Objective
To investigate the feasibility of internal mammary sentinel lymph node biop
sy as a method to refine and thereby improve nodal staging in breast cancer
.
Summary Background Data
The internal mammary lymph node status is a major prognostic factor in brea
st cancer. If positive, prognosis is less favorable. However, staging this
regional nodal basin is not performed routinely, thus discarding additional
staging information.
Methods
in a consecutive series of 256 patients with primary breast cancer, sentine
l node biopsy was performed based on lymphoscintigraphy, intraoperative gam
ma probe detection, and blue dye mapping using 10 mCi (370 MBq)Tc-99m-nanoc
olloid injected peritumorally and 0.5 to 1.0 mt Patent Blue V injected intr
adermally, During surgery. whenever possible, both axillary and internal ma
mmary sentinel nodes were sampled.
Results
Lymphoscintigraphy showed axillary sentinel nodes in 95% (243/256) and addi
tional internal mammary sentinel nodes in 25.3% (65/256). The overall succe
ss rate of axillary sentinel node biopsy was 97% (249/256). Sampling the in
ternal mammary basin, based on the results of lymphoscintigraphy, was succe
ssful in 63% (41/65), In three patients a small pleural lesion resulted fro
m staging this basin. This technique revealed internal mammary metastases i
n 26.8% (11/41). In 7.3% (3/41), internal mammary nodes showed metastatic i
nvolvement without accompanying axillary metastases.
Conclusions
internal mammary sentinel node biopsy is feasible without serious additiona
l complications. it improves nodal staging in breast cancer by identifying
higher-risk subgroups with internal mammary nodal metastases, which might b
enefit from altered adjuvant treatment regimens.