Axillary lymph node dissection versus the sentinel lymph node technique in breast cancer.

Abstract

The optimal management of carcinoma of the breast continues to undergo evolutionary changes and modification. Historically, radical mastectomy was replaced by modified radical mastectomy without negatively impacting outcomes. More recently, most general surgeons and surgical oncologists have adopted partial mastectomy with or without irradiation. Numerous comparative studies have demonstrated that breast conservation can be accomplished in most patients with breast cancer without placing patients at increased risk. The question concerning management of axillary lymph nodes has yet to be definitively answered. The case has been made that axillary dissection is unnecessary for most patients with breast cancer and serves as a staging procedure with little or no therapeutic benefit. Others have reported that approximately one third of patients undergoing axillary dissection for positive nodes is associated with an approximate 30% to 35% therapeutic efficacy. Some authors have suggested that early disease associated with favorable histopathology have such a low instance of nodal risk that they can be safely followed with very favorable long-term cure rates. The advent of sentinel lymph node technology has been shown to be associated with far more accurate pathologic assessment and in many cases, accurately defines the patients not needed to be subjected to axillary dissection. Sentinel lymph node detection can now be achieved in more than 95% of patients with breast cancer with false negative rates in fewer than 5% of patients followed for 5–10 years. Axillary failures are seen in fewer than 3% of patients who have undergone a standard complete axillary dissection. While it is true that long-term observation of patients undergoing sentinel lymph node determination with negative histopathology and immunopathology are likely to be associated with a somewhat higher axillary failure rate, the differences are most likely to be quite small. A recently reported joint study of patients with stage I and stage II breast cancer suggest that axillary dissection is overused and irradiation is underused.1 Silberman et al2 attempt to compare morbidity of axillary lymph node dissection and sentinel lymph node determination in patients with breast cancer. The data provided by these authors derives from their experience with 93 patients studied from 1986 to 2000. The authors do not identify the mechanisms by which these patients were selected. It is not clear that their series represents a consecutive series but rather a highly selected group of patients from the authors’ overall surgical practice. The disease-free interval and survival rates compare very favorably with numerous reports in the literature undergoing sentinel lymph node management of the axillary contents. The authors’ provocative discussion relating to the morbidity of axillary dissection is dealt with in some detail. Discussions in the recent literature suggesting that axillary dissection is associated with a 40 to 60% morbidity is most likely overstated. Silberman et al somewhat overstate the potential problems of sentinel node procedures relating to allergy to the dye and emphasize an unacceptable false negative rate. Collected data are now reaching maturity and indicate an exceedingly small failure associated with false negative sentinel node detection. The authors also overstate the risk associated with delaying adjuvant therapy dictated by the need for delayed axillary dissection for the patient population having positive sentinel nodes. The data provided in the manuscript concerning the topic of lymphedema rely for the most part on circumferential measurements and patient-driven opinion. These types of data are vulnerable to subjective bias. A more accurate assessment of lymphedema has been shown to best be measured by water displacement techniques.3 It is highly unlikely that breast cancer management will revert to gold standards of the past. It is more likely that risk assessment in the near future will be dictated by genomics and microarray analyses.