Disabilities Affect Breast Cancer Treatment

BOSTON, Nov. 7 -- For reasons that are not clear, women with disabilities who develop breast cancer are less likely to be given optimum treatment.

A retrospective database analysis found that women on disability insurance and Medicare at the time of a breast cancer diagnosis were twice as likely to die of any cause as other breast cancer patients, according to Ellen McCarthy, Ph.D., of Beth Israel Deaconess Medical Center and Harvard Medical School.

Also, they were 30% more likely to die of their cancer, Dr. McCarthy and colleagues reported in the Nov. 7 issue of Annals of Internal Medicine.

"Because clinical trials typically exclude this population, there is little scientific evidence available to guide doctors in their treatment decisions," Dr. McCarthy said. "Consequently, very little is known about cancer treatment for individuals with disabilities."

One thing that is known, she and colleagues noted, is that "many women with traits that can suggest a social disadvantage -- including older age, race or ethnicity, low socioeconomic status (income or education), rural residence and lack of health insurance -- do not receive breast-conserving surgery."

The same was true among women with disabilities. The researchers found that 43.2% of women with disabilities were offered breast-conserving surgery, compared with 49.2% of other patients.

The findings remerged from an analysis of information from 11 Surveillance, Epidemiology, and End Results (SEER) databases, involving 100,311 women who were diagnosed with breast cancer from 1988 to 1999.

Women who qualified for Social Security disability insurance and Medicare at the time of diagnosis were considered disabled, Dr. McCarthy and colleagues said.

The analysis found:

• Disabled women were 20% less likely to be offering breast-conserving surgery. The odds ratio was 0.80, with a 95% confidence interval from 0.76 to 0.84.
• Those who were offered breast-conserving therapy were less likely to get radiotherapy (the odds ratio was 0.83, with a 95% confidence interval from 0.77 to 0.90) or axillary lymph node dissection (the odds ratio was 0.81, with a 95% confidence interval from 0.74 to 0.90).
• Those with disabilities had a hazard ratio for all-cause death of 2.02, with a 95% confidence interval from 1.88 to 2.16.
• And the hazard ratio for cancer mortality was 1.31, with a 95% confidence interval from 1.18 to 1.45.

The lack of radiation therapy is particularly worrying, Dr. McCarthy said. "This means that they are at higher risk that their cancer will come back and they could potentially experience greater rates of cancer-related morbidity," she added.

"Because this is such a large study, we hope it will serve as a starting point for understanding what is happening [among disabled populations] when it comes to cancer treatment," Dr. McCarthy said. "These findings tell us that there are indeed differences in treatment decisions, but do not tell us the reasons for these differences."

Indeed, the reasons for the differences are probably "multi-factorial," said co-author Lisa Iezzoni, M.D., also of Harvard Medical School. For instance, for some women, their disabilities may create a greater risk of death, she said.

Physicians may also assume that physical appearance is less important to women with disabilities, and therefore may be less likely to offer breast-conserving therapy, rather than mastectomy, she said.

"And logistical issues could also be playing a role," Dr. Iezzoni said. "The women with disabilities may, for example, be unable to arrange for daily transportation to and from radiation therapy treatments."