Abstract
At the moment, one in nine women has a lifetime risk for developing breast cancer. The most important prognostic factor is the histologic status of the axillary lymph nodes. Removal of these nodes might lead to morbidity in terms of lymphedema and shoulder complaints. In the nineties, the sentinel lymph node concept was introduced in breast cancer care. It is the first lymph node to receive lymph drainage from a primary tumour and will therefore contain metastatic disease if lymphatic metastasis occurs. This thesis evaluates new developments and reports consequences of the introduction of the sentinel lymph node biopsy. The initial experience with scrape cytology, a new technique for intraoperative examination, is described. Intraoperative examination has the advantage that if metastatic disease is detected, removal of the axillary lymph nodes can be performed in the same operation. A disadvantage is the risk for false-negative results. The results of scrape cytology are comparable with the results of frozen section and imprint cytology; it is therefore a useful method for intraoperative examination. To avoid the equivocal cytology results, the sentinel lymph node biopsy under local anesthesia preceding the breast surgery was introduced. Results of the biopsy performed under general and local anesthesia are comparable. A hospital-based and literature study was performed on regional recurrence after a negative sentinel node biopsy. The incidence of axillary relapse appeared much lower than expected conform the false negative results of the validation phase studies. The natural course of axillary recurrence seems to resemble locoregional recurrence after removal of all axillary lymph nodes. The Memorial Sloan-Kettering Cancer Centre (NY, USA) nomogram predicts the risk for non-sentinel node metastases after a positive sentinel node biopsy. The nomogram also predicts with reasonable accuracy the risk for non-sentinel node metastases for a Dutch population of breast cancer patients. A comparison of estimations of surgical oncologists for the risk for non-sentinel lymph node metastases with the MSKCC nomogram showed only moderate concurrence. The type of hospital nor the amount of experience of the surgeon seemed to influence predicting abilities and the variation between the individual predictions of the various surgeons for the scenarios was important.
