The Search for Occult Metastases in Breast Cancer: Does It Add to Established Staging Methods?

Abstract

In 1974 a project was initiated in which patients with apparently operable breast carcinoma underwent special Investigations in an attempt to identify occult metastases in bone and liver. One hundred and seventy‐two patients have been followed for two years or more and their axillary node histological findings reviewed. From analysis of these patients the following conclusions may be drawn. Careful clinical assessment, especially measurement of the primary tumour and palpation of the axillary nodes, remains a fundamental guide to the likelihood of early recurrence. Histological confirmation of node metastases is as valuable as clinical assessment, but is not superior unless other features of node histology are considered. Micrometastases do not increase the probability of early recurrence except in comparison with a group whose nodes lack both metastases and other unfavourable features. The majority of special Investigations do not have additional predictive value, though a bone scan is useful in the small number (less than 10%) in whom it is positive.

Non-sentinel lymph node involvement in patients with breast cancer and sentinel node micrometastasis; too early to abandon axillary clearance

“…29 30 In addition, it may be necessary to look at the host lymph node response, because this may also influence the ability of a micrometastasis to expand. 26 In this setting, it is interesting to note that Colpaert et al found a survival advantage for patients with SLN micrometastases and hypothesised that this may result from an enhanced host immune response. 31 Whatever the outcome of single tumour cells in the circulation or in organs may be, it should be appreciated that the very fact that they are detected implies that access to the lymphatics or blood vessels has been gained, and that a line of defence has been breached in the metastatic pathway.…”

Clinical evidence of breast cancer micrometastasis in the era of sentinel node biopsy

“…In studies of breast cancer, various authors have been using the term "micrometastasis", which is described simply as small deposits of metastatic tumor in the regional lymph nodes. Various other defi nitions have also been reported: metastasis less than 1.0 mm 2,17 metastasis occupying less than 20% of the lymph node sectional area, 18 and even differentiating between metastases less than 1.3 mm and metastases 1.3 to 2.0 mm. 19 The size criteria are subjectively defi ned in the medical literature.…”

Importance of Missed Axillary Micrometastases in Breast Cancer Patients

“…Several techniques have been shown to increase the detection of axillary lymph node metastases. Serial sectioning (generally four to six sections of each paraffin block) of each node with H&E staining increases detection by 7–33%(1,5,6,10,12,26–30). Immunohistochemistry (IHC) is a powerful technique in which monoclonal antibodies to cytokeratin proteins are incubated with tissue sections to obtain a colored reaction product.…”

“…Several studies of breast cancer micrometastases have failed to demonstrate a negative prognostic impact (1,4–6,16,18,26,32,38). There are, however, significant limitations to these studies.…”