Prognostic Value of Lymphogenic Micrometastasis of Patients with Breast Carcinoma : A Multicenter Cohort Study.

Introduction: Since the introduction of sentinel lymph node biopsy (SLNB) for staging breast cancer, lymphogenic micrometastases are commonly detected. The prognostic meaning of these small lymph node metastases and the consequences regarding the indication for adjuvant systemic treatment is under debate. Currently, robust data with a long time follow up are lacking. Method: Between January 2000 and December 2002 1411 patients with a cT 1-2 N 0 breast carcinoma underwent surgery in seven hospitals in the Netherlands. Pathological examination of the sentinel node consisted of serial sectioning of SLN9s and HE 95% CI 0.58-2.39, HR 2.47; 95% CI 1.69-3.63, HR 4.36; 95% CI 2.70-7.04 respectively). Disease free survival was similar too in the pN 0 and pN 1micro group, and worse for pN 1a and pN ≥1b (HR 0.96; 95% CI 0.56-1.67 vs. HR 1.64; 95% CI 1.19-2.27, HR 2.95; CI 1.98-4.42). Distant metastases were more commonly observed in the pN 1micro group than in the pN 0 group (HR 1.22; 95% CI 0.60-2.49), but not significantly and far less than in the pN 1a and pN ≥1b group (HR 2.26; 95% CI 1.49-3.40, HR 3.49; 95% CI 2.12-5.77). Conclusion: After a relative long time of follow up disease free and overall survival for patients with micrometastasis in SLNs is comparable to patients without lymphogenic metastasis and more favourable than patients with macrometastasis. The presence of micrometastatic disease in the SLN is in itself not an indication for adjuvant systemic therapy. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 307.