INTERNAL MAMMARY NODE STATUS - A MAJOR PROGNOSTICATOR IN AXILLARY NODE-NEGATIVE BREAST-CANCER

Background: The internal mammary lymph nodes (IMN) have received little attention in recent years, yet are a well-documented site of metastasis and a major prognostic factor in early-stage breast cancer. Methods/Results: Ten-year follow-up of the final 195 patients treated by extended radical mastectomy (ERM) in this practice (selected largely on the basis of medial tumor location, and comprising 15% of all patients treated from 1965 to 1978) found IMN + in 24% of all cases: 36% of AX + versus 18% of AX patients (p = 0.0023). In a multivariate analysis, the disease-free survival impact of IMN + (p = 0.004) was second only to axillary node involvement (p < 0.0005), and surpassed tumor size (p = 0.077). IMN + was equally frequent for tumors less than, or greater than, 2 cm (24%), and was not significantly related to patient age. Among AX - patients, there was a twofold greater risk of recurrence or death at 10 years for IMN + than for IMN-. Among T1NO patients, 19.6% were IMN +. Conclusions: Failure to consider IMN status in the steadily enlarging cohort of T1NO breast cancers may result in the undertreatment of a significant proportion of stage I patients. Systemic adjuvant therapy should be considered for T1NO patients with central or medial tumors.