[Sentinel node biopsy in T2 breast cancers larger than 3 cm and clinically negative axilla compared with the T1-T2 <3 cm standard indication].

Objective: To present our experience in the application of sentinel node (SN) biopsy in patients with breast cancer T > 3 cm without clinical evidence of axillary metastasis.
Material and Method: Retrospective study of 393 cases in the period 2001--2006, divided into group (A) 47 patients with 3-5 cm T2N0 tumours and group (B) 346 patients T < 3 cm, N0. We employed the combined technique with 99mTc-colloidal rhenium sulphide and isosulfan blue dye. Preoperative lymphoscintigraphy was performed and the SN was located intraoperatively with a gamma ray detection probe and the blue dye. Axillary lymph node dissection was completed only when the SN was positive for metastasis in the histopathology analysis or not located.
Results: The SN detection rate for T2 > 3 cm was 94 % in the scintigraphy and 96 % with the probe, with no statistically significant differences between T < 3 cm (97 % and 98 %). In T2 > 3 cm, the final staging was 45 % pN0, 8 % pN1mi, 34 % pN1a, 11 % pN2a and 2 % pN3a. We found statistically significant differences (p < 0.05) when compared with palpable T < 3 cm and non-palpable cancer (62 % pN0 and 74 % pN0, respectively). In the follow-up of T2 > 3 cm (median 42.88 months) we did not find any axillary relapse which could be considered a false negative of the technique.
Conclusion: The detection of sentinel lymph nodes is feasible and safe in tumours larger than 3cm with clinically negative axilla. Axillary lymph node dissection can be avoided in 45 % of these patients and therefore, we consider that they should be included as a general indication in breast cancer SN detection.