Value of high-dose radiation therapy for isolated osseous metastasis in breast cancer in terms of oligo-recurrence.

BACKGROUND

For many years, patients with recurrent or distant metastatic cancer have been considered to be at the last stage of their lives because it was considered that the cancer had spread throughout the whole body. However, the development of methods for the early detection of recurrence or distant metastases allows the detection of limited site recurrence or single organ metastases, called oligometastases or oligo-recurrence. Additional local treatment for oligometastatic or oligo-recurrent lesions such as radiation therapy could be efficacious. The purpose of the current study was to evaluate radiation therapy for solitary osseous metastasis of breast cancer in terms of oligometastasis and oligo-recurrence.

PATIENTS AND METHODS

One hundred and thirteen breast cancer patients were treated with radiation therapy for osseous metastases at Kitasato University Hospital, Japan between January 1998 and March 2003. Out of them, seven patients had solitary osseous metastases with primary and other sites controlled. These patients were registered in the current study, three had lumber spine metastases, three pelvic and one thoracic spine. The median time between the initial treatment of the primary lesions and diagnosis of the osseous metastases was 44 months (range: 10-95 months). The median total radiation dose was 46 Gy (30-50 Gy; BED: biological effective dose, 39-60 Gy10).

RESULTS

The median follow-up time was 40 months (range: 11-80 months). All the patients were alive at the last follow-up. Only one patient relapsed in terms of pain from the osseous metastasis. This patient was treated with 30 Gy (BED 39 Gy10) irradiation, the lowest total dose among the seven patients.

CONCLUSION

Radiation therapy for solitary osseous metastasis might be efficacious and moreover, high dose could be useful for long-term pain relief of osseous metastasis.