Combination of radiological and biochemical methods to assess bone mineral density of mandible in fully edentulous patients after chemotherapy: a 5-year prospective study

Background: Osteoporosis is of concern in breast cancer patients who are undergoing chemotherapy. This study compared the bone mineral density (BMD) index of the mandible and hip hinge between patients who were undergoing chemotherapy or breast cancer, and fully edentulous Chinese patients without cancer over a period of 5 years. Method: 120 fully edentulous patients with an average age of 69 who had undergone mastectomy for grade two or three non-metastatic invasive breast ductal carcinoma. This was followed by administration of 5-fluorouracil, cyclophosphamide, and doxorubicin. The 118 fully edentulous cancer-free patients were included as a control group. The first assessment point was 6 months after chemotherapy treatment. The BMD and panoramic and side views of the mandible were measured by γ-ray and the BMD of left hip hinge was measured using dual energy X-ray absorptiometry. The serum and urine level of bone-specific alkaline phosphatase (BAP), carboxyterminal cross-linked telopeptide of type I collagen (ICTP), as well as liver and renal function tests were determined. These examinations were performed annually for 5 years. Result: The cancer patients demonstrated a statistically significant (p < 0.05) increase in bone resorption of mandible and hip, and an increase in BAP and ICTP levels when compared with the control group. Although data were collected annually there was no statistical significance for the first 3 years. Conclusion: Breast cancer patients undergoing chemotherapy displayed significant resorption of mandibular bones compared with the healthy control, which might result in difficulties in fitting dentures, as it would cause pain and mucosal friction. Thus, concurrent therapy to decrease mandibular bone loss and special considerations in dentures are warranted for these patients.