Hairy cell leukemia

What is hairy cell leukemia?

Hairy cell leukemia (HZL or HCL of “hairy cell leukemia”) is a chronic cancer. Patients degenerate certain white blood cells (B lymphocytes) and start to multiply uncontrollably.

Despite the name “leukemia”, HZL is not one of the blood cancer diseases (leukemia), but of the lymph node cancer diseases (malignant lymphoma). In fact, hairy cell leukemia is attributed to non-Hodgkin’s lymphoma, as is Chronic Lymphocytic Leukemia (CLL) among others.

Note: Physicians distinguish the classic hairy cell leukemia and the hairy cell leukemia variant (HZL-V). The latter is much rarer, but runs more aggressive.

Causes and frequency of HZL

The causes of hairy cell leukemia are unknown. Experts suggest that insect repellents (insecticides) and pesticides (herbicides) may favor the development of this form of cancer. People who work in the agricultural sector, namely, have an increased risk of disease.

Hairy cell leukemia is rare: every year, only three out of every one million people get it. Most of them are men: they are three to four times more likely to be affected by hairy cell leukemia than women. The mean age of onset is between 50 and 55 years. It can also meet younger or older adults. Hairy cell leukemia does not occur in children.

Hairy cell leukemia: symptoms

Hairy cell leukemia is a chronic cancer that usually progresses slowly. For the first time, most sufferers notice little of their illness for a long time. Gradually, however, the cancer cells (“hair cells”) in most patients displace the healthy blood cells, ie the normal white and red blood cells as well as the platelets. In about 70 percent of all patients with hairy cell leukemia, the number of all three types of blood cells is below their respective lower limits. Doctors then speak of one pancytopenia.

It triggers different symptoms: The lack of red blood cells causes a anemia (Anemia). Typical signs are weakness, fatigue, reduced load capacity and pale skin, The lack of functional white blood cells weakens the immune system: the patients are prone to infections, The deficiency of platelets increases the Bleeding tendencyFor example, gum or nose bleeding is easy. Also bruises (bruises) are easier to form.

Typical of hairy cell leukemia is – in addition to the lack of healthy blood cells – also one enlarged spleen (Splenomegaly). Sometimes she gets in the way Pressure in the left upper abdomen noticeable.

Rarer signs Hairy cell leukemia is an enlarged liver and swollen lymph nodes. Also rare are the three so-called B symptoms: fever over 38 degrees Celsius, weight loss and night sweats. This symptom trio is common in cancer and various infectious diseases.

Hairy cell leukemia: examinations and diagnosis

In patients who have the symptoms described above, the doctor will first check the To raise medical history (Anamnese). He gives a detailed account of the symptoms, asks about possible pre- or underlying diseases and whether the patient was exposed to any toxic substances (such as insecticides).

This is followed by a thorough physical examination, Among other things, the doctor, whether the lymph nodes (such as in the neck region or under the armpits) are swollen. He also scans the abdominal wall to check if the spleen is enlarged. More precisely, this can be done with a ultrasound of the abdomen.

However, a reliable diagnosis of hairy cell leukemia is only through blood tests possible. In most cases, the degenerate B cells can be detected with their “hairy” appearance. The blood analyzes also help distinguish between the two subtypes of hairy cell leukemia:

Most patients have the Classic hairy cell leukemia, It is characterized among other things by the fact that the number of lymphocytes (a form of the white blood cells) and the platelets is usually reduced. In the rare Hairy cell leukemia variant it looks different: Here, the lymphocytes are significantly increased. The measured values ​​for the platelets are usually normal.

Also important in hairy cell leukemia is one Examination of the bone marrow: The doctor takes a sample of the bone marrow (bone marrow puncture) and can be accurately analyzed in the laboratory.

Hairy Cell Leukemia: Treatment

As long as a hairy cell leukemia does not cause discomfort and the number of healthy blood cells is not diminished, it is said: Wait and watch, At this stage of the disease no therapy is necessary. Instead, the doctor will regularly check the patient’s blood (at least every three months).

When the readings of blood cells fall and / or symptoms develop, patients should be treated. Most will be one chemotherapy Patients receive certain anticancer drugs (cytostatics) that inhibit the proliferation of cancer cells. For hairy cell leukemia, the active ingredients are cladribine (2-chlorodeoxyadenosine, 2-CDA) and pentostatin (deoxycoformicin, DCF). They are among the so-called purine analogs.

In certain cases, other treatment options come into question:

An example is the active ingredient Interferon-alpha, It inhibits the proliferation of cancer cells and activates defense cells of the immune system. The drug has to be injected under the skin several times a week, often for years. Interferon-alpha, for example, is used to treat patients who, for some reason, are not allowed to receive purine analogues for chemotherapy. Even with a cancer relapse, the drug can be helpful if chemotherapy does not help.

Another therapy option for hairy cell leukemia is an immunotherapy with so-called monoclonal antibodies (such as rituximab), These are artificially produced antibodies that can affect the immune system of the body: they bind specifically to the cancer cells and thus signal the immune cells of the immune system to destroy the degenerate cell. Rituximab is administered directly into a vein every one to two weeks. It may be prescribed for hairy cell leukemia if a patient is not allowed to receive or tolerate purine analogues (chemotherapy) and interferon-alpha for medical reasons.

Sometimes hair cell leukemia may also make sense in combining chemotherapy (with purine analogues) and immunotherapy (with rituximab). Doctors then speak of one chemoimmunotherapy.

In almost all patients with classic hairy cell leukemia, the cancer cells have a specific genetic mutation. It is called BRAF V600E designated. Then so-called BRAF inhibitors help against the cancer. However, the use of these drugs needs to be further investigated, for example, when it comes to the optimal dosage and duration of therapy. However, they are sometimes used when other therapies (chemotherapy, interferon-alpha, moboclonal antibodies), for example, may not be used or are not tolerated.

Hairy cell leukemia variant

The very rare hair cell leukemia variant (HZL-V) does not respond well to chemotherapy with purine analogues. Also interferon-alpha is not very effective. For example, chemoimmunotherapy (chemotherapy with purine analogs plus rituximab) is more suitable. If it comes to a short-term relapse, the patient can Spleen removed become (splenectomy). This can improve the blood levels of cancer patients. The surgery may also be useful if a patient is not allowed to receive chemotherapy with purine analogues for medical reasons.

Hairy Cell Leukemia: Prognosis

The prognosis for classic hairy cell leukemia is generally good. Most patients respond well to the treatment of chronic disease. For example, many sufferers can continue to pursue their profession. In addition, one can expect a normal life expectancy, if the therapy works well.

The prognosis for the hair cell leukemia variant (HZL-V) is less favorable. It runs more aggressively than the chronic-creeping classic Hairy cell leukemia, The usual treatment does not work so well with the HZL-V. This can shorten the survival time of those affected.