EXPERIENCE OF SENTINEL NODE BIOPSY ALONE IN EARLY BREAST CANCER WITHOUT FURTHER AXILLARY DISSECTION IN PATIENTS WITH NEGATIVE SENTINEL NODE

Abstract

The aims of surgical therapy of breast cancer are loco-regional tumour control and staging. Axillary staging is still considered the single most important prognostic indicator in breast cancer. Surgical removal of axillary nodes remains the standard way to assess their involvement in most centres. The morbidity associated with axillary dissection (AD) is well recognized. In recent years sentinel node biopsy (SNB) has evolved. Multiple studies suggest it has the same accuracy as AD in axillary staging and less morbidity in early breast cancer (EBC). SNB has become the standard of practice in EBC in many parts of the world. In Australia, the preference has been to wait for the results of the Sentinel Node versus Axillary Clearance (SNAC) trial as well as other international trials before accepting SNB as a standard of care. The experience of a single surgeon with SNB alone in EBC without further completion axillary dissection (CAD) in negative sentinel node (SLN) is described in the present paper. An audit was done of the senior author's prospective data from the Royal Australasian College of Surgeons database. Other information was added retrospectively from case notes. Between December 2000 and December 2003, 154 EBC cases (153 patients) underwent SNB alone. An average of four SLN was removed. Of these cases, 31.8% had positive SLNs (excluding 2.6% cases that had isolated tumour cells), of these, 93.9% had metastases (39.1% micro- and 60.9% macro-metastases) in axillary-SLN (ASLN) and almost all of these had CAD. ASLNs were the only positive nodes in 73.9%. Extra-ASLN retrieved in 68.8% of 34% demonstrated on lymphoscintigraphy. Of these, 12.1% were positive (6.1% micro- and macro-metastases each), all internal mammary. Mean follow up was 22.1 months. There was one local-regional-systemic and one systemic recurrence over this time. SNB has a valid role in staging of the axilla particularly in low-risk patients. After adequate self audit, SNB offers a minimal morbidity and reliable method of axillary staging. Patients choosing SNB alone must understand that the long-term results of the randomized controlled trial are still pending for level I evidence of long-term efficacy.