Webinar: Understanding Hairy Cell Leukemia
February 23, 2023
Speaker: Dr. Tim Call, Mayo Clinic
Hosted by the Hairy Cell Leukemia Foundation (HCLF) with Dr. Tim Call from the Mayo Clinic. Moderated by Anna Lambertson, HCLF Executive Director.
Presentation Materials
Transcript of Dr. Call’s Slide Presentation
Dr. Tim Call:
The slides you'll see today are a combination of slides that I have put together as well as my colleague, Dr. Sameer Parikh. Sameer is now leading our Hairy Cell Leukemia efforts at the Mayo Clinic.
But first a timeline. In the late fifties, early sixties, it became evident that there was a condition of B-cell malignancy that was unique. Prior to this time, it had been lumped together with chronic lymphocytic leukemia or various lymphomas. Hairy cell leukemia is about 2% of all adult leukemias. There's a male predominance about a four to one.
Pancytopenia means low blood counts, low white count, low platelets.
Hairy Cell Leukemia often presents with low blood counts. In Hairy Cell Leukemia, only about 15% is with white blood cell count increased. (Whereas in most leukemias, your white blood cell count is increased.)
Hairy Cell Leukemia presents with low monocytes. A monocyte is a type of white blood cell, a type of immune cell that is made in the bone marrow and travels through the blood to tissues in the body.
Hairy Cell Leukemia can present with a large spleen, some of you may have significant bone pain. HCL may present with infection. In some patients Hairy Cell Leukemia is simply found because you went in and had a blood count as part of a physical and you find some of these numbers are low.
(Slide 5)
I want to spend a little time on this slide. I use it often in my office and it talks about the bone marrow function.
So the bone marrow is an organ like any organ - heart, lung, kidneys - but it's diffusely located within the marrow cavity. And it takes initial early forms of white cells, platelets and matures them into the various cell lines … the red cells, the white cells, the platelets.
White blood cells, there are various subtypes. The hairy cells are lymphocytes. That's not as common as what's called neutrophils. Neutrophils fight bacterial infections. Another cell that helps to fight infections by engulfing organisms are monocytes. So in hairy cell we have an increase of lymphocytes and a resulting decrease in neutrophils and monocytes and that's what makes it more likely to have infection.
So this is a real life case of a patient of mine. 48 years old. It was the day before his wedding and he presented with cough and fever. He was found to have a pneumonia, but because he was getting married the next day, he didn't take the advice to be admitted for IV antibiotics. He took oral antibiotics. But unfortunately, he presented back to the emergency room and was airlifted into Rochester. What he had was pancytopenia. So he had low hemoglobin, he was anemic, low platelets. He had more lymphocytes than neutrophils and monocytes. They started him on antibiotics. His counts, his pneumonia was improved. He was on a ventilator for about 10 days and his blood counts initially were better. But then three weeks later he was found again to have low blood counts. And so we (the Mayo Clinic) were consulted.
(Slide 7)
Now as we look at hairy cell, we generally will use a bone marrow to diagnose. You can diagnose it on the peripheral blood on a blood sample using what's called flow cytometry. You see on the right hand side of slide 7 the various red and blue colors that uses what are called antigens on the cells, there are specific markings. I've listed them there … CD19 and CD20, et cetera.
And then the flow cytometry, each of those dots is in individual cells.
I put the barcode there to say, each leukemia has a unique set of what's called immunophenotype or antigens that mark it as a specific leukemia. So chronic lymphocytic leukemia would have some similarities but some differences. The barcode is just to think about when you hear us talking about all of these markers. What we're doing is just trying to get the code for the cells so we can make the diagnosis.
Another thing that's almost always positive is a marker called BRAF. And we'll talk more about that.
(Slide 8)
The patient was noted to have mild splenomegaly, enlargement of the spleen. He had a low monocyte count. Hairy cells were seen on the blood smear. He had what's called a leukoerythroblastic smear, which meant that we were seeing cells that normally would be in the marrow but they were out circulating because the marrow had been replaced. And so a bone marrow biopsy was performed.
