Routine level VI lymph node dissection for papillary thyroid cancer: surgical technique

Understanding the relationship between age and thyroid cancer

Unique among malignancies, age is a key prognostic indicator for well-differentiated thyroid cancer. Patients aged <45 years can have the same degree of disease involvement and a distinctly different prognosis than those aged >45. Although the reason for the association between age and outcome is not entirely clear, it does imply that there is something intrinsic to either the cancer or the treatment that is age dependent. This article explores the characteristics of the normal thyroid and thyroid cancer that are age dependent. It then provides theories for the relationship between advanced age and poor prognosis, in addition to treatment options tailored to age at diagnosis.

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L. Brunaud Thyroid cancers are the most common endocrine cancer. Cervical lymph node metastases are observed in 20 to 60% of patients with papillary thyroid cancer. In 2008, no prospective randomized study has defined whether prophylactic central neck dissection should be performed during initial surgery for papillary thyroid cancer. Prophylactic lymph node dissection remains controversial. Pros and cons for routine lymph node dissection of the central cervical compartment are discussed in this review of the literature which includes data from international and French consensus conferences.

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L. Brunaud Thyroid cancers are the most common endocrine cancer. Cervical lymph node metastases are observed in 20 to 60% of patients with papillary thyroid cancer. In 2008, no prospective randomized study has defined whether prophylactic central neck dissection should be performed during initial surgery for papillary thyroid cancer. Prophylactic lymph node dissection remains controversial. Pros and cons for routine lymph node dissection of the central cervical compartment are discussed in this review of the literature which includes data from international and French consensus conferences.

Lymph node dissection in the lateral neck for completion in central node-positive papillary thyroid cancer

BACKGROUND

In papillary thyroid cancer, quantitative relationships may exist between central and lateral neck lymph node metastases, which may be of clinical usefulness.

METHODS

This comparative analysis of central and lateral neck lymph node metastases was undertaken in 88 patients with untreated papillary thyroid cancer who underwent compartment-oriented lymph node dissection in the central and ipsilateral lateral neck. In 32 of these patients, the contralateral lateral neck was dissected in addition.

RESULTS

Central lymph node metastases were categorized in increments of 0 (22 patients), 1-5 (29 patients), 6-10 (12 patients), and more than 10 positive nodes (25 patients). With more than 5 positive nodes, the rates and numbers of lateral lymph node metastases increased from between 45% and 69% to 100% and from a mean of between 2 and 3 to between 6 and 8 lymph node metastases (all P < .001) in the ipsilateral neck; and from between 0% and 33% to between 60% and 71% (P = .009) and from a mean of between 0 and 1 to between 3 and 7 lymph node metastases (P = .003) in the contralateral neck. Lateral lymph node metastases in the contralateral neck always coexisted with metastases in both the central and the opposite lateral neck. When only patients with positive lateral nodes were considered, the successive increase in the number of lateral lymph node metastases was still present. Altogether, the ipsilateral neck harbored more often lateral lymph node metastasis with more positive lateral nodes than the contralateral neck.

CONCLUSION

These histopathologic associations may provide a foundation for more evidence-based decisions regarding lymph node dissection of the lateral neck compartments in patients with node-positive papillary thyroid cancer.

Management of the solitary thyroid nodule

Thyroid nodules are common, with up to 8% of the adult population having palpable nodules. With the use of ultrasound, up to 10 times more nodules are likely to be detected. Increasing numbers of nodules are being detected serendipitously because of the rising use of imaging to investigate unrelated conditions. The primary aim in investigating a thyroid nodule is to exclude the possibility of malignancy, which occurs in about 5% of nodules. This begins with a thorough history, including previous exposure to radiation and any family history of thyroid cancer or other endocrine diseases. Clinical examination of the neck should focus on the thyroid nodule and the gland itself, but also the presence of any cervical lymphadenopathy. Biochemical assessment of the thyroid needs to be followed by thyroid ultrasound, which may demonstrate features that are associated with a higher chance of the nodule being malignant. Fine-needle aspiration biopsy is crucial in the investigation of a thyroid nodule. It provides highly accurate cytologic information about the nodule from which a definitive management plan can be formulated. The challenge remains in the management of nodules that fall under the "indeterminate" category. These may be subject to more surgical intervention than is required because histological examination is the only way in which a malignancy can be excluded. Surgery followed by radioactive iodine ablation is the mainstay of treatment for differentiated thyroid cancers, and the majority of patients can expect high cure rates.

