What is Leukemia?
Leukemia means malignant disease, or cancer, of the blood-cell-producing areas in the bone marrow. When we think about cancer, it usually involves one of the organs of the body. Instead of the abnormal cells concentrated in one area, they are scattered irregularly throughout the bloodstream. But rather than the cells of the blood being the prime source, they are the aftermath. The disease commences in the manufacturing centres of the white cells. The main place is the bone marrow. There are various kinds, but most are the so-called “acute forms” in childhood, and the age between two and five years is the most probable.
There is an enormous increase in the number of white cells produced, and because of this overproduction, very young, immature cells termed blast cells are present in large numbers, and these are poured out into the general circulation. Although the cause of cancer in general is still an enigma, at least son-le of the causes of leukaemia has become well-established. It is well-known that in many animals leukaemia is transmitted by a virus, although this has not yet been proved conclusively in humans.
In humans, however, there is a distinct relationship with irradiation. Evidence has now been available for some years of the massive increase in leukaemia in victims following the atomic bomb explosions in Japan.
Patients who were treated for severe back pain (due to ankylosing spondylitis) with radiotherapy have since shown a greatly increased incidence of leukaemia in later life.
It is also well-known that pregnant women who undergo X-ray examinations give birth to children who run a higher-than-average risk of later developing leukaemia. Even prenatally the X-rays are able to disrupt the sensitive cellular mechanism later to produce severe disease. For this reason doctors are strong in advising pregnant women to defer, if possible, any form of X-ray during pregnancy.
It is known that leukaemia is more common in children with Down’s syndrome (mongolism). It is also significant that the chromosomal anomaly occurs on the same chromosome as does the Down’s syndrome aberration.
Exposure to certain chemicals, particularly benzene, may also be a cause. It seems that the disease is increasing in frequency. Figures for Great Britain showed that 722 died from it in 1949, 939 in 1957, and 1495 in 1967. No doubt improved methods of diagnosis accounted for some, but certainly not all of these increases.
There are various forms of acute leukaemia. Some affect chiefly children, others afflict adults more commonly. There seems to be a preponderance of males to females, the ratio being about three to two.
From a practical point of view the most probable combination of symptoms from the start are anaemia haemorrhage and infections. Often it starts off with symptoms similar to a child with ordinary red cell anaemia. In fact, there is often anaemia present. There may be a mild fever, weakness, pains in the bones and perhaps pains in the joints. There may be abnormal bleeding, such as from the gums, 108 nose or into the bladder. This may be the first indication that all is not right. The child may have a tendency to bruise easily. Sometimes there is an enlargement of the lymph glands in various parts of the body, or the liver or spleen (in the upper part of the abdominal cavity) may enlarge, but this is not always the case. They all vary. It seems that children with Down’s syndrome are more likely to develop the disorder. How does the doctor diagnose it? The doctor can call on many special tests. Initially the blood count will be checked, and this may show too many white cells – sometimes there are abnormally low numbers. But their shape and type is highly abnormal. It indicates that many are being formed. Often there is red cell anaemia also, and the platelets, the clotting factor, may be deficient.
In more detail, the symptoms will be a collection of these. Often when first seen the patient will be pale, quite ill and be running an elevated temperature from an underlying infection that may or may not be obvious. It may be a simple sore throat, a bout of bronchitis, tonsillitis, pleurisy or pneumonia or something else. There may be obvious bruising of the skin or mucous membranes, or frank bleeding from the gums or lower part of the intestinal system. The spleen may be enlarged, and it may be possible to feel it jutting from below the rib margin on the upper left-hand side of the abdomen. In some cases there may be enlargement of the lymph glands in the neck, under the arms and in the groin.
Blood tests and tests of bone marrow show the telltale story. There is the presence of typical leukaemic cells in profusion. As the disease advances it may infiltrate many other organs of the body. The central nervous system seems particularly vulnerable, and involvement may occur early, producing signs of meningitis and infiltration of the nerves of the head or extremities. The skin, testes, pelvic organs, kidneys, liver and intestine may also be attacked, and symptoms may occur as a result of this.
The triad of anaemia, haemorrhage and infection immediately arouses suspicion of leukaemia, and indicates that blood tests should be carried out to establish the diagnosis.
