In this 505-patient retrospective study, extended lymphadenectomy was associated with longer overall survival after matching—but also more postoperative morbidity.

• After propensity-score matching, median overall survival was 19 months with extended versus 13 months with regional lymphadenectomy; disease-free survival was comparable in the full cohort.
• Extended dissection yielded more nodes (median 7 vs 2) and was associated with higher morbidity (34.2% vs 24.2%).

The findings support considering extended nodal dissection for T1b or higher disease, but do not prove a survival benefit: treatment was not randomized, and residual confounding may remain.