Implicaciones de la biopsia selectiva de ganglio centinela en cadena mamaria interna sobre la radioterapia adyuvante en mujeres con cáncer de mama sin invasión axilar / Role of internal mammary sentinel lymph node biopsy in adjuvant radiotherapy in women with breast cancer without axillary involvement

Objetivo: Determinar la implicación de la biopsia selectiva de ganglio centinela (BSGC) a nivel de la cadena mamaria interna (CMI) en la radioterapia (RT) adyuvante cuando no se realiza BSGC a nivel axilar en pacientes con cáncer de mama. Pacientes y métodos: Se realizó un estudio analítico retrospectivo seleccionando pacientes con cáncer de mama en estadios precoces diagnosticado entre enero de 2008 y diciembre de 2016. Se incluyeron únicamente aquellas pacientes con indicación de BSGC y migración exclusiva del radiotrazador a CMI. Se recogieron las características clínicas de las pacientes y anatomopatológicas del tumor, el tratamiento quirúrgico, el tratamiento adyuvante, la recurrencia locorregional y la supervivencia global. Resultados: Se diagnosticaron un total de 2.622 carcinomas infiltrantes de mama. Se documentó drenaje exclusivo a CMI en 23 pacientes (2,2%). En el 65,2% (15/23) se localizó el ganglio centinela en CMI y se extrajeron una media de 1,61 ganglios. Se administró RT adyuvante sobre CMI en el 75% de las pacientes que recibieron RT sobre cadenas ganglionares. Se administró quimioterapia en el 52,2% (12/23) y hormonoterapia en el 87% (20/23) de las pacientes. Se encontró asociación estadísticamente significativa entre la localización del ganglio centinela y la RT sobre la CMI (p<0,003) y también entre el resultado del ganglio centinela y la RT a este nivel (p<0,006). Una de las pacientes presentó una recidiva mamaria y otra tuvo metástasis óseas. La mediana de seguimiento fue de 60 meses. No se notificó ningún fallecimiento. Conclusiones: Tanto el éxito en la localización del ganglio como el resultado de la biopsia en CMI modifican de manera significativa la RT a este nivel

Objective: To determine the role of internal mammary sentinel lymph node (IM-SLN) biopsy in adjuvant radiotherapy in female patients with early-stage breast cancer when axillary lymph node biopsy is not performed. Patients and methods: Retrospective cohort study of female patients with early-stage breast cancer diagnosed between January 2008 and December 2016. Only patients with an indication for SLN biopsy and migration of the radiotracer into the internal mammary nodes were included. Data were recorded and analysed on the patients' clinical features, tumour histology, surgical treatment, adjuvant treatment, locoregional recurrence and overall survival. Results: A total of 2,622 invasive breast carcinomas were diagnosed. Twenty-three (2.2%) patients had exclusive drainage to the internal mammary nodes. IM-SLN was detected in 65.2% (15/23) of patients, with a mean of 1.61 nodes harvested per patient. Seventy-five per cent of patients receiving adjuvant radiation therapy received it on the internal mammary chain. Chemotherapy and endocrine therapy were administered to 52.2% (12/23) and 87% (20/23) of patients, respectively. A statistically significant association was found between IM-SLN identification and radiotherapy to the internal mammary chain (P<.003), as well as between IM-SLN involvement and radiotherapy to the internal mammary chain (P<.006). One patient developed breast cancer recurrence and another patient developed bone metastases. The median follow-up was 60 months. No deaths were reported. Conclusions: Both IM-SLN identification and involvement modify the rate of radiotherapy to the internal mammary chain in patients with early-stage breast cancer

Therapeutic attitude towards internal mammary chain drainage in patients with breast cancer.

Internal mammary chain (IMC) is one of the main local lymph drainages in breast cancer. However, internal mammary chain sentinel lymph node biopsy (IMC-SLNB) is not always performed. The purpose of this research is to evaluate the outcomes of IMC-SLNB in our institution from 2008 to 2014. We analyzed 1346 women with breast cancer. Six-hundred twenty-two sentinel node biopsies were carried out, one out of ten in IMC territory. Adjuvant radiotherapy in this area was added when positive. IMC-SLNB is feasible, it may change tumour stage, modify adjuvant therapy and change prognosis in selected patients.