(Slide 9)
When we look at pictures on the lower right hand corner, you see a typical hairy cell. The red blood cells are in the background. This cell is a little bit bigger than the normal lymphocyte and you see these projections around the outside, kind of a shagged border. So that's in the blood smear.
Bone marrow on the upper right you see a normal bone marrow, which is a combination of cells and fat. The fat is digested out in a side preparation, but those holes were where fat was.
If you're 50 years old, you should have roughly 50% cells and 50% fat. This gentleman is 48 and you see that his marrow is almost completely replaced with cells. And then the higher power, you see those nuclei are separated, and that's what the pathologists call a starry sky appearance. So this is really confirming that this was hairy cell leukemia, both on the bone marrow and on the blood. It had the typical markings that we just talked about.
(Slide 10)
These projections, what are they? So the cell has a surface membrane and normally it's more smooth but with hairy cell there is overexpression of what's called beta-actin and other substances which cause the cell membrane to develop those changes. When you treat, that reverses to normal, especially if you're using something like a BRAF inhibitor.
So today we'll talk about classical treatment of hairy cell and then targeted therapy. So classical treatment of hairy cell involves chemotherapy, like cladribine, which affects DNA, breaks cell growth in that way. There is Rituxan or monoclonal CD20 which attacks the surface membrane on the cell surface.
But in the last 20, 25 years we've found that these cells, there's internal speak. So one mutation or substance will speak to the other so that as they're getting this intracellular speak or these intracellular signals which cause the cell to proliferate. And there's a cartoon there showing some of that.
(Slide 12)
Now this slide is more for reference. This is one slide that really talks about the testing that's done. It's a good summary slide that talks about the antigens you look for by flow. One thing you'll see in the middle I wrote ‘expert pathology review’. Sometimes hairy cell is very clearly hairy cell, sometimes there'll be changes and say this may be what's called hairy cell variant. But there are mimickers.
One of the most common things we've seen over the years that mimics hairy cell is splenic marginal zone lymphoma and it's treated differently. It would probably respond to cladribine but is treated in a different fashion. And so you really want to make sure that your pathologist who's looking at this has seen other hairy cell disease.
There are algorithms for treatment of hairy cell, but it's really important that we know this for sure. And this is easily done if your doctor is not sure or concerned. Many major medical centers offer pathology review. Slides can be sent to the National Cancer Institute or National Institutes of Health. Major places such as Mayo, MD Anderson, or Ohio State have pathologists that will review outside cases. It gets charged but it is something that your pathologist could request a review of. I'm not saying you have to, but if you think it's hairy cell, then you don't have to go to one of these facilities, but at least have your slides reviewed at one of these facilities.
(Slide 13)
So talking about treatments. Today we're talking to a group. Some of you are new in this experience and don't need treatment yet. Some are in the middle of treatment. Some had treatment 15, 20 years ago. So these slides will year to year change. But the hallmark that has really been present for treatment of hairy cell has been what are called purine nucleoside analogs.
Pentostatin, which is given intravenously every two weeks for up to six months or cladribine, which can be given either as a continuous seven-day infusion or a two hour IV infusion. Some countries have oral available, but these are the classic therapies.
So when we talk about rates, CR means complete response, no sign of anything.
Overall response rate means how many people responded even if it was a partial response.
PFS (progression free survival) talks about durability, how long progression free. That number means from when you were treated until the first sign of it recurring.
For both cladribine and pentostatin, you can see progression-free survival in the range of eight to 12 years. For cancer, that's a long time. Again, we'd rather not have hairy cell leukemia at all, but we see overall survival over 10 years for 80 to 95%.
So these (two purine analogs) tend to be equally effective.
(Slide 14)
So then, can we improve on that? We don't have overall long-term survival rates. We can look at response rates and we can look at what's called MRD free survival (this is a specific slide from the MD Anderson group). So this means if we are monitoring with very, very sensitive flow cytometry to pick up the smallest clone possible, how long until we can see that clone develop? That does show that there's a difference so that if you add Rituxan to cladribine on the right hand side, this is in terms of months, you see a higher number of people who were remaining MRD negative. Now I caution you in that when we look at this, we don't know what the long-term survival is, we don't know how long until somebody needs treatment.