The normal white-cell count of the blood, usually between 4.0 and 11.0 thousand million cells per litre (written as 4.0 – 10.0 x 109/L), can rise dramatically to figures of 50.0 or more. Many primitive blast cells may be in evidence. However, in certain so-called leukemic forms, there may be a dramatic reduction in the white cell count to 1.0 or less. The precise type of leukemia usually depends on the nature of the white cells in greatest evidence (and so the profusion of names in this disease).
With the development of specialised units in many large hospitals, usually located in key capital cities, intensive therapy is now available. This usually encompasses powerful, relatively new drugs, and parents will soon become familiar with names such as prednisone, vincristine, mercaptopurine, methotrexate, cyclophosphamide and various others. Also, in more recent years, marrow transplants have become popular and dramatically successful. Cells taken from the bone marrow of a suitable person (ideally a twin of the patient) can often take hold and produce normal white cells. National bone marrow registers are being set up in Australia to quickly match suitable donors with patients. This will again enhance the chances of successful treatment. Collectively, this has made the outlook for the leukaemia patient much better than at any previous time in history. Now many centres claim “cures” for their youthful patients. Of course, only the future will prove if this will last a lifetime, but the current evidence seems to indicate that, in many cases, it probably will. What is the important message here? Parents must be alert to the possible symptoms of leukaemia, and report any untoward symptoms – the kind we have talked about – to the doctor immediately. Even simple recurring nosebleeds or bleeding gums warrant investigation. This can easily be arranged. If by some misfortune leukaemia is present, the sooner this is treated, the better. Becoming associated with a major centre is the ideal. Acute cases are not treated at home, and there is no place for do-it-yourself remedies. Specialised instruction and care is mandatory. Unfortunately, there are still a few misguided parents around who think that natural remedies and good food may cure their child. This is not so. Please be cautioned. We certainly condone do-it-yourself remedies whenever practical, but this disease is not one of them.
Acute lymphoblastic leukaemia responds dramatically to treatment, and instead of being a death sentence, a cure seems possible. To quote from one eminent authority: “One of the most remarkable events in malignant disease is that a complete remission is now possible in about 95 per cent of children with lymphoblastic leukaemia.” A “complete remission” means “a complete return to normal of the blood and bone marrow, no abnormal signs such as an enlarged spleen, and no evidence of the disease elsewhere.” To achieve this situation with a malignant disease certainly gives reason for optimism. This has occurred only in the past few years, and is a result of the research and aggressive approach that has recently been made in therapy.
Gaining complete remission is the start. After this, vigorous follow-up treatment is needed to retain this situation and prevent recurrences.
Various forms of drug therapy are now in wide use. These will vary in form from centre to centre, and from patient to patient. In fact, the pattern is changing rapidly.
Generally speaking, therapy entails the use of the so-called cytotoxic drugs, including vincristine and prednisone. Also in use are cytosine arabinoside, daunorubicin, asparaginase and BCNU. When remissions have taken place, other drugs are introduced to maintain the good work. Drug names such as 6-mercaptopurine, methotrexate and cyclophosphamide are well-established.
When the remission has settled down, maintenance treatment with combinations of these drugs is kept up. Marrow transplants also form an important and often successful form of treatment.
The treatment of leukaemia is in a specialised unit in a major hospital where doctors who expert in this particular specialty are in charge.
Therapy is intensive, and there is often accompanying toxicity due to medication, which is quite separate from the symptoms invoked by the disease itself. “However, the aggressive approach to the treatment of acute leukaemia is justified by the results,” one investigator says, and gives the results of Burchenal who collected the results of 157 cases of proven leukaemia of all types from around the world who were still alive after five years, and of whom 103 are free from disease five to 17 years later. Subsequent journal reports are giving progressively more satisfactory results each year.
Once, the outlook for children with acute leukaemia was less than five months. Now, with intensive combination therapy, it is more than three years, and in many cases it seems curable. Today’s aim is to cure the disease totally although this may rarely be the case, the outlook is increasingly promising.
Leukemia requires prompt attention from the doctor. The sooner a definitive diagnosis is made, the quicker modern treatment can be started and the greater is the chance of a cure or at least a greatly enhanced life span compared to yesteryear.