Leukemia (CLL)

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This in-depth overview shares everything people who've been diagnosed with chronic lymphocytic leukemia (CLL) need to know, complete with insights and advice from leading medical experts.

Chronic Lymphoctic Leukemia (CLL) Overview

Chronic lymphocytic leukemia (CLL) is a type of cancer that starts in bone marrow, the spongy tissue in the center of your bones where new blood cells are made. CLL affects the immature blood cells that give rise to white blood cells called lymphocytes, which help your body fight infections.

Scientists don’t know exactly what causes CLL. A genetic change in white blood cells causes them to become abnormal and to divide faster than usual. These abnormal cells crowd out healthy cells. Eventually, so many of the cancer cells are produced that they start to spread to other organs.

What doctors know and still need to learn about CLL, from leukemia specialist Dr. Nicole Lamanna

Fortunately, researchers have learned a lot about CLL over the years. What they’ve learned has helped them develop new and more targeted treatments that work better against this cancer, and that can now extend survival for people who are diagnosed.


What Increases Your Risk for CLL?

Risk factors are things that make you more likely to develop CLL. Having these risks doesn’t mean you will definitely get this type of cancer–only that you are slightly more likely to be diagnosed.

Your risk for CLL may be higher if you:

  • Are over age 50. CLL is most common in older adults. About 9 out of 10 people with this cancer are older than 50. Yet it is possible to be diagnosed at other ages.
  • You’re Caucasian. White people are more likely to develop CLL than are people of other races.
  • You have other family members with CLL. Having a sibling, parent, or other close relative who’s been diagnosed with a blood and bone marrow cancer might increase your risk.
  • You’ve been exposed to certain chemicals. Some herbicides and pesticides (for example, Agent Orange used during the Vietnam War) can make you more likely to develop this cancer.

What Are the Symptoms of CLL?

It’s uncommon for people with CLL to have symptoms early in the disease, according to SurvivorNet’s experts. They say someone can live with CLL and feel perfectly fine.


People often have no symptoms of CLL until their disease has progressed, says Dr. Matthew Davids, Associate Director of the Dana-Farber CLL Center

After you’ve had this cancer for awhile, you may notice symptoms like:

  • Swollen lymph nodes
  • Tiredness
  • Fever
  • Pain in the upper left part of your belly
  • Night sweats
  • Weight loss
  • Frequent infections

If you have any of these symptoms, it doesn’t necessarily mean that you have CLL. But it’s worth talking to your doctor if they’re out of the norm for you.

Getting a Diagnosis

Your doctor has several ways to diagnose CLL, including blood tests, genetic tests, bone marrow tests, and imaging tests.

  • Blood tests. A blood test checks the number of cells and cell types in your blood, to look for any abnormalities that could signal CLL. Your doctor might also check for increased amounts of certain proteins or enzymes in your blood.
  • Flow cytometry. This test looks for certain markers that help identify cancer cells in a sample of blood or bone marrow.
  • Bone marrow tests. These tests use a small sample of fluid or tissue that your doctor removes from your bone marrow during a biopsy. The samples are examined in a lab to see if they have the size, shape, and other characteristics of cancer.
  • Genetic tests. Tests such as fluorescence in situ hybridization (FISH) analyze the genetic material inside the leukemia cells to look for abnormalities. This gives doctors a better sense of how to move forward with treatment.


SurvivorNet expert, medical oncologist Dr. Julie Vose, discusses the importance of genetic testing following a CLL diagnosis

You may need additional tests, including x-rays and imaging scans, if there’s a possibility that the cancer has spread to other parts of your body. If your doctor is concerned that leukemia cells might have reached your brain or spinal cord, you may get a spinal tap, which analyzes a small sample of fluid from around the spinal cord.

Which Treatment is Right for You?

Unlike other cancers, CLL is a chronic disease that people can live with for many years. Your doctor will find the most appropriate treatment for you based on the type of symptoms you have, and whether your cancer is growing slowly or is more aggressive.

In the early stages of CLL, treatment might not be necessary. Your doctor may do something called watchful waiting. This doesn’t mean that your doctor will ignore you, but that you’ll get regular check-ups to see if your symptoms get worse or your cancer has spread.


Dr. Nicole Lamanna, on how your doctor will monitor you after your diagnosis

Once it is time to start treatment, your doctor will help you choose from these options:

  • Radiation therapy uses high-energy x-rays to stop cancer cells from growing.
  • Chemotherapy uses powerful drugs to stop cancer cells all over your body from dividing.
  • Targeted therapy is a group of treatments that blocks proteins and other substances the cancer needs to grow.
  • Immunotherapy such as CAR T- cell therapy amplifies your own immune system’s response to help it locate and fight the cancer.
  • Bone marrow (stem cell) transplant is a way for your doctor to give you very high doses of chemotherapy. Chemo damages immature blood cells, called stem cells, in your bone marrow. After you get chemotherapy drugs, you’ll receive healthy stem cells from yourself or a donor to replace the ones treatment damaged.

These are the standard treatments for CLL, but they’re not the only ones. BTK inhibitors are a pill you take every day to reduce the chance of the cancer coming back. Another is venetoclax (Venclexta), which comes in a pill. This is typically combined with another type of drug called a monoclonal antibody, to keep people with this cancer in remission. You’ll need to stay on these drugs long-term to keep your cancer from returning.


New treatments are keeping people with CLL in remission longer, says Dr. Julie Vose

If you’ve tried a number of therapies and they stopped working for you, or if you want to add on another treatment to boost the effectiveness, your doctor might recommend that you enroll in a clinical trial.

Dr. Matthew Davids, on how clinical trials are helping doctors discover new and more effective CLL treatments 

Clinical trials test out new, and possibly more effective treatments for cancers like CLL. Enrolling in one of these trials could give you access to a state-of-the-art drug before it’s available to everyone else.

CLL is a long-term disease. That means you’ll probably stay in close touch with your oncologist for many years to come. Your doctor will do regular check-ups to monitor for any delayed side effects of your treatment, and to see if your cancer has come back. Going to every scheduled appointment can help ensure that if your cancer does return, you can get on treatment quickly to stop it.