‘It’s A Marathon, Not A Sprint’: Understanding How Chronic Lymphocytic Leukemia Grows

CLL develops as abnormal lymphocytes build up in the blood, bone marrow, lymph nodes, and sometimes the spleen. When patients understand how CLL develops, they often feel more comfortable with their treatment plan or “active surveillance” approach.

“I usually start by teaching the patient about what the bone marrow is,” Dr. Gary Schiller, director of the Hematologic Malignancy Stem Cell Transplant Program at UCLA’s David Geffen School of Medicine, tells SurvivorNet.

“I tell them that the bone marrow is one of the largest organs in the body stretching from the skull to the upper arms and upper legs and all the bones in between the pelvis, the vertebra, the ribs, the skull … I tell them that the job of the bone marrow is to manufacture blood cells,” he adds.

How and Why CLL Emerges

Early on, many people feel completely well, and CLL may be discovered simply because a routine blood test shows a higher-than-normal lymphocyte count. Over time, the number of CLL cells may increase, lymph nodes or the spleen may become enlarged, or the bone marrow may have less room to make healthy blood cells.

CLL begins in long‑lived “memory” B cells, the lymphocytes that remember past infections.

As Dr. Schiller explains, B cells are made in the bone marrow, trained in the lymph nodes, and some become antibody‑producing cells after exposure to bacteria or other foreign substances.

Others stay dormant, retaining a memory of that exposure — and it’s these long‑lived memory cells that are most prone to transforming into CLL.

Importantly, a high white blood cell count by itself does not necessarily mean treatment is needed. Doctors look at the whole picture and, most importantly, whether the disease is showing meaningful progression or causing problems.

If all seems stable, doctors may recommend a “watch and wait” approach, which involves monitoring the disease, rather than actively treating it.

‘Watch and Wait’: Monitoring CLL

Your doctor may track how quickly your lymphocyte count is rising, sometimes looking at the lymphocyte doubling time, or how long it takes for the lymphocyte count to double.

A rapidly rising count can be a sign that CLL is becoming more active.

Doctors also monitor for:

• Progressively enlarged lymph nodes or spleen
• Worsening anemia or low platelets
• Symptoms such as significant fatigue, fevers, drenching night sweats, or unintentional weight loss

This is why regular visits and blood tests are important. The trend over time can tell your care team much more than any single blood test.

This “watch and wait” approach is still an active strategy that allows your care team to watch for meaningful changes and begin treatment when there is a clear reason to do so. Studies have not shown a survival benefit from routinely treating early, asymptomatic CLL compared with careful observation.

‘A Marathon,’ Not a Sprint

Dr. Schiller urges his patients to think of CLL as more of a marathon, not a sprint. Careful long-term planning is key.

The goal is to understand its pace, recognize when that pace changes, and use treatment when it is most likely to help you.

“If you have slowly growing weeds that really over many, many, many years may replace your nicely manicured grass, you will have a different approach than you might if you had a weed on the lawn that rapidly — in the course of one season — displaced everything on the lawn,” Dr. Schiller explains.

With slow-growing CLL, it’s best to watch, monitor, and “carefully and judiciously” consider when treatment, and the side effects that come with treatment, are truly necessary.

Questions To Ask Your Doctor

• How and how often will my CLL be monitored?
• What signs and symptoms should I look out for at home?
• What are my options if/when symptoms do appear?
• Should I make any adjustments to my diet, activity level, etc.?

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