This data is not mature enough for that, but it does show that we may see a higher clearance of MRD or minimal disease in the marrow using rituximab. So right now either is possible, but we do know that the side effects or complications are a bit higher when we add the Rituxan.
Some of you have been treated with cladribine, some cladribine and Rituxan.
(Slide 15)
And there is a targeted agent called Vemurafenib, also another one called dabrafenib, which target BRAF. It is not approved for upfront treatment.
We did more Vemurafenib at the beginning of the COVID and again I'll come to that. But there's another drug called Obinutuzumab. The folks at Memorial Sloan Kettering, Dr. Park et al, have been doing a study that is showing initial very good response rates to Vemurafenib, which is oral and obinutuzumab, which is an antibody and a finite treatment over four cycles, so four months.
(Slide 16)
When we come to relapsed hairy cell leukemia, there are really a lot of options.
First of all, if you don't have a response to treatment, you want to have the pathology reviewed. Is there something different? Hairy cell variant? HCLv doesn't tend to respond as well to cladribine alone. This is one where we'd want cladribine plus rituximab.
Options for a patient with relapse is retreating with the same drug or switching between cladribine and pentostatin.
The thing with this is the longer response you have to the first treatment, the more likely you'll respond to just repeating that again. So if the response is 11 years or 15 years, it's very good rationale to retreat with cladribine plus or minus Rituxan. If on the other hand the response is short, two or three years later and I've had a number of these cases that are the minority, then I almost always would add Rituxan to the cladribine rather than just use the same treatment alone.
(Slide 17)
We talked about targeted therapy. One of the big things in the last decade has been the drug Vemurafenib. This is used for primarily malignant melanoma that have this BRAF molecule. It's found that BRAF is present in 99% of HCL cases and the overall response rate using Vemurafenib is very high. It's about 90 plus percent. But the complete response is not as high and the time to recurrence is short, nine to 12 months. There's been a lot of interest in combining rituximab or obinutuzumab with Vemurafenib. The second bullet on the left-hand side is work from Dr. Tiacci in Italy showing that as compared with a nine month relapse-free survival with single agent Vemurafenib, the combination has a very high response rate. And at 37 months, so three plus years, the majority of patients were staying in remission. And again with obinutuzumab very robust results.
So this is being watched a lot. But I want to say there's not as much data using this in frontline as there is with Cladribine plus Rituxan. This is more used in relapse, but because of the immunosuppression noted with COVID-19 or the worry with immune suppression with COVID-19, at least for a couple of years, we tended to use the Vemurafenib based regimens more.
Ibrutinib is another drug for CLL. It has a more modest response rate in HCL but it can cause stable disease for a number of months or years. It's continuing to be looked at and there are some newer Ibrutinib like drugs that may be going into some trials.
I'm only going to mention moxetumomab. Dr. Kreitman from the National Cancer Institute has been the force behind it. Moxetumomab pasudotox is an immunotoxin. It was found to have a reasonable response rate and some very good long-term responses. But this is currently to the best of my knowledge not available.
(Slide 18)
Points for supportive care. So if you already have a low white blood count or neutrophil count and we give you something like cladribine which can affect that, there are drugs called pegfilgrastim or Neulasta that can be given to boost up the white count. We watch for any signs of infection and we often use prophylaxis with a Bactrim type drug or an antiviral. Because we can see, let's call it pneumocystis or recurrent shingles or zoster. One thing that's really clear is that if a person with hairy cell presents with an ongoing active infection, then we strongly consider trying Vemurafenib first until their counts improve and we get the infection under control and then later we can go to the purine nucleoside. So presentation at time of infection, we do tend to use Vemurafenib and we generally can get it approved. We might have to appeal with the insurer.
We like to at some point look at how has the marrow responded. With the purine nucleosides like cladribine you can see continuing improvement in the marrow for up to a year or more. With the BRAF inhibitors they start improving within the first couple weeks.
