Sentinel lymph node (SLN) biopsy for staging of breast cancer is highly accurate in predicting axillary nodal status. However, clinical trials typically exclude patients with prior procedures that might disturb lymphatic drainage. We hypothesized that prior breast or mantle radiation would prevent successful lymphatic mapping. As part of a prospective clinical trial, breast cancer patients with prior radiation (XRT) underwent lymphatic mapping and SLN biopsy (SLNB) for axillary staging.In a database of 900 patients undergoing SLNB, 5 patients had a history of prior radiation, 2 with mantle XRT for Hodgkin's disease and 3 with lumpectomy and XRT for DC1S. The 2 patients with mantle XRT had T2 invasive ductal cancers, 3.8 cm and 2.2 cm. Of the 3 patients with lumpectomy and XRT for DC1S, each had local recurrence, one with invasive pleomorphic lobular cancer 1.5 cm and the other 2 with DC1S. SLNB was performed by dual injection technique with technetium and isosulfan blue at the time of mastectomy. In all patients, a sentinel node was successfully identified, one by blue dye only, one by technetium only, and three by both techniques. One to four sentinel nodes were retrieved from each patient. Pathologic exam of the SLNs included H&E and cytokeratin immunohistochemical staining on 3 levels. Two patients had positive SLNs by H&E, one with metastasis 0.4 cm and no additional positive nodes at axillar)' dissection and the other with metastasis 1.5 cm and an additional 7/16 positive nodes. There are no regional recurrences at 10, 16, 25, 26, and 29 mos. post-op.Contrary to our hypothesis, lymphatic mapping and SLN identification was technically successful in 100% of patients, even though they had prior XRT. This may be because 4 of the 5 patients had XRT at least 5 years before SLNB, giving time for new lymphatic drainage to develop. Patients with prior breast and axillary field XRT should undergo SLNB in clinical trials until more data is accumulated to confirm its reliability.
ASJC Scopus subject areas
- Cancer Research