Papillary thyroid cancer and its surgical management

Role of sentinel node in differentiated thyroid cancer: a prospective study comparing patent blue injection technique, lymphoscintigraphy and the combined technique

PURPOSE

The purpose of the present study was to evaluate the feasibility and reproducibility of the sentinel lymph node (SLNs) biopsy in differentiated thyroid cancer using patent blue injection, lymphoscintigraphy and the combined techniques.

METHODS

Between January 2011 and January 2013, 82 consecutive patients were enrolled in our prospective multicentre study. Inclusion criteria were 18 years of age, preoperative diagnosis of differentiated thyroid carcinoma, no evidence of lymph node enlargement and multifocal neoplasm. To investigate the benefits of each procedure, all patients underwent total thyroidectomy plus central compartment lymphadenectomy, and in all cases, the SLN was identified via one of three techniques using the same protocol.

RESULTS

Lymphoscintigraphy was used in five patients, patent blue injection was used in 40 patients, and a combined technique was used in 40 patients to identify sentinel lymph nodes (SLN). SLNs were identified in 61 cases. In the patent blue injection technique, the sensitivity, specificity and false negative rates were 88.9, 94.4 and 3.8%, respectively. In the lymphoscintigraphy technique, the percentages of sensitivity and specificity were 100%, and the percentage false negative was 0%. For the combined techniques, the corresponding values were, respectively, 69.2, 90, and 17.4%. Metastases were detected in nine cases of lateral-cervical nodes, ipsilateral tumour metastases were observed in eight cases, and contralateral tumour metastasis was observed in one case.

CONCLUSION

Additional well-designed randomized studies are needed to validate and further optimize the SLN biopsy in patients with differentiated thyroid cancer.

Skip lateral neck node metastases in papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinomas (PTCs) are commonly associated with lymph node metastases (LNMs), which are thought to disseminate sequentially, first to the central compartment and later to the lateral compartment. However, a small number of patients have skip metastases to the lateral compartment without central LNMs. This study was performed to evaluate the clinicopathologic characteristics of skip metastases in PTC.

METHODS

We reviewed the medical records of 147 patients who underwent total thyroidectomy with central neck dissection plus modified radical neck dissection (RND) for PTC. A single surgeon performed all operations. The patients were classified as either present or absent skip metastases. The clinicopathologic characteristics were statistically analyzed.

RESULTS

Skip metastases were found in 32 patients (21.8%) and occurred commonly with primary tumors of the upper pole, and with tumors ≤1 cm in diameter. Skip metastases were less common in patients with multifocal disease. Patients with skip metastases had fewer metastatic lateral nodes that were more frequently found at a single level: mostly at level III (96.9%) and level II (34.4%).

CONCLUSIONS

Although skip metastases occur in only a small number of patients, the lateral compartment should be carefully evaluated for skip metastases, even though primary tumors are either single focus, located in the upper pole, or ≤1 cm in diameter.

Micrometastases in thyroid cancer. An important finding?

Differentiated thyroid cancer is a cancer with a good prognosis but the presence of lymph node metastases is associated with increased rates of loco-regional recurrence and in some reports decreased survival. This has led to an increased interest in the lymph node status with guidelines calling for routine central node dissection and increased interest in lateral compartment node sampling and sentinel node biopsy. We know from studies in regions where routine central and ipsilateral node dissection is the preferred surgical management of differentiated thyroid cancer that lymph node metastases are present in the majority of cases and that many of these are micrometastatic deposits. However, where routine node dissection is not performed recurrence rates are relatively low suggesting that not all micrometastatic disease progresses to a loco-regional recurrence or that the majority of disease is mopped up by adjuvant radioactive iodine. This review examines the available evidence for the significance of micrometastatic disease in differentiated thyroid cancer and suggests that it is probably of little clinical significance and does not warrant further aggressive surgical intervention. We would expect a conservative surgical approach combined with adjuvant radioactive iodine to lead to durable disease control.

Role of metastasectomy in the management of thyroid carcinoma: the NIH experience

BACKGROUND AND OBJECTIVES

We studied the impact of metatasectomy on disease outcome in 29 advanced nonmedullary thyroid carcinoma (ThyrCa) patients who were operated on between 1969 and 2001 at NIH to further define its role in the management of this malignancy.

METHODS

Data were extracted by retrospective chart review. A