[Which lymphadenectomy in papillary thyroid gland carcinoma?].

Abstract

Background: The optimal treatment of papillary thyroid carcinoma (PTC) is still debated, also with respect to nodal treatment.

Method: Retrospective analysis of a personal series of 159 patients with PTC, with respect to nodal disease, follow up 1-27 (mean 8) years.

Results: In 42 patients with clinical, macroscopic nodal disease (cN1) a therapeutic lymphadenectomy was performed, with pN1 status in 41 (98%) patients. 117 patients had no clinical or intraoperative suspicion of nodal involvement (cN0), with occult nodal disease in 5/29 (17%) patients undergoing prophylactic (elective) lymphadenectomy, and in 2/88 (2.3%) patients without primary lymphadenectomy (metachronous nodal disease) (p < 0.005). Nodal recurrences were observed (1-5 years after primary treatment for cure) in 5/42 (12%) pN1 and in 3/114 (2.6%) cN0, pN0 tumors (p = 0.009), with unfavourable outcome in 2 and 1 patients, respectively. The 20-year tumor specific survival was 100% in TNM I + II (low risk) patients (including pN1 and N0 tumors); the survival rate was deteriorated by stage pN1 vs. N0 in TNM high risk patients (50% vs. 86%; p = 0.03).

Discussion: The intraoperative macroscopic staging (cN) remains important:--clinical nodal disease warrants a systematic node dissection (microdissection), for preventing (curable or serious) nodal recurrences. Occult nodal disease does not evolve frequently in clinical nodal recurrence. A less radical (and only central) prophylactic lymphadenectomy, avoiding surgical morbidity, may be oncologically adequate. More sensitive detection of nodal positivity (frozen section of sampling tissue or sentinel nodes, immunohistochemistry) appears not rationale. In pN0, cN0 tumors use of prophylactic 131I may represent overtreatment, and follow up controls may be conducted less rigorously.