Late-stage breast cancer survival 'lower in UK'
Women with late-stage breast cancer have lower survival rates in the UK than five other high-income countries, including Sweden and Canada, suggests a study in the British Journal of Cancer.
In the UK, 28% of women with the most advanced cancers survived for three years, compared with 42% in Sweden.
Researchers looked at more than 250,000 women diagnosed between 2000 and 2007.
Cancer Research UK questioned whether women were receiving the best treatment.
The study, carried out by the International Cancer Benchmarking Partnership, investigated whether international differences in survival could be explained by delays in diagnosis.
Led by researchers at the London School of Hygiene and Tropical Medicine, the study analysed data on women from Australia, Canada, Denmark, Norway and Sweden up to three years after diagnosis.
For all stages of breast cancer, the study found that three-year survival was 87-89% in the UK and Denmark, and 91-94% in the other four countries.
One-year survival varied less, from 94.3% in the UK to 98.4% in Sweden.
But for women with the most advanced breast cancers, one-year survival ranged from 53% in the UK to 67% in Sweden - and there was still a 14% difference between the UK and Sweden in three-year survival for those with late-stage breast cancer.
In the UK, similar proportions of women were diagnosed in the early stages as in most of the other countries. One year after diagnosis, survival for women with early-stage breast cancer was close to 100% in all six countries.
It was only for women with late-stage breast cancer that survival percentages were lower in the UK.
This suggests that lower overall breast cancer survival in the UK is not because women are being diagnosed at a later stage than in other countries, the study says.
In Denmark, only 30% of women with breast cancer were diagnosed at an early stage, compared with 42-45% elsewhere.
This suggests that low overall breast cancer survival in Denmark - the only country that had not fully implemented a national breast screening programme before 2007 - was due to women being diagnosed at a later stage of disease.
Generally, women eligible for screening (typically 50-69-year-olds) are diagnosed at an earlier stage than younger and older women.
The UK also had the highest proportion of women with missing information about their stage at diagnosis.
The study also found that international differences in survival were also wider for older women.
Three-year survival was 4% higher in Sweden (96%) than in the UK (92%) for women aged 50-69, but for women aged 70 years or more, the difference was 12% (Sweden 91% compared with 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.
Dr Sarah Walters, lead author from the Cancer Research UK Cancer Survival Group at the London School of Hygiene and Tropical Medicine, said the reasons for low overall survival in the UK and Denmark were different and needed different solutions.
"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."
Sara Hiom, Cancer Research UK's director of early diagnosis, said international comparisons were useful in helping to understand what was 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.
"We know that UK women diagnosed with breast cancer are not routinely given CT scans to check if the disease has spread, which could mean we aren't always accurately staging more advanced disease.
But we also need to investigate the possibility that fewer women with later stage breast cancer in the UK receive the best treatment for their circumstances."
Eluned Hughes, head of public health at Breakthrough Breast Cancer, said: "If breast cancer survival rates matched the best in Europe, 1,000 extra lives would be saved in England alone, so work to bridge the gap is crucial."