Breast-conserving treatment with or without radiotherapy in ductal carcinoma-in-situ: ten-year results of European Organisation for Research and Treatment of Cancer randomized phase III trial 10853--a study by the EORTC Breast Cancer Cooperative Group and EORTC Radiotherapy Group. Lumpectomy and radiation therapy for the treatment of intraductal breast cancer: findings from National Surgical Adjuvant Breast and Bowel Project B-17. Absolute risk reductions for local recurrence after postoperative radiotherapy after sector resection for ductal carcinoma in situ of the breast. Radiotherapy and tamoxifen in women with completely excised ductal carcinoma in situ of the breast in the UK, Australia, and New Zealand: randomised controlled trial.
The European Organisation for Research and Treatment of Cancer conducted a randomized trial investigating the role of radiotherapy (RT) after local excision (LE) of ductal carcinoma-in-situ (DCIS) of the breast. We analyzed the efficacy of RT with 10 years follow-up on both the overall risk of local recurrence (LR) and related to clinical, histologic, and treatment factors.
                After complete LE, women with DCIS were randomly assigned to no further treatment or RT (50 Gy). One thousand ten women with mostly (71%) mammographically detected DCIS were included. The median follow-up was 10.5 years.
                The 10-year LR-free rate was 74% in the group treated with LE alone compared with 85% in the women treated by LE plus RT (log-rank P < .0001; hazard ratio [HR] = 0.53). The risk of DCIS and invasive LR was reduced by 48% (P = .0011) and 42% (P = .0065) respectively. Both groups had similar low risks of metastases and death. At multivariate analysis, factors significantly associated with an increased LR risk were young age (< or = 40 years; HR = 1.89), symptomatic detection (HR = 1.55), intermediately or poorly differentiated DCIS (as opposed to well-differentiated DCIS; HR = 1.85 and HR = 1.61 respectively), cribriform or solid growth pattern (as opposed to clinging/micropapillary subtypes; HR = 2.39 and HR = 2.25 respectively), doubtful margins (HR = 1.84), and treatment by LE alone (HR = 1.82). The effect of RT was homogeneous across all assessed risk factors.
                With long-term follow-up, RT after LE for DCIS continued to reduce the risk of LR, with a 47% reduction at 10 years. All patient subgroups benefited from RT. In 1993, findings from a National Surgical Adjuvant Breast and Bowel Project (NSABP) trial to evaluate the worth of radiation therapy after lumpectomy concluded that the combination was more beneficial than lumpectomy alone for localized intraductal carcinoma-in-situ (DCIS). This report extends those findings.
                Women (N = 818) with localized DCIS were randomly assigned to lumpectomy or lumpectomy plus radiation (50 Gy). Tissue was removed so that resected specimen margins were histologically tumor-free. Mean follow-up time was 90 months (range, 67 to 130). Size and method of tumor detection were determined by central clinical, mammographic, and pathologic assessment. Life-table estimates of event-free survival and survival, average annual rates of occurrence for specific events, relative risks for event-specific end points, and cumulative probability of specific events comprising event-free survival are presented.
                The benefit of lumpectomy plus radiation was virtually unchanged between 5 and 8 years of follow-up and was due to a reduction in invasive and noninvasive ipsilateral breast tumors (IBTs). Incidence of locoregional and distant events remained similar in both treatment groups; deaths were only infrequently related to breast cancer. Incidence of noninvasive IBT was reduced from 13.4% to 8.2% (P = .007), and of invasive IBT, from 13.4% to 3.9% (P < .0001). All cohorts benefited from radiation regardless of clinical or mammographic tumor characteristics.
                Through 8 years of follow-up, our findings continue to indicate that lumpectomy plus radiation is more beneficial than lumpectomy alone for women with localized, mammographically detected DCIS. When evaluated according to the mammographic characteristics of their DCIS, all groups benefited from radiation. 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. As a consequence of mammographic breast screening programmes, ductal carcinoma in situ is diagnosed with increasing frequency. Mastectomy for localised ductal carcinoma in situ is thought to be an over-treatment by many physicians, but there is much controversy as to whether complete local excision alone is sufficient. We aimed to assess the effectiveness of adjuvant radiotherapy and tamoxifen.
                We used a 2x2 factorial design in a randomised controlled trial. Between May, 1990, and August, 1998, 1701 patients recruited from screening programmes were randomised to both treatments in combination or singly, or to none, or to either one (eg, radiotherapy) with an elective decision to give or to withhold the other (ie, in this case tamoxifen). Patients had complete surgical excision of the lesion confirmed by specimen radiography and histology. Patients have been followed up at least once a year. Median follow-up was 52.6 (range 2.4-118.3) months. Our primary endpoint was the incidence of ipsilateral invasive disease.
                Ipsilateral invasive disease was not reduced by tamoxifen but recurrence of overall ductal carcinoma in situ was decreased (hazard ratio 0.68 [0.49-0.96]; p=0.03). Radiotherapy reduced the incidence of ipsilateral invasive disease (0.45 [0.24-0.85]; p=0.01) and ipsilateral ductal carcinoma in situ (0.36 [0.19-0.66]; p=0.0004), but there was no effect on the occurrence of contralateral disease. There was no evidence of interaction between radiotherapy and tamoxifen.
                Radiotherapy can be recommended for patients with ductal carcinoma in situ treated by complete local excision; however, there is little evidence for the use of tamoxifen in these women.
This review confirms the benefit of adding radiotherapy to breast conserving surgery for the treatment of all women diagnosed with DCIS. No long-term toxicity from use of radiotherapy was identified.