SIR: It is perhaps ironic that the animal rights activists have used the recent sad death of Linda McCartney from cancer to write letters attacking the use of animals in medical research.

We all know that Linda McCartney was a campaigner for animals. However, perhaps not everyone realises that major medical advances in cancer treatment have depended on the use of animals in research. Thus several cancers - including skin cancer, cancer of the uterus, testicular cancer and Hodgkin's disease - are now treated successfully by a combination of surgery, radiotherapy, chemotherapy and bone marrow transplantation. And eight out of 10 children now survive the commonest childhood cancer, acute lymphoid leukaemia, compared with just one in 10 only 30 years ago.

Animals will be essential if we want to continue to make progress in beating cancer and other serious illnesses. The recent discovery of two substances that shrink tumours in mice - with no side effects and no build-up of resistance - is a good example. While we cannot yet be sure that these substances will work the same way in people, there is no doubt that we would not even have the prospect of this promising treatment without the studies using mice. And if the treatments don't live up to their early promise, valuable information will still have been added to the store of knowledge about cancer and its treatment.

While animals are still needed in medical research, we must make sure that they are looked after properly, used in minimum numbers and only when there is no alternative. These restrictions are in fact already laid down in the UK controls on animal research.

?Barbara Davies

Deputy Director, RDS

Understanding Animal Research in Medicine

58 Great Marlborough Street, London?

Converted for the new archive on 14 July 2000. Some images and formatting may have been lost in the conversion.