Clinicopathological characteristics of breast cancers with axillary skip metastases.

OBJECTIVE: The presence of discontinuous or "skip" metastases in breast cancer is crucial for determining the optimal therapeutic choice. In this study, we compared the clinicopathological characteristics and prognosis of patients with or without skip metastases (SMs).

METHODS: We retrospectively analyzed the records of 1,502 breast cancer patients who underwent radical mastectomy and a separate group of 118 patients who had sentinel lymph node biopsies (SLNB). The median follow-up time was 10 years.

RESULTS: Axillary lymph nodes (ALN) were involved in 814/1502 patients, and SMs was found in 119 patients (14.6%). Age, tumor size, location, clinical stage, and the proportion of interpectoral lymph node (IPN) metastases were similar in patients with or without SMs (p > .05). In stage I and II disease, the event-free survival rate of patients with SMs was significantly lower than patients without (p < .05); there was no significant difference in stage III patients (p > .05). The Cox multivariate analysis showed that the tumor size, number of lymphatic metastases, lymph node involvement, and SMs were important prognostic factors. The false-negative rate of SLNB was 12.0% (3/25).

CONCLUSION: Axillary lymphatic SM is difficult to predict, but their presence can predict a poorer prognosis for stage I and II patients. SM could occur in SLNB-negative patients.