(Slide 22)
When we look at toxicities of Vemurafenib and rituximab, you see there's a number of things listed there. I want to point out that on the middle of that table it says grade one or two. So those are less serious. Grade four is much more serious. So grade four will be very, very serious. Grade three would be moderate. Grade one or two are mild. So these you're always going to see a lot more. So don't let that cause fear. Skin rashes are quite common. One of the things that's quite common is just feeling fatigued and achiness. Due to the toxicities many of the studies are written for 960 milligrams twice daily. Most of us have found that the majority of our patients don't tolerate over 240 twice daily to 480 twice daily.
(Slide 23)
This is the Ibrutinib data.
(Slide 26)
And there is another drug, dabrafenib, which is a BRAF inhibitor and trametinib, which is what's called a MEK inhibitor. They are also being combined to see if we can get better responses.
(Slide 27)
An old treatment which can rarely be required if somebody is not responding would be a splenectomy. And also interferon is an old treatment which we hardly ever use anymore.
(Slide 28)
Often after treatment we monitor the blood counts weekly until they've improved and then gradually increase that. There's a debate going on whether a bone marrow biopsy is needed. And having sat at the table, there are people on both sides of that, what's not debated is if you do a marrow, don't do it too early, especially if you're looking at cladribine response.
The people who say don't do a marrow, it's because, if your blood counts are completely normal, your spleen's normal then if there's a half of 1% of hairy cell in your marrow, it could still go away. And where we see doing second opinions, we see people who get over treated.
(Slides 29 through 31)
COVID I mentioned really changed things. This is a paper that we co-wrote in 2021. And the deal with this is when we look at our immune system, hairy cell in and of itself will lower neutrophils and monocytes, which make you more prone to infections.
So treating the HCL actually improves that. Cladribine and pentostatin, they can treat the hairy cells, but they will transiently lower the neutrophils and they will lower the helper T-cells. Helper T-cells are very important for fighting infections, especially atypical infections like TB or viral infections. And in fact in HIV/AIDS, this is a cell that is the lowest and is monitored to look for successful therapy. And then rituximab we've mentioned what it does is it can affect the memory B cells. So these are the ones that are involved in antibody production response to immunizations. So as you look at this, you realize there's no one answer for everybody.
We do know that Vemurafenib does not significantly lower any of these.
So on one hand we could say we want to avoid cladribine and use Vemurafenib and Rituxan, but we know Vemurafenib only lasts about nine to 12 months. So we get much better responses with Vemurafenib and Rituxan. So we may decrease our risk of having infections in one area, but we may decrease our chance of responding to a vaccine. So the only good thing about this is we're talking about it, we're thinking about this and going forward, we're going to strategize more on how to look at what we're treating and what we're doing to the immune system.
Transcript of Question & Answer Session
Anna Lambertson:
Dr. Call, thank you so much.
I am going to jump into some of the questions that have been coming through the Q&A.
So earlier in your presentation, you were discussing purine analogs and you talked about overall survival rate. Can you clarify what you mean by overall survival rate?
Dr. Tim Call:
So, let's just go the basics. Number one, with any drug we want to try to use in cancer, we want to look at What's the overall response rate? So how many people show response? Traditionally in cancer, if you want for it to be called a response, you need to see a 50% reduction. It doesn't mean that it is a complete response. So overall response rates are generally going to be higher.
And you see there are ranges, the ranges I put down there were overall response rates of 70 to a hundred. Well that's just looking at multiple different studies. There's going to be some difference. Partial response - we don't tend to use partial in hairy cell, but with certain tumors you will. That would be how many are at least 50% improved. And complete response means we don't see anything.
Now complete response rate becomes harder in the era of our improved diagnostic work. So for many years, much of the literature did not use sensitive flow cytometry. So if you have a complete response, the bone marrow looks normal and you don't see any hairy cells, but you can find one in 10,000 cells, does that mean you're not in response? So when I'm talking complete response here, I'm talking about classically looking – the spleen is down, the bone marrow looks normal with microscopy.
Then I talked about progression-free survival. Now that's not alive or dead survival. Progression-free survival is the time until there's an event.
