# Neoadjuvant Chemotherapy and Nodal Response Rates in Luminal Breast Cancer: Effects of Age and Tumor Ki67

**Autores:** Judy C Boughey, Tanya L Hoskin, Matthew P Goetz
**Revista:** Ann Surg Oncol (2022)
**PMID:** 35569077 | **PMCID:** PMC9466990
**DOI:** [10.1245/s10434-022-11871-z](https://doi.org/10.1245/s10434-022-11871-z)
**Fuente:** PubMed Central (open access full-text)

## Relevancia
Cohorte de 315 pacientes ER+/HER2- cN+ con NAC. Tasa pCR nodal 24.8% global, pero hasta 36% en <50 años con Ki67≥20%, frente a 2.6% en ≥50 años con Ki67<20%. Permite identificar candidatas a NAC con probabilidad realista de conversión a ypN0 y evitar NAC ineficaz en subgrupos luminales de bajo Ki67.

## Abstract
Neoadjuvant chemotherapy (NAC) is standard for most triple-negative and human epidermal growth factor receptor 2 (HER2)+ breast cancers, and frequently downstages node-positive (cN+) disease, permitting omission of axillary dissection. In estrogen receptor (ER)+/HER2- disease, response rates are lower. Whether Ki67 is associated with axillary downstaging in ER+/HER2- disease is unknown.

With institutional review board approval, we queried our institutional database to identify all patients with primary ER+/HER2- biopsy-proven cN+ breast cancer treated with NAC followed by surgery from January 2012 to December 2021. Nodal pathologic complete response (pCR) rates were evaluated by pretreatment Ki67 and patient age.

315 patients (median age 50 years) were included. Nodal pCR rate was 24.8% (78/315) and was higher in patients aged < 50 years than ≥ 50 years (31.8% versus 17.7%, p = 0.004). Ki67 was available on 236 patients (74.9%). Median Ki67 was 29.0% (range 1-98%) and did not differ by age category (p = 0.23). Patients with nodal pCR had higher Ki67 (median 40.3% versus 25.0%, p < 0.001). Nodal pCR rates were 28.4% (Ki67 ≥ 20%) versus 8.1% (Ki67 < 20%) (p < 0.001). On multivariable analysis, Ki67 and age category were predictive of nodal pCR. Combining these two parameters together, nodal pCR rates in age < 50 years were 35.8% when Ki67 ≥ 20% versus 14.3% with Ki67 < 20% (p = 0.02). In contrast, for age ≥ 50 years, nodal pCR was 21.0% for Ki67 ≥ 20% versus 2.6% with Ki67 < 20% (p = 0.008).

In ER+/HER2- breast cancer, nodal downstaging with NAC is associated with age (< 50 years) and Ki67 (≥ 20%). Age and Ki67 should be considered for NAC decision-making and can identify patients with high rates of nodal downstaging (36%) who would benefit from NAC to enable axillary preservation.

## Texto completo
Texto completo disponible en PMC: [PMC9466990](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9466990/). El estudio analiza dos variables clínicas (edad y Ki67) como predictoras de pCR ganglionar en ER+/HER2- cN+ tratadas con QT neoadyuvante. La combinación de edad <50 y Ki67 ≥20% identifica un subgrupo con tasa de conversión a ypN0 del 36%. Útil para la selección de pacientes con buena probabilidad de conversión cN+→ypN0 dentro del subtipo más resistente.

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*Datos de PubMed. Citar: doi 10.1245/s10434-022-11871-z*
