Pioneering Spanish provinces in terms of early prevention of breast cancer, such as Navarre and the Basque Country, record lower death rates, although the trend is towards the figures levelling out all over Spain. These are the results of a study carried out by Spanish researchers, which analyses the number of women who died between 1975 and 2005.
“The Canary Islands, Balearic Islands, some parts of Catalonia, Valencia and Murcia, as well as the south west region, have higher breast cancer death rates, although there is a trend towards the geographical differences disappearing”, Marina Pollán, one of the authors of the article published recently in the Annals of Epidemiology and head of the Cancer Epidemiology Department at the Carlos III Health Institute, tells SINC.
The research, which uses data gathered by the National Statistics Institute (INE) from 1975 to 2005 in all the Spanish provinces (except Ceuta and Melilla), divides patients into three age groups — those under 45, those between 45 and 64, and those over 65.
The results show that, until 1992, the death rate in women under 45 was higher in the Mediterranean and south west regions than in other parts of the country. From that year onwards, the deaths started to fall, although mortality rates are still “somewhat higher” in the south west.
A similar trend was seen among patients aged between 45 and 65, with the highest death rates being recorded in the north, the Mediterranean region, and the south west until 1995. Deaths among women aged over 65 were most significant in the north eastern provinces, the centre, south west and the northern part of the Mediterranean region, with this trend decreasing over the course of the study period.
The gradual disappearance of these geographical differences is due to “the uniform distribution of early prevention programmes, reproductive therapy, obesity and other factors relating to lifestyle over recent years”, the authors stress.
The importance of early prevention
The study, carried out by scientists from the Carlos III Health Institute and the Public University of Navarre, suggests that, aside from the progress achieved in breast cancer treatment, early prevention programmes play a fundamental role in reducing mortality.
This has been the case in Navarre and the Basque Country, which started these kinds of programmes in 1990 and 1995, respectively, and had them up and running within a little more than a year. These initiatives could explain why these two regions are leaders in the decline in breast cancer mortality among women aged over 65.
The research also looks into delayed mortality among patients. Although deaths from this kind of cancer are on the fall, this reduction is lower among older age groups.
“As there is now a greater probability of surviving breast cancer for many years, the mortality rate among older women includes not only those cases with a worse prognosis in women who were diagnosed over the age of 65, but also deaths among patients who were diagnosed when they were younger and who managed to survive for longer”, explains Pollán.
María D.Ugarte, Tomás Goicoa, Jaione Etxeberria, Ana F. Militino y María Pollán. “Age-Specific Spatio-Temporal Patterns of Female Breast Cancer Mortality in Spain (1975-2005)”. Annals of Epidemiology. Vol. 20, No. 12. Diciembre 2010. Doi:10.1016/j.annepidem.2010.07.102