臨床病理学ジャーナル

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Central Node Neck Dissection for Papillary Thyroid Carcinoma: Clinical Implications, Surgical Complications and Follow up. A Prospective vs a Restrospective Study

Maria Rosa Pelizzo, Isabella Merante Boschin, Maddalena Variolo, Giovanni Carrozzo, Costantino Pagetta, Ornella Lora, Andrea Piotto and Chiara Dobrinja

Introduction: The treatment and particularly the extension of surgical therapy of papillary thyroid carcinoma (PTC) remain still controversial in some issues, especially for the lack of preoperative information or variables that allow predicting the level of aggressiveness of the tumor.

Aim of the study: The purpose of the study was to assess the impact of the central node neck dissection (CNND) on surgical outcome and disease free- follow up of PTC- patients operated on at our center by evaluation of postoperative complications (parathyroid and recurrent nerve damage, hemorrhage rates) and pts rates presenting detectable serum Thyroglobulin (TG) or TG-Antibodies (TG-AB) values, at the time of 131Iodine treatment and subsequently at 6-12 months, combined with neck high-resolution ultrasound (HRUS) The results of a prospective study on 149 pts preoperatively diagnosed and HR-US staged N0-PTC who underwent total thyroidectomy and CNND were compared with the results of a retrospective study on 114 similar postoperatively diagnosed PTC-pts who received total thyroidectomy, without nodes dissection.

Materials and methods: 149 patients who underwent total thyroidectomy (TT)+CNND from March 2012 to August 2013 (group-A) and 114 patients who underwent TT from January to December 2011 (group-B) were compared on the following variables: gender, age, histological variant of PTC, tumor size, TNM stage, multifocality, vascular invasion, thyroiditis, expression of BRAF mutation, surgical complications (transient postoperative hypocalcemia and hypoparathyroidism, temporary or permanent dysphonia and hemorrhage), values of TG and anti- TG Ab in suspension or under TSH stimulus, in pre-ablation and on the last clinical and instrumental evaluation of the patient. Statistical analysis was performed using the Student t-test and Fisher. A p value less than 0.05 was considered statistically significant.

Results: Comparing the patients of group-A with group-B the following variables present with statistically significant differences: transient postoperative hypocalcemia (group-A 50.3% vs group-B 21.9% , p<0.0001) , association with lymphocitary chronic thyroiditis (group-A 63.1% vs group-B 37.7%, p<0.0001), median postoperative serum TG value (group-A 1,05 ng/L vs group-B 2,4 ng/L , p=0.01), median postoperative anti-TG antibodies value (group-A 903 kU/L vs group-B 118.5 kU/L, p=0.006 ), median value of anti-TG antibodies at the last follow up after radioiodine therapy (group-A 481,5 kU/L vs group-B 35 kU/L, p=0.0001).

The following variables do not present statistically significant differences: gender (females 83.2% group-A vs group-B 82.5%, p ns), mean age at diagnosis (>45 years group-A 59.7% vs group-B 53.1%, p ns) , the histological subtypes (p ns), microcarcinomas (group-A 29,5% vs group-B 35%, p ns) , pT (p ns) , presence of multifocal lesions (group A 45.6% vs group B 55.3%, p ns), temporary dysphonia ( 7,4% group-A vs. group B 2.6%, p ns), definitive dysphonia (group-A 1,3% vs group-B 0,9%, p ns), post-operative hemorrhage (group-A 2% vs group-B 1.8%, p ns), radioiodine therapy (group-A 80.6% vs group-B 80.7%, p ns), rhTSH (group-A 88.3% vs group-B 82.6%, p ns), median value of TG at the last follow up after radioiodine therapy (group-A 0,2 ng/ml vs group-B 0,3 ng/ml, p ns), median value of TG at the last follow-up in patients not receiving therapy (group-A 0.4 ng/ml vs group-B 0.3 ng/ml, p ns).

Discussion and conclusion: In our study we observed that the CNND has allowed a more complete postoperative staging, the TG values after surgery were lower in patients in group A vs group B patients (p<0.0001). Moreover, in group-A any recurrence occurred whereas in group B it was observed a case of relapse at 8 months.