Omitting axillary lymph node dissection is associated with an increased risk of regional recurrence in early stage breast cancer: a systematic review and meta-analysis of randomized clinical trials

•Breast cancer is a global problem that accounts for 12.5% cancer diagnoses worldwide;•There is a strong tendency in clinical practice to avoid the ALND as first treatment;•Omitting ALND was associated with a significant increase in regional recurrence;•Omitting ALND was associated with a significant reduction in lymphedema events;•In sensitive analysis NALD was associated with a reduction in OS and DFS events. Breast cancer (BC) is a global problem, however, despite ALND is considered the standard treatment for early stage BC with node-positive, there is no sufficient data to determine which of these patients should undergo it. Thus, the aim of this systematic review was to clarify if there is any difference between NALND and ALND in terms of safety and prognosis of the patients. A shearch was carried in PubMed, Embase and Cochrane databases for studies that compared NALND and ALND. The statistics was performed in R software, in which a restricted maximum likelihood estimator random-effect model were employed to compute risk ratios and hazard ratios with 95% CI. Heterogeneity was accessed with I2 statistics. There was 7 included studies, involving 7.338 patients, of whom 3.710 were randomized to omission of ALND. The follow-up period ranged from 5 to 10 years, with participant ages varying from 53 to 61 years. The analysis revealed significant increase in 10 years regional recurrence (RR 1.43; 95%CI 0.78 to 2.64; I²=0%) and a significant decrease in lymphedema (RR 0.35; 95% CI 0.23 to 0.53; I²=60%), however no significant result was found for last reported OS (HR 0.96; 95% CI 0.79 to 1.17; I2= 6%) or DFS (HR 1.002; 95% CI 0.960 to 1.045; I2=55%). Our data suggest that while the NALND offers benefits in terms of preventing lymphedema, it was associated with a higher risk of 10 years regional recurrence. Thus, further studies are necessary to fully assess the role of these techniques in BC management.