Page 97 - Sentinel lymph node biopsy in oral cavity cancer - Inne J. den Toom

No statistical significant difference between pT1 and pT2 tumours was found for isolated regional disease free survival (Figure 4), disease specific survival and overall survival using either the 7th or 8th edition of TNM classification. Because of the small numbers of pT3 tumours, no statistical analysis was performed comparing pT3 with pT1 and/or pT2 tumours. Incidence of occult lymph node metastases according to pT classification was analyzed for both classifications and is listed in Table 4, showing in the 8th classification a decreased incidence in all T classifications, particularly for pT3 tumours. Table 4. Incidence of occult lymph node metastases by T classification T classification pT1 pT2 pT3 Total 7th TNM 40/152 (26%) 21/44 (48%) 3/3 (100%) 64/199 (32%) 8th TNM 17/88 (19%) 38/92 (41%) 9/19 (47%) 5 64/199 (32%) 95