Are the Technical Conditions for SLN Detection Satisfactory14

Investigations of Breast Cancer Cases As a Basic Parameter

In the year 2001 there was still a high degree of uncertainty about the safety of the SLN concept in breast cancer treatment; many institutions are involved in clinical, partly multicenter, studies, but definitive results answering the most important question, that of the false-negative rate and its implications, are not yet available.

One of the latest fairly extensive studies to be performed was carried out in 466 cases by Cox et al. (1998), who give a preliminary answer on the relative success rates of the different methods of diagnosis in ensuring correct diagnosis of the primary. The percentage ratio of stereotactic biopsy to excision biopsy found by Cox et al. was 46.2% to 53.8%.

The failure rate for identification of a sentinel node in the axilla was 5.6%. The failures were compensated by axillary revisions, in 15.4% of which cancer involvement was detected. In Cox's series there was only one case with skip metastasis, which developed after prior excisional biopsy.

The results of Cox's investigations, published under the senior authorship of Reintgen, give an overview and are obviously representative for many investigations of other groups in this field. They can be a measure of information to patients and of further improvements. The main data are listed in Table 1.

With respect to the current constant and steadily discussed problem of how to treat DCIS cases in which, because of early stromal invasion that has not been detected histologically, the disease cannot be safely resected, even when the Van Nuys (Silver-stein et al. 1995) or Holland (Holland et al. 1994) classification of DCIS following identification of high-grade types (see also International Consensus Conference (2002) is applied, the results of Cox et al. (1998) are of special interest. These authors had 87 cases with noninvasive ductal breast cancer (DCIS) in their series of 466 cases. In 4 of these cases (4.6%) cancer-positive SLNs were found. This rate is in keeping with most percentages presented in evaluations already published.

With respect to these results, it would have been dangerous to omit the check on the axillary nodes in all cases of DCIS. Therefore, in DCIS cases investigation of the SLN(s) with avoidance of full axillary revision could become the method of choice in the future.

In enquiries into the value of our imaging systems in addition to the primary physical examination, our experience and the results of clinical studies have shown that we have to extend our evaluation procedures intensively to include DCIS and, because in these cases the putative invasion rate is low, also to include a search for the SLN(s), which can more easily be found than in the case of highly extended invasive cancers.

In contrast to this constellation stands the question of the security of the results obtained in the search for the SLN(s) as a function of pT stage.

Schlag and Bembenek (2000) have tried to find an answer to this problem, which has often been discussed. Their results are shown below.

Table 1. Important factors for determining significance of sentinel lymph node (SLN) investigations in breast cancer cases (n=422)

Mean value

Cancer infiltration

Rate of cases

Hot nodes

Blue nodes

Hot and

Positive

of harvested

rate of the

with positive

0 0

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