Acute lymphoblastic leukaemia

Bone marrow releases billions of new cells into the blood every day. In acute lymphoblastic leukaemia one branch of that production line breaks loose: immature forerunners of lymphocytes multiply without stopping and pack the marrow from the inside, leaving no room for normal blood-making. That is why the illness is shaped less by what has appeared in excess than by what has suddenly run short.

What goes wrong inside the marrow

A lymphocyte has a long path to maturity. The fault happens right at the start: the cell picks up damage in its genes, sticks on an early rung and never grows up. What it does keep is the ability to divide, and divide it does, endlessly.

These cells are called blasts. They cannot fight infection, but they take up room. Within a few weeks they crowd out the lines that make red cells, platelets and healthy white cells, then spill into the blood and settle in the liver, spleen and lymph nodes, sometimes in the linings of the brain and in the testicles.

The word "acute" describes pace, not severity: from the first vague complaints to the full picture takes weeks rather than years.

How it first shows itself

Early on it all looks like a cold that will not clear or plain exhaustion, and that is what misleads people most.

• weakness that rest does not fix, breathlessness on an ordinary walk, pallor: red cells are short;
• bruises from the lightest knock, pinpoint red spots on the shins, bleeding gums, nosebleeds that drag on: platelets are short;
• fever with no obvious cause, one infection after another, slow recovery: almost no healthy white cells are left;
• dull pain in the bones of the arms and legs; in a child this often looks like a limp with no injury, refusing to walk, asking to be carried;
• painless lumps in the neck, armpits and groin, and a heavy feeling under the left ribs;
• appetite and weight falling away, night sweats.

Any one of these turns up in dozens of harmless conditions. What should raise concern is several at once, and the fact that over two or three weeks things get worse rather than better.

Signs that cannot wait

Some situations are more dangerous to sit on than the disease itself. Call emergency services instead of waiting for an appointment if:

• the face, neck and arms swell, veins stand out on the neck and chest and lying flat makes breathing hard: enlarged nodes in the chest can press on a large vein;
• the temperature goes above 38 °C in someone already on chemotherapy: fever with a low white cell count is an emergency and antibiotics are needed within hours;
• bleeding will not stop: a nosebleed lasting over twenty minutes, bleeding gums, blood in the urine, black tarry stools;
• sudden severe headache with vomiting, confusion, seizures or double vision;
• breathlessness at rest, chest pain, grey or bluish skin.

If none of that applies but tiredness, bruising and a low fever have gone on for weeks, see a doctor this week rather than next month. A plain blood count with a differential answers most of the question.

Who tends to get it

It is a rare disease, and in most cases no cause can be named: the fault arises by chance as a cell divides, not from diet, lifestyle or anyone's oversight. Parents of an affected child deserve to hear that plainly — there was no way to prevent it. Only a few circumstances are known to raise the odds above usual:

• age: the peak is in children of two to five, with a second rise after fifty;
• Down syndrome and some other inherited genetic conditions;
• chemotherapy or radiotherapy given earlier for another tumour;
• heavy irradiation, of the kind an accident causes, not an ordinary X-ray;
• long occupational contact with benzene;
• deeply suppressed immunity.

Leukaemia is not catching and is not inherited in the everyday sense: one case in a family almost never puts the others at risk.

What the tests show

The starting point is a full blood count. Any combination can be telling: low haemoglobin, few platelets, an odd white cell number and, above all, blasts on the film, which have no business being in the blood at all.

Only a marrow examination confirms the diagnosis. A needle draws a little liquid marrow from the pelvic crest, under local anaesthetic in adults and brief sedation in children. Almost everyone feels a pull at the moment of sampling and carries a bruise for a few days.

The sample is then studied several ways at once: under the microscope, by the proteins on the cell surface, and by chromosomes and genes. This is not over-caution — the fault that turns up decides the regimen directly. Spinal fluid is taken separately by lumbar puncture, because blasts hide well in the linings of the brain, where drugs penetrate poorly. The full picture takes a week or two, but treatment starts before all of it is in.

What treatment involves

This is not a short course but a two to three year programme in stages. The first is the most intensive and happens as an inpatient: corticosteroids combined with several chemotherapy drugs, aimed at clearing blasts from the marrow and restoring normal blood-making.

Consolidation courses follow, and after them a long maintenance phase on tablets, largely at home with regular blood checks. Throughout, drugs are repeatedly given into the spinal canal so the disease cannot return by way of the nervous system.

In certain genetic subtypes targeted drugs that block that specific fault, or immunotherapy, are added. A marrow transplant is not discussed with everyone, only with those at high risk of relapse or those who have already relapsed.

In children the results are among the best in cancer medicine. In adults the outlook is more modest and depends heavily on the genetics of the disease, but here too the aim is cure rather than containment.

Getting through the months of treatment

The gaps between courses cost more than the courses themselves: while the marrow rebuilds, a person is defenceless against infection.

• take your temperature daily and keep your unit's number to hand;
• careful dental care and a soft brush: the mouth is a doorway for infection;
• stay away from anyone in the acute phase of an infection, particularly chickenpox or measles;
• live vaccines are off limits during treatment; the schedule is reviewed with the haematologist, for household members too;
• raise sperm or egg storage before therapy begins, because afterwards it is too late;
• clear any new product first, including over-the-counter and herbal ones.

Tiredness, nausea, hair loss and mouth ulcers are unpleasant but manageable: for almost every side effect something can be done. There is no need to keep quiet about them or wait for the next scheduled visit.

Online consultation

A remote appointment is a place to go through blood results and work out which test comes next. The doctor can explain the regimen you have been given, help with side effects, help you shape the questions for your haematologist, and tell you what genuinely needs urgent face-to-face assessment. Marrow sampling, transfusions and drug administration are always done in person.

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