One of the first studies to examine whether pain over the course of metastatic breast cancer differs by race has found that non-Caucasians may experience poorer pain control when compared with Caucasians.
Still, the finding was not surprising considering that the available literature shows that minority populations experience disparities in health outcomes, said the lead author, Liana D. Castel, PhD, a postdoctoral fellow at the Cecil G. Sheps Center for Health Services Research at the University of North Carolina at Chapel Hill. “Cancer pain seems to follow the same pattern as other medical outcomes in minorities.”
“We know that there's significant untreated pain in cancer patients in general, and we know that there are susceptible populations,” commented Margaret M. Eberl, MD, MPH, a pain and palliative medicine physician in the Department of Anesthesia at Roswell Park Cancer Institute and Assistant Professor of Oncology. Previous studies have shown an increased incidence and inadequate pain management in women, the elderly, and ethnic minorities.
In the study published at the end of last year in Cancer (2007;112:162–170), Dr. Castel and her colleagues studied a data set of 1,124 women with metastatic breast cancer and bone metastases who received two bisphosphonate drugs or intravenous pamidronate in an international chemotherapy clinical trial conducted by Novartis from October 1998 to January 2001.
The study included women from 19 countries; 82% of non-Caucasians were from the United States. The average age of women was 57.5.
The outcome was defined as the time to reach a pain score of 7 or above as measured on the Brief Pain Inventory (BPI) scale of 0 to 10. Interferences encompassed how pain had “interfered with general activity, mood, walking ability, normal work, relations with other people, sleep, and enjoyment of life.” The BPI was administered repeatedly over a year.
Non-Caucasians reached a pain level of 7 or higher significantly earlier during a year of follow-up compared with Caucasians.
Besides race, other predictors for greater pain were inactive performance status and having had radiotherapy in the previous 80 days. The literature indicates that radiation is a significant predictor of pain in breast cancer patients, Dr. Castel noted.
Other predictors of interference hazards were younger age, not being employed full time, inactive performance status, prior hospital admission, and previous radiation treatment. Survival did not differ by race up to 400 days but was significantly worse at 700 days.
One of the study's strengths is that the authors looked at how pain remains the same or diverges over time as opposed to measuring just one point in time, commented Roshan Bastani, PhD, Professor of Public Health and Associate Director of Cancer Prevention and Control Research at UCLA's Jonsson Comprehensive Cancer Center. “Many studies look at one point in time and then compare groups.”
Although the paper includes a fairly large overall sample, the number of minority women included is still relatively small, she said. In addition, minority women who participate in a clinical trial may be different from those found in the general population.
Another factor to keep in mind, noted Marcin Chwistek, MD, Attending Physician in the Pain Management Center and Supportive Oncology Care at Fox Chase Cancer Center, is that available data on African Americans show that they have a higher overall incidence of cancer and a higher death rate from the disease, which could also be linked to the pain they experience.
Over two years, non-Caucasian women had higher death rates in this study, which could indicate more aggressive cancer associated with more advanced bony disease and more difficult pain control. Still, knowing for sure is difficult because the study is a secondary analysis, Dr. Chwistek said.
The secondary analysis also raised questions for Dr. Eberl: “I was left wondering how non-Caucasian women who are not on bisphosphonate therapy and have bone metastases might experience pain. Maybe non-Caucasian women respond differently to bisphosphonates in regard to their pain.” Additionally, the study does not address what other treatments or pain management therapies patients were receiving, she said.
Why Pain Disparities May Exist
Although this study did not address why pain disparities exist between non-Caucasians and Caucasians, an Institute of Medicine report, titled “Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care,” offers some insight.
“Some have theorized that there are cultural differences that would lead to minority versus non-minority patients refusing pain medication at different rates,” Dr. Castel said. If all pain differences were based solely on varying preferences, then differences like the ones she and her colleagues found would not reflect an unfairness, or true disparity. However, there is a lot of evidence for true disparities in the literature, she added.
Reporting bias may be one reason pain disparities exist, Dr. Bastani said. “Pain is a perception of what you feel. There may be some difference by ethnicity as to how you report it.”
In addition, patients may be reluctant to discuss pain due to fears of distracting their physicians from treating the disease, and mistrust of the health care system by minority patients may further impact how they report pain.
Dr. Eberl noted that it is also possible that non-Caucasian patients have pain that remains undertreated due to factors related to their health care providers, such as the clinicians not feeling like they have the knowledge to adequately manage pain or not knowing how to ask patients about the issue. Providers may also have inherent biases regarding different groups of patients.
Also creating problems could be insurance coverage restrictions, time constraints, and provider reimbursement, she said.
Another contributing factor is that non-Caucasian patients may have poor access to pain medications, Dr. Chwistek said. For example, pharmacies in minority neighborhoods may be less likely to stock opiates, as was shown in a survey several years ago of 347 pharmacies in New York City, where pharmacists reported that disposal regulations, illicit use, fraud, low demand, and fear of theft all contributed to their having an inadequate supply of pain medications.
Improving Pain Treatment
“There's room for improvement in general pain management for all patients, but particularly for minority patients,” Dr. Castel said. On the systems level, policy makers and administrators can ensure an adequate supply of analgesics in facilities that primarily serve minority populations. Ensuring that information from assessments of both pain and pain risk factors are used appropriately on the encounter level is also crucial.
Reliable assessment of pain over time in cancer and approaching care according to evidence-based clinical practice guidelines is key to helping patients, Dr. Castel said.
“Using clinical practice guidelines reduces ambiguity. The more ambiguity there is in clinical practice, the more the miscommunication that can bias decision-making, creating more room for continued disparities.”
The 0 to 10 pain score assessment can provide a jumping-off point for discussion between doctors and patients.
Doctors also need to be aware that non-Caucasians tend to have worse pain relief outcomes, Dr. Bastani noted. “Physicians should be a little more careful and persistent about asking whether patients are okay and about encouraging them to report pain.”
Patient education can also help, she added. Patients should understand that pain is unfortunately associated with cancer and that it is important to control this symptom. “Patients should know that they do not need to suffer and that they have permission to ask for relief.”