CANCER OF THE THYROID CANCER OF THE THYROID • Cancer of the thyroid is a malignant neoplasm of the gland. • Thyroid cancer is the most common form of an endocrine system cancer. • Thyroid cancer affects more women, and the incidence is higher in Asian Americans. • Incidence increases with age. • The average age at time of diagnosis is 45 years. Risk Factors • Radiation exposure – external radiation to the head and neck in infancy and childhood, and subsequent development of thyroid carcinoma. (Between 1949 and 1960, radiation therapy was commonly given to shrink enlarged tonsil and adenoid tissue, to treat acne, or to reduce an enlarged thymus.). • Adults at higher risk for thyroid cancer include those who were given radiation treatment during childhood for lymphoma and neuroblastoma. • Personal or family history of goiter Types • Papillary and well-differentiated adenocarcinoma (most common) – Growth is slow, and spread is confined to lymph nodes that surround thyroid area. Cure rate is excellent after removal of involved areas. • Follicular (rapidly growing, widely metastasizing type) – Occurs predominantly in middle-aged and older persons. Brief encouraging response may occur with irradiation. Progression of disease is rapid; high mortality. • Parafollicular-medullary thyroid carcinoma – Rare, inheritable type of thyroid malignancy, which can be detected early by a radioimmunoassay for calcitonin. • Undifferentiated anaplastic carcinoma – The most aggressive and lethal solid tumor found in humans. Least common of all thyroid cancers. Usually fatal within months of diagnosis. • Thyroid lymphoma – Appears after 40 years of age. May have history of goiter, hoarseness, dyspnea, pain, and pressure. It has good prognosis. Clinical Manifestations • On palpation of the thyroid, there may be a firm, irregular, fixed, painless mass or nodule. • Firm, palpable, cervical masses that are suggestive of lymph node metastasis • Hemoptysis (indicates tracheal involvement) • Airway obstruction (large tumour blocking the trachea). • Difficulty in swallowing (tumour blocking the oesophagus) • The occurrence of signs and symptoms of hyperthyroidism is rare. Diagnosis • A thyroid scan will detect a “cold” nodule with little uptake. The scan shows whether nodules on the thyroid are “hot” or “cold.” Tumors that take up radioactive iodine are called “hot” nodules and are nearly always benign. If the nodule does not take up the radioactive iodine, it appears as “cold” and has a higher risk of being malignant • FNA biopsy – ultrasound-guided fine-needle aspiration (FNA) to take tissue sample for pathologic examination. • Surgical exploration. • Ultrasound scan. • CT scan • MRI • Positron emission tomography (PET) • Elevations in serum calcitonin are associated with medullary thyroid cancer. • In papillary and follicular cancers, serum thyroglobulin is elevated • Physical Examination: Lesions that are single, hard, and fixed on palpation or associated with cervical lymphadenopathy suggest malignancy. Management • Surgical removal is extensive, as required. • Postoperative radiation therapy is commonly done to reduce chances of recurrence. • Follow-up includes periodic 131I uptake scan to detect evidence of recurrence. • Thyroid replacement. • Thyroid hormone is administered to suppress secretion of TSH. • Such treatment is continued indefinitely and requires annual checkups. • For unresectable cancer, patient is referred for treatment with 131I, chemotherapy, or radiation therapy. • In families with a history of medullary thyroid cancer, encourage family members to get genetic testing done and have thyroid screening on a regular basis. Nursing care • Explore patient's feelings and concerns regarding the diagnosis, treatment, and prognosis. • Provide all explanations in a simple, concise manner and repeat important information as necessary because anxiety may interfere with patient's processing of information. • Stress the positive aspects of treatment (high cure rate). • Encourage support by significant other, clergy, social worker, nursing staff, as available. Patient Education • Instruct the patient on thyroid hormone replacement and follow-up blood tests. • Stress the need for periodic evaluation for recurrence of malignancy. • Supply additional information or suggest community resources dealing with cancer prevention and treatment. • Assist patient in identifying sources of information and support available in the community.
