Chronic lymphocytic leukemia (CLL) is a form of cancer that affects the blood — specifically a type of white blood cells called lymphocytes — and bone marrow. CLL is the most common leukemia in adults. Being diagnosed with chronic lymphocytic leukemia can come as a shock, since many people are symptom-free when they learn they have the disease. The good news is that CLL has a survival rate that is higher than many other cancers.

While it’s true that there is no known cure for CLL yet, many cases are very slow to spread. If you are diagnosed with a more aggressive form of the disease, there is also much hope, as every year brings newer, more effective treatments that can extend both the quality and quantity of life.

• CLL Definition
• CLL Symptoms and Causes
• CLL Risk Factors
• CLL Diagnosis and Treatment
• CLL Stages and Survival

CLL Definition

What Is the Definition of Chronic Lymphocytic Leukemia?

Chronic lymphocytic leukemia, or CLL for short, is a type of cancer that affects the blood and bone marrow. This disease is called “chronic” because it is slow-growing, and “lymphocytic” because it affects a group of white blood cells known as lymphocytes. CLL occurs mainly in older patients and is the most common form of leukemia in adults.

CLL Symptoms and Causes

What Are the Symptoms of Chronic Lymphocytic Leukemia?

The four major symptoms of CLL are night sweats, fevers and chills, weight loss, and general fatigue. These are called the B symptoms and they are also commonly associated with Hodgkin lymphoma and non-Hodgkin lymphoma. CLL symptoms may also include bone pain, easy bruising and bleeding, swelling of lymph nodes under your arms or in your neck or groin, and swelling of your abdomen.

This may sound frightening at first, but don’t panic. Not all of these symptoms occur in all cases. It’s also important to remember that for many patients, CLL symptoms won’t appear until several years after an initial diagnosis.

What Is the Cause of Chronic Lymphocytic Leukemia?

The exact cause of CLL is unknown, but scientific advances are helping researchers develop a fuller understanding of the disease. Currently, CLL is most typically tied to mutations in chromosomes 11, 13, and 17. The good news is, being able to identify specific mutations like a 17p deletion, can help your hematologist-oncologist decide which CLL treatment is right for you.

CLL Risk Factors

What Are the Risk Factors for Chronic Lymphocytic Leukemia?

While it’s true that you can prevent some types of cancer by avoiding certain risk factors, unfortunately, experts don’t know of many risk factors associated with CLL yet. According to the Mayo Clinic, these factors may increase the risk of CLL:

• Age: Most people diagnosed with CLL are age 70 or older. Risk increases with age.
• Race: If you are white, you are more likely to develop CLL, but the reasons for this are unclear.
• Family History: If one of your immediate family members (parent, sibling, child) has developed CLL or another type of blood cancer, you may be at increased risk.
• Exposure to chemicals: Some studies have linked herbicides and insecticides to an increased risk of CLL, but more research is needed.

Gender has also been noted as a potential risk factor for CLL. More men than women are diagnosed with the disease, but the reasons for this are unknown.

Once researchers identify the cause of CLL, reliable prevention techniques may soon follow.

CLL Diagnosis and Treatment

How Is Chronic Lymphocytic Leukemia Diagnosed?

While there is, unfortunately, no early screening process for CLL, there are a number of accurate testing methods for the disease. And while CLL is sometimes found incidentally, during unrelated lab work or procedures, this is what a routine diagnosis might look like.

• Physical Exam: First, your doctor is likely to administer a physical exam, paying special attention to prominent lymph nodes and checking your abdomen for swelling. He or she will also likely ask about family medical history, pre-existing conditions and your overall health.
• Blood Tests: If you are displaying symptoms of CLL, your doctor should order blood tests to give you a definitive diagnosis. The two main blood tests for CLL include a complete blood count (CBC), in which the levels of lymphocytes will be a main focus (as elevated numbers is a likely sign of CLL), and flow cytometry, which uses markers to determine whether or not the lymphocytes in the sample cells contain CLL.
• Bone Marrow Biopsy: While a CBC with flow cytometry of your blood is the main diagnostic test for CLL, a bone marrow biopsy may be required for some patients. During the biopsy, a small amount of bone marrow tissue will be withdrawn with a needle, most likely from your hip. While you may briefly feel some pain, a local anesthetic is commonly used to make patients more comfortable. The sample will then be examined to determine if the CLL is in your bone marrow.
• Lymph Node Biopsy: Although not always required, your physician may ask you to undergo a lymph node biopsy. During this procedure, a surgeon or an interventional radiologist will take either the entire lymph node or a piece of the lymph node for further evaluation.

