MedWire News: White women living in the UK have a higher age-standardized incidence rate of breast cancer than any other ethnic group, while Indian, Pakistani, and Black women tend to have more advanced disease at diagnosis than other ethnicities, study results demonstrate.

Differences in breast cancer survival among ethnic groups were minimal, although Black African women showed a slightly higher mortality than other groups.

“More advanced stage at diagnosis could reflect a more aggressive form of disease, later presentation because of a lack of awareness about symptoms or a mistrust of the health system, lower uptake of screening, or delays in diagnosis,” Ruth Jack (King’s College London, UK) and colleagues comment in the British Journal of Cancer.

Studies in the USA consistently show that White women have a lower incidence of breast cancer than Black women. However, Black women are less likely to receive systemic chemotherapy and hormone therapy, more likely to receive inappropriate treatment compared with national guidelines, and more likely to die from their disease.

Noting that the picture seems less clear in the UK, the researchers examined breast cancer characteristics in the Thames Cancer Registry (TCR) - an area of South East England, which is the most ethnically diverse in the country.

Searching the database, they found that among 33,024 breast cancer cases where ethnicity was recorded, White women had the highest age-standardized breast cancer incidence rates.

Using White women as the baseline group, incidence rate ratios for other groups were as follows: Indian (0.68), Pakistani (0.59), Bangladeshi (0.23), Black Caribbean (0.80), Black African (0.66) and Chinese (0.54).

After excluding patients with stage not known, Pakistani women were most likely to be diagnosed with metastatic disease (17%) followed by Black African (15%), Bangladeshi (13%), Black Caribbean (11%), Indian (11%), Chinese (10%), and White women (7%).

There were some significant differences in terms of treatment between ethnic groups; in particular, compared with Whites, Black African women were less likely to have a record of cancer surgery (63% vs 72%) and hormone therapy (32% vs 54%), and more likely to receive chemotherapy (38% vs 29%).

Differences in survival between groups were minimal although Chinese patients had a lower mortality than their White counterparts (hazard ratio [HR]=0.63) while Black African women had a higher mortality (HR=1.09)

“It is encouraging that there is little variation in survival, suggesting that some of the survival differences found in previous US studies may reflect the problems some groups have in accessing effective treatments in US healthcare systems,” Jack and colleagues conclude.

Source : Current Medicine Group