The role of sentinel lymph node biopsy in patients with ductal carcinoma in situ or with locally advanced breast cancer receiving neoadjuvant chemotherapy.

BACKGROUND: A significant number of patients who are initially diagnosed with pure DCIS will harbor missed or occult invasive disease at their definitive surgery. To provide more accurate staging information and to avoid a second operation, some investigators believe that SLN mapping should be performed in DCIS patients. The role of SLN biopsy after neoadjuvant chemotherapy in patients with advanced breast cancer is controversial. METHODS: A review of the literature was performed to determine the role of SLN biopsy in patients with DCIS or advanced breast cancer receiving neoadjuvant chemotherapy. The success rate of SLN biopsy after neoadjuvant chemotherapy was investigated as well as the percentage of positive SLNs in patients with DCIS. RESULTS: Two consecutive studies revealed metastatic disease to the regional lymph nodes in up to 13% of DCIS patients. In addition, 10% of DCIS patients were upstaged to infiltrating ductal carcinoma at their definitive therapy. The ability of the SLN to predict the status of the remaining non-SLNs after neoadjuvant chemotherapy is unknown. False-negative rates range from 0% to 33%. The success rate for SLN identification for the combined series varies from 84% to 97%. CONCLUSIONS: SLN biopsy is a minimally invasive technique that can be used to evaluate the regional nodal status of DCIS patients. Performing a SLN biopsy during the initial surgical procedure may avoid a second operation in some DCIS patients who are diagnosed with invasive disease at their definitive operation. The success rate of sentinel node identification does not seem to be altered after neoadjuvant therapy. However, the ability of the SLN to predict the pathologic status of the adjacent non-SLNs remains unknown. Therefore, until further prospective randomized trials are conducted, it cannot be assumed that all the regional nodes have the same biologic response to chemotherapy as the SLN.

Worldwide experience with lymphatic mapping for invasive breast cancer.

Lymphatic mapping and sentinel lymph node (SLN) biopsy have changed the standard of surgical care for women with invasive breast cancer. The rate of successful axillary SLN identification varies from 90% to 99%. Recurrence rates after a negative SLN biopsy have been remarkably low. Internal mammary node drainage has been noted in 8% to 22% of cases, but whether to harvest these extra-axillary sites of drainage remains controversial. Because of the low morbidity associated with the lymphatic mapping procedure, all women with invasive breast cancer should be considered as candidates for this more accurate staging technique.

National trials involving lymphatic mapping for melanoma: the Multicenter Selective Lymphadenectomy Trial, the Sunbelt Melanoma Trial, and the Florida Melanoma Trial.

Radioguided surgery and lymphatic mapping provide more accurate staging and a less morbid operation for the patient with malignant melanoma. It has rapidly become the standard of care for the nodal staging of this disease. Regional and national trials have been designed to address various questions that concern the application of this technique. The Multicenter Selective Lymphadenectomy Trial (MSLT), being performed by Donald Morton at the John Wayne Cancer Institute, is a national trial that will address whether this surgical strategy provides a survival benefit for patients. The national, industry-sponsored SunBelt Melanoma Trial (SBMT), with Kelly McMasters from the University of Louiville as the principle investigator, will determine the role of molecular staging in patients who undergo sentinel lymph node (SLN) harvest. In another arm of the study, the role of adjuvant interferon alfa (IFN) will be examined in patients with minimal disease in the regional basin, those patients with just one microscopically positive SLN. Finally, the Florida Melanoma Trial (FMT), with the central office and laboratory located at the Lakeland Regional Cancer Center, is a regional, industry-sponsored trial that will determine whether all patients with a positive SLN need to undergo a complete lymph node dissection (CLND) of the affected basin. Clinicians await the results of these three trials to help to determine the final role of radioguided surgery in patients with malignant melanoma.

The staging of malignant melanoma and the Florida Melanoma Trial.

Lymphatic mapping and sentinel lymph node (SLN) biopsy have changed the standard of care for patients with malignant melanoma, by providing a less morbid procedure to obtain the nodal staging information that is critical for therapeutic decisions. Detailed examination of the SLN identifies patients who have an increased risk for recurrence and death. Patients whose melanoma is upstaged with very sensitive assays based on reverse transcriptase polymerase chain reaction technology are better targeted for clinical trials or surgical or adjuvant therapies. In the future, melanoma may be "ultrastaged" by examining the SLNs, peripheral blood, and bone marrow. This may improve identification of patients who are surgically cured of their disease and therefore can be spared the side effects of more radical surgery or the toxicities of adjuvant therapy. The lymphatic mapping procedure is the most accurate way to determine the tumor status of the regional lymph nodes.