A prospective study of the value of axillary node sampling in addition to sentinel lymph node biopsy in patients with breast cancer☆
Introduction
Currently there is considerable interest in sentinel lymph node biopsy (SLNB) as an alternative staging technique to conventional axillary surgery in women with primary breast cancer. Sentinel node biopsy has been reported as a minimally invasive, accurate means of staging the axilla, allowing selective axillary dissection only in those patients with axillary nodal disease.1., 2. Women with a tumour free sentinel node (SLN) are highly unlikely to have metastases in the remainder of the axilla3 and can therefore be spared the potential morbidity of a full axillary dissection. Furthermore, since fewer nodes are excised, a more detailed histological examination is feasible thus improving staging accuracy.
The two main parameters for assessing the success of a SLNB practice are the identification rate and the false negative (FN) rate. A completion axillary lymph node dissection (cALND) should be carried out until an acceptable level of accuracy has been demonstrated. An identification rate of >90% and a FN rate of ≤5% have been suggested as acceptable.4 A number of studies from experienced centres have reported excellent results with FN results below 5%.1., 2., 5., 6., 7. However, many more studies have shown FN rates higher than the 5% guidelines, even as high as 29%.8., 9., 10., 11.
A number of factors are thought to contribute to FN results. One important factor is a heavy tumour load in the true SLN which is thought to result in the diversion of the blue dye or isotope to a tumour free ‘neo-sentinel node’.12 Several reports in the literature have highlighted the importance of palpating the axilla for clinically suspicious non-SLNs and have advocated biopsy of such nodes to minimise FN results.11., 13., 14., 15., 16. These reports suggest palpation for clinically involved nodes may reduce but not entirely eliminate all FN cases.
Axillary sampling is frequently used in the UK as a means of staging the axilla, either routinely for all patients or selectively in those patients thought to be at low risk of axillary disease. This method involves palpating the lower axilla and excising a minimum of four lymph nodes thought most likely to contain metastases. Several studies have shown AS techniques to be as accurate as ALND with no difference in axillary recurrence rates between women staged by the two methods.17., 18., 19. Other studies, however, have concluded that AS is not as accurate as ALND and metastases may be missed if less than 10 nodes are examined.20., 21.
The first aim of our study was to compare the accuracy of a ‘combined sentinel node+sampling procedure’ (SLNB+AS) to SLNB alone. We have further evaluated whether additional AS is useful only in those patients with clinically suspicious nodes or if routine additional sampling in all cases further improves accuracy.
The second aim of the study was to evaluate if in the presence of a tumour positive SLN, a tumour free AS predicts those patients with no further disease in the axilla. A number of studies have shown that in 38–66% of cases with metastasis in the SLN, no further disease is found when cALND is undertaken.1., 2. We investigated whether women with a positive SLN but no further disease in the axilla could be identified by additional AS and therefore spared a cALND.
Section snippets
Patients and methods
As part of an on-going study of sentinel node biopsy in women with primary invasive breast cancer, 67 combined sentinel node+sampling procedures were performed in 66 consecutive women (1 patient with bilateral breast cancer). All patients were operated on by the same surgeon (PSS) between February 2000 and July 2001. Local Ethical Committee approval was given for the study and written informed consent was obtained from all participants.
The study group consisted of both screen detected and
Results
The median age of the patients was 55 yr (range 27–86 yr). Lymphoscintigraphy identified sentinel nodes in 49/66 cases (74.2%). Intra-operatively sentinel nodes were identified in 65/67 cases (identification rate 97.0%). The median number of sentinel nodes excised per case was 2 (range 1–8) and the median number of nodes excised for the combined SLNB+AS was 5 (range 2–14). The median total number of nodes harvested (SLNB+AS+cALND) was 16 (range 7–35).
In 83% cases the sentinel node(s) were
Discussion
The major limitation of the technique of sentinel node biopsy is the FN rate and several explanations have been suggested as to why this may occur. Firstly, tumour cells may occasionally pass through to second tier nodes whilst tracers used to identify the SLN remain in the first echelon nodes. The second suggestion is that lymphatic flow from a particular area may differ at times resulting in tumour cells and tracers migrating to different nodes.22 These two problems may be difficult to avoid.
Acknowledgements
Dr S.-Y. Chan and Dr J. Gearty, Consultant Pathologists, City Hospital. Dr A. Notghi, Consultant in Nuclear Medicine, City Hospital. Mr I. Donovan, Consultant Surgeon, City Hospital.
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Cited by (20)
Sentinel node biopsy versus low axillary sampling in women with clinically node negative operable breast cancer
2013, BreastCitation Excerpt :Some centers in the UK have adopted a 4-node axillary sampling (4NAS) [12,13] to predict axillary nodal status. A modification of 4NAS is the concurrent use of blue dye to improve identification of lymph nodes [14–17]. We reasoned that predicting axillary lymph node status would be more easily achieved by excising fatty tissue in an anatomically defined area in the lower axilla or low axillary sampling (LAS).
Axillary Dissection
2012, Current Problems in CancerUse of Reoperative Sentinel Lymph Node Biopsy in Breast Cancer Patients
2008, Journal of the American College of SurgeonsCitation Excerpt :The ability of reoperative SLNB to predict the presence or absence of axillary nodes positive for metastasis has proved to be reliable. Positive SLNs were found in 9 of 45 (20%) successful reoperative procedures and are within the range of published values for patients undergoing SLNB for the first time.7,13,16-18 There have been no local, axillary recurrences in any patients after a mean of 26 months followup.
Management of the axilla in women with breast cancer
2007, BreastCitation Excerpt :This did not include those who purported to practice sentinel node biopsy and did not distinguish between blind and dye-assisted sampling. In a prospective comparison study involving 200 patients, Macmillan concluded that sentinel node biopsy may have little to offer four node samplers.14,15 The sentinel node was present in the four node sample in 77% of the cases, whilst no sentinel node was found in 4% of the cases.
A clinicopathological scoring system to select breast cancer patients for sentinel node biopsy
2006, European Journal of Surgical OncologyCitation Excerpt :It is postulated that involved lymph nodes associated with large tumours may have blocked afferent pathway to the lymph node giving rise to false-negative rate. In some studies, preoperative chemotherapy and large tumour size have been shown to be associated with an unacceptably high false-negative rate for sentinel node biopsy.27,28 Having fewer numbers of node to stage axilla leads to loss of prognostic information such as final number of involved nodes and extra-nodal spread.29
Continued axillary sampling is unnecessary and provides no further information to sentinel node biopsy in staging breast cancer
2005, European Journal of Surgical OncologyCitation Excerpt :Nodes that are felt to be suspicious at the time of the mapping procedure irrespective of radio-isotope or dye uptake should also be biopsied as sentinel nodes.9,19,25,26 Several studies have evaluated the role of axillary sampling either to validate the technique, to stage the axilla or as an adjunct to predicting the status of the residual axilla following a positive SLNB.24,27–29 Hoar and Stonelake have shown that by performing an axillary sampling procedure in addition to a SLNB lowered the false negative rate from 14.3 to 3.6% and increased the overall accuracy and sensitivity.28
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Work presented to the Nottingham International Breast Cancer Meeting, September 2001.