Locally advanced thyroid cancer. Issues of diagnosis and treatment
Authors: Yakovleva L. P. , Kropotov M. A. , Allahverdiev A. K. , Tigrov M. S. , Gavryshchuk P. A. 
Published: December 2022

Background. From 10 to 20% of highly differentiated papillary thyroid cancer show signs of local prevalence: invasion into the surrounding fatty tissue, organs and tissues adjacent to the gland — the anterior muscles of the neck, recurrent nerve, esophagus, laryngopharynx, larynx, trachea. A tumor that has a massive spread, often with life-threatening symptoms in the form of dysphagia, stenosis of the trachea or larynx, has no alternatives to surgical treatment.

Aim. Evaluation of the results of extended and extended-combined interventions for locally advanced highly differentiated thyroid cancer (immediate surgical and long-term results of treatment).

Materials and methods. During the period from 2010 to 2021, 82 patients with locally advanced thyroid cancer were operated on. This cohort included patients in whom the tumor process spread not only to the neck, but also to the mediastinum: either in the region of the upper thoracic inlet, or there was a lesion of deeper parts of the mediastinum. The average age is 56.8 years. The ratio of men and women: 34 (41.5%) and 48 (58.5%), respectively. According to the prevalence of the tumor process, T4 tumors were diagnosed in 54.8% (n= 45). 37 patients had T3 (45.2%) tumors. In 57.3% (n= 47), the primary tumor was combined with the presence of a metastatic lesion in the regional lymph nodes of the neck. 34.1% (n 28) had distant metastases. In all cases it was a lesion of the lungs. Papillary thyroid cancer was verified in 89.6%. 21 patients underwent operations with resection of the larynx and trachea: in 7 cases, laryngectomy with resection of 5 to 8 rings of the trachea, in 4 cases, circular resections, in 6 cases, “shaving”, in 2 cases, “terminal” resections of the trachea with plasty of the defect of the sternum-clavicle-mastoid muscle, in 2 patients the plates of the thyroid cartilage were resected while maintaining the integrity of the organ. In 24 patients, mediastinal lymph node dissection (sternotomy) was performed; in 2 cases, mediastinal lymph node dissection was performed thoracoscopically. In 2 cases, resection of bone structures was performed — the manubrium of the sternum and sternoclavicular joints. In 33 patients, removal of the primary tumor, paratracheal, paraesophageal metastases and metastatic conglomerates from the posterior mediastinum (4 cases) was performed through the cervical approach.

Results. The postoperative period in this group of patients was complicated by the development of pneumonia in 52 (63.4%) patients. Purulent mediastinitis developed in 6 (7.8%) patients, arrosive bleeding in 6% (n= 5), osteomyelitis of the sternum in 2 (2.4%) cases, gastric bleeding in 1 patient (1.5%), lymphorrhea in 2 (2.4%), parathyroid insufficiency developed in 70.7% (n 58) of observations. Postoperative mortality was 6% (n= 5).

OS and disease-free survival amounted to 66.7% and 53.4%, respectively. Death from the progression of the disease occurred in all cases due to the growth of distant metastases against the background of resistance to radioactive iodine that developed during treatment or the implementation of new metastatic foci in terms of 2 to 5 years.

Conclusions. This group of patients demonstrates satisfactory results of OS and disease-free survival, but requires further dynamic monitoring and evaluation of the effectiveness of drug treatment of radioiodine-resistant tumors.