Core data
Data on positive SCC histology was available for all 388 patients; of which 191 patients had undergone a neck dissection. Positive metastatic lymph nodes were found in 21 of these 191 patients (Table 1). Only three studies reported the level of the positive lymph nodes(13, 14, 18). Ng et al, Gidley et al. and Cristalli et al. had reported a total of 33 cases undergoing prophylactic neck dissections of which 5 patients had positive nodal involvement. 3 of these patients were found to have nodes in level II of the neck with the levels not reported in the remaining 2 patients(13, 14, 18). The data on tumour grading based on Modified Pittsburgh classification were available in 128 out of the 191 patients with the following percentages; T1 = 4.68%, T2 = 24.21 %, T3 = 20.31%, and T4 = 50.78%.