total MPN population = 297,709 in 2010
If you take the U.S. population of 309,000,000 (2010) and divide it by 100,000, you come up with 1 in every 1091 or 100 per 109,000 people = 91 per 100,000 (approximately) have PV, ET or MF.
According to the National Organization for Rare Disorders (NORD), “polycythemia vera affects slightly more men than women. The disorder is estimated to affect approximately 2 per 100,000 in the general population. If we use the numbers in the MPN Landmark Study, 44 to 57 per 100,00…..we should not be in the rare disease category (yes, I know…I repeated myself, for emphasis!)
A 2003 study, in Connecticut using a fancy algorithm, projected 22 per 100,000 for PV and 24 per 100,000 for ET.
So how many MPN patients are there?
Who knows?…..it’s somewhere between 2 in 100,000 (according to NORD), 92 to 120 per 100,000 (estimate based on the MPN Landmark Study) or is it 91 per 100,000 (as Marketscan database on MPN Research Foundation website would suggest) – big discrepancy, wouldn’t you say?
The Landmark Study and Marketscan numbers are close enough…..but we should never hear 1 or 2 per 100,000 people, that’s crazy, inaccurate data! I think it is safe to say, that almost 100 or more, per 100,000 people have one form of MPN or another (the studies above establish that).
Dr. Vikas Gupta, a MPN Specialist from Canada, chimed in via Twitter “taken together, prevalence would be 1 in every 1000 persons affected with a MPN. Sometimes incidence and prevalence can be confusing the way data are presented.”
Let’s Go the Next Step, Apply some Logic and Firsthand Observations
Given the difficulty in making an MPN diagnosis from the local level, most general practitioners don’t know what to look for, our actual numbers are probably greater than 100 per 100,000. Just think, many patients had their MPN anywhere from 1 to 10 years before ever receiving the official diagnosis.
So that leads to my next hypothesis, how many people are walking around today, without a clue, with an “undiagnosed MPN”, inside of that 1 to 10 year window? They may have reported symptoms to their doctor and perhaps received a diagnosis of:
- Chronic fatigue syndrome
- Pruritis (itching), etc.
Rest assured ……As research progresses and genetic testing becomes more commonplace (3-10 years out), we may see our numbers increase many times over. Someone (perhaps a leading researcher or MPN specialist) should step forward and clarify the numbers, because as things stand….they are both confusing and conflicting. – October 2019 update, thank you to Dr. Hasselbalch for overwhelmingly confirming this article.
Let’s work Together
My hope in presenting this article is that our greater (realistic) numbers will draw more attention to MPNs, pull in new pharma players who may see a much larger opportunity, thereby committing new or expanded research dollars to provide better treatments or perhaps even a cure (sometimes hard to imagine….but I’m always optimistic).
I think we, collectively as patients, should reach out to our local news media (newspaper, TV or a small town news digest) and offer to share your story, creating MPN Awareness. I see this approach most likely to work in small to mid-sized cities. My local newspaper had no interest in PV Reporter / David Wallace or my activities to help in the MPN community (until this article was published shortly after the one you are reading) . Patients should take an active role in spreading the word in their community. If you would like to share you story with PV Reporter, please drop me a note and we will work together to get the word out.
April 30, 2018 – This is a very important article that should have gotten more attention in the MPN Community. I knew before I started researching / writing this research paper, that our prevalence & incidence were far under reported. As Dr. Vikas Gupta, a MPN specialist from Canada stated above, “taken together, prevalence would be 1 in every 1000 persons affected with a MPN. Sometimes incidence and prevalence can be confusing the way data are presented.”
Although I drew some criticism, the positive support far outweighed the negative. I was very pleased to receive this message from Janet, who clearly appreciated my effort for “honest, investigative reporting.” Thank you for your support!
I’ve been meaning to message you for a while since reading your article “Are Myeloproliferative Neoplasms a Rare Disease?” I just want to let you know how much I appreciate your research and effort and to say that I agree with you 100%!
I was diagnosed with ET JAK2+ last year, and like a lot of people had elevated platelets years prior to diagnosis. One of the first things that came across my mind was “how many other people have/and or had this disease and have/had no idea??!”
So…since diagnosis (and being told how rare this disease is),I have told literally a handful of people other than my immediate family. And what has surprised (and confused) me is that out of that handful of people, one person has told me, “My sister has had that for years!” Another said, “Oh! My grandma has that.”
Two weeks ago, my dental hygienist told me that her mother had it and had taken Hydrea years for it.
At my grandson’s ballgame a few weeks back, my son was talking with a friend and the friend mentioned that his mother has ET and had just started Hydrea.
Just a strange coincidence?? Maybe.
Of course, I’m still learning about how things work, but I just don’t get the numbers? I am totally convinced that there are undiagnosed or misdiagnosed cases, but what about those that HAVE been diagnosed? I’ve noticed that in some of the online support groups that almost daily there are people being added that say that they were JUST diagnosed with an MPN.
When are the numbers going to change? When will this data be updated?
Another thing that confused me as far as statistics go is that during a live webinar presented by Voices of MPN (Incyte) a few weeks back, the rep stated that there were 80,000 cases of ET. That’s a big difference between the 135,000 that’s reported in most other studies! Why the discrepancy?
Like you, I just can’t help but feel that if the true numbers were presented, that there could possibly be more research interest for MPNs.
Anyways, this has been my experience and observation so far and I just wanted to share them with you and let you know how much I appreciated your article. It made me feel like maybe I wasn’t crazy after all.