[Discussion on the indications of internal mammary sentinel lymph node biopsy in breast cancer in the era of precision medicine].

Objective

To determine the clinical benefits of internal mammary sentinel lymph node biopsy (IM-SLNB) acquired by breast cancer patients with clinically positive axillary lymph node (ALN), and further optimize the IM-SLNB indications.

Methods

All primary breast cancer patients with clinically positive ALN from February 2014 to September 2017 were prospectively recruited in this study. IM-SLNB was performed under the guidance of the modified injection technique. The success rate and visualization rate of IM-SLNB, metastatic rate of internal mammary sentinel lymph node (IMSLN) and its related factors were analyzed, and the clinical benefits were accessed according to the current guidelines.

Results

Among 126 patients, all of 94 patients (74.6%) who showed internal mammary drainage successfully underwent IM-SLNB. The incidence of internal mammary artery bleeding and pleural lesion were 4.3%(4/94) and 9.6%(9/94), respectively. The metastatic rate of IMSLN was 38.3% (36/94), which was significantly associated with the number of positive ALN (P<0.001) and tumor size (P=0.024). The lymph node staging of 94 patients who underwent IM-SLNB was more accurate. Among them, 36 cases with positive IMSLN underwent internal mammary radiotherapy (IMRT), while the other 58 cases with negative IMSLN avoided radiotherapy.

Conclusions

IM-SLNB should be routinely performed in patients with positive ALN. IM-SLNB can provide more accurate staging and guide tailored IMRT to benefit more breast cancer patients.