Background: The impact of age on local recurrence rate of patients affected by early breast cancer is still unclear. The standard of care for older adult largely varies depending on patient- and tumor-related features, but also on national guidelines. We recently presented the 10 years median follow update of the APBI-IMRT Florence phase III trial. The primary aim of the present analysis is to identify the potential relationship between age and ipsilateral breast tumor recurrence (IBTR) in this setting of patients. Methods: This retrospective analysis was performed on the whole series of 520 patients who were enrolled in the trial after breast conserving surgery and randomized to receive APBI or whole breast irradiation. We analyzed patients stratified by age (70+ vs 40-69 years). Results: At a median follow up time of 10.7 years, we recorded 15 IBTR events. Four hundred and three patients (77.5%) were aged less than 70 years old (11 IBTR) and 117 patients (22.5%) were aged 70 years or older (4 IBTR). At the univariate analysis the age (70+ vs 40-69 years) was not significantly correlated with IBTR occurrence (HR 1.33, 95% CI 0.42-4.17; p=0.63). The only significant prognostic factor was adjuvant endocrine therapy, also at the multivariable analysis (HR 0.26, 95% CI 0.07-0.94; p=0.041). Main results are summarized in the table. Within the luminal-like patients (n=437; 12 IBTR events), the age did not impact on the IBTR rate (HR 0.91, 95% CI 0.19-4.31; p=0.91) and adjuvant endocrine therapy lost its significance (HR 0.32, 95% CI 0.09-1.11; p=0.072). Conclusions: Our trial subanalysis did not demonstrate a significant effect of age on IBTR rate for early breast cancer patients receiving a breast conserving therapy. Due to the low number of events, the benefit of adjuvant endocrine therapy is unclear and calls for further investigations. Clinical trial information: NCT02104895.