The United Kingdom saw an unprecedented fall in the death rate from breast cancer during the 1990s, a new analysis finds. Researchers believe the improvement is due mainly to better treatment, especially the widespread use of the drug tamoxifen.
“This is the first time that improvements in the treatment of any type of cancer have ever produced such a rapid fall in national death rates,” said Sir Richard Peto, professor of medical statistics at the University of Oxford. Peto last week presented the results of an overview of 300 treatment trials, involving some 200000 women worldwide, to the second European breast cancer conference in Brussels.
Until the late 1980s, death rates from breast cancer climbed steadily in many Western European countries, although not in the United States. The reasons for the increase in Europe were unclear, said Peto, although later childbearing, earlier menarche, and other hormonal influences were probably important. But since 1990, the death rate from breast cancer has fallen in the UK by about 30% overall. The United States has also seen a decline, and other European countries are beginning to follow suit.
The use of adjuvant treatments after surgery—tamoxifen, chemotherapy, and well-targeted radiotherapy—can account for much of the improvement in Britain, says Peto, together with earlier diagnosis of the disease through screening. Tamoxifen may particularly help to explain Britain's lead because British doctors adopted its widespread use in around 1985, earlier than in the United States or other European countries.
As treatment is still improving in Britain and elsewhere, death rates are expected to continue to fall, Peto said. 