[Sentinel node biopsy without systematic axillary dissection: study about 1000 procedures]

To assess daily practice of 1000 sentinel node (SN) biopsies in breast cancer.

Prospective review of 1000 consecutive sentinel node biopsies between February 2001 and June 2004. Analyses concerned technical aspects of sentinel node detection, pathologic results of the tumor and sentinel node, treatment and follow-up.

Nine hundred and seventy-eight SN were detected (98.7%). In univariate analyses, age, pathologic tumor size (20 mm) and method of detection (blue dye or isotopic vs. combined) were statistically significant. One hundred and fifty-six cases (16%) underwent immediate axillary dissection (AD), whereas 116 (12%) had a delayed AD. There were 923 invasive or micro-invasive carcinoma with detected SN: 282 SN (30.5%) were involved, either with macrometastases (166) or with micrometastases (116), 34% had positive non-sentinel node. Age and metastasis size were predictive for AD involvement. Sixteen percent of micrometastatic SN had positive AD, there was no predictive factor for axillary involvement. After a median follow-up of 20 months, there were 4 axillary recurrences: 1 (0.1%) after negative SN without AD, 1 (0.1%) after positive SN with positive AD, 1 (4.3%) after micrometatastatic SN without AD, and 1 (8.3%) after macrometastatic SN without AD. There were 55 ductal carcinoma in situ and 54 micro-invasive cancer: positive SN (with negative AD) were detected in only 2 cases (2.3%). There were initially 112 ductal carcinoma in situ diagnosed by percutaneaous biopsy, 25 of them (22%) had invasive disease on definitive histology. Among there, 12 had involved SN (with 4 positive AD).

With a high detection rate and low recurrence rate, SN biopsy is considered in our institute as a reliable procedure and is used to evaluate regional nodal status of early breast cancer. Thus, 70% of AD can be omitted.