Quality of Life in Breast Cancer Patients with Bisphosphonate-related Osteonecrosis of the Jaws and Patients with Head and Neck Cancer: A Comparative Study Using the EORTC QLQ-C30 and QLQ-HN35 Questionnaires

Background/Aim: This exploratory study aimed at examining the diagnostic utility, validity and reliability of already established quality of life (QoL) measures in cancer patients with osteonecrosis of the jaws (ONJ). Patients and Methods: This was a prospective, observational, controlled clinical study. Female patients diagnosed with metastatic breast cancer and stage 2 or 3 ONJ (group I), metastatic breast cancer alone (group II), or cancer of the oral cavity (group III) were questioned. The EORTC QLQ-C30 version 3.0 and the QLQ-HN35 head and neck-specific questionnaires were used. Results: Completed questionnaires were obtained from 64 patients. Overall internal consistency was acceptable to excellent with a Cronbach's alpha of 0.728 to 0.892. The Spearman-Brown coefficient was 0.888 and 0.872 for QLQ-C30 and HN35, respectively. Several scales of the questionnaire were sensitive to patient group: Global health status/Qol, HN Social eating, HN Pain, HN Swallowing, HN Senses, Role Function. Symptom intensity correlated with ONJ stage (2 vs. 3). Conclusion: EORTC QLQ-HN35 in conjunction with QLQ-C30 is a valid and informative tool in assessing QoL in patients with metastatic breast cancer and ONJ. Administration of the instrument to patients with ONJ of various nationalities is feasible and such efforts would greatly assist in recording the additional health burden created by this complication of bisphosphonate therapy. The use of HN35 module may be feasible in patients with any type of metastatic cancer who develop ONJ. Since its recognition in 2003, osteonecrosis of the jaws (ONJ) has become one of the most discussed adverse effects of bisphosphonate (BP) drugs (1). The crude incidence of ONJ among patients with cancer prescribed with bisphosphonates is reported to be approximately 5% in relatively large-sized studies (2). A 4% incidence has been reported in patients with multiple myeloma receiving zoledronate, despite adherence to expert recommendations on prophylaxis to reduce risk of ONJ (3). The current widespread use of bisphosphonates as inhibitors of bone resorption is directly attributable to their efficacy in improving the quality of life (QoL) for patients with metastatic bone cancer (4). The improvement in health- ralated QoL in patients being administered bisphosphonates justifies their recommendation (4, 5). However, a recent study recorded ONJ-related decline in QoL in a retrospective cohort of cancer patients (6). Four published studies evaluated pain, as experienced by a total of 172 patients with ONJ. The overall prevalence of pain in these studies was