[Modulation of the axillary lymph node dissection in breast cancer]

Several studies showed the reliability of the sentinel lymph node (SN) technique in the evaluation of the N parameter in breast cancer so much to induce surgeons to limit the axillary dissection to the biopsy of the SN alone (SNB) in case this is negative to the extemporaneous examination. After a period of focusing on the identification technique, biopsy and histological examination of the SN (October 97-January 98) always followed by a complete dissection of the three axillary node levels (ALND), we started a study to evaluate the reliability of a limited dissection of the 1st level of the axilla (FLND) in women with T < 3 cm, N0-1a, M0, that did not undergo any neoadjuvant treatment and in which the SN resulted free from metastases. We started this phase of the study in February 1998 till May 2001. In the present paper we show the results related to this period.

We enrolled 256 women with T < 3 cm, N0-1a, M0. In 49 cases we used vital dye, in 23 dye + radioguided surgery (RGS) and in 184 RGS only. The extemporaneous histological examination of the SN has been performed with thin sections, dyed with EE. When SN was negative to the intraoperative examination, we limited the dissection to the 1st level of the axilla, except that in 3 patients, with SN located to the 2nd level, in which we did an ALND. The FLND has been performed in 17 cases with a minimally invasive technique. The definitive histological examination of the SN always included the immunohistochemistry. If the SN was positive, usually underestimated to the intraoperative examination, the patients had an adjuvant chemotherapy.

In 203/207 patients (98.1%) SN was found to the pre-operative lymphoscintigraphy. During surgery the SN was identified in 46/49 (94%) using the vital dye, in 22/23 (96%) using the vital dye + RGS and in 176/179 (98.3%) using RGS. To the extemporaneous histological examination SN was negative in 140, metastatic in 101; to the histological definitive results of the SN we noticed 6 false negative, since others lymph nodes than SN were positive (4 cases) or for evidence of micrometastases at the immunohistochemistry which were not detected at the extemporaneous examination (2 cases). On 107 cases of N+ the SN was the only metastatic lymph node in 42 (39.3%). The false negative percentage was 5.6% and the diagnostic accuracy of the SNB was 97.5%. In the group treated with FLND we only noticed two cases of light lymphedema (1.4%).

Our results are in concordance with the international literature and they induced us, from June 2001, to begin a new phase of the study in which we limit the dissection of the axilla to the SN only, if not metastatic, in women with T1 breast carcinoma.