1. Clonal hematopoiesis isn’t cancer. But it can progress to become cancer.

Clonal hematopoiesis can be further categorized into two main types:

clonal hematopoiesis of indeterminate potential (CHIP)
clonal cytopenia of undetermined significance (CCUS)

The distinction between the types is that patients with CCUS also experience a drop in their blood counts, known as cytopenia.

Both are considered precursor conditions to a cancer type known as myelodysplastic syndromes (MDS), which can advance to acute myeloid leukemia (AML).

Clonal hematopoiesis can also put you at risk for several chronic health conditions, such as atherosclerotic cardiovascular disease.

However, the definition of clonal hematopoiesis is still being debated in the field. The only way to distinguish CCUS and CHIP from leukemia is with a bone marrow biopsy. A pathologist must look at your bone marrow cells under a microscope to determine if there is abnormal growth or any concern for leukemia.

2. Clonal hematopoiesis is often found when diagnosing another cancer.

In cancer centers like MD Anderson, clonal hematopoiesis is frequently discovered when a patient is undergoing a genetic workup for a solid tumor diagnosis. For example, a patient will receive a lung biopsy, and that tissue will be compared with a blood draw to confirm the mutations found in the lung tissue weren’t introduced during the biopsy or surgery. The blood serves as a control for comparison, and it’s often how we learn a patient has mutations in their bone marrow, leading to a CCUS or CHIP diagnosis.

3. Some gene mutations are linked to a higher risk of clonal hematopoiesis advancing to leukemia.

We use a scoring system called the Clonal Hematopoiesis Risk Score to help determine whether a patient is at low, intermediate or high risk of having their diagnosis progress to leukemia. The scoring system considers several things, including the patient’s:

Age,
blood laboratory values and
the type and number of gene mutations.

We focus on mutations in the myeloid genes associated with MDS and AML, including TP53, FLT3, JAK2, RUNX1, IDH1/2, as well as the splicing factor genes of SRSF2 and SF3B1. These mutations can put a patient at higher risk of seeing their diagnosis progress to leukemia.

There is also a subset of clonal hematopoiesis associated with mutations in the lymphoid cells. These mutations can lead to other blood cancers like chronic lymphocytic leukemia, but less is known about them at this time.

Also, if a patient has a primary tumor and has received treatment such as chemotherapy, radiation therapy or a targeted therapy, it increases the risk of the disease progressing.

4. There isn’t a treatment for clonal hematopoiesis.

Currently, there isn’t a treatment for CCUS approved by the Food and Drug Administration (FDA), so patients are monitored for signs of progression. When we first see patients, we test their gene mutation levels so we have a baseline to track if there is an increase in the number of mutated cells and if new mutations arise. Gene mutations can be tested through a blood draw or a bone marrow biopsy.

If I see a patient’s blood counts drop, we go digging to see why. But typically, patients with CHIP have their blood count checked every six months to a year. Patients with CCUS or patients who have scored as at high risk for progression will have their blood count checked every three months.

Keep in mind that the increase of mutated cells or the number of mutations does not necessarily mean the condition has progressed to cancer. A pathologist must examine the bone marrow biopsy to confirm a cancer diagnosis, so if you have high-risk gene mutations, you should receive a bone marrow biopsy every year.

5. MD Anderson is conducting clinical trials to find treatments.

At MD Anderson, we’re investigating treatment approaches for high-risk patients through clinical trials.

I’m leading two clinical trials in clonal hematopoiesis, one investigating an oral targeted therapy called olutasidenib in patients with CCUS. It’s an IDH1 inhibitor, so the hope is that it prevents cells with the IDH1 mutation from reproducing. The other clinical trial is exploring an oral low-dose chemotherapy for high-risk patients with CCUS. My colleague Guillermo Garcia-Manero, M.D., is leading two other clinical trials exploring whether the cause of the drop in blood counts in CCUS patients is related to inflammation in the body and if these patients benefit from the anti-inflammatory drugs canakinumab and DFV890.

It’s important to keep in mind that we’re still early in our understanding of this condition. The first paper on clonal hematopoiesis was published about a decade ago, but statistically, by age 60, 10% of the world will have clonal hematopoiesis. With each decade, the percentage of people affected by the diagnosis increases 1by 0%, so there is a need to learn more for our patients.

If you or a loved one has been diagnosed with clonal hematopoiesis, make sure you seek treatment at a cancer center like MD Anderson that is leading research and clinical trials. This is the only way to ensure you get treatment and the only way to help advance our understanding so we can find new treatment options.

Request an appointment at MD Anderson online or call 1-877-632-6789.