If you’ve been diagnosed with CLL, your doctor will likely recommend additional tests to diagnose and determine the presence of genetic mutations. These follow-up tests are important—knowing your CLL subtype can help you and your medical team decide which treatment is right for you.

I’ve Been Diagnosed with Chronic Lymphocytic Leukemia, What Now?

The first thing you should do is take a deep breath. Receiving a cancer diagnosis can be intimidating and you have a right to be concerned, but there are also many promising treatment options for CLL and, very likely, many long years ahead.

Ask your doctor how to proceed. If possible, consult a specialist. With telemedicine, you may even be able to speak to a leukemia specialist from the comfort of your own home. For a large number of asymptomatic patients, treatment may not be necessary for several months or even years, as this disease is generally slow-moving. If your doctor believes proceeding with treatment right away is the best course for you, there are a number of options to consider.

What Is the Treatment for CLL?

Because CLL grows slowly, you may not need treatment right away. But if you do, several methods available, with more on the way in clinical trials.

Common first-line treatments for CLL include chemotherapy, monoclonal antibodies and targeted therapies. A treatment plan for many CLL patients may include both chemotherapy and monoclonal antibodies, which assist your immune system in fighting the cancer cells.

The advantage of targeted therapy drugs is that unlike chemotherapy, which attacks all rapidly growing cells, targeted therapy drugs like ibrutinib (Imbruvica), acalabrutinib (Calquence) and venetoclax (Venclexta) are designed to target proteins specific to CLL that make them different from normal cells.

Many patients go into long remissions while others may need to progress to more aggressive therapies like a stem cell transplant or CAR T-cell therapy. Talk to your doctor and to a CLL specialist to get the care that’s right for you.

When Will My Doctor Know it’s the Right Time to Treat?

Usually, treatment is not initiated until there are certain indications to treat. In general, your oncologist will wait until the CLL leads to significant symptoms, lower blood counts, large lymph nodes, or a large spleen. There have been numerous studies that show treating earlier is not always better.

What Is Watch and Wait for Chronic Lymphocytic Leukemia?

Watch and wait refers to the period after you’ve received a CLL diagnosis but before treatment starts. Due to the nature of CLL, some patients take years to display symptoms following an initial diagnosis.

Some patients feel uneasy or anxious in this watch-and-wait phase, knowing they have cancer but are not receiving immediate treatment. Try not to worry. To date, no evidence shows that delaying treatment until symptoms appear has a negative impact on patient outcomes. Many CLL patients enjoy happy and productive years without symptoms or treatment.

Is There Anything I Can Do About My CLL During This Period?

While no intervention is needed during this time, doctors typically recommend that patients be cautious in regards to infections. CLL makes patients more prone to infectious diseases. Frequent hand-washing and limiting exposure to friends and family who are ill may be beneficial.

Also, make sure to speak to your physician about immunizations. While live vaccines are not typically recommended for CLL patients, recombinant or dead vaccines like the flu and pneumococcal vaccines are strongly recommended.

For information about CLL and COVID-19, read our Coronavirus & Cancer FAQs.

CLL Stages and Survival

What Are the Stages of CLL?

Oncologists are moving away from staging CLL because genetic markers are more useful and provide better prognostic data. However, there are two staging systems for CLL. The Rai System is usually used in the United States, and the Binet System is commonly used in Europe.

The Rai staging system is based on blood counts and the results of a physical examination, taking into account whether or not your spleen and lymph nodes are enlarged. Using this information, the system has five stages (0-IV) to classify risk.

• Stage 0 is considered low risk.
• Stages I and II are considered intermediate risk.
• Stages III and IV are considered high risk.

The Binet System stages CLL based off of the number of affected lymph node groups and whether or not you have anemia (low red blood cell count) or thrombocytopenia (low blood platelet count). It’s broken down into three stages: A, B, and C.

• Stage A has less than three areas of enlarged lymphoid tissue, no anemia and no thrombocytopenia
• Stage B has three or more areas of enlarged lymphoid tissue, no anemia, and no thrombocytopenia
• Stage C patients have anemia and/or thrombocytopenia regardless of lymphadenopathy

What Is the Survival Rate of Chronic Lymphocytic Leukemia?

The five-year survival rate of CLL for patients older than 20 is a robust 85%, according to statistics published by the American Cancer Society in January 2020. Additionally, the American Journal of Managed Care lists an estimated median survival rate at 10 years. Many patients live with CLL for decades and stay active and have a good quality of life.

While much of this may be overwhelming or frightening, take solace in the fact that you likely have many years ahead of you.