Page 77 - Sentinel lymph node biopsy in oral cavity cancer - Inne J. den Toom

If >1 SLN was positive, 2/5 (40%) of the patients had additional neck metastases compared to 4/31 (13%) in patients with a single positive SLN. In 2/13 (15%) patients with solely positive SLN(s) additional non-SLN metastases were found (vs. 17% if syn- chronous presence of negative SLNs were present). If more positive than negative SLNs were present (>50% SLN positive) additional non-SLN metastases were found in 3/14 (21%) patients compared to 3/22 (14%) if a similar or higher number of negative than positive SLNs were found (Table 3). Review of literature Eleven studies had categorized the size of tumour deposits in SLNs.6,11-20 Including the data from our study, ITC was present in 17% of 234 patients (range 0-37%), micrometastasis in 41% (19-100%) and macrometastasis in 43% (0-76%) (Table 3). Additional non-SLN metastases were mainly found in levels I, II and III and sometimes in level IV or V.7,13,15,16,21,22 The pooled prevalence of non-SLN metastasis in patients with 4 positive SLN(s) of the present study and 26 other studies was 31% (156/511).6,7,11-17,21-37 The pooled probability of non-SLN metastasis in the present study and 8 other studies was 13% (4/32), 20% (11/55) and 40% (19/49) for ITC, micro- and macrometastases, respectively.6,11,13,15-17,23,25 This probability was 26% (37/144) for micro- and macrome- tastases combined. Including our results, a higher pooled prevalence for additional non-SLN metastases had been found when >1 positive SLNs were present (29% vs. 24%)11,13,16,22-24,30, absence of negative SLNs (40% vs. 19%)13,15,16,22-24,30,33,37 and in case of a positive SLN ratio of more than 50% (38% vs. 19%).13,16,22-24,30,33 Results are shown in Table 3. 75