Income and Race Linked to Breast Cancer Survival
Lower-income women appear less likely to survive breast cancer than their more-affluent counterparts, and later diagnosis may largely explain why, a new study from the online journal BMC Cancer suggests.
Using data on more than 100,000 U.S. women diagnosed with breast cancer between 1998 and 2002, Dr. Xue Qin Yu, a researcher at the Cancer Council New South Wales in Kings Cross Australia, found that those living in the most economically depressed areas were almost one-third more likely to die by the end of 2005.
When other factors were weighed, the timing of a woman's diagnosis seemed to explain much of the income gap. 13% of lower-income women were more likely to be diagnosed at a later stage, after the cancer had spread beyond the breast, compared to less than 10% for those women in the higher-income areas.
Lower rates of recommended treatments were also a factor. The study found that women in poorer areas were less likely to receive radiation as a part of their first course of treatment. 48% of low-income women received radiation therapy versus 55 to 58% of the more affluent women. Radiation is typically recommended to destroy any remaining cancer cells after a breast tumor, or the breast itself, has been surgically removed. Lack of insurance, poorer overall health, treatment refusal, or doctor bias could all play a factor, according to Dr. Yu.
Race also seems to contribute to the connection between socioeconomics and breast cancer survival. Previous studies have shown that black women die of breast cancer at a higher rate than white women. The American Cancer Society reports that out of 100,000 women in the United States, 33.5 black women will die of breast cancer, versus 24.4 white women and 15.8 Hispanic women. In the Australian study, just under 80% of black women were alive one year after diagnosis, versus approximately 90% of women of other races.
Much of the racial gap appeared to be explained by the differences in diagnosis and treatment, but biological factors also play a role. A study published by the Journal of the National Cancer Institute this year indicated that black women die of breast cancer at a higher rate even when they see the same doctors and receive the same treatments. In addition, African-American women have a higher incidence of more aggressive disease, such as triple negative breast cancer.
Sources Include: BMC Cancer, the American Cancer Society, and The National Cancer Institute