Clinical Trial Summary
The early diagnosis and evaluation of breast cancer is of great significance to its treatment
and prognosis. Among the multiple factors affecting the prognosis, the degree of axillary
lymph node metastasis is one of the most vital factors.
Accurately understanding the status of axillary lymph nodes prior to surgery allows better
prediction of staging, enables correct treatment plans, and guides the scope of node
dissection during surgery. For patients with early breast cancer or clinically negative
axillary lymph nodes, sentinel lymph node biopsy (SLNB) can largely avoid complications such
as upper extremity lymphedema caused by axillary lymph node dissection (ALND). Thus, clinical
identification of negative lymph nodes becomes more valuable. Based on clinical verification,
the NCCN guidelines (edition 2019) made the following recommendation: SLNB is performed for
patients with clinically negative axillary lymph nodes, and the biopsy findings determine
whether ALND is included; ALND is performed for patients with clinically positive axillary
nodes. Currently, imaging examinations have limitations is assessing axillary lymph nodes.
Finding an accurate and non-invasive method in preoperative axillary assessment has been a
project that needs to be urgently addressed. Ultrasonography has advantages in its
simplicity, non-invasiveness, economy, and on radiation, however it is highly subjective,
dependent upon examiner's experience and knowledge, and is difficult to detect deeper and
small lesions. Molybdenum Target examination plays an important role in diagnosis of breast
cancer, however it is expensive and limited in evaluating the whole axilla. PET-CT is
restricted by its high cost and is not a routine examination in China.
Therefore, computed tomography (CT) scan is more advantageous in determination of lymph node
metastasis. The 2014 GORO KUTOMI study suggested that lymph node morphology assessed as clear
by preoperative CT was an independent predictor of sentinel lymph node metastasis. CT scan
can not only evaluate the presence or absence of distant metastasis and pectoralis muscle
invasion, but also provide intuitive, accurate and detailed evaluation of axillary,
supraclavicular, and pectoralis major intramuscular lymph nodes. The diagnostic criteria of
magnetic resonance imaging (MRI) is relatively vague; CT can also obtain imaging data of the
lungs, mediastinum, whereas MRI has no such function. Based on previous studies, we will
further explore and evaluate axillary node status using prone positioning CT scan and
ultrasound in patients with breast cancer.
A total of 500 patients who are newly diagnosed with operable breast cancer in Liaoning
Oncology Hospital are approached and recruited. Inclusion criteria: 1. preoperative chest CT
and axillary Doppler ultrasound examination in the prone position; 2. perform ALND; 3.
regular follow-up post surgery, short-term and long-term. Exclusion criteria: history of
other benign or malignant tumors causing axillary lymphadenopathy.
Comparisons are made:
A: between suspiciously positive and suspiciously negative axillary lymph nodes B: between
LNSD positive among suspiciously positive axillary lymph nodes and negative axillary lymph
nodes f C: between positive and negative AAUS D: between positive and negative AAUS among
negative lymph nodes detected by CT scan E: between positive and negative AAUS among lymph
nodes with negative LNSD
Chi-square test and t test are used to assess statistical significance between groups.
Methods: Lymph node short diameter (LNSD) is measured using CT scan imaging (LNSD > 1cm is
considered positive), axillary lymph node status is assessed according to axillary lymph node
Doppler ultrasound. ALND will be performed in patients with positive axillary lymph nodes on
CT scan; PALND will be performed for those with negative axillary lymph nodes on CT scan but
positive on AAUS; SLNB will be performed for those with negative axillary lymph nodes on CT
scan and on AAUS.
The prognosis in each patient group is to be evaluated by short-term observational indicators
(e.g. lymphedema and/or status of axillary lymphatic return), and long-term indicators (e.g.
lymphedema and/or axillary lymph node recurrence). The accuracy of CT scan assessing positive
lymph nodes and positive AAUS will be evaluated according to the postoperative histology
results.
