Predictors of axillary lymph node metastases in women with early breast cancer in Singapore.

INTRODUCTION

The presence of axillary lymph node metastases is an important prognostic factor in breast cancer. Sentinel lymph node biopsy (SLNB) is an emerging method for the staging of the axilla. It is hoped that with SLNB, the morbidity from axillary lymph node dissection (ALND) can be avoided without compromising the staging and management of early breast cancer. However, only patients found to be SLNB negative benefit from this procedure, as those with positive SLNB may still require ALND. Our objective is to study the various clinico-pathological factors to find predictive factors for axillary lymph node involvement in early breast cancer. It is hoped that with these factors, we will be better able to identify groups of patients most likely to benefit from SLNB.

METHODS

A retrospective study of 380 early breast cancer cases (stage T1 and T2, N0, N1, M0) in women treated in the Department of General Surgery, Tan Tock Seng Hospital, between January 1999 and August 2002, was conducted. Incidence of nodal metastases was correlated with clinico-pathological factors, and analysed by univariate and multivariate analyses.

RESULTS

Approximately 35 percent of the 380 cases of early breast cancer had nodal metastases. Multivariate analyses revealed four independent predictors of node positivity: tumour size (p-value equals 0.0001), presence of lymphovascular invasion (p-value is less than 0.0001), tumours with histology other than invasive ductal or lobular carcinoma (p-value equals 0.04), and presence of progesterone receptors (p-value equals 0.05).

CONCLUSION

We have found independent preoperative predictive factors in our local population for the presence of nodal metastases. This information can aid patient selection for SLNB and improve patient counselling.