Postoperative Radiation Therapy (RT) after conservative breast surgery is well known to reduce the risk of local recurrence resulting in a survival benefit, regardless of the age (Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) et al. 2011), but the absolute benefit on survival is limited in elderly patients as this is more influenced by prior comorbidities.

To date, few conclusive data are available on the treatment of choice for early-stage breast cancer (BC) in elderly patients. Notwithstanding the presence of biologically more favorable prognostic factors with respect to younger patients, older women are at high risk of presenting with BC when it has already reached a late stage, mostly because of poor BC awareness (Diab et al. 2000; Linsell et al. 2008).

In addition, women older than 70 years tend to be excluded from most large-scale clinical trials (Wildiers et al. 2007), and this category is frequently associated with noncompliance factors, as functional limitation, travel distance or comorbidities could lead to under-treatment (Donato et al. 2003).

Recently, results from FAST-Forward and FAST, two large randomized controlled trials testing five-fraction regimens over 5 weeks or 1 week for adjuvant whole breast radiotherapy, have been published (FAST Trialists group et al. 2011; Murray Brunt et al. 2020; Brunt et al. 2020). The FAST-Forward randomized trial (Murray Brunt et al. 2020) (n = 4096; median age = 61 years) showed that ultra-hypofractionation (5 fractions) results in non-inferior local control rates and similar adverse event profile when compared to 40 Gy in 15 fractions over 3 weeks. The smaller FAST trial (FAST Trialists group et al. 2011; Brunt et al. 2020) randomized 915 women aged > 50 years and affected by early BC to receive 50 Gy in 25 fractions over 5 weeks or two hypofractionated schedules of 30/28.5 Gy in 5 fractions of 6/5.7 Gy once weekly over 5 weeks after breast-conserving surgery. At a 9.9-year median follow-up, no differences were shown between 28.5 and 50 Gy in terms of any moderated/marked physician-scored breast adverse events and local recurrence rates were overall low and similar between arms (overall 11 ipsilateral BC events and 96 deaths), although the trial was not designed to demonstrate efficacy for local control.

At the European Institute of Oncology (IEO), about 700 early breast cancer patients a year are treated with adjuvant RT; many of them live far from Milan, and some have important disability or social/clinical challenges making long therapies unacceptable. For these selected patients, although evidences on five fractions in breast cancer irradiation are still growing, 'real-life data' might provide additional insights with respect to randomized controlled trials (Rodin et al. 2021).

In 2011, based on the encouraging first results coming from FAST trial (FAST Trialists group et al. 2011), adjuvant whole breast radiotherapy treatment in five fractions was implemented in our facility.

To be updated