Lower breast cancer incidence seen in Asian American women may be caused by a lower screening mammography rate in this group, according to a study of nearly 8,000 women published April 27 in the Journal of Surgical Research.
Researchers led by Dr. Ashwini Paranjpe from the University of Miami in Florida found that Asian Americans were less likely to have had a mammogram within the past two years than Caucasian women after controlling for education, insurance, family income, marital status, and country of birth. This, in turn, could be creating misleading incidence rate numbers.
"This was surprising in that, while the disparities among African American versus white women is well-known, and often underpinned by socioeconomic factors, this was a new finding for us," said corresponding author Dr. Anees Chagpar from Yale University to AuntMinnie.com.
Racial disparities exist in breast cancer screening, with minority ethnic groups generally facing disadvantages compared to Caucasian women. counterparts. But Asian American women have a lower breast cancer incidence rate, the reasons for which have been explored by researchers. Genetics and sociodemographic factors have been suggested, but other research suggests that lower screening rates may be a bigger factor, which can produce misleading results.
"If Asians had a disproportionately lower rate of mammography use, their low incidence rate may not be something to celebrate," the study authors wrote. "Rather, this may be a call to educate women in this population so as to improve early detection rates."
Paranjpe and colleagues wanted to find out whether breast cancer screening practices were different between Asian American and non-Hispanic white women in a national population-based study.
The team looked at data from 7,990 women over 40 years old. Out of the total, 6.12% were Asian American and 93.88% were non-Hispanic white, which the authors wrote represented 3,258,610 Asian and 50,016,810 non-Hispanic white women in the U.S., respectively.
After controlling for sociodemographic factors, the researchers found that Asian women were significantly less likely to report having a mammogram within the past two years compared with Caucasian women, with an odds ratio of 0.68 (p = 0.047).
Paranjpe et al found that the rates of having a mammogram within the last two years were not significantly different between Caucasian and Asian American women (74.46% vs. 71.49%, respectively). This also goes for the proportion of mammograms that were done for routine screening versus those performed due to a problem. Similar proportions of Caucasian and Asian women reported having their last mammogram because their doctor recommended it.
The researchers also found that Caucasian women were significantly more likely to report that they were informed they had dense breast tissue on a mammogram than Asian American women (25.38% vs. 17.74%, respectively). However, no significant differences were found between the two groups when it came to the rate at which they were advised more follow-up tests.
Follow-up MRIs were more frequent in non-Hispanic white women, at 14.18% compared with 6.08% seen in Asian American women (p = 0.048). But the researchers found no significant differences between the two groups after controlling for sociodemographic variables that vary between the two populations.
The study authors wrote that there are several barriers to screening mammography among Asian women. These include a lack of knowledge about screening guidelines, lower perceived risk, superstitions, cultural modesty, and language barriers among others.
Chagpar said that a team effort is needed from family physicians to ObGyns to radiologists to encourage Asian women to get screened through outreach and education.
"We are continuing to look at disparities among various racial and ethnic groups, and across various axes of care beyond screening mammography," Chagpar told AuntMinnie.com. "There is certainly a lot more work that could be done, particularly in the Asian population, to discern why these disparities exist, and what can be done to mitigate them."
