[Proposal for an extended pTNM classification of thyroid carcinoma : Commentary on deficits of the 8th edition of the TNM classification (German version)]

Minimal extrathyroid extension in papillary micro carcinoma of the thyroid is an independent risk factor for relapse through lymph node and distant metastases

Aims: Minimal extrathyroid extension (mETE) is no longer considered in the new 8th edition of the AJCC/UICC staging system. Therefore, papillary thyroid microcarcinoma with mETE previously staged as pT3 will now be staged as pT1a and most likely not receive adjuvant radioiodine therapy. However, it remains unclear if mETE is associated with higher aggressiveness in papillary thyroid microcarcinoma. Therefore, the aim of this study was to investigate if mETE is associated with higher risk of lymph node or distant metastases. Methods: 721 patients with thyroid papillary microcarcinoma presenting at our department for postoperative counseling from 05/1983 to 8/2012 were included in this retrospective analysis (median follow-up time 9.30 years). The impact of mETE on the presence of lymph node metastases at thyroidectomy and relapse through lymph node and distant metastases was assessed by logistic regression and Fine-Gray model analyses. Results: 10.7% (n = 77) of patients had mETE. mETE was an independent risk factor for lymph node metastases at thyroidectomy with an adjusted odds ratio of 4.33 (95%CI: 2.02-9.60, p<0.001) in multivariable analysis. Patients with mETE had significantly more relapses through lymph node (over 5 years: 13.1% vs. 1.25%; P < 0.001) and distant metastases (over 5 years: 7.8% vs. 1.1%; P < 0.001) compared to patients without mETE. mETE was an independent risk factor for relapse through lymph node and distant metastases in multivariable analysis (hazard ratio: 7.78, 95%CI: 2.87-21.16, p< 0.001 and 4.09, 95%CI: 1.25-13.36, P = 0.020). Conclusion: mETE is a statistically significant and independent risk factor for relapse through lymph node and distant metastases in papillary microcarcinoma. Therefore, future studies should evaluate, if patients with mETE and microcarcinoma might benefit from intensified surveillance and therapy.

[Completion thyroidectomy after less than total resection for postoperatively diagnosed follicular thyroid cancer]

As there are no reliable preoperative or intraoperative markers to identify follicular thyroid cancer (FTC), the postoperative histopathological diagnosis frequently raises the question of completion surgery. The oncological necessity must not be questioned by an allegedly increased morbidity. The operation is particularly indicated if there is evidence of distant or lymph node metastasis, the presence of a broadly invasive FTC, or evidence of extensive angioinvasion. Prophylactic lymphadenectomy is not indicated. There are no clear data that minimally invasive oncocytic FTC poses a special risk. Risk factors such as tumor size and age must be assessed as a biological continuum and require an individual assessment. Utilizing the technical options and thorough planning enables a completion thyroidectomy to be performed without increased risk.