The Comprehensive Management Of Differentiated Thyroid Carcinoma

BACKGROUND AND OBJECTIVES The thyroid carcinoma is the most frequent endocrine cancer. According to the latest epidemiological survey, the incidence of thyroid cancer, mainly differentiated, is one of the most rapidly increasing human cancers. The differentiated thyroid cancer is the most common histotype in the thyroid cancer. Managing differentiated (ie, papillary, follicular) thyroid carcinoma can be a challenge, because no prospective randomized trials of treatment have been done. Results from ongoing randomized trials will not be available for many years, given the typically prolonged course and relative infrequency of these tumors. Most of the information about treatment comes from studies of large patient cohorts in which therapy has not been randomly assigned. This accounts for much of the disagreement about managing differentiated thyroid carcinoma. The aim of this study is to retrospectively evaluate the patients diagnosed with differentiated thyroid carcinoma in our department from Jun. 2003 to Jun. 2008 in terms of the clinical and histopathological features, conjugating with literature retrieval, thereby summarize the optimal treatment. To discuss the epidemiology and the other treatments for differentiated thyroid carcinoma.Methods It was discussed epidemiological characteristic of differentiated thyroid carcinoma according to the latest literature retrieval. Protocols of 72 patients undergoing reoperation for thyroid cancer from June 2003 to August 2006 were reviewed. Causes for reoperation were as follows: residue of the tumor locally as the inappropriate initial operation; local recurrence and cervical lymph node metastasis; before ¹³¹I ablation which differentiated thyroid cancer with distant place metastasis. Protocols of 70 thyroid microcarcinoma patients undergoing operation from June 2003 to September 2007 and protocols of 452 differentiated thyroid carcinoma patients undergoing total thyroidectomy from June 2003 to June 2008 were reviewed. It was discussed the surgical strategy of the thyroid gland resection extent. Protocol of 83 papillary thyroid cancer patients undergoing radical thyroidectomy and modified radical neck dissection whose lymph node dissection number was over 8 in the period June 2003 to June 2006 were reviewed. To investigate the regular pattern of cervical lymph node metastases of papillary thyroid cancer, and determine the treatment of selective lymph node dissection in patients with papillary thyroid cancer. It also wanted to discuss the other treatments for the common and refractory differentiated thyroid carcinoma.Result It was well recognized that the incidence of differentiated thyroid carcinoma was closed related with exposure to radiation. The youngest children were most sensitive to radiation-induced carcinogenesis and it became apparent that the radiation-induced thyroid carcinomas were much less influenced by gender, virtually always papillary (solid and follicular variants), more aggressive at presentation and more frequently associated with thyroid autoimmunity. The overall incidence of differentiated thyroid carcinoma was generally not considered to be influenced by the iodine intake of a population, whereas the distribution of the types of thyroid carcinoma seemed to be related to the intake of iodine, with fewer of the more aggressive follicular and anaplastic carcinomas and more papillary carcinomas in iodine rich areas. That more frequent use and higher resolution of medical imaging had led to an increased detection rate of small, subclinical tumours, which in turn accounts for the higher incidence of differentiated thyroid carcinoma. Thyroid cancer was related with family history of thyroid caner and thyroid morbidity. A significantly more frequent hormone replacement therapy and contraception and more frequent miscarriages in women with thyroid cancer were noteworthy. The rate of residual in thyroid and cervical lymph node confirmed by postoperative pathology were 47.1% and 81.4% (35/43) respectively in our 72 cases of reoperation thyroid cancers. About 50% thyroid microcarcinoma in 70 cases and 66.4% differentiated thyroid carcinoma in 452 cases thyroid total thyroidectomy needed total thyroidectomy. Total thyroidectomy should be the stand surgery strategy for differentiated thyroid carcinoma. Lymph node metastasis of papillary thyroid cancer(PTC) was commonly presented in the level VI central compartment (unilateral PTC 72.3% and bilateral PTC 88.9%) , the second was in the levelIII, IV lateral compartment (unilateral PTC 57.9% and bilateral PTC 50-66.7%) .Level V and I are seldom found metastasis ( unilateral PTC 0-20.1% and bilateral PTC 25-33.3%) .Thyroid capsular invasion (88%) and follicular variant(85.7%) of PTC easy metastasis to the cervical lymph node. Focal malignant of benign thyroid diseases (27.3%) and encapsulated variant (25%) are seldom found metastasis. Metastatic lymph nodes may found in the lateral compartment of cervical lymph node and free in the central compartment in the upper pole PTC. Routine level VI central compartment LND at the time of thyroidectomy is advocated. Anus perineum of PTC need explore the opposite side level VI. The upper pole PTC should be treated by selective neck dissection (at least levels III,IV, and VI). With a higher risk PTC (capsular invasion and follicular variant) of PTC should underwent selective LND at levels II through VI. Radioactive iodine (RAI) was the major adjuvant treatment of well-differentiated papillary cancer of the thyroid, which could reduce the mortality and local recurrence of thyroid cancer. RAI was benefit for the follow-up of Tg. Thyroid hormone replace treatment after thyroid operation with the L-enantiomer of tetraiodothyronine (L-T(4)) was not only maintenance the normal thyroid hormone level but also benefit high-risk thyroid cancer patients by decreasing recurrence, growth and delitescence metastasis of tumour. The role of adjuvant external radiotherapy and chemotherapy were limited for the thyroid cancer. A follow-up strategy emphasizing routine cervical ultrasonography and unstimulated thyroglobulin was effective in identifying patients with recurrent papillary thyroid cancer. RAI whole-body scanning (WBS) and positron emission tomography (PET) computed tomography were useful in the detection of recurrence and/or metastases of differentiated thyroid carcinoma.