It was found, in an analysis conducted by Dr. Liana Castel of the University of North Carolina at Chapel Hill and colleagues, that non-whites experience poorer pain control among women with this disease.
Studies done showed that chronic or recurrent pain affects 30 percent of all cancer patients and 60 to 90 percent of patients with advanced cancer.
Pain can be caused by age, race, tumour type, genetics, psychosocial context, and culture. However, it is unclear how pain is influenced by changes over the course of disease due to factors including radiation, surgery, and chemotherapy.
The current study was among the first to examine whether race plays a role in patients' experiences in pain over the course of metastatic cancer.
Dr. Castel and co-investigators studied 1,124 women with metastatic breast cancer and bone metastases who received standard treatment in an international chemotherapy clinical trial conducted from October 1998 to January 2001.
The study comprised women in 19 countries; the majority (82%) of non-whites were from the US. A test called the Brief Pain Inventory—which is based on a scale of zero to ten in pain severity—was administered repeatedly over a year to determine pain levels.
The authors found that non-white women reached a pain level of seven or higher on the Brief Pain Inventory scale significantly earlier during a year of follow-up, compared with white women.
A score of 7 or higher on the scale commonly designates severe (vs. moderate or mild) pain. Besides race, other predictors for greater pain were inactive performance status and preceding radiation treatment.
Dr. Castel and her co-authors note that their findings confirm published evidence that non-Caucasians are at highest risk for undertreatment of pain, including inadequate dosing and poor access to medication.
Racial/ethnic minority patients have also been shown to be at greater risk for breast cancer mortality.
The authors conclude that research should seek to uncover and resolve the reasons for these racial disparities.
In addition, "clinicians should use information about known risk factors to inform more aggressive and earlier intervention among non-Caucasian women with metastatic breast cancer," say the authors.
The study is published in the January 1, 2008 issue of CANCER, a peer-reviewed journal of the American Cancer Society.