A longitudinal examination of cancer pain: The role of gender and breakthrough pain

Pain is common in cancer and cancer treatment. Cancer-related pain has a detrimental effect on an individual's quality of life (QOL). Yet longitudinal studies examining the role of consistent pain, breakthrough pain (BTP; pain flares that interrupt controlled baseline pain), and pain characteristics and their relationship with QOL are lacking. This six-month longitudinal study involving cancer patients with pain examined the severity, characteristics, BTP, and treatment and their relationship with QOL. Subjects (N=96, 29% minority, 66% female, 56.3±10.3 years old) had breast, colorectal, lung, or prostate cancer or multiple myeloma. Pain severity and characteristics are summarized over the course of the six-month time frame. Pain levels in the sample decreased slightly over time, but not significantly and the reasons for this decrease are explored. Consistent pain and BTP scales were strongly correlated with most functioning scales at baseline, though pain at its least was the strongest predictor (r2 physical functioning = -.47, p<.001 was the strongest relationship, r2 cognitive functioning = -.18, p=.08 was the weakest) and was related to all functioning scales (except the diarrhea symptom subscale) significantly or at trend level. Consistent pain at its least was also strongly correlated with all the Barriers Questionnaire scales (p<.05) and CESD (p=.01) at baseline. Correlational patterns remain similar over time. In addition we found that earlier pain predicts QOL and to a lesser extent depression in later waves of data, though the pain variables with the strongest predictive relationship differ depending on whether it is three or six-month results which were examined. This study provides important information regarding the role of pain over time, while highlighting the importance of addressing that pain in cancer patients. These results suggest improving cancer pain management will improve quality of life.