9685 Background: Age ≤35 years is considered as a bad prognostic factor in women with breast cancer (BC). Methods: Clinical and pathological data of 926 women ≤35 years with invasive non metastatic BC, consecutively treated between 1990–99 in 8 french institutions were analysed. Clinical and pathological size, node involvement, histological type, SBR histological grading, hormone receptors (HR), and treatment characteristics were analysed for all patients. Distant Recurrence Free Survival (DRFS) and overall survival (OS) were analysed using Kaplan Meier estimates and comparisons were made using the logrank test. Multivariate analyses were carried out using Cox hazards model. Results: With a median FU of 87 months,239 deaths, 177 loco-regional and 323 distant recurrences were observed. Five and 10 years survival rates were 82.2% and 66.5%. Five and 10 years DRFS rates were 67.2% and 50.8%. No difference was observed according to age (≤30 years old, 31–33 and 34–35, p = 0.74) neither in DRFS nor in OS (p=0.99 and p = 0.74). Compared to T1, T2 was associated with a RR of 1.65 [1.23–2.22], and T3/T4 with a RR of 2.73 [1.92–3.88] for the OS (p<10-4) and T2 was associated with a RR of 1.57 [1.23–2.02], and T3/T4 with a RR of 2.25 [1.65–3.07] for the DRFS (p<10-4). Compared to negative node involvement, pN1 status was associated with a RR of 2.22 [1.60–3.09], and pN2 with a RR of 4.35 [3.14–6.03] in OS (p<10-4) and pN1 nodes involved was associated with a RR of 2.64 [2.01–3.47], and 4 and more with a RR of 4.22 [3.17–5.62] for the DRFS (p<10-4). Compared to positive HR, negative HR were respectively associated with a RR of 1.37 [1.05–1.82] (p=0.019), and 1.49 [1.14–1.96] (p<10-2) in OS. But no difference was observed according to HR in DRFS. Compared to grade I in SBR, grade II and III were respectively associated with a RR of 2.40 [1.35–4.27], and 2.61 [1.46–4.65] for the OS (p<10-3) and a RR of 1.86 [1.20–2.89], and 1.75 [1.12–2.72] in DRFS (p<10-3). Multivariate analysis results will be presented during the meeting. Conclusions: In these retrospective analyses, the most important prognostic factor for YA with breast cancer is tumour size followed by pathological grade (SBR), pN and HR status. No significant financial relationships to disclose.