Is breast cancer sentinel lymph node mapping valuable for patients in their seventies and beyond?

Background Axillary lymph node dissection (ALND) is performed less commonly for the axillary staging of elderly patients because it is felt to uncommonly alter therapy. Sentinel lymph node (SLN) dissection can accomplish axillary staging with less morbidity, but it is unclear if it alters subsequent therapy. Methods Review of a prospectively collected breast cancer SLN mapping database. Medical records were reviewed to supplement the database. Results Among 730 breast cancer SLN mapping patients, 261 (35.8%) were ≥70 years of age (range 70 to 95). The overall SLN identification rate was 98.8% among those <70 and 97.1% for those ≥70 (P = .11) and 100% and 99.4%, respectively (P = .25), among the most recent 500 patients. SLN metastases were detected by hematoxalin and eosin staining (H&E) in 24.2% of those <70 and 13.4% of those ≥70 (P < .01) and by immunohistochemistry staining (IHC) only in 4.6% and 5.0% of patients, respectively. No elderly patients with histologically negative SLNs underwent ALND, but 88.9% of patients with H&E metastases and 84.6% with IHC metastases underwent ALND. Of the H&E-positive women, 88% underwent adjuvant systemic therapy versus 55% of H&E-negative women (P < .01). Hormonal therapy was administered to 86.9% of SLN-positive women and 54.3% of SLN-negative women (P < .01) and cytotoxic chemotherapy was administered to 24% of SLN-positive patients versus 2.8% of SLN-negative patients (P < .01). SLN status was associated with significantly different rates of systemic therapy for patients with tumors <1 cm and 1 to 2 cm, but not with tumors >2 cm. Mean follow-up was 15.4 months. No patient experienced local or regional recurrence. Distant metastases occurred in 8.2% of patients with SLN metastases and in no patients with negative SLNs (P < .01). Conclusions The results of SLN mapping and biopsy in elderly patients significantly influences subsequent therapy decisions, including ALND, hormonal therapy, and cytotoxic chemotherapy. SLN biopsy should be recommended to elderly breast cancer patients.