Bisphosphonate-Related Osteonecrosis of the Jaw in Breast Cancer Patients: A Retrospective Cohort Study

Introduction

Bisphosphonates are anti-resorptive drugs used in osteoporosis, bone metastases, and multiple myeloma. A serious adverse effect is bisphosphonate-related osteonecrosis of the jaw (BRONJ), whose etiology remains partly understood, with risk factors including treatment duration, intravenous administration, and dental surgery. This study aimed to estimate the prevalence of osteonecrosis of the jaw (ONJ) after dental extractions in patients treated with bisphosphonates.

Materials and Methods

We conducted a retrospective cohort study of female patients treated with bisphosphonates for cancer-related bone metastases. Clinical characteristics, prior therapy, and outcomes were reviewed. Bisphosphonate therapy was interrupted for several months before dental extractions, in coordination with the oncology team, as a preventive measure.

Results and Discussion

Ten female patients (mean age 54.6 years) were included, all treated with intravenous aminobisphosphonates for breast cancer with bone metastases (100%) for over two years, and all had undergone prior dental extractions (100%), the apparent triggering factor. Mean follow-up was 4 years. By AAOMS staging, eight patients presented initially at stage I or II and achieved complete healing after temporary drug discontinuation and local care. The remaining two patients were refractory to conservative management, progressing to stage III and requiring extensive surgery.

Conclusion

ONJ is a rare but serious complication of bisphosphonate therapy, particularly with prolonged intravenous use for bone metastases. While early-stage lesions often heal after treatment discontinuation, refractory cases can progress and require surgery. Preventive dental evaluation and treatment before starting bisphosphonate therapy is strongly recommended.