Predictors of Axillary Lymph Node Involvement in Women with T3 Breast Cancers: Analysis of 1988–2003 SEER Data

BackgroundWe investigated characteristics associated with axillary lymph node (LN) status in patients with T3 breast cancers and hypothesized that LN status is an independent predictor of survival.MethodsCharacteristics associated with axillary LN metastasis among women with T3 breast cancers were identified from the 1988–2003 Surveillance, Epidemiology, and End Results (SEER) database. The primary outcome was breast cancer-specific mortality. Cox models were used to calculate adjusted hazard ratios (aHR) and 95% confidence intervals (CI).ResultsA total of 12,778 patients with T3 breast cancers were analyzed (8201 LN+, 3695 LN–, 882 unknown). LN+ patients were more likely to be <50 y, married, and have ER+/PR+, grade 3 invasive ductal cancers (P<0.01 for each). Most patients underwent mastectomy (87.4%). Post-mastectomy radiation was more commonly used in LN+ patients (P<0.01). LN+ patients had higher breast cancer-specific mortality (36.2% versus 16.4%, P<0.01) and were more likely to die during the follow-up period (aHR = 2.87, 95% CI: 2.62–3.15) compared with LN– patients.ConclusionsAnalysis of the SEER database indicated that several patient and tumor characteristics predict a higher likelihood of axillary LN involvement in patients with T3 breast cancers. LN status was an independent predictor of survival in women with T3 breast cancers.