The Eortc Trial 22881-10881 << Boost Versus No Boost >> Trial In Conservative Management Of T1 T2 Breast Cancers: Results And Updated Discussion

The "Boost versus no boost" trial measured the impact of a boost dose of 16 Gy on local control as part of breast conserving management. Material and methods: 5569 early stage breast cancer patients were entered. All underwent tumorectomy followed by whole breast irradiation of 50 Gy. 5318 patients with microscopically complete excision were randomized to no boost or to a 16 Gy boost, while 251 patients with an incomplete excision were randomized between a boost dose of 10 Gy or 26 Gy. The median follow up is 5.1 years. Results: In the 5318 patients with a complete excision, 182 patients in the no boost group and 109 patients in the boost group, had a local recurrence resulting in a 5 year actuarial recurrence rate of 6.8% (95% CI: 5.7 - 7.8%) and 4.3% (95%CI: 3.4 - 5.2%) respectively (p<0.0001) and a reduction of the hazard rate on local recurrence with a factor of 0.59 (99% CI: 0.43-0.81). Young age (HR=2.22) remained the most important prognostic factor for local recurrence in a multivariate prognostic factor analysis. So far, there is no significant difference in late morbidity and only a minimal impairment of cosmesis in the boosted group. The publication of this trial in 2001 was considered by most oncologists as the new reference strategy for this group of patients. A few arguments raised against such a conclusion are presented and discussed in the discussion.