CHICAGO — “Routine use of axillary lymph node dissection (ALND) should be abandoned.”
That’s the conclusion based on 10-year survival data from the American College of Surgeons Oncology Group (ACOSOG) Z0011 randomized study comparing sentinel lymph node dissection (SLND) alone to ALND in women with clinical T1-2 N0 M0 breast cancer and a positive sentinel node presented at the 2016 American Society of Clinical Oncology (ASCO) Annual Meeting.1
The study’s hypothesis was that SLND alone achieves similar locoregional control and survival as level I and II ALND for patients treated with breast conserving therapy and adjuvant systemic therapy. Previously, no significant difference in 5-year locoregional recurrence or survival was observed between ALND and SLND; however the study was criticized for its short follow-up, 6.3 years , said Armando E. Giuliano, MD, Cedars-Sinai Medical Center, Los Angeles, California.
Patients with clinically node negative breast cancer with 1 or 2 sentinel nodes with immunohistochemically detected metastases were randomly assigned to receive SLND (n = 446) or SLND plus ALND (n = 445). All patients were scheduled to received whole breast irradiation and systemic therapy.
Baseline patient characteristics were similar for age, tumor size, Bloom-Richardson score, estrogen receptor status, adjuvant systemic therapy, tumor type, and stage.
Those in the SLND alone arm had a median of 2 lymph nodes removed; in contrast, those randomly assigned to ALND had a median of 17 nodes removed (P < .001). A total of 17.6% of patients in the ALND arm had 3 or more involved nodes, compared with 5.0% of those in the SNLD arm (P < .001). A total of 106 patients (27.4%) treated with ALND had additional positive nodes removed beyond the sentinel node(s).
At a median follow-up of 9.25 years, by treatment arm, there were no statistically significant differences in local (P = .13, ALND vs SLND) or regional recurrence (P = .28; ALND vs SLND), Dr. Giuliano said. Only 2 nodal regional recurrences were observed in the ALND arm, while there were 5 in the SLND alone arm.
“Only 1 additional regional recurrence was seen after 5 years,” Dr. Giuliano said.
The 10-year locoregional recurrence-free survival was 93.8% for the ALND arm and 94.7% for the SNLD alone arm (P = .36). The 10-year overall survival for patients undergoing SLND plus ALND was 83.6% vs 86.3% for sentinel node biopsy (HR, 0.85; 95% CI, 0.59-1.24; P = .40), and disease-free survival was 78.2% vs 80.2% (HR, 0.85; 95% CI, 0.62-1.17; P = .32).
Hormone receptor status, Bloom-Richardson score, and tumor size were associated with locoregional recurrence, not the operation itself, he said. Multivariable analysis found that age, estrogen receptor, tumor size, and adjuvant systemic chemotherapy — not type of operation — were associated with 10-year overall survival.
Of the 605 radiation case reports reviewed, 11% of patients had received no radiation. Review of 228 detailed radiation therapy records found that in 18.9% of patients, a third field had been used, a protocol deviation. However, this third field use was equal between ALND and SLND. An unplanned analysis found that if a patient did not receive irradiation, local recurrence increased significantly (P = .004), and overall survival decreased (P = .03). However, radiation therapy was not associated with node recurrence (P = .80) nor was a third field associated with overall survival (P = .35).
1. Giuliano AE, Hunt K, Ballman KV, et al. Ten-year survival results of ACOSOG Z0011: a randomized trial of axillary node dissection in women with clinical T1-2 N0 M0 breast cancer who have a positive sentinel node (Alliance). Oral presentation at: 2016 ASCO Annual Meeting; June 3-7, 2016; Chicago, IL.