Viviana Galimberti will report on ten-year results of the IBCSG 23-01 trial. The phase III IBCSG 23-01 multicenter, randomized, non-inferiority trial compared disease-free survival (DFS) in breast cancer patients with one or more micrometastatic (≤2 mm) sentinel nodes (SNs) randomized to either in axillary dissection (AD) or no axillary dissection (no-AD). Results after 5 years showed no difference in DFS between the arms. Viviana will report results after a median follow-up of 9.8 years.

Sherene Loi will present final safety data and efficacy results of IBCSG 45-13/BIG 4-13 (KEYNOTE-014), a phase Ib/II study evaluating safety and efficacy of pembrolizumab and trastuzumab in patients with trastuzumab-resistant HER2-positive metastatic breast cancer. The trial evaluated pembrolizumab in PD-L1 positive, unresectable loco-regional or metastatic BC and in a parallel cohort of patients with PD-L1 negative BC during the phase II part.

Gini Fleming will present an update of overall survival results in SOFT. The primary results of SOFT at 5.6 years median follow-up found adding OFS to T did not provide a significant benefit in the overall study population of premenopausal women with HR+ BC (Francis et al, NEJM 2015). For those women at sufficient risk for recurrence to warrant adjuvant chemotherapy and who remained premenopausal, the addition of OFS improved disease outcomes. Follow-up was immature for overall survival (OS). Gini will report a planned update with visit cut-off of 31Dec16 after 8 years median follow-up.

Olivia Pagani will report the update on the aromatase inhibitor question of the combined results of TEXT and SOFT. After 5.7 years median follow-up, we found that adjuvant E+OFS significantly improved disease-free survival vs T+OFS in premenopausal women with HR+ BC (Pagani et al, NEJM 2014). Follow-up was immature for overall survival. IBCSG now reports a planned update with visit cut-off of 31Dec16 after 9 years median follow-up.

In addition to these plenary session talks, the following three topics have been accepted for poster presentation:

Marco Colleoni will show the final results of IBCSG 41-13 TREND, a randomized phase II trial evaluating the endocrine activity and efficacy of neoadjuvant degarelix versus triptorelin in premenopausal patients receiving letrozole for primary endocrine responsive breast cancer. Neoadjuvant endocrine therapy with GnRH analogue and aromatase inhibitors is effective in selected premenopausal patients. Degarelix, an antagonist of GnRH, has immediate onset of action through binding to GnRH receptors in the pituitary gland and blocking their interaction with GnRH. Its suppressing activity in premenopausal women might be faster and better maintained than with GnRH analogues, and thereby provide significant clinical value for pts who are candidates for short-term neoadjuvant endocrine therapy.

Karin Ribi will present a poster on the impact on patient-reported symptoms and quality of life in the IBCSG 37-05/BIG 1-07 SOLE trial. Previous studies showed that the burden by symptoms related to endocrine therapy can be substantial. Even if symptoms improve during the treatment course, extending treatment implies continuation of symptoms. IBCSG has compared differences in patient-reported symptoms and quality of life between extended continuous and intermittent letrozole over the first two years of trial treatment.

Karin Ribi will also report on the impact of different chemotherapy schedules on quality of life in the IBCSG 42-12/BIG 2-12 SNAP trial. This randomized phase II trial assessed three alternative reduced maintenance chemotherapy regimens using nab-Paclitaxel after a short term induction phase at conventional doses as first line treatment in patients with metastatic breast cancer. For all three regimens median progression-free survival was greater than achieved with full dose docetaxel (historical reference). Symptom palliation and quality of life are important when deciding on therapeutic agents and schedules in this patient population.