Prevalence and correlates of joint pain among Chinese breast cancer survivors receiving aromatase inhibitor treatment

BACKGROUND: Aromatase inhibitor (AI)-induced joint pain is a common toxicity of AI treatment. Although many studies have been conducted to examine the occurrence and severity of AI-induced joint pain in breast cancer survivors, none of the studies focused on the Chinese population with breast cancer. Given that the differences in cultural background and the genetic structure between Asians and Caucasians may contribute to different phenotypes of joint pain, this cross-sectional study was therefore conducted to examine the prevalence of AI-induced joint pain among Chinese breast cancer survivors receiving AI treatment and the correlates of pain. METHODS: This cross-sectional study was conducted in a tertiary hospital in China. Breast cancer survivors undergoing AI treatment were recruited to complete the following questionnaires: a self-designed baseline data form, the Nordic Musculoskeletal Questionnaire (NMQ), the Brief Pain Inventory (BPI), the 36-Item Short Form Health Survey (SF-36), and the Functional Assessment of Cancer Therapy-Breast (FACT-B). Based on the assessment results of NMQ (if the participant indicated pain in specific body parts), participants were then invited to complete other questionnaires to specifically assess the joint symptoms, including the Oxford Knee Score (OKS), the Oxford Hip Score (OHS), the Michigan Hand Outcomes Questionnaire (MHQ), and the Manchester Foot Pain Disability Questionnaire (MFPDQ). Descriptive analysis was used to analyse participants’ baseline data and the prevalence of pain. Stepwise multiple regression was used to identify the correlates of pain. RESULTS: Four hundred and ten participants were analysed. According to the NMQ, 71.7% of the participants experienced joint symptoms in at least one joint, and the most frequently mentioned joint was knee (39.0%). The diagram in BPI indicated that 28.0% of the participants had the worst pain around knees. In patients with knee pain, the mean OKS score was 40.46 ± 6.19. The sub-scores of BPI for pain intensity and pain interference were 1.30 ± 1.63 and 1.24 ± 1.79, respectively. Patients’ poorer physical well-being/functioning, previous use of AI treatment, presence of osteoarthritis, and receiving of physiotherapy were identified as four common correlates of greater severity of pain and pain interference (p < 0.05). CONCLUSIONS: Chinese breast cancer survivors can experience joint pain at various locations, particularly knees. In addition to increasing the use of interventions for pain alleviation, a comprehensive assessment of survivors’ conditions such as physical functioning, history of AI treatment, and presence of osteoarthritis should be emphasized to identify survivors who need more attention and tailored interventions.