Thyroid Cancer Information PDF

Thyroid RADTH-23-1 BY DR POPOOLA A.O Consultant Clinical Oncologist Department of Radiology, Oncology Unit. Lagos State University College of Medicine ,Ikeja. Thyroid cancer though rare, is the most common endocrine cancer.  Annual incidence of thyroid of thy...

Thyroid RADTH-23-1 BY DR POPOOLA A.O Consultant Clinical Oncologist Department of Radiology, Oncology Unit. Lagos State University College of Medicine ,Ikeja. Thyroid cancer though rare, is the most common endocrine cancer.  Annual incidence of thyroid of thyroid 0.5 – 10 per 100,000 women population and 0.3 – 4.7 per 100,000 men population in most countries A global estimate suggested a total of 87,000 new cases world wide each year. Iceland and Hawaii being among the countries with the highest incidence rates has 12-15 per 100,000 women population and 3.9- 4.7 per 100,000 men population Nigeria has incidence rates of 1.7 per 100,000 women population and 0.8 per 100,000 men population. There is female preponderance of thyroid cancer in all races with the female to male ratio varying about 1.5:1to about 4:1. Mainly due to excess female incidence between 25 and 50 years. Thyroid cancer is rare in childhood and adolescence. The incidence increases with age and the median age at diagnosis is 45 to About 80%of all thyroid cancers are differentiated carcinomas derived from the follicular cells. These differentiated thyroid carcinomas are the papillary and follicular cells. One consistently implicated risk factor for thyroid cancer is a history of thyroid gland exposure to ionizing radiation particularly before puberty. Increased incidence of differentiated thyroid carcinoma among the Nuclear fallouts: Atomic bombing and radiation accidents ,medically or Follicular thyroid carcinoma has been reported to be higher in iodine deficient giotrous areas, while papillary carcinoma is the most frequent thyroid carcinoma in iodine rich area. Other risk factor implicated includes heredity, and history of benign thyroid disease. Protective effects have been reported with high consumption of fresh fish, certain vegetables, wine, and cigarette smoking. Most differentiated thyroid cancers present as asymptomatic thyroid nodule. Thyroid carcinoma may be localized to the thyroid gland Present with lymph node metastasis Reports have shown that most patients with thyroid cancer are clinically Euthyroid and have normal serum thyrotropin concentration. Hyperthyroidism with thyrotoxic symptoms presentation is rare.  RADTH-23-2 Thyroid function tests though no diagnostic of thyroid carcinoma is very important in the management and follows up of the thyroid cancer cases. Full blood count (FBC), serum electrolytes and urea (E & U), and liver function tests (LFT) are done for further assessment of the thyroid cancer patients and preparation for therapy. Chest radiograph (CXR) is done to rule out pulmonary of rib metastases. Patients with thyroid nodules were formerly evaluated by radioiodine or technetium – 99m imaging study. This is necessary as the imaging gives anatomic and functional evaluation of a palpable thyroid nodule, detection of. occult or minimal cancer, detection of metastatic deposits and in assessment of therapy. Radioiodine – 123 and technetium – 99m are preferred to radioiodine – 133 for routine scanning because the former deliver much lower radiation dose to the However in the postoperative assessment and management of differentiated thyroid cancer cases, radioiodine- 131 is preferred. Thyroid ultrasonography has been found to be very valuable in the diagnosis and management of thyroid of thyroid carcinoma. Ultrasound guided fine needle aspiration cytology has become the first choice procedure in the definitive diagnosis of thyroid carcinoma. Computerized tomography [CT] scan is useful in assessing the tumour, extent of The most widely used staging system – the TNM system, takes consideration of the prognostic factors. Based on the staging system, about 80%- 85% of the differentiated thyroid cancers belong to the risk group and hence less mortality. The low risk group includes patients less than 35 years of age, with papillary or follicular histology, primary tumour T1 or T2 (not penetrating capsule), no distant or lymph node metastases. The high risk group include the tall –cell, columnar cell and diffuse scleroding variants of the papillary thyroid carcinoma and the widely invasive , poorly differentiated and hurthle cell variants of the follicular carcinoma. The management of differentiated thyroid carcinomas requires an integrated approach involving in most cases: -Surgical excision, -Radioactive iodine therapy and thyroid hormone suppression of thyrotropin concentrations. Anaplastic-Radiotherapy and Chemotherapy