BALTIMORE, Md.—That there are differences in cancer pain among survivors, based on socio-demographic characteristics, was the hypothesis of a study of disparities in cancer pain conducted by Carmen R. Green, MD, of the University of Michigan, Ann Arbor, and colleagues. The researchers found that being female was the greatest predictor of pain following a diagnosis of cancer; pain severity for pain since diagnosis was predicted by female gender and black race.

According to the National Cancer Institute, the majority of people diagnosed with cancer will be alive in 5 years. Approximately 60% to 85% of people with advanced cancer and nearly 40% of 5-year cancer survivors report pain. Currently, there is a gap in knowledge regarding cancer-related chronic pain, especially among underserved and minority cancer survivors. Specifically, it remains unknown whether increased health disturbances seen with chronic pain are more pronounced in survivors of cancer.

A random, cross-sectional mail survey study was conducted among adult survivors of breast, colorectal, lung, or prostate cancer or multiple myeloma with an initial diagnosis within the previous 2 years. Subjects were identified by the Michigan State Cancer Registry. Of the 198 participants, 31% were black, 50% were female, and median age was 68 years. Questions focused on socio-demographics, cancer and treatment history, pain, and quality of life. Information was also collected regarding type of pain (acute, chronic, breakthrough), pain causing incidents (e.g., accidents, illnesses, surgeries) in the past 6 months, treatment sought for pain, effectiveness of pain treatment and modalities, and health care utilization for pain.

Of the respondents, 19.5% were currently experiencing pain from cancer and pain since diagnosis (42.6%), including more women than men (P<0.001). Women also experienced greater severity (P=0.04). No racial differences were observed in pain incidence; however, blacks experienced more pain interference and disability. Patients who experienced pain had greater depressive symptoms, poorer functioning, and more symptoms on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire.

Blacks had lower incomes (P=0.04) and were more likely to have stage II, III, or IV cancer (P=0.01). More women lacked health insurance (P=0.02). Most of the participants (81.4%) had been diagnosed with breast or prostate cancer. Whites had more surgical treatments (P=0.01) and women had higher rates of chemotherapy (P <0.001), radiation (P =0.005), and hormone therapy (P =0.006).The investigators, who presented their research during The American Pain Society’s 29th Annual Scientific Meeting, examined predictors of both current pain and pain at any time since cancer diagnosis. Included were age, gender, race, income, education, and type of cancer; chemotherapy, which was related to any current pain; radiation and hormone treatments, which were predictive of having had pain since diagnosis; and cancer surgery, which patients listed as the most common cause of pain.

Most common types of pain were pain flares and those caused by activities, both of which were more common for women. More blacks than whites attributed cancer as their cause of pain (31% vs 7%; P=0.05) and fatalism was more common for blacks (P=0.008) than whites (P =0.04). Fatigue was greater among women (P=0.05), while blacks had more loss of appetite (P=0.02) and constipation (P =0.001).

The investigators concluded that the high prevalence of cancer-related chronic pain among survivors in general—particularly among women and blacks—reveals an unmet research and policy need.