Some breast cancer patients on neoadjuvant chemo may avoid axillary lymph node dissection

A sentinel lymph node biopsy (SLNB) during surgery that showed no signs of cancer was associated with a low risk for breast cancer recurrence in the axillary (armpit) lymph nodes for patients with large, operable breast tumors and no clinical signs of the cancer in the axillary lymph nodes prior to neoadjuvant (presurgery) chemotherapy, according to data from the GANEA 2 clinical trial presented at the 2016 San Antonio Breast Cancer Symposium, held Dec. 6-10.

"Axillary lymph node dissection (ALND), which is an invasive surgical procedure in which many of the lymph nodes in the armpit are removed, is often performed to check whether a patient's cancer has spread outside the breast after neoadjuvant chemotherapy," said Jean-Marc Classe, MD, PhD, head of surgery at the Institut de Cancerologie de l'Ouest René Gauducheau in Nantes, France. "ALND has a high risk for serious complications and long-term sequelae. So we wanted to assess the feasibility and safety of the less invasive procedure of SLNB for patients treated with neoadjuvant chemotherapy for a large breast cancer.

"We found that for patients with no proof of cancer in the axillary lymph nodes before neoadjuvant chemotherapy, SLNB during the surgery after neoadjuvant chemotherapy was safe because those who had a negative SNLB and did not have an ALND had a very low risk of an axillary relapse at three years after surgery," continued Classe, who is also professor of oncology at the Medical University in Nantes. "We had expected more axillary lymph node relapses than we observed, so this is very exciting and will hopefully mean that more patients are spared the potential complications of invasive ALND."

Classe and colleagues enrolled in the trial 590 patients with large, operable breast tumors who had no cancer in the lymph nodes as determined by axillary sonography with fine needle cytology. All patients received neoadjuvant chemotherapy and then underwent surgery and SLNB.

Cancer cells were detected in the SLNB samples from 139 patients. These patients all then underwent ALND. No cancer cells were detected in the SLNB samples from 432 patients. Among these 432 patients, follow-up was available for 416. Median follow-up for these patients was 35.8 months.

At three years, disease-free survival in the patients who had no cancer in the SLNB sample and, therefore, did not receive ALND was 94.8 percent. One patient had homolateral axillary lymph node relapse. The other nine relapses were metastatic (n=3) or recurrences in the breasts (n=6). Overall survival was 98.7 percent.

"The disease-free and overall survival results we observed for the patients who underwent only an SLNB after neoadjuvant chemotherapy are comparable with the historical survival rates for patients in this situation who have ALND rather than SLNB," said Classe. "Therefore, an ALND could be avoided by patients who have no signs of cancer in the axillary lymph nodes following a sonographic axillary assessment prior to neoadjuvant chemotherapy and SLNB during surgery after neoadjuvant chemotherapy."

Classe noted that longer follow-up of the patients is needed to further confirm the safety of SLNB for these patients.