The impact of the American College of Surgeons Oncology Group (ACOSOG) Z0011 trial: An institutional review.

BACKGROUND: Axillary dissection (AD) was historically recommended for all patients with breast tumor involvement discovered by sentinel lymph node biopsy (+SLNB). However, after the ACOSOG Z0011 trial, omission of AD became the recommendation for selected patients with a +SLNB. We report the impact of ACOSOG Z0011 on the completion AD rate in patients with +SLNB at our institution.

METHODS: We retrospectively reviewed all patients diagnosed with breast cancer between March 2009 and February 2013 (n = 1781). This cohort was divided into two groups: 1) those diagnosed BEFORE Z0011 and 2) those diagnosed AFTER Z0011. We calculated both the percentage of patients with a +SNLB who underwent AD and, from those patients, the percentage who did and did not meet the Z0011 criteria.

RESULTS: The BEFORE group contained 849 patients; 144 had +SLNB and from those 113 underwent AD. The AFTER group contained 932 patients: 139 had +SLNB and from those 73 underwent AD. The completion AD rate in the BEFORE group was 78.5%, compared to 52.5% in the AFTER group (p < 0.001). From the patients who met the Z0011 criteria, 75.6% of the BEFORE patients underwent AD, compared to only 2.2%% in the AFTER group (p < 0.001). Among those who did not meet the Z0011 criteria, a similar percentage of patients underwent AD in each group (BEFORE 79.8%, AFTER 74.4%, p = 0.384).

CONCLUSION: Following the publication of the ACOSOG Z0011 trial, we experienced a significant decrease in the completion AD rate among patients with a +SLNB who met the Z0011 inclusion criteria.