So you get diagnosed with hairy cell disease, you get cladribine or you get Vemurafenib. From when you started cladribine or Vemurafenib day one to the first sign clinically of the hairy cells starting to recur. If it does and for some people it never does, it's progression-free survival. I wish they might have used a different word, but it means time from time one to an event.
Overall survival is how many people are alive at five, 10, 15, 20 years. And again, the good news here is that it's generally in the 90 to 95% range.
Anna Lambertson:
I wanted to ask you a couple questions about cladribine and Rituximab. So when do you as a physician decide to use cladribine alone or cladribine plus rituximab? What are the main questions or factors that you look into before making that decision with the patient?
Dr. Tim Call:
So that's a good question. In my practice it's been a moving target. I think that more and more I have moved towards adding rituximab especially if somebody is young, vital. If we can only have to treat it once, then I'd like to only treat it once. If a person has multiple other medical conditions and the side effects are slightly higher using the Rituxan, then I might draw back a little bit because the data shows excellent response with cladribine.
The work from MD Anderson, the National Institute of Health and National Cancer Institute showed that using concurrent cladribine and rituximab does result in less MRD and likely will have a longer response. So I've tended to do that now.
Then came COVID-19 and the vaccines. And so then it became evident that if you use rituximab, at least for six to 12 months you're affecting the B-cell population. So you're going to blunt the chance of having an immune response to a vaccine. So I would say I'm getting to the point where I'm more of a dual therapy person, but in the last several years went back more to monotherapy because of the vaccine issues.
Anna Lambertson:
Thank you. And in the dual therapy option at frontline, do you prefer concurrent or delayed rituximab?
Dr. Tim Call:
That's very easy to answer. Studies have shown from Dr. Kreitman again that delayed has a lower benefit ratio or overall complete response and progression-free survival to concurrent. So we tend to start it concurrently.
Anna Lambertson:
Thank you. We've received a number of questions in the Q&A where the patient is concerned that their blood counts have remained low after treatment. I think there's an opportunity here to clarify what patients can expect in recovery after treatment. So they've been treated with cladribine or cladribine and rituximab. When can they expect their platelets, their neutrophils, et cetera to improve?
Dr. Tim Call:
So when you look at red blood cells, white blood cells and platelets, they all have different lifespans. So if you give chemo or you give a bone marrow transplant, the first thing to generally recover is going to be the white cells, then the platelets, then the hemoglobin because red blood cells may live 120 days, so they're going to be made slower.
So in general you tend to see the white count come up first, then the platelets, then the hemoglobin. That's post chemo, post big radiation, et cetera. So with cladribine or cladribine Rituxan, I do use Neulasta if they're already neutropenic and I will generally see the neutrophils starting to come up within the first two to three weeks. I monitor weekly initially until either clearly comes up. Platelets often will be coming up in three, four, five weeks. It may take a couple of months for the hemoglobin to get back up to normal.
So that's what we see now. But it’s not uncommon for patients to have white blood cell counts remaining safe but still slightly low for several years. I think of a patient from the twin cities who we watched his neutrophils for four or five years and now after a number of years now they're normal. And platelets likewise can be a little slow in certain patients. I think it just has to do with, we all have different sensitivities to the drugs. I have another patient where counts were very slow to come up but then within six months they're headed down. Well that makes me more worried about a relapse and so that's a place where I would do a marrow sooner to see if we didn't get the right response.
Anna Lambertson:
And more specifically, one individual in the Q&A said they're 20 years past treatment, but their platelets still have stayed pretty low, in the 70 to 80,000 range. And they're wondering is that okay? Should they be worried? Is this an indication that treatment is needed again? Why would platelets be in that range well past when one's treatment is completed and when other counts have seemingly normalized?
