Pain changes in patients with bone metastases of breast cancer after palliative radiotherapy and bisphosphonates administration

Bone metastases are frequently occurring in advanced forms of breast cancer. Radiotherapy (RT) is an effective treatment of bone metastases. Available data show us the 60-80% reduction in bone pain due to RT. Bisphosphonates widely used in the treatment of this category of patients. The results of some studies demonstrated efficacy increase due to combination of RT and bisphosphonates. The main purpose of our study to assess the pain response rate in combination of large fractionated RT regimens and bisphosphonates. Methods: Our randomized study was conducted for 215 patients with bone metastases of breast cancer, which received palliative therapy in Russian Scientific Center of Roentgenoradiology from 2000 to 2010. We used 3 or 4 fractionated regimens by 6,5 Gy in one treatment fraction once in 2 or 5 days. In control arm treatment regimen 3Gy in 10-16 fractions was used. Results: Complete regression of pain demonstrated at 3 months period of follow-up in bisphosphonates group – 66,5%, in bisphosphonates free group – 62,2% ( P >0,05). Better complete response rate were observed with concurrent use of bisphosphonates and radiotherapy in large fractionated regimens. The higher frequency of pain reduction was registered with ibandronate – 96,3% ( P =0,006). Conclusion: Concurrent use of ibandronate and large fractionated radiotherapy permitted the higher pain reduction rate ( P =0,006) and analgetic use reduction ( P =0,001).