Chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia is a cancer of the blood in which mature-looking but useless B lymphocytes pile up in the bone marrow, the blood and the lymph nodes. They do not so much divide quickly as refuse to die on schedule, which is why the disease unfolds slowly, over years and sometimes decades. Hence its central paradox: the diagnosis sounds alarming, yet many people with it are given no treatment at all and are simply monitored at regular intervals. Clearing it away entirely is rarely achieved, but holding it in check with modern drugs works for a long time, and for many people life expectancy is no different from anyone else's.

What happens in the blood

Healthy B lymphocytes recognise microbes and set antibody production in motion. In this disease one altered lymphocyte begins copying itself without restraint, and its offspring fill the bone marrow, the blood, the lymph nodes and the spleen. They cannot defend anything, yet they take up room, so over time there are too few red cells, too few platelets and too few working immune cells — hence the pallor, the bruising and the repeated infections.

What causes the change is unknown. It mostly affects people over sixty, men about twice as often as women, and under the age of forty it is very rare indeed. If a close relative has had this leukaemia or another cancer of the lymphatic system, the risk is slightly above average, but by so little that no special screening is offered to the family. It is not catching, and its onset is not linked to lifestyle, diet or stress.

How it is usually found

The typical story runs like this: someone has a blood count taken before an operation, at a routine check or for something entirely unrelated, and the doctor notices a raised lymphocyte number. There are no complaints at all. Most cases surface this way, and such a chance finding is rather good news: the disease has been spotted at its quietest.

Far less often the trigger is an enlarged lymph node that the person has felt themselves. The nodes in this disease are painless, soft and mobile, they turn up in the neck, the armpits or the groin, and instead of shrinking after a cold they persist for weeks.

Signs not to put down to age

Symptoms do not appear in everyone and usually arrive later than the changes in the blood tests. It is worth raising the following with a doctor:

• enlarged painless lymph nodes lasting more than three or four weeks;
• tiredness that does not lift after a proper night's sleep and a rest;
• night sweats heavy enough to mean changing the bedding;
• weight loss without dieting;
• a temperature above 38 degrees lasting for days with no sign of a cold;
• one infection after another: chest infections that drag on, shingles, small wounds that will not close;
• bruises and bleeding gums for no reason, and pinpoint red spots on the skin;
• pallor and breathlessness on exertion that used to be comfortable;
• a feeling of heaviness or fullness under the left ribs, which is how an enlarged spleen makes itself known.

Every one of these turns up in a dozen harmless conditions, and most of the time that is exactly what is behind them. They are still worth checking, and the check starts with an ordinary blood test.

Which tests give the answer

The first step is a full blood count with a differential. In this disease the lymphocytes are persistently high, and on the film the laboratory sees characteristic cells that break as the slide is made. That alone is not enough, because lymphocytes also rise with viral infections, so the test is usually repeated a few weeks later.

The diagnosis is confirmed by flow cytometry, a test that uses the proteins on the cell surface to show that all these lymphocytes come from one and the same altered ancestor. A single tube of blood from a vein is enough. A bone marrow sample is no longer needed by everyone and is reserved for unclear pictures or for the point just before treatment starts.

The genetic features of the cancer cells are examined as well, above all faults involving the TP53 gene. This is not a formality: the choice of drugs follows directly from the result. All groups of nodes are examined and felt, the size of the liver and spleen is assessed, and the stage is set from the overall picture. Computed tomography is not done routinely for everyone.

When treatment starts and what it involves

Starting treatment earlier does not lengthen life in this disease — large trials have settled the question. So in the quiet phase the choice is watchful monitoring: a blood test and a review every few months. That approach is psychologically hard to live with, but it spares people years of needless side effects.

Treatment begins when there is a reason: haemoglobin or platelets fall, nodes or spleen grow rapidly, the lymphocyte count doubles over a short period, fever, night sweats and weight loss persist, or infections become relentless.

Modern therapy rests on targeted drugs that block the survival machinery of the cancer cell: inhibitors of Bruton's tyrosine kinase, and medicines that release the brake on programmed cell death. They are taken as tablets, often continuously or in courses of fixed length, and antibodies against the CD20 protein are added to them. Classical chemotherapy is used less now and in particular situations. Radiotherapy has a small role, for instance on one bulky node that is causing trouble; removing the spleen and bone marrow transplantation remain options for a few. There are many names and many schedules, and the choice is always individual: it depends on the genetics of the disease, on age, on the kidneys, the heart and other conditions.

Complications worth knowing about in advance

The main danger is not the cancer itself but infection, because the body stops producing effective antibodies. An ordinary cold turns into pneumonia easily, and any fever calls for a phone call to the doctor rather than a wait-and-see approach. Vaccines against flu, pneumococcus and coronavirus are recommended; live vaccines are not.

The immune system can also turn on the body's own blood cells: occasionally red cells or platelets are destroyed, which shows up as sudden pallor, a yellow tinge, dark urine or unexpected bruising. Separately, the risk of skin cancer is raised, so unprotected sunbathing and tanning beds are out, and a new mark or a scab that will not heal is a reason to be seen.

The rare but most serious complication is the transformation of a slow disease into an aggressive lymphoma. It is suspected when the general state changes abruptly: over a few weeks a single node grows fast, fever sets in, weight falls away and exhaustion takes over. That situation does not wait for a scheduled appointment — a doctor should be contacted straight away.

Online consultation

A doctor online helps exactly where time tends to be lost: going through a blood test with raised lymphocytes and explaining what it means and whether it needs repeating, setting out which investigations are genuinely required and in what order, and helping you prepare questions for the haematologist before the face-to-face visit.

The format also fits the monitoring years. You can talk unhurriedly about each new set of results, about side effects of tablets, about vaccines, travel and exercise, and work out in good time whether a new symptom belongs to the group that means calling today. Making the diagnosis, prescribing anti-cancer drugs and running the treatment are for a haematologist in person — what the consultation does is get you there prepared, and no later than you should be.

This material is for information only and does not replace medical advice.