• Chronic lymphocytic leukemia (CLL) is a common form of leukemia in adults that often does not cause any symptoms until it becomes advanced.
• Your doctor may recommend starting treatment right away or taking a watch-and-wait approach.
• The prognosis (outlook) for CLL depends on many factors, but most people live for at least five more years after diagnosis.

Chronic lymphocytic leukemia is a type of blood cancer that most commonly affects older adults. In early stages, CLL may not cause any symptoms or require any treatment. However, as it progresses, you may begin to feel sick and need to treat your CLL.

How Does CLL Develop?

CLL develops in the lymphocytes, which are white blood cells that help the body fight infection. Lymphocytes and other blood cells are produced in the bone marrow. In people with CLL, mutations (changes) develop in lymphocytes, causing them to become abnormal and grow very quickly. As CLL progresses, leukemia cells crowd out the normal blood cells in the bone marrow and begin causing symptoms. CLL cells may also collect in the spleen, lymph nodes, and other organs.

Prevalence of CLL

More than 20,000 people will be diagnosed with CLL this year in the United States. CLL diagnoses represent more than one-third of leukemia cases in adults, making it the most common type of leukemia in this age group.

CLL can affect B lymphocytes (B cells) or T lymphocytes (T cells). According to Cancer.Net, around 95 percent of people with CLL have B-cell CLL, which develops from B lymphocytes.

Signs and Symptoms of CLL

Often, CLL does not cause symptoms until the disease becomes more advanced. Many people discover they have CLL only after routine exams or blood tests come back with unusual results. There are several possible signs and symptoms of chronic lymphocytic leukemia:

• Low levels of red blood cells (known as anemia) can lead to fatigue, dizziness, and shortness of breath.
• Low white blood cell counts can increase the risk of infections.
• Low levels of platelets, blood cell fragments needed for proper clotting, can cause bleeding problems and easy bruising.
• An enlarged spleen may lead to pain or feelings of fullness in the upper left abdomen.
• An enlarged liver can cause symptoms including fatigue, abdominal pain, nausea, and vomiting.
• Swollen lymph nodes may appear as lumps in the neck, armpit, or groin.
• Symptoms known collectively as B symptoms may include fever, chills, night sweats, weight loss, and tiredness.

Other, more common health conditions also cause these symptoms. If you notice any symptoms that could be signs of CLL, talk to your doctor.

Diagnosis of Chronic Lymphocytic Leukemia

Doctors will often first suspect a person has leukemia after reviewing the results of their routine blood work. An evaluation for the diagnosis will always include collecting your health and symptom history and performing a physical exam, in which a doctor checks for any signs of disease.

Several tests can be helpful when diagnosing CLL. Blood samples can be used for tests like a complete blood count, which measures the levels of different types of blood cells.

The main steps for a CLL diagnosis are the following:

• Test results showing a high B lymphocyte count for at least three months
• Analysis of the proteins found on the surface of the leukemia cells
• Examination of blood cells under a microscope

Chronic Lymphocytic Leukemia vs. Small Lymphocytic Lymphoma

Doctors consider CLL to be the same disease as small lymphocytic lymphoma (SLL). Both conditions lead to high levels of abnormal lymphocytes and are generally treated the same way. If leukemia cells are mostly found in the blood and bone marrow, the person is diagnosed with CLL. If most of the cancer cells are located in the lymphatic system, the diagnosis is SLL.

Additional Testing for CLL Diagnosis and Staging

Blood tests can also be used to determine the levels of proteins like lactate dehydrogenase and beta-2 microglobulin. High levels of these proteins in the blood may be a sign of cancer.

Occasionally, doctors use bone marrow tests to diagnose CLL. A bone marrow biopsy entails removing a small sample of cells, and a bone marrow aspiration involves taking tissue from inside the bone. Bone marrow tests are not always necessary for diagnosing CLL.

A health care professional may further study cells from blood or bone marrow samples in a lab to learn more about what genes or proteins they contain. This information can help a doctor tell the difference between the various types of leukemia and estimate prognosis.

