Previous reports of breast cancer have generally analyzed patients with one to three positive lymph nodes as a single group, often leading to controversy regarding the practical clinical applicability. The present study separately analyzed the survival outcomes of Stage T1-T2 breast cancer patients according to whether one, two, or three axillary nodes were pathologically positive.
The records of 5,996 patients were available for analysis from the population-based Saskatchewan provincial registry between 1981 and 1995. Because the reliability of the nodal assessment depends on the number of lymph nodes sampled, only those 755 patients with Stage T1-T2 disease and eight or more nodes examined were analyzed further for overall survival and cause-specific survival (CSS).
Patients with one and two positive nodes had nearly indistinguishable survival plots, but those with three positive nodes had a distinct trend toward worse survival. The overall survival rate of patients with one, two, and three nodes at 5, 10, and 15 years was 82.7%, 77.0%, and 79.0%, 64.8%, 60.9%, and 52.8%, and 48.8%, 48.0%, and 40.9%, respectively (p = .11). The corresponding CSS rates at 5, 10, and 15 years were 89.4%, 82.0%, and 81.3%, 78.87%, 72.9%, and 62.1%, and 72.7%. 69.0%, and 55.6% (p = .0004). The use of regional radiotherapy did not confer any apparent survival benefit in terms of either overall survival or CSS.
Patients with one or two positive nodes had a similar CSS. However, those with three positive nodes fared worse, with a significantly reduced CSS compared with those with one or two involved nodes. Thus, the survival data among patients with one to three nodes positive reveals clearly relevant differences when analyzed separately.