Specifics of regional recurrences in lateral tissue of the neck after surgical treatment of highly differentiated thyroid cancer

Abstract

   Introduction: Despite the fact that highly differentiated thyroid cancer is included in the group of malignant neoplasms with a favorable prognosis, data on the high frequency and recurrence of relapses are reported. The presence of metastatic lymph nodes in HDTC increases the risk of regional relapse by up to 27 %. According to the literature, the factors that increase the risk of recurrence are: histological type, stage, depth of extrathyroid invasion, the presence of metastatic lymph nodes, age, and the volume of primary surgical intervention. Lateral neck dissection should be performed in patients with morphologically verified metastatic thyroid cancer, but there is still no clear consensus on the volume of dissection.   Aim: Assessment of factors affecting the risk of regional recurrence in the lateral neck tissue and the localization of recurrence.   Materials and methods: The study included 56 patients with HDTC, in whom metastatic lateral neck nodes were identified and verified. All patients previously underwent unilateral or bilateral neck lymph node dissection in various institutions. During the period of dynamic follow-up, these patients revealed regional recurrences in the lateral tissue of the neck. The patients were observed and treated for recurrence at the N. N. Blokhin National Medical Research Center of Oncology of the Ministry of Health of Russia.   Results: Age over 55 years is a prognostically significant factor affecting the frequency of regional relapse in the lateral neck tissue (p = 0.002). The presence of metastatic nodes in the lateral tissue of the neck at the initial treatment is a prognostically significant factor that increases the risk of regional recurrence in the lateral tissue of the neck (p = 0.017). According to the results of a single-factor analysis, a statistically significant effect of the stage on the risk of regional relapses in the lateral neck tissue was noted (p = 0.014). In 35.7 % of cases, recurrent nodes were localized in the level V.   Conclusion: Main risk factors for relapse are clinico-morphological, such as age, aggressive type of HDTC, stage of the disease, N1b status after primary surgery, as well as technical defects during primary surgical treatment.