Axillary surgery in patients with breast cancer with one to three positive micro- or macrometastases in the sentinel lymph nodes: an observational study.

BACKGROUND

The Japanese Society for Sentinel Node Navigation Surgery conducted a multi-institutional prospective cohort study to compare sentinel node biopsy (SNB) with SNB followed by axillary lymph node dissection (ALND) in breast cancer patients with positive sentinel lymph node (SLN).

PATIENTS AND METHODS

Female patients with breast cancer with cT1-3N0-1M0 were eligible. In cases of one to three positive micro- or macrometastases in the SLN confirmed by histological or molecular diagnosis, SNB alone (SNB group) or additional ALND (ALND group) was performed under physician's discretion. The primary endpoint was the 5-year regional node (RN) recurrence rate in the SNB group. Propensity score matching (PSM) was performed to compare the prognosis between the two groups.

RESULTS

Of the 871 eligible cases registered between 2013 and 2016, 308 underwent SNB alone. At the median follow-up of 6.3 years, 5-year RN recurrence rate was 2.7%. After PSM, 209 cases were matched in each group. Breast-conserving surgery and mastectomy were performed in 225 (54%) and 193 cases (46%), respectively. One-positive SLN was recorded in 366 cases (88%), two in 48 (11%), and three in 4 (1%). Macro- and micrometastases in SLN were diagnosed in 271 (65%) and 147 cases (35%), respectively. Regional nodal irradiation (RNI) was performed in 42 (20%) and 13 (6%) cases of the SNB and ALND group. The 5-year RN recurrence rate was 2.1% and 2.0%, respectively.

CONCLUSIONS

ALND is not necessary for early breast cancer patients with one-positive SLN despite type of breast surgery.