Aims: Presence of axillary lymph node metastases is considered the most important prognostic factor for breast cancer survival. In a period of increasing popularity for the sentinel node procedure, clarity about the possible relation between axillary dissection and survival is essential. This study investigated whether the total number of removed lymph nodes and the ratio of invaded/removed lymph nodes (lymph node ratio (LNR) would prove to be independent prognostic factors for survival.
Methods: Data from 453 consecutive patients with stage I or II breast cancer were studied retrospectively. The total number of removed lymph nodes and the LNR were analysed for their prognostic value in comparison with known prognostic factors.
Results: Node-negative patients with < 14 lymph nodes removed had a 10 year survival of 79% compared with 89% in patients with > or = 14 lymph nodes removed (P=0.005). The 10 year survival for patients with an LNR > or = 0.2 was 52%, compared with 73% for patients with an LNR < 0.2 (P<0.0001). A Cox proportional hazards model showed that, for node-negative patients, only age and total number of removed lymph nodes were significant prognostic factors. For node-positive patients, age, total number of removed lymph nodes and the LNR were significant risk factors for survival outcome. The LNR was also significantly associated with the presence of distant metastases during follow-up (hazard ratio 3.56, range 1.63-7.77).
Conclusions: In stage I and II breast cancer, a favourable prognosis was found for node-negative patients with > or = 14 removed lymph nodes. Before axillary lymph node dissection with its well-defined survival prognosis is replaced by less invasive staging methods, long-term survival using new staging techniques needs to be defined. For node-positive patients, the LNR proved to be an excellent predictor for survival outcome or development of metastatic disease. Selection of lymph node-positive patients based on the LNR may guide specific adjuvant treatment choices.