Collaborative Group on Observational Studies of Breast Cancer Survivors (COBS)
COBS Collaborators: login here
COBS Study Protocol (PDF)
COBS Data Sheet (PDF) - revised 27 July 2007; minor revision for clarification purposes
More than a million breast cancer survivors from all five continents
Breast cancer is the commonest cancer in women worldwide. In the last few decades, the number of women being diagnosed with the disease has increased while breast cancer mortality rates have decreased in most countries. This reduction in mortality is largely due to improved treatment, and to earlier diagnosis, eg through screening. As a result of these changes the number of breast cancer survivors is now increasing rapidly and in the US alone there are more than two million breast cancer survivors.
Despite the recent success in reducing breast cancer mortality rates, some breast cancer treatments have side-effects that may be severe or even fatal. Trials of radiotherapy for early breast cancer provide some information regarding the nature and characteristics of these side-effects (EBCTCG), but the relatively small number of women included, the limited length of follow-up, and the limited amount of information collected about each woman in most trials leaves many questions unanswered. Some of these questions can be answered by observational studies of breast cancer survivors, as these allow larger numbers of women to be studied and also allow a longer period of follow-up.
The aim of this collaboration, which is sponsored jointly by CTSU and the International Association of Cancer Registries, is to bring together information from cancer registries and elsewhere on the long-term side effects of treatment in breast cancer survivors.
The initial objective of the collaboration is to improve understanding of the side-effects that may occur following radiotherapy for breast cancer. Radiotherapy has been shown to reduce the risk of death from breast cancer for many categories of patient. However, the treatment often involves some unwanted irradiation of other tissues, particularly the heart and lungs. This can lead to an increased risk of several diseases and also of death from causes other than breast cancer. In the past, these risks have sometimes been large enough to reduce substantially the beneficial effect of the radiotherapy on survival. (EBCTCG). Better knowledge about the side-effects that can occur following breast cancer radiotherapy should facilitate the development of treatment guidelines, not only for breast cancer, but also for several other cancers.
The initial meeting of the collaborators took place in Oxford in January 2007.
If you have data that might be relevant to this project, or you would like further information about it, please contact us.
Contact details:
Fax: +44 (0)1865 743982
Tel: +44 (0)1865 743501
Email: cobs@ctsu.ox.ac.uk
Website: www.ctsu.ox.ac.uk/projects/cobs
