2. SLNB DR and the analysis of impact factors on the SLNB DR
Of the 356 patients enrolled, 325 had at least one SLN that was
successfully stained black by CNS. The overall SLNB detection rate (DR)
was 91.29% (325/356). SLNB was performed in both sides of the pelvis in
252 patients, resulting in a bilateral DR of 70.79%. A total of 8873
lymph nodes and 1456 SLNs were removed from 356 patients. The average
numbers of lymph nodes and SLNs removed from each patient were 24.92 and
4.48, respectively (Table S1). The total number of SLNs accounted for
16.41% of all lymph nodes (1456/8873). A dramatically higher overall DR
was observed for those with smaller tumour sizes (<20 mm)
(97.75% vs. 71.91%; p = 0.000), and for those without
lympho-vascular space invasion
(LVSI) (94.07% vs. 85.83%; p = 0.009). However, no differences based
on age, histologic type or grade, stage, depth of stromal invasion,
surgical approach, menopausal status, or prior chemotherapy treatment
were observed in the overall SLN DR (p >0.05). A relatively
higher SLN DR was found for patients with stage Ia2-Ib1 disease (93.05%
vs. 86.60%; p = 0.055), squamous carcinoma (92.43% vs. 82.05%; p =
0.062), well-differentiated tumours (98.55% vs. 90% and 88.66%; p =
0.055), and without deep stromal invasion (DSI) (93.58% vs. 88.76%; p
= 0.107) (Table 1).