Dr. Tim Call:
Like most doctors, I'm not really good on the why. Where I would be concerned is if, let's say you had treatment 10 years ago and the platelets were 30,000 and then they got to be 80 or 85 and now they're running between 70 and 80 but they've been stable. I'm not overly concerned about that. If on the other hand you start seeing the platelets going 90, 80, 70, 60, I don't really like to see the platelets much under 50 to 60,000, that's where I would do a bone marrow and look and see. And if the bone marrow's clear, then it's just every time we use a drug like cladribine, we do hit a few of the bone marrow stem cells so you don't have quite the reserve in the marrow.
Again, everyone responds a little differently, but in terms of numbers, so with platelets, we don't tend to have spontaneous bleeding unless the platelets are down in the range of 10 to 15,000 or less. So we're built with a great reserve there. So if their platelet counts are low in the seventies and are stable, I don't tend to do too much.
Anna Lambertson:
And on the topic of remission. You’re monitoring their blood counts and seeing how things are going. How often do you recommend your patients’ blood be drawn and reviewed? This is in remission, so treatment has been completed.
Dr. Tim Call:
If the patient has been treated with cladribine, with or without Rituxan, they've had a good response, and counts are normal. I will generally monitor once things are in the normal range, maybe every three to four months for a year, then every six months for a number of years, often five plus. And if I see nothing then I will move them to an annual.
I tend to like to continue to see our patients because we can see trends that will alert us. So let's say we know that the monocyte low count goes low, we don't know exactly why, but it does go low when hairy cell's active.
So let's say your hemoglobin platelets and white counts are normal, but your monocyte count is going down. That's going to make me say, we may not need to do a bone marrow, do anything. But I don't want to lose track of you and then down the road you have a significant relapse. A number of my long-term patients, I just see annually, many patients I see every six months. If there's been a previous relapse then no less than every six months. With Vemurafenib based therapies, I would do it more frequently just because we don't have the long-term data.
Anna Lambertson:
Thank you. I want to make sure we spend a few minutes talking about HCL variant because we know that there are several people on today's webinar who have hairy cell variant. What is the rate of recurrence that they might expect? What does the research say and what can patients with HCL variant expect for their overall quality of life?
Dr. Tim Call:
Those are great questions. I can't be definitive on a lot of the specifics because again, we're now looking at a rare variant of a rare disease and it makes it very frustrating to have that because there aren't large series of this. We've looked and seen better response with cladribine plus rituximab. I think that the standard therapy for HCL variant would be in my mind cladribine and rituximab. I've had patients with HCL variant do very well for long periods, years, but it has a higher propensity to recur. But if it does recur, if it was a number of years, if it's five, 10, 15 years, you could go back and retreat it with cladribine and Rituxan again.
This is again where you really want to be sure you go to a center of excellence or at least have your pathology reviewed because not all hairy cell variant is hairy cell variant.
If you have a recurrence of a variant, then more and more we're looking at are there other novel therapies that could be used? They tend to be BRAF negative, so Vemurafenib is not a possibility. But now through various companies, one's Tempus, samples of bone marrow can be sent and run a panel of what's called next gen sequencing for 20, 50, several hundred markers. And sometimes we will find clues that we may use other drugs.
So if you're in that situation where hopefully you're treated and it's responding and you're doing okay, then there's nothing to do. But if you're getting into a loop where you’re treated, it's back then really escalate to try to get next gen sequencing done on the tumor to see if there's anything, look at more immune therapies in that regard.
Anna Lambertson:
I think this really underscores the need for ongoing research in hairy cell variant. We have quite a lot more to learn and we really need to look at alternate treatments for this rare subset of what is already a rare disease.
We have received half a dozen questions related to fatigue, and so if you would be so kind to speak to that a little bit. We have individuals who have completed treatment or are going through treatment and they're experiencing a lot of fatigue, ongoing tiredness. There's someone who reached out to us last week who finished their treatment four or five months ago and they just feel exhausted. Another person who reached out from another country and said that it's been a year since they've completed treatment and blood counts are good, but they just have this ongoing fatigue. What do we understand causes that and is there anything they can do to improve that to perhaps diminish this feeling of fatigue that many patients do report?
