Sentinel Lymph Node Biopsy(SNB) in Early Stage Breast Cancer, When Less is More?

The latest American Society of Clinical Oncology(ASCO) guidelines on early stage breast cancer sentinel lymph node biopsy (sentinel lymphnode biopsy, SNB) was released on Marth 24, 2014.

"Women with operable breast cancer and multicentric tumors, with ductal carcinoma in situ (DCIS) who will undergo mastectomy, who previously underwent breast and/or axillary surgery, or who received preoperative/neoadjuvant systemic therapy may be offered SNB." with intermediate evidence and moderate recommendation strength--excerpted form ASCO on SNB.

Viviana Galimberti, MD PhD
Photo: Oncology Frontier

At St. Gallen Breast Cancer Conference 2015, Vienna, Austria, Viviana Galimberti, MD PhD, Codirector of Moleculare Breast Care, European Institute of Oncology(IEO) discussed some topics on SNB with "Oncology Frontier(肿瘤瞭望)"。

Less extensive procedures are keeping the trend of local therapy in breast cancer. More and more studies are trying to prove the omission of axillary dissection is safe. Could you summarize the latest updates and what conclusions we can draw from them?
 

Dr Galimberti: There are two important trials linked to sentinel node biopsy. One is the IBCSG trial which randomized patients with sentinel node biopsy with micrometastases. One arm received axillary resection and one arm didn't. After a median follow-up of five years, we have found that there is no evidence that axillary resection improves outcomes. This is an important finding because even if we perform conservative treatment or mastectomy, when we find a micrometastatic sentinel node (<2mm) then we can avoid axillary resection.

The other important trial is the Z0011 study that randomized patients undergoing conservative surgery plus sentinel node biopsy and those found to have one or two nodes with macrometastases (>2mm) were randomized to axillary resection versus no axillary resection. Even in this case, the overall survival and disease-free survival was similar. So again, in this case, we can omit axillary resection if we perform adjuvant treatment and whole breast radiation.
　

Neoadjuvant chemotherapy is widely used now. Patients benefit from such therapy. However， some questions come up with it. In your lecture you addressed one of this questions regarding sentinel node biopsy after neoadjuvant chemotherapy. What’s the significance and feasibility of it and how do we interpret the results of biopsies in such a setting?

Dr Galimberti: This is another important issue. The concern is if the patient starts with a negative axilla and after neoadjuvant therapy you perform a sentinel node biopsy. A lot of studies have confirmed that it is safer because we can find it easily and there is a good identification rate but also a low false negative rate.

The controversy is if a patient had a confirmed positive axilla with fine needle biopsy before neoadjuvant treatment, and for those who became negative after the therapy, should you perform sentinel node biopsy? Several prospective trials (SNAC, SENTINA and Z1071) showed that performing sentinel node biopsy and axillary resection found a very high false negative rate, so they recommended caution in not performing axillary resection in those cases. But no one studied the outcomes for these patients.

We did a study that showed that even if we performed sentinel node biopsy on those who were sentinel node-positive and then became negative, there is no difference in outcome.

Could you talk about your experience with second axillary sentinel lymph node biopsy for breast cancer recurrence?

Dr Galimberti: At the beginning of the sentinel node experience, we thought it would be impossible to repeat node biopsy when there is a recurrence. We have published a study recently showing that sometimes lymphoscintigraphy can reveal a new sentinel node in the axilla again, and that there is another opportunity to avoid axillary resection again with a sentinel lymph node biopsy.

Reproduced from "Oncology Frontier"

Reference:

[SG-BCC2015]乳腺癌前哨淋巴结活检在新辅助化疗后的应用--VivianaGalimberti博士访谈
2015/3/25 17:14:49 肿瘤瞭望 公众微信