Researchers from the London School of Hygiene & Tropical Medicine found that survival was lower for women in the UK despite them being diagnosed at the same time as those in Australia, Canada, Denmark, Sweden and Norway. They are now calling for an investigation into whether the treatment of women with late-stage breast cancer in the UK meets international standards.
The study included 257,362 women diagnosed with breast cancer during 2000-7 and recorded in cancer registries in six countries.
The proportion of women in the UK surviving at least three years after being diagnosed with late-stage breast cancer (TNM*** Stages III and IV) was 87-89% in the UK and Denmark, and 91-94% in the other four countries.
For women with the most advanced cancers (TNM Stage IV), one-year survival ranged from 53% in the UK to 67% in Sweden. The proportion of women in the UK surviving at least three years after being diagnosed ranged from 28% in the UK to 42% in Sweden.
Dr Sarah Walters, lead author from the Cancer Research UK Cancer Survival Group at the London School of Hygiene & Tropical Medicine, said: “What is special about this study is that routinely-collected data from cancer registries enabled us to monitor international trends and differences in breast cancer survival for all women with breast cancer, not just the small and selected groups of women usually included in clinical trials.
“The reasons for low overall survival in the UK and Denmark are different. In Denmark, women are diagnosed with more advanced disease, but survival at each stage is similar to that in other countries. In the UK, women are diagnosed at a similar stage as elsewhere, but survival is lower than women with the same stage of disease in other countries.
“The roll-out of national mammography screening will be expected to improve overall survival in Denmark. In the UK, we should now investigate whether the treatment of women with later-stage breast cancer meets international standards. There is particular concern that this is not the case, especially for older women.”
International differences in survival were also wider for older women. Three-year survival was 96% in Sweden and 92% in the UK for women aged 50-69 years, but for women aged 70 years or more, survival in Sweden was 91% compared to 79% in the UK.
These findings suggest that older women with breast cancer and women with more advanced disease may be treated less aggressively in the UK than in the other five countries.
Sara Hiom, Cancer Research UK’s director of early diagnosis, said: “International comparisons like this are vital in helping us better understand what is influencing cancer survival. We’re beginning to see some important clues now, but while we’re closing the survival gap for breast cancer, UK women continue to fare worse than in these other countries.”
The study, led by the Cancer Research UK Cancer Survival Group at the London School of Hygiene & Tropical Medicine, was conducted for the International Cancer Benchmarking Partnership and funded by the Department of Health.
- S Walters, C Maringe, J Butler, B Rachet, P Barrett-Lee, J Bergh, J Boyages, P Christiansen, M Lee, F Warnberg, C Allemani, G Engholm, T Fornander, M L Gjerstorff, T B Johannesen, G Lawrence, C E McGahan, R Middleton, J Steward, E Tracey, D Turner, M A Richards, M P Coleman and The ICBP Module 1 Working Group. Breast cancer survival and stage at diagnosis in Australia, Canada, Denmark, Norway, Sweden and the UK, 2000-2007: a population-based study. British Journal of Cancer. doi: 10.1038/bjc.2013.6
Image: Mammogram. Credit: ©iStock.com/photovideostock