Avoiding dissection and irradiation in breast cancer
The ACOSOC Z0011 trial demonstrated that patients with cT1-2N0 breast cancers and 1 to 2 involved sentinel lymph nodes (SLNs) having breast-conserving therapy had no difference in locoregional recurrence or survival after SLN biopsy alone or axillary lymph node dissection (ALND), report researchers at New York’s Memorial Sloan Kettering Cancer Center and Cedars-Sinai Medical Center in Los Angeles. However, it was still unclear i) if the results are generalizable and ii) what the importance of nodal radiotherapy (RT) is.
In the present study, the authors determined the rates of ALND and nodal recurrence in patients eligible for ACOSOG Z0011. The results confirmed that – even without preoperative axillary imaging or routine use of nodal RT – ALND can be avoided in a large majority of Z0011-eligible patients. “This approach has the potential to spare substantial numbers of women the morbidity of ALND”, comment the authors.
All patients eligible for Z0011 (n=793) underwent SLN biopsy; indications for ALND were metastases in ≥ 3 SLNs or gross extracapsular extension.
16 percent of patients had ALND; age, estrogen receptor, progesterone receptor, or HER2 status did not influence ALND.
5-year event-free survival after SLN alone was 93 % with no isolated axillary recurrences.
Cumulative 5-year rates of breast + nodal and nodal + distant recurrence were 0.7 % respectively.
In 484 SLN-only patients with known RT fields and follow-up ≥ 12 months, the 5-year cumulative nodal recurrence rate was 1 %. This did not differ significantly by RT fields.
ALND can be avoided in a large majority of Z0011-eligible patients with excellent regional control, even without preoperative axillary imaging or routine use of nodal RT.