CT assessment of breast cancer for pathological involvement of four or more axillary nodes

To predict the likelihood of ≥4 pathologically positive axillary nodes in breast cancer patients by computed tomography (CT) before neoadjuvant chemotherapy (NAC).

Inclusion criteria for the 97 patients reviewed were lymph nodes (LNs) pathologically proved positive with standard level I-II axillary dissection, contrast-enhanced CT was performed before surgery, contralateral breast cancer was not present, and NAC was not given before surgery. The size, number, and level of both ipsilateral and contralateral axillary LNs were studied by contrast-enhanced high-resolution CT for pathologically positive LNs in breast cancer patients.

Level III LN was only detected in ipsilateral axilla of patients with ≥4 pathologically involved nodes. The number of ipsilateral level I-II LNs is the only factor significantly related to the pathological involvement of ≥4 axillary nodes. Increasing numbers of contralateral level I-II LNs are significantly related to increasing numbers of ipsilateral level I-II LNs. For the criterion of maximal LN size ≥5 mm, if contralateral level I-II LNs were negative and the cutoff points for ipsilateral level I-II LNs were 0-2 and ≥3, the sensitivity and specificity for ≥4 pathologically involved nodes would be 84.6 and 73.3%. If contralateral I-II LNs were positive, the negative predictive value was 80.0%.

Level III LN detection in ipsilateral axilla and the number of level I-II LNs in bilateral axilla will be helpful to predict ≥4 pathologically positive axillary nodes.