Several factors must have a role in improved figures
BMJ 1996; 312 doi: https://doi.org/10.1136/bmj.312.7031.640 (Published 09 March 1996) Cite this as: BMJ 1996;312:640
- Andrew Carnon,
- David Hole,
- Charles Gillis,
- David Brewster
- MRC research fellow Principal epidemiologist Director West of Scotland Cancer Surveillance Unit, Ruchill Hospital, Glasgow G20 9NB
- Director of cancer registration Information Services Division, NHS in Scotland, Edinburgh EH5 3SQ
EDITOR,—Mike Quinn and Elizabeth Allen's suggestion that better treatment in breast cancer has led to a fall in mortality from 1990 onwards is interesting.1 As the authors imply, the widespread use of tamoxifen can be only part of the explanation.
A more direct way of looking at the outcome of changes in treatment is to analyse trends in survival. Survival rates among 34107 women with breast cancer diagnosed between 1968 and 1987 have been calculated from data from the Scottish cancer registries.2 Figure 1 shows the five year relative survival rates for women aged between 35 and 74 with breast cancer diagnosed during four quinquennial periods before the introduction of the United Kingdom's national breast screening programme. Survival increased monotonically from 1968-72 to 1983-7 in each age group. The increase in five year relative survival between 1968-72 and 1983-7 was larger in the age groups under 55 (11% and 9% for women aged 35-44 and 45-54 respectively) than in the older age groups (9% and 6% for women aged 55-64 and 65-74 respectively).
Five year relative survival rates by year of diagnosis
While use of tamoxifen since the early 1980s could partly explain recent improvements in survival in postmenopausal women, it could not account for the large increase in survival in the youngest age group, which is unlikely to have been prescribed tamoxifen.3 This implies that treatment factors other than the use of tamoxifen must have a role. These are likely to include more effective and widespread use of chemotherapy and radiotherapy, the emergence of multidisciplinary breast cancer teams, and increasing specialisation of breast cancer surgeons.