If a person is diagnosed with CLL, they may need to undergo imaging tests to determine whether the leukemia is contained within the blood and bone marrow or has spread to other organs.

CLL Stages

Doctors use leukemia staging information to predict a person’s outlook and determine which treatments may be most helpful. There are a couple of CLL staging systems. Doctors in the U.S. generally use the Rai system, while European doctors use the Binet system. Both systems are based on factors like:

• Lymphocyte count
• Levels of red blood cells and platelets
• Any liver or spleen enlargement
• Any enlarged lymph nodes

Treatment of CLL

Treatments can often keep CLL under control for a long time. When recommending a treatment plan for chronic lymphocytic leukemia, your doctor will take into account factors including your:

• Age
• Overall health
• Personal preferences
• Subtype and stage of CLL

Watch and Wait

CLL is a slow-growing leukemia, and some people don’t need to start treatment right away. People with early-stage CLL who use a watch-and-wait approach have regular follow-up visits with their doctor to monitor their leukemia. If a person begins to develop symptoms or tests show that CLL is getting worse, doctors may recommend starting treatment.

Medications for CLL

Chronic lymphocytic leukemia treatment often includes multiple drugs. Chemotherapies block cancer cells from growing and dividing, which causes those cells to die. Targeted therapy medications, including monoclonal antibodies and kinase inhibitors, block specific genes or proteins that cancer cells rely on to survive. This helps slow down disease progression. Targeted therapies may be less likely to cause treatment side effects.

In many cases, multiple medications are given together to treat CLL. Some treatment options include:

• Targeted therapy drugs such as ibrutinib (Imbruvica), acalabrutinib (Calquence), venetoclax (Venclexta), and obinutuzumab (Gazyva), alone or in different combinations
• The combination treatment called FCR, which includes two chemotherapy drugs, fludarabine (Fludara) and cyclophosphamide (Cytoxan), and the targeted therapy drug rituximab (Rituxan)
• The steroid drug prednisone along with rituximab

If CLL relapses (comes back) soon after being treated, doctors may recommend switching to different medications.

Bone Marrow Transplant

People with CLL who are younger, don’t have other major health issues or risk factors, and have had a relapse or refractory disease (doesn’t respond to treatment) may be able to undergo allogeneic bone marrow transplant. During this procedure, a person is given high-dose chemotherapy. This aggressive treatment kills leukemia cells along with cells that produce new blood cells. Following chemotherapy, the person receives new progenitor blood cells from a donor. Those cells divide and make healthy blood cells for the person who received the transplant.

Other Treatment Options

Doctors sometimes recommend other procedures to treat specific CLL symptoms. Among them is radiation therapy, used to treat enlarged lymph nodes. Additionally, if a person with CLL has an enlarged spleen, their doctor may recommend surgically removing it. People with CLL may also be able to access new treatment options by participating in oncology clinical trials.

Prognosis for Chronic Lymphocytic Leukemia

In general, about 88 percent of people with CLL will live for five years or more after being diagnosed. However, your doctor can better estimate your individual CLL prognosis by considering your personal characteristics. Factors that may lead to a worse prognosis include:

• Older age
• Certain gene changes within leukemia cells
• High levels of cells that contain the protein ZAP-70 or CD38
• High levels of beta-2 microglobulin in the blood
• Lymphocytes that grow quickly
• High numbers of immature white blood cells (in some cases)

When estimating your outlook, your doctor may consider a system called the CLL International Prognostic Index (CLL-IPI). This system takes into account specific gene mutations, CLL stage, and age. Your doctor can use the CLL-IPI to give you a risk score that provides information about survival rate and treatment. If you have a low risk score, you’re likely to have a better outcome and may not need any treatment. If you’re in a high-risk group, you may have a worse prognosis and your doctor may recommend more aggressive treatment.

Feeling Your Best With CLL

Whatever type or stage of CLL you have and wherever you are in your treatment journey, there are steps you can take at home every day to feel your best and improve your quality of life. Your overall health is an important factor that your oncologist will consider when recommending treatment options. The better your health is in general, the more treatment options you are likely to have.

Talk With Others Who Understand

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