• What is initial treatment of papillary thyroid cancer?
Surgery is the primary treatment for papillary thyroid cancer. Unlike for many cancers, surgical removal of the primary tumor is indicated even in the presence of metastatic disease [8]. Total or near-total thyroidectomy is used to treat patients with tumors > 1 cm or with tumors < 1 cm and associated risk factors (eg, contralateral nodules, affected lymph nodes, metastasis, history of radiation, first-degree family history of papillary thyroid cancer, or age > 45 years) [6]. There is a lower risk of recurrence in patients treated with total thyroidectomy versus lobectomy in papillary thyroid cancer [9,10]. Thyroid lobectomy may be used in small (< 1 cm) unifocal tumors without the presence of the associated risk factors listed above.
Patients with central or lateral neck lymph node involvement should also undergo central-compartment (level VI) neck dissection. Therapeutic lateral neck compartmental lymph node dissection is recommended in patients with biopsy-proven metastatic lateral cervical adenopathy [6,7]. The role of unilateral or bilateral prophylactic central-compartment nodal dissection (PCND), that is, lymph node dissection in the level VI compartment of neck in patients without evidence of lymphadenopathy, is controversial. The data for the possible benefit of PCND are inconclusive [11] although the ATA recommends the procedure for locally invasive T3 and T4 tumors [6].
The American Thyroid Association (ATA) and National Comprehensive Cancer Network (NCCN) guidelines [6,7] recommend a preoperative cervical ultrasound in patients with biopsy-proven papillary thyroid cancer to evaluate the presence of disease in the cervical lymph nodes, especially in the lateral and central compartments, and in the contralateral thyroid lobe. If suspicious lymph nodes are found, FNA confirmation is necessary only if this would change management. Systematic use of other preoperative imaging studies, such as CT or MRI, is not recommended [6,7].
Surgical Treatment
The patient underwent a total thyroidectomy with bilateral central neck dissection and selective supraclavicular left-sided lateral neck dissection. Lymph nodes on both sides of the neck (paratracheal nodes) as well as the left supraclavicular nodes were removed. Pathology showed multifocal papillary cancer with extracapsular extension to the paratracheal soft tissue, 14/14 lymph nodes affected, stage IVA T4N1 bM0.
• How is papillary thyroid cancer staged?
• How should this patient be treated after surgery? Is any adjuvant therapy indicated?
TSH Suppression
In an effort to reduce risk of recurrence, patients should receive lifelong suppression of TSH using supraphysiologic doses of levothyroxine after total thyroidectomy. This is based upon the hypothesis that TSH is a growth factor for thyroid cancer cells [12,13]. Although a meta-analysis [14] supports the efficacy of TSH suppression therapy, some authors have questioned its widespread use, especially in light of the adverse effects of its use over the long term [15]. Many support its use only in high-risk patients [16], arguing that there is no evidence of benefit for low-risk patients [17]. This view is reflected in the ATA guidelines, which recommend TSH suppression below 0.1 mU/L for high-risk and intermediate-risk patients, while normal or slightly below normal TSH levels are recommended for low-risk patients [6].