B1: Breast cancer relative survival
RATIONALE: Breast cancer is the most frequent female cancer in the Western world. This pathology has a good prognosis after modern preventive strategies and novel therapies have been introduced. Today, 80% of women with a diagnosis of breast cancer are alive at 5 years.
Breast cancer patients undergo hospitalization for diagnostic purposes, surgery and or medical therapy. The therapeutic scheme is internationally standardized.
Risk factors for breast cancer are still not well known; family history, reproductive history, environmental exposure to chemical agents are associated with breast cancer risk.
Five years survival after breast cancer diagnosis is a good indicator of early diagnosis because of appropriate screening procedures, of the quality and efficiency of the health structure providing care, and of the quality of the surgical/medical treatment after hospital admission.
Important: It is very difficult to date back cancer onset. It depends on the timeliness of specialist examinations patients do. A good proxy, even if not free from distortion, is represented by the date of first diagnosis.Unfortunately, nowadays it is not possible to date back first cancer diagnosis from administrative data. Thus, survival 5 years after breast cancer diagnosis is possible only in those areas where ad hoc cancer registers are available.
Moreover, because survival rate after cancer diagnosis depends largely on care and treatment after diagnosis, not necessarily supplied from a single trust, comparisons are allowed only between macro-geographical areas.
NUMERATOR: The observed five year survival rate of patients diagnosed with breast cancer.
DENOMINATOR: The expected survival rate among a population with the same age structure.
STATISTICAL METHODS: Breast cancer death rates may vary between organizations because of many factors, such as demographics (age, body mass index), concomitant pathologies, stage, histology, family history for the same or a different tumour, genetic diagnosis of a high risk family, and therapy. Standardization or stratification is highly recommended to account for at least those aspects of case mix which can be certainly identified.
HOW TO USE THIS INDICATOR:
- for comparative evaluation between populations resident in different areas or of different socio-economic status;
- for analysis of trend over time;
- for evaluation of new preventive techniques (i.e.: mammography).
- Gilligan MA, Neuner J, Zhang X, Sparapani R, Laud PW, Nattinger AB. Relationship between number of breast cancer operations performed and 5-year survival after treatment for early-stage breast cancer. Am J Public Health 2007 Mar;97(3):539-44.
- Gort M, Broekhuis M, Otter R, Klazinga NS. Improvement of best practice in early breast cancer: actionable surgeon and hospital factors. Breast Cancer Res Treat 2007 Apr;102(2):219-26.
- NHS. Performance Indicators. July 2000
- OECD. Statistics, Data and Indicators. Health Data 2004. Available from: http://www.oecd.org/topicstatsportal