Sentinel Node Biopsy in Breast Cancer : Clinical and Immunological Aspects
Abstract: The most important prognostic factor in breast cancer is the axillary lymph node status. The sentinel node biopsy (SNB) is reported to stage the axilla with an accuracy > 95 % in early breast cancer. Tumour-related perturbation of T-cell function has been observed in patients with malignancies, including breast cancer. The down-regulation of the important T-cell activation molecules CD3-ζ and CD28 may cause T-cell dysfunction, anergy, tolerance and deletion.The expression of CD3-ζ and CD28 was evaluated in 25 sentinel node biopsies. The most pronounced down-regulation was seen in the paracortical area, where the best agreement between both parameters was observed. CD28 expression was significantly more suppressed in CD4+ than in CD8+ T-cells.From the Swedish sentinel node database, 109 patients with breast cancer > 3 cm planned for both SNB and a subsequent axillary dissection were identified. The false negative rate (FNR) was 12.5%. Thirteen cases of tumour multifocality were detected on postoperative pathology. The FNR in this subgroup was higher (30.8%) than in patients with unifocal disease (7.8%; P = 0.012).From the Swedish SNB multicentre cohort trial, 2246 sentinel node-negative patients who had not undergone further axillary surgery were selected for analysis. After a median follow-up time of 37 months (range 0-75), 13 isolated axillary recurrences (13/2246; 0.6%) were found. In another 14 cases, local or distant failure preceded or coincided with axillary relapse (27/2246; 1.2%). In conclusion, the immunological analysis of the sentinel node might provide valuable prognostic information and aid selection of patients for immunotherapy. SNB is encouraged in breast cancer larger than 3 cm, if no multifocal growth pattern is present. The axillary recurrence rate after a negative SNB in Sweden is in accordance with international figures. However, a longer follow-up is mandatory before the true failure rate of the SNB can be determined.
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