Key Surgical takeaways from EBCC15

European Breast Cancer Conference 2026 (EBCC) was an excellent multidisciplinary conference organised by EBCCouncil, in collaboration with EORTC, EUSOMA, and EUROPA Donna (Conference Chairs: I Rubio, S Mastora, J Cortez), with delegates from around the world in attendance.

The following key takeaways are potentially noteworthy for breast surgical practice and discussions.

Abstracts can be viewed on the conference website here.

Radiotherapy extent guided by nodal response to primary chemotherapy

• The RAPCHEM (BOOG 2010-03) study (Mauritz F et al., Senior Author: L Boersma), a prospective Dutch registry, evaluated tailored de-escalation of locoregional radiotherapy based on (cN+) nodal response to NeoAdjuvant Chemotherapy (NACT) before either conservation or mastectomy. Across all risk subgroups (ypN0, ypN1, >ypN2), in 848 patients, the 10-year LRR was 2.4%, 3.2%, and 2.8%, respectively, with no significant differences between subgroups, while RFS was 79% and OS was 83%. The authors propose no regional RT and no chest wall RT if mastectomy is performed in ypN0, and no RT of axilla levels 3-4 in ypN1. 

Boost Radiotherapy in Breast Conservation

• Dutch Radiotherapy Registry (Verreck E et al.): A dataset of 34,504 patients from 2012 to 2016, with a median follow-up of 8.3 years, was inspired by the Assisi Think Tank Meeting 2024, which proposed excluding a boost in patients with a 10-year local recurrence (LR) risk of less than 6% without a boost. Most patients (90%, 82%, 75%, and 87%) in the registry in the specified subgroups received a boost (out of the entire cohort, 4% were aged ≤40 years, 23% had grade 3 tumours, 11% had triple-negative breast cancer, and 6% had focally positive margins). 64% received (neo)adjuvant systemic therapy (39% chemotherapy ± targeted therapy, 52% endocrine therapy). LR occurred in 1% (n=343) of patients, with half (n=174, 51%) experiencing solitary LR, and the remainder experiencing regional recurrences and/or distant metastases. Of the 15,953 patients who received a boost, 0.9% developed LR compared to 1.1% of the 17,321 patients without a boost. Across all subgroups, the 8.3-year LR rate was below 6% (without boost) and 3% (with boost). This topic also recurred in various discussions, including debates on margins and current indications for a boost, considering significant improvements in targeted systemic therapies since the EORTC Boost study. 

Radiotherapy effects in implant reconstruction

• The OPBC-09 PRExRT study (Wimmer K et al., Senior Author: W Weber), an international multicentre retrospective real-world investigation, included patients with breast cancer who underwent nipple- or skin-sparing mastectomy with prepectoral immediate reconstruction with or without polyurethane-coated (PUC) implants following PMRT. Among 1183 women (2016 to 2022) across 19 sites in 13 countries, 773 (65.3%) received non-PUC implants and 410 (34.7%) received PUC implants. PUC implants were associated with fewer surgical revisions due to capsular contracture (35.7% vs 10.1%; hazard ratio [HR], 3.7; 95% CI, 2.6-5.4; p < 0.001), but also with a higher risk of complications in the setting of PMRT. The study’s retrospective design is a limitation; however, it includes a large dataset, and the trend towards de-escalating indications for chest wall radiotherapy (see NSABP51, RAPCHEM studies) may limit future data of this kind. 

NACT without surgery 

• Non-surgical approach following post-NACT pCR (Kuerer et al. JAMA Onc, May 2025) – a revisited discussion on this single-arm, prospective, phase 2 non-randomised US multicentre trial involving women over 40 years with cT1-2N0-1M0 TNBC or HER2+ BC with less than 2cm residual imaging response, demonstrating the feasibility of a non-operative approach in cases with confirmed pCR on post-NACT VAB (no oncological events at a median follow-up of 55.4 months). 