Dr. Tim Call:
Good question. First of all, when hairy cell is active, one of the biggest causes of fatigue is the fact that you have it. But also that often the hemoglobin's low. So hemoglobin, the red cells, carry oxygen and so many people present with fatigue. I would say that the majority of my patients we've treated with cladribine or Vemurafenib note improvement in their fatigue over one to three months, the majority. Now again, that's not everybody, but that's the majority. We’re giving very powerful medications which are tolerable, but they do have effects. And so I'd say the majority of people see a progressive increase in fatigue.
If I'm looking at a patient and they're having fatigue and bone pain, then I'm going to say, well we might need to consider repeating a marrow. But again, let's say we started out with 80% hairy cell and after treatment it was 0.5% and three years later or two years later you're still fatigued and it's 0.5%. Then it may be that the hairy cell is not the cause but it certainly can be the drugs themselves, everybody responds differently. There's a whole field developing of pharmacogenomics. So our genes affect how we metabolize. We have to realize it affects everyone differently.
So I think what you can do is, usually hairy cell comes on slowly, you have fatigue and most people decrease activity.
So what I would say is look at what your baseline fitness is and try to get back to that or something more. Exercise, yes. I strongly am a proponent. There are even studies in patients on hospice that the more they walk in the house, the longer they live. I’m not saying go out and jog around the block 16 times but walk around the block if you can, then maybe try twice a day.
Number two, see your doctor and say “I'm really having a lot of fatigue. What if it's something other than the hairy cell?” Get an evaluation for fatigue. So looking at is your thyroid okay? Is your vitamin B12 okay? Considering an overnight oximetry to make sure you don't have sleep apnea. I don't want to say those things to divert you from the fact that the cause could very well be the HCL treatment. But if it's getting six, 12 or more months, then I would want to make sure we're not missing something.
Anna Lambertson:
We do have a few people who have asked a question about unrelated surgery and what they as individuals who have hairy cell leukemia may need to keep in mind. So one individual may need to have teeth extracted, perhaps some teeth implants, another individual may need to have knee surgery or knee replacement. What do you generally advise your patients who have hairy cell leukemia to be aware of if they're having these surgeries that aren't related to their HCL and could there be complications caused by their HCL that their surgeon should be aware of?
Dr. Tim Call:
I would want you to talk with your physician but I would ask where are you in the hairy cell experience? Are you just recently diagnosed within a month of treatment and your neutrophils are still low? Once you have been treated and the monocytes and the neutrophils are back to good levels, then the risk of infection goes down dramatically. So I'd say if you're within three months of completing treatment and your counts look reasonably well, you probably could have surgery. On the other hand, if you're one of those people whose neutrophils are staying low, then they may want to delay elective surgery. So a tooth extraction or the knee surgery can be put off.
If you're not in the window of risk, I think you can have pretty much anything done as long as your platelets are adequate for what the surgeon wants and the neutrophils are normal or close to it.
I think the harder question is what if you have hairy cell, you're being observed, you haven't been treated yet, your platelets are a bit low - that's where it's going to take some wisdom working with your doctor.
Anna Lambertson:
There are some concerns about secondary cancers or disease. Does having Hairy Cell Leukemia mean that a patient is at high risk of having another cancer or autoimmune disease? How do you generally respond to that type of question from patients who are concerned?
Dr. Tim Call:
So the big thing is to have the Hairy Cell Leukemia under control or in remission. And yes, treatments we use now, we can sometimes see more cancers down the road. However, most of the data on secondary cancers in hairy cell and in chronic lymphocytic leukemia, which is related, are the environmentally induced cancers. So for example, with melanoma. So sun protection makes good sense. Smoking in patients who've had chemotherapy like cladribine, you may have higher chance of bladder cancer, throat cancer, lung cancer. Anything that's an environmental carcinogen, UV light or tobacco, that's really the biggest thing you can intervene. Live a healthy lifestyle and have age-appropriate screenings, like mammograms and other periodic screenings.
Anna Lambertson:
We have reached the end of our time for today's webinar.
Dr. Call, we’re grateful to you for bringing your expertise and knowledge to these presentations and discussions. And thank you to everybody who registered and joined from across the United States and beyond.
This transcript has been edited for clarity.