The role of radiation treatment in the management of women with stage IV breast cancer has historically been confined to providing relief of painful bony metastases or other symptomatic areas of breast cancer. Unlike treatment of earlier stage breast cancer, radiation therapy has not been routinely used to prevent local cancer recurrence in the breast and axilla or other localized sites of disease. The results of a recent clinical study reported by investigators at Duke University, however, suggests that radiation therapy may reduce cancer recurrences and improve survival when used in women who have achieved a complete remission through conventional chemotherapy treatment.
The clinical study sought to evaluate whether the immediate delivery of high-dose chemotherapy with autologous stem cell transplantation would produce a better outcome than the delivery of the same treatment at the time of actual cancer recurrence for patients who achieved full remission through conventional chemotherapy. While all patients were supposed to be treated with consolidative radiation therapy, 28% of patients failed to receive radiation treatment and could not establish a preliminary evaluation regarding the role of radiation treatment. Overall, the patients treated with radiation therapy had a lower relapse rate and were more likely to be alive without evidence of cancer recurrence. The probability of relapse was 36% in patients not treated with radiation as compared to 19% in patients treated with radiation. Patients treated with radiation were also less likely to relapse at their initial site of disease. A 28% local failure rate was observed in patients treated with radiation compared to 62% in patients not treated with radiation. Thirty-one percent of patients treated with radiation were alive without evidence of cancer recurrence at 4 years from treatment as compared to 21% of patients not treated with radiation. Patients treated with radiation were also more likely to live longer, with 30% alive 4 years from treatment as compared to only 16% of patients not treated with radiation.
It is important to understand that this clinical study was not designed to evaluate the role of radiation therapy in patients achieving a complete remission to chemotherapy. This information has limited immediate application because of the small number of patients and the investigators' inability to perform a direct controlled comparison of the treatments. Future clinical studies will need to be designed to evaluate the role of radiation in a more formal manner. However, consolidative treatment with radiation therapy after chemotherapy-induced clinical remissions does appear to reduce the risk of cancer recurrence and may improve a patient's chance of overall survival. (
Journal of Clinical Oncology, Vol 17, No 3, pp 887-893, 1999)