Objective: To ascertain whether prophylactic neck dissection offers an advantage for patients with papillary thyroid carcinoma (PTC) in the absence of clinically metastatic lymphadenopathy.
Design: A retrospective study of 108 PTC patients without clinically metastatic lymphadenopathy who were treated at Tenri Hospital between 1977 and 1987. We compared the cumulative non-recurrence rate of cervical metastasis between 68 patients who underwent lymphnode operation (OP group) and 40 patients without any lymphnode operation (non-OP group). There were no significant differences in age and the stages of primary tumors between the two groups. Furthermore, we compared the cumulative non-recurrence rate of cervical metastasis among 40 patients with D0, 26 with D1, 27 with D2 and 2 with D3 dissection and found no significant differences in age and the stages of primary tumors. The mean follow-up period was 16.1±3.0 (MEAN±SD) years.
Results: The rate of occult lymphnode metastasis was 79.4% in the OP group. The 20-year non-recurrence rates were 92.6% in the OP group and 87.5% in the non-OP group and generalized Wilcoxon test showed no significant difference between the two groups. The 20-year non-recurrence rates were 87.5% in D0, 92.3% in D1 and 100% in the D2 and D3 dissection group. Generalized Wilcoxon and Logrank tests showed, that there were also no significant differences among them. No patients died of PTC.
Conclusion: Although patients with PTC in the absence of clinically metastatic lymphadenopathy had many occult metastases, the frequency of recurrences of cervical metastasis was low. Furthermore, non-recurrence rate in patients without any prophylactic operation was not significantly different compared to patients who underwent some prophylactic dissection. Thus, prophylactic neck dissection does not seem to offer any advantage for patients with PTC in the absence of clinically metastatic lymphadenopathy.
