Low-dose
aspirin reduces death rates from range of
cancers by between 20 and 30 percent
Benefit unrelated to dose,
gender or smoking -- but increases with age
The London School of
Hygiene & Tropical Medicine (LSHTM) has
contributed to a study showing that a low
dose of aspirin reduces the occurrence of
several common cancers. The study is
published in today'sLancet.
The work was started and
carried out by Professor Peter Rothwell in
Oxford, and is based on an overview of
several randomised trials of aspirin. These
have been primarily concerned with reducing
heart attacks, but have also gathered
information on deaths from cancer.
The trial contributing
most information to the overview has been
the Thrombosis Prevention Trial (funded
jointly by the Medical Research Council and
the British Heart Foundation) which was
carried out by Tom Meade when he was with
the Medical Research Council.
Professor Meade is now
Emeritus Professor of Epidemiology in
LSHTM's Department of Non-Communicable
Disease Epidemiology.
As well as confirming that
low dose aspirin reduces large bowel cancer
cases reported in another recent study also
led by Professor Rothwell and to which
Professor Meade contributed, it also reduces
total deaths due to cancer because it
affects several common individual cancers,
such as those of the oesophagus (gullet),
lung, stomach, pancreas and possibly the
brain. Reductions in deaths are around
20-30%.
Benefit is unrelated to
aspirin dose from 75mg upwards, gender or
smoking habit but increases with age.
Aspirin may need to be taken for at least
five years before it confers benefit,
probably longer for some cancers, but
benefit is generally greater the longer
aspirin has been taken.
Hitherto, advice about
aspirin has been mainly concerned with
reducing heart attacks and strokes in those
who have already had them. Caution should be
exercised by those who are so far free of
these conditions because, unless a person's
risk of them is very high, the benefit may
be outweighed by the risk of serious
bleeding.
Professor Meade says: 'These
are very exciting and potentially important
findings. They are likely to alter clinical
and public health advice about low dose
aspirin because the balance between benefit
and bleeding has probably been altered
towards using it', although Professor Meade
adds that this does not mean everyone should
automatically take aspirin. Health
professionals and others will now have to
consider the practical implications.
