# RISAS Sub-Análisis: PET/CT Pre-NAC + Subtipo Molecular como Predictores de ypN0 Axilar

**Autores:** van Amstel FJG, de Mooij CM, Simons JM, Mitea C, van Diest PJ, Nelemans PJ, van der Pol CC, Luiten EJT, Koppert LB, Smidt ML, van Nijnatten TJA
**Revista:** British Journal of Surgery (2024)
**PMID:** 39302345 | **PMCID:** PMC11414043
**DOI:** [10.1093/bjs/znae203](https://doi.org/10.1093/bjs/znae203)
**Fuente:** PubMed Central (open access)
**Trial:** RISAS (NCT02800317) — sub-análisis

## Relevancia
Sub-análisis del ensayo RISAS que evalúa predictores de respuesta nodal completa (ypN0) post-NAC. **Conclusión clave: el subtipo molecular es el predictor dominante** (OR 40 para HR-/HER2+ y OR 14.82 para HR+/HER2+ frente a HR+/HER2-), mientras que la extensión de la enfermedad axilar en PET/CT pre-NAC NO es un predictor significativo. Apoya la estratificación por biología tumoral más que por carga axilar inicial.

## Abstract

**Background:** Axillary disease extent according to baseline [18F]fluorodeoxyglucose PET/CT combined with pathological axillary treatment response has been proposed to guide de-escalation of axillary treatment for clinically node-positive breast cancer patients treated with neoadjuvant systemic therapy. The aim of this study was to assess whether axillary disease extent according to baseline [18F]fluorodeoxyglucose PET/CT and breast cancer molecular subtype are predictors of axillary pCR.

**Methods:** This study included clinically node-positive patients treated with neoadjuvant systemic therapy in the prospective RISAS trial (NCT02800317) with baseline [18F]FDG PET/CT imaging available. The predictive value of axillary disease extent according to baseline PET/CT and breast cancer molecular subtype to estimate axillary pCR was evaluated using logistic regression analysis.

**Results:** Overall, 185 patients were included, with an **axillary pCR rate of 29.7%**. The axillary pCR rate for patients with limited versus advanced baseline axillary disease according to [18F]FDG PET/CT was 31.9% versus 26.1% respectively. **Axillary disease extent was NOT a significant predictor** of axillary pCR (OR 0.75 (95% CI 0.38-1.46) (p=0.404)). 

**Significant differences by molecular subtype:**
- HR+/HER2-: 7% (reference, lowest)
- HR+/HER2+: OR 14.82
- HR-/HER2+: OR 40 (highest)
- Triple-negative: OR 6.91 (p<0.001)

**Conclusion:** **Molecular subtype is a significant predictor of axillary pCR** after neoadjuvant systemic therapy, whereas **axillary disease extent according to baseline [18F]FDG PET/CT is not**.

## Acceso
Disponible en PMC: https://pmc.ncbi.nlm.nih.gov/articles/PMC11414043/

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*Datos de PubMed/PMC. Citar: doi 10.1093/bjs/znae203*
