Breast Cancer Vol. 11 No. 3 August 2004 Review Article Clinical Considerationsin BreastCancer Sentinel Lymph Node Mapping: A Moffitt Review Charles E. Cox .1, Laura White .1, Nicholas StowelW, John Clark .1, Daniel Dickson .1, Ben Furman *~, Elizabeth Weinberg*1, James Jakub .2, and Elisabeth Dupont *~ * ~Departmentof Surgery, ComprehensiveBreast Cancer Program, H. Lee Moffitt Cancer Center and Research Institute at the University of South Florida, and *2ComprehensiveBreast Program Lakeland Regional Cancer Center Lakeland, USA. Lymphatic mapping redefined the clinical significance of axillary lymph nodes in the treatment of breast cancer. Current literature supports the concept that any patient diagnosed with invasivebreast can- cer should in fact have their sentinel lymph nodes evaluated. However, there are many cases of "special situations in lymphatic mapping".These special situations mark an important point that should be consid- ered: When and who should undergo lymphatic mapping? A summary of these considerations/cases will be the focus of this report. Breast Cancer 11:225-232, 2004. Key words: Lymphatic mapping, Sentinel lymph node biopsy, Breast cancer In 1994, the Moffitt Cancer Center (MCC) began a phase I trial of SLN biopsy followed by a complete axillary lymph node dissection (CALND). One hundred eighty- six patients were mapped (Phase I), are received a CALND following SLN biopsy. This group revealed one false negative SLN biopsy, resulting in a FNR of 1/54 (1.85~ 1)and no patient to date has developed a clinical recurrence in the axilla after a negative SLN biopsy. In anoth- er MCC study, the SLN was successfully identified in 2036/2100 (97.07%) of patients. In the remain- ing 64 (3.0%) patients in whom mapping failed to demonstrate a SLN, a CALND was performed and metastatic disease was found in 14/64 (21.9)% 1) . In our most recent series of patients mapped at MCC from April 1994 to February 2004, 3767 of 3856 (97.7%) patients were mapped successfully (Fig 1). This constitutes a mapping failure rate of only 2.3%. Successful breast cancer lymphatic mapping is marked by the ability to locate the sentinel lymph nodes (SLN). The success of SLN mapping is based on many factors, such as surgeon experi- Reprint requests to CharlesE. Cox, Director,Breast ProgramH. Lee Moffitt Cancer Center 12902 Magnolia Drive Tampa, Florida 33612, USA. E-maikcoxce@moffitt.usf.edu Received March 13, 2004; accepted March 22, 2004 ence, mapping agents, and localization technique. Two factors shown to affect the success of SLN mapping are age and body mass index (BMI) 2~. An important measure of mapping accuracy is the false negative rate (FNR). A false negative is defined as a negative SLN when nodes higher in the lymphatic basin are positive. The FNR in lym- phatic mapping is the percentage of positive pati- ents that are missed by SLN mapping. This value is calculated by dividing the number of false nega- tives by the number of false negatives plus the number of true positives (FN/(FN + TP). Howev- er the true test is clinical outcome of the axilla in patients mapped with negative nodes and followed for axillary recurrence. A critical element in the reduction of false neg- atives is the thorough histologic evaluation of the sentinel node. Studies by those shown in Table 1 have confirmed that detection of micrometastafic disease in the SLN results in detection of 6-27% of patients who have additional nodal disease upon CALND ~6~. Thus, micrometastafic disease detect- ed in the SLN of a patient with invasive breast can- cer warrants a CALND to avoid false negative ass- essment of the axillary basin. When accomplished in this manner, an absolute reduction of 2.5% in the overall false negative rate for lymphatic map- ping in breast cancer will be achieved. 225