# SN FNAC — Sentinel Node Biopsy After Neoadjuvant Chemotherapy in Biopsy-Proven Node-Positive Breast Cancer

**Autores:** Boileau JF, Poirier B, Basik M, Holloway CMB, Gaboury L, Sideris L, et al.
**Revista:** Journal of Clinical Oncology (2015)
**PMID:** 25452445 | **PMCID:** —
**DOI:** [10.1200/JCO.2014.55.7827](https://doi.org/10.1200/JCO.2014.55.7827)
**Fuente:** PubMed (abstract only — full text vía DOI/institución)

## Relevancia ⭐ PIVOTAL
Tercer ensayo prospectivo pivotal junto a Z1071 y SENTINA que define la viabilidad de SLNB tras NAC en pacientes cN+. La diferencia clave: **uso obligatorio de inmunohistoquímica (IHC)** y considerar **ypN0(i+) ≤0.2mm como positivo** logra una FNR aceptable de **8.4%**. Esto enfatiza que la patología axilar post-NAC debe ser estricta: cualquier célula residual debe contar.

## Abstract

An increasing proportion of patients (>30%) with node-positive breast cancer will obtain an axillary pathologic complete response after neoadjuvant chemotherapy (NAC). If sentinel node (SN) biopsy (SNB) is accurate in this setting, completion node dissection (CND) morbidity could be avoided.

In the prospective multicentric SN FNAC study, patients with biopsy-proven node-positive breast cancer (T0-3, N1-2) underwent both SNB and CND. Immunohistochemistry (IHC) use was mandatory, and SN metastases of any size, including isolated tumor cells (ypN0[i+], ≤0.2 mm), were considered positive. The optimal SNB identification rate (IR) ≥90% and false-negative rate (FNR) ≤10% were predetermined.

From March 2009 to December 2012, 153 patients were accrued to the study. The SNB IR was **87.6%** (127/145; 95% CI, 82.2-93.0%), and the **FNR was 8.4%** (7/83; 95% CI, 2.4-14.4%). If SN ypN0(i+)s had been considered negative, the FNR would have increased to 13.3% (11/83; 95% CI, 6.0-20.6%). There was no correlation between size of SN metastases and rate of positive non-SNs. Using this method, **30.3% of patients could potentially avoid CND**.

In biopsy-proven node-positive breast cancer after NAC, a low SNB FNR (8.4%) can be achieved with mandatory use of IHC. **SN metastases of any size should be considered positive.** The SNB IR was 87.6%, and in the presence of a technical failure, axillary node dissection should be performed.

## Implicaciones prácticas
- Considerar **ITC (≤0.2 mm) como ypN+** y NO omitir ALND
- IHC obligatoria en todos los SLN tras NAC
- Si no se identifica SLN (fallo técnico) → ALND

## Acceso
Artículo no disponible en PMC. Acceder vía [DOI](https://doi.org/10.1200/JCO.2014.55.7827) o suscripción institucional.

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*Datos de PubMed. Citar: doi 10.1200/JCO.2014.55.7827*
