Sequencing of chemotherapy and radiation therapy in early-stage breast cancer: updated results of a prospective randomized trial. Absolute risk reductions for local recurrence after postoperative radiotherapy after sector resection for ductal carcinoma in situ of the breast.
The optimal integration of chemotherapy with radiation (RT) for patients with early-stage breast cancer remains uncertain. We present the long-term results of a prospective randomized trial to address this question.
                Two hundred forty-four patients were randomly assigned after conservative breast surgery to receive 12 weeks of cyclophosphamide, doxorubicin, methotrexate, fluorouracil, and prednisone (CAMFP) before RT (CT-first) or after RT (RT-first). Median follow-up for surviving patients was 135 months.
                There were no significant differences between the CT-first and RT-first arms in time to any event, distant metastasis, or death. Sites of first failure were also not significantly different.
                Among breast cancer patients treated with conservative surgery, there is no advantage to giving RT before adjuvant chemotherapy. However, this study does not have enough statistical power to rule out a clinically important survival benefit for either sequence. Evaluate the effects of radiotherapy after sector resection for ductal carcinoma in situ of the breast (DCIS) in patient groups as defined by age, size of the lesion, focality, completeness of excision and mode of detection.
                A total of 1,067 women in Sweden were randomly assigned to either postoperative radiotherapy (RT) or control from 1987 to 1999, and 1,046 were followed for a mean of 8 years. The main outcome was new ipsilateral breast cancer events and distant metastasis-free survival analyzed according to intention to treat.
                There were 64 ipsilateral events in the RT arm and 141 in the control group corresponding to a risk reduction of 16.0 percentage points at 10 years (95% CI, 10.3% to 21.6%) and a relative risk of 0.40 (95% CI, 0.30 to 0.54). There was no statistically significant difference in distant metastasis-free survival. There was an effect modification by age, yielding a low effect of RT in women younger than 50, but substantial protection in women older than 60 years. The age effect was not confounded by focality, lesion size, completeness of excision, or detection mode. There was no group as defined by our stratification variables that had a low risk without radiotherapy.
                Our results indicate that younger women have a low protective effect of conventional RT after sector resection. Older women benefit substantially. We caution that the age effect was seen in a subgroup analysis. Further search with conventional clinical variables for a low risk group that does not need RT does not seem fruitful.
The data included in this review, from three well-conducted randomised trials, suggest that different methods of sequencing CT and RT do not appear to have a major effect on recurrence or survival for women with breast cancer if RT is commenced within seven months after surgery.