Leukaemia literally means 'white blood'
and that is when there are too many white blood cells in the circulation.
This can be caused by overproduction of white blood cells in the bone marrow,
or by cells not being properly processed in terms of maturing normally in that environment.
The main types of leukaemia are either chronic,
which can develop slowly over months and years, or acute leukaemia which can develop in a
few days. The acute leukaemias tend to involve, for
example acute lymphoplastic leukaemia in younger children, and older adults will tend to develop
acute myeloid leukaemia. Chronic leukaemias mainly occur in adults, and the commonest
type is chronic lymphocytic leukaemia, which may not require any treatment whatsoever.
Different leukaemias require different treatments, some chronic leukaemias do not require any
treatment, and are simply observed over years and may never require any treatment.
Other treatments include tablets, and some of these tablets now are targeted to certain abnormal
genes in the leukaemia cells, and many patients will stay on these tablets lifelong, but with
minimal or no side effects and are effectively cured with the use of a tablet.
Other types of tablets involve the use of oral chemotherapy, which can be used for some
chronic types of leukaemia. The acute leukaemias tend to need more intensive treatment, and
this usually involves treatment in the hospital with intravenous chemotherapy which is intensive
and often will require regular antibiotic therapy and transfusions.
Some patients will also need a stem cell transplant. Stem cells are the cells in the bone marrow
that make all the other cells, and stem cell transplantation can allow for a higher cure
rate in some of the aggressive types of the leukaemia.
Stem cells are used to allow us to give higher doses of treatment for patients with leukaemia and lymphoma.
This allows a higher cure rate. Stem cells can be obtained either from the
patient themselves, or from a tissue type match donor. In general, using the patients
own stem cells is called autologous stem cell transplantation, and is mainly used for patients
with lymphoma, or multiple myeloma. For patients with leukaemia, we tend to use donor stem
cells, the source of stem cells can either be a brother or sister. There is a roughly
one in four chance of any brother or sister being a tissue match with the patient.
If the sibling is not a match then we can find alternative donors from either unrelated donor volunteer
banks, and there are now over 25 million people worldwide who are potential donors on those banks.
More recently we have been using half-matched family members, so that would mean that any
parent, or any child of a patient would be half a match, and therefore we're much more
likely to find donors for almost every patient we look for nowadays.
The donor needs to be a tissue match with the patient, and therefore routine blood tests
are done to confirm they are a match. The donor will need to have a routine medical,
a bit like an insurance medical, to make sure they are fit to be a donor.
Historically, we have tended to collect stem cells from the bone marrow where they are
in a steady state, but in more recent years we've tended to collect stem cells from the
blood, which is a much easier procedure. Bone marrow collection involves the use of
a general anaesthetic and usually a stay in the hospital, whereas collecting stem cells
from the blood can be done by giving the donor a blood hormone which moves the stem cells
from the bone marrow into the blood, and therefore the stem cells can then be collected from
the blood, and that's usually done on a single morning as an outpatient.
Collecting stem cells from a donor is very safe, and usually involves no long-term side-effects.