EBCTCG session key points

EBCTCG session (session lead: R. Hill) summary points (with G. Mannu):

1. Endocrine therapy: Approximately 25% proportional reduction in recurrence and distant recurrence with five additional years of aromatase inhibitor treatment after some prior aromatase inhibitor therapy.
2. Ovarian function suppression: Previous research shows tamoxifen alone reduces the risk of recurrence by up to half; adding ovarian function suppression to tamoxifen further reduces the risk by about one-fifth. Benefits appeared greater in women aged under 45 years.
3. Axillary surgery: Axillary recurrences are rare. More axillary surgery is not linked to differences in mortality but is associated with increased lymphoedema (to ~20%).
4. BMI: Distant recurrence rates appear associated with an increase in BMI (relative risk = 1.06 per 5 kg/m2), particularly in pre-menopausal women (4.1% absolute extra risk with 12 kg/m2 difference).

Surgery versus Surveillance 

• Loris trial (Wallis M et al.) – RCT designed to test non-inferiority in a 1:1 ratio among 932 women aged 45 years and older with screen-detected low or low-intermediate grade DCIS, comparing active monitoring to surgery. However, poor recruitment necessitated revising the target sample size to 188. The “as treated” analysis at 5 years revealed that the rate of ipsilateral invasive BC was 2.9% (2/69) in the surgical arm and 10.7% (12/112) in the active monitoring arm. Although the estimated HR fell within the 5% acceptable non-inferiority margin, only a larger sample size with enough events can definitively establish non-inferiority of active monitoring compared to surgery.
• Lord trial (Wesseling et al.) – similar to the Loris population, this multicentre study used a patient-preference design after initial randomisation proved infeasible. On an intention-to-treat basis, ipsilateral invasive BC occurred in 1% (4/363) of women assigned to standard treatment versus 6% (63/1,060) of women undergoing active surveillance. The overall invasive BC incidence (including those detected at primary surgery) was comparable: 9% (33/363) in the standard-treatment group and 6% (63/1,060) in the active surveillance group. The standard revealed invasive Grade 2 and 3 in 46.4% (n=13), with no HER2+ cases, versus surveillance with 70.9% (n=39), including 3.9% HER2+ (n=2). The conclusion was that the surveillance so far is non-inferior.

Surgical Sustainability 

• BuGS trial – breast green surgery (Vanni et al.) – an RCT comparing Bugs (n=55) protocol (awake surgery with regional blocks, day surgery admission, telemedicine follow-up, waste segregation, etc.) versus standard (n=55) showed reduced operating room occupation time (73.04 vs 96.62 min; p = 0.003), shorter length of hospital stay (0.35 vs 1.23 days; p = 0.0001), and decreased surgical waste-related carbon emissions, with no difference in post-operative pain, immediate complications, or quality of life outcomes. This was a small RCT; it indicates potential applicability in breast surgery, including oncoplastic procedures. 

Breast cancer in older women

• E Brain, a leader in elderly breast oncology at Institut Curie, France, discussed the challenges and choices faced by older patients with breast cancer. He noted that while over 50% in this age group have some form of cancer, less than 10% are included in clinical trials overall, including near-exclusion from most breast drug trials (chemotherapy, targeted therapy, and CDK4/6 inhibitors). Understandably, this is due to comorbidities and competing causes of mortality; however, there is a need to improve participation through multimodal support, such as geriatric services. 

EBCC Manifesto session: “Breaking the age barriers: ending discrimination in breast cancer care”

• In line with concerns about age-bias raised in the conference’s first session, the final session focused on ways to eliminate age bias in breast cancer care for both younger and older women. After discussion and voting, the key recommendations that stood out to me for addressing age-related barriers were: designing pragmatic, age-specific trials for both young and old, facilitating their participation, implementing personalised breast cancer screening for women who are not eligible for population-based screening - both younger and older - prioritising the assessment of biological age during routine checks, conducting geriatric assessments, addressing specific needs such as fertility preservation for younger women and maintaining independence for all, and advocating for European adoption of harmonised legislation, including guarantees for a ‘cancer free certificate’ and the ‘right to be forgotten’.

Author: Amit Agrawal, Consultant Oncoplastic Surgeon & Affl. Associate Professor, Cambridge University & Hospitals.