Follow-up after intraoperative sentinel node biopsy of N0 neck oral cancer patients.

The objective of the study was to evaluate the validity of sentinel node (SN) biopsy in early oral cancer patients focusing on the accuracy of intraoperative diagnoses of SN status, recurrences in follow-up and impact on patient survival. Previously untreated N0 oral cancer patients were candidates for the study. Using a radioisotope method, an intraoperative SN biopsy was performed. Patients with a positive frozen section of SN underwent immediate neck dissection as a single-stage procedure; they were followed in our outpatient clinic. Forty-five cT1-2N0 patients with squamous cell carcinoma were analyzed. There were seven patients with positive SN, five of whom were detected by intraoperative frozen section analysis. The sensitivity, specificity and accuracy of the intraoperative frozen section analysis of SN were 71.4, 100 and 95.6%, respectively. There were 13 recurrences in the course of all patients treated. Those with positive SN showed a tendency toward recurrence. Three patients with negative SN suffered from delayed ipsilateral neck recurrence. These were considered false negatives at a rate of 7.9%. The 5-year overall survival rate of all patients was 91.1%. SN-positive patient survival was significantly poorer than that of SN-negative patients. Positive SN had a negative impact on the survival. SN biopsy was shown to be a valuable method for determining the neck status of early oral cancer patients. The concordance rate of intraoperative multislice frozen section analysis of SN and patient neck status at the time of operation was 95.6%. SN-positive patients exhibited a tendency toward cancer recurrence. There were three cases of false negatives not conforming to the SN concept and their rate was 7.9%. Positive SN had a negative impact on patient survival.