South Asians comprise the largest ethnic group in the UK, making up almost 3% of the population.
The research team tracked the health and survival of almost 116,000 women who had been diagnosed with primary invasive breast cancer in England and Wales between 1986 and 1990, using information supplied to the National Cancer Registry. Their progress was monitored until 1995.
The Asian women were much younger than other women when they were diagnosed with breast cancer. They averaged just under 52 compared with almost 63 for other women. And three times as many of them were younger than 40.
The annual rate of breast cancer among South Asian women was also lower: 40.5 per 100,000 compared with 57.4 per 100,000 among all other women, a difference of 29%.
Adjusted for age, over 70% of the Asian women were alive five years after diagnosis, compared with just under 67% of all other women with the disease.
Affluence is known to boost health and survival, and typically, survival rates were around 9% higher among the most affluent groups for all women. But even among the poor and disadvantaged, survival rates were still between 3% and 8% higher in Asian women.
The authors note that the differences in survival were not accounted for by differences in how advanced the disease was at diagnosis.
Journal of Epidemiology and Community Health