Extent of prophylactic lymph node dissection in the central neck area of the patients with papillary thyroid carcinoma: comparison of limited versus comprehensive lymph node dissection in a 2-year safety study

BACKGROUND

To compare the "comprehensive" (including bilateral paratracheal, pretracheal, prelaryngeal lymph nodes) (CCND) with "limited" (saving contralateral paratracheal lymph nodes) central node dissection (LCND) for postoperative complications and disease recurrence rate in sonographically node-negative papillary thyroid carcinomas.

MATERIALS AND METHODS

From 2003 to 2005, 114 consecutive patients, diagnosed as sonographically node-negative thyroid papillary carcinomas, were included retrospectively. Among them, the LCND was performed in 56 patients and CCND in 58 patients, in combination with total thyroidectomy, based on the operator-dependent decision. We compared the complication rates and the recurrence rates between these two groups with a mean follow-up duration of 2 years.

RESULTS

Transient hypocalcemia was more frequent in the CCND group than in the LCND group (48.3% vs 26.8%, P = .02, odds ratio [OR] = 2.55). However, the other complication rates were similar in the two groups. In addition, the immediate postoperative reduction of parathyroid hormone (PTH) was more evident in the CCND group. The postoperative PTH levels increased up to a similar level (12.4 vs 11.8 pg/mL) over 6 months. The incidence of permanent hypocalcemia did not differ significantly between the two groups. Four (7.1%) and five recurrences (8.6%) were found in two groups, respectively, implying similar oncological safety during the 2-year follow-up.

CONCLUSION

The LCND with total thyroidectomy could be an alternative treatment option for node-negative papillary thyroid carcinomas, because LCND had fewer short-term hypocalcemia and similar oncological outcomes during the 2-year follow-up. Further study enrolling a large number of patients with long-term follow-up is needed.

Thyroid surgery in the tropics

In the tropics thyroid surgery is carried out either by general surgeons or ear, nose and throat surgeons and there are few places with a subspecialist endocrine or head and neck surgeon. The aim of this review is to determine the pattern of thyroid pathology, surgery and surgical outcomes in the tropics. A review of thyroid surgery in tropical regions was carried out based on published articles in English in Medline (1965-2004). The findings are also discussed in the light of the authors' own experience of thyroid disease and thyroid surgery in four continents. The pattern of thyroid pathology varies in the tropics, particularly in regions where endemic goitre is common. Endemic goitre usually regresses with iodine therapy. There is a rising incidence of thyroid autoimmune disease, particularly Graves' disease and Hashimoto's thyroiditis, probably related to an environmental immunological stimulus associated with development. Surgery is indicated for the same reasons as in the developed countries: thyrotoxicosis (more often in the absence of radioactive iodine therapy), solitary thyroid nodule and multinodular or malignant goitre. However, a preoperative cytological diagnosis will only be available in important centres where there is a pathologist. Malignancy appears more prevalent in nodules and goitres in the tropics than in the developed countries, perhaps because patients with malignancy are more likely to be referred to a surgeon. Nonetheless, the evidence suggests that thyroid surgery can be carried out safely with a minimum of complications even in remote mission hospitals with limited facilities for investigation. Standards can be set in terms of surgical outcomes; for example, mortality (0%), permanent recurrent laryngeal nerve (RLN) injury (<2%), re-exploration for haematoma(<2%), permanent hypocalcaemia (<5%) and wound infection (2.5%). The choice of operation depends on the local pathology and the likelihood of being able to obtain lifelong thyroxine. Total thyroidectomy should be avoided whenever possible if thyroxine supplies are unreliable. Advanced thyroid cancer presents a therapeutic challenge and some cases will be unresectable. The management options are limited by the resources available. Similar surgical outcomes should be able to be achieved no matter where the surgery is carried out.