Anaplastic thyroid carcinoma

Anaplastic thyroid cancer is a form of thyroid cancer which has a very poor prognosis due to its aggressive behavior and resistance to cancer treatments. Its anaplastic cells have poor differentiation, including dedifferentiation. Anaplastic thyroid cancer is a form of thyroid cancer which has a very poor prognosis due to its aggressive behavior and resistance to cancer treatments. Its anaplastic cells have poor differentiation, including dedifferentiation. Anaplastic tumors have a high mitotic rate and lymphovascular invasion. They rapidly invade surrounding tissues (such as the trachea). The presence of regional lymphadenopathy in older patients in whom needle aspiration biopsy reveals characteristic vesicular appearance of the nuclei would support a diagnosis of anaplastic carcinoma. It is always considered as stage IV. Unlike its differentiated counterparts, anaplastic thyroid cancer is highly unlikely to be curable either by surgery or by any other treatment modality, and is in fact usually unresectable due to its high propensity for invading surrounding tissues. Palliative treatment consists of radiation therapy usually combined with chemotherapy. New drugs, such as fosbretabulin (a type of combretastatin), bortezomib and TNF-Related Apoptosis Induced Ligand (TRAIL), are however being under investigation in vitro and in human clinical studies. Based on encouraging Phase I and II clinical trial results with fosbretabulin, a type of drug that selectively destroys tumor blood vessels, clinical trials have been evaluating whether the drug can extend the survival of patients with ATC. The role of external beam radiotherapy (EBRT) in thyroid cancer remains controversial and there is no level I evidence to recommend its use in the setting of differentiated thyroid cancers such as papillary and follicular carcinomas. Anaplastic thyroid carcinomas, however, are histologically distinct from differentiated thyroid cancers and due to the highly aggressive nature of ATC aggressive postoperative radiation and chemotherapy are typically recommended. The National Comprehensive Cancer Network Clinical Practice Guidelines currently recommend that postoperative radiation and chemotherapy be strongly considered. No published randomised controlled trials have examined the addition of EBRT to standard treatment, namely surgery. Radioactive iodine is typically ineffective in the management of ATC as it is not an iodine-avid cancer. Imbalances in age, sex, completeness of surgical excision, histological type and stage, between patients receiving and not receiving EBRT, confound retrospective studies. Variability also exists between treatment and non-treatment groups in the use of radio-iodine and post-treatment thyroid stimulating hormone (TSH) suppression and treatment techniques between and within retrospective studies.