Complete Pathological Response Prediction After Neoadjuvant Treatment Using Excisional Biopsy By Radiofrequency In Breast Cancer From II-III UICC Stages.

Breast cancer is a set of at least 4 different diseases, currently known as intrinsic genomic subtypes. Two of them are the so-called HER2-enriched, characterized by the HER-2 oncogene amplification, and the basal-like, which correlates closely with some of the triple negative tumors (TNBC). These subtypes are very sensitive to the primary medical treatment (neoadjuvant or Presurgical). The use of modern medical treatments as initial treatment, can allow the complete disappearance of cancer in the breast and axilla (pathologic complete response, CPR) in 40% of patients with TNBC and around 60% of patients with HER2-positive tumors in stage II and III.

The need of local surgery in patients where the tumor disappeared completely (CPR) after primary medical treatment, is recently questioned, the improvement is not clear and radiotherapy could be sufficient to assure the locoregional disease control.

The use of conventional diagnostic techniques (MRI, ultrasound, mammography and PET) is not enough reliable to determine the pathological complete response, making difficult to adopt an attitude of surgical abstention. The existence of a minimally invasive technique that could reliably determine the absence of cancer after primary medical treatment surgery, could avoid the surgery in these cases.

Percutaneous biopsy guided by ultrasound radiofrequency is a technique that allows the complete resection of breast lesions up to 2 cm of diameter with minimal aggression to the mammary gland from the area of the initial tumor after the neoadjuvant treatment.

Several studies report the use of this technique in patients with breast cancer. Results show a good tolerability of the technique by the patients and suggest that it would not only reduce the need of the re-excision, but also reduce the rate of local recurrence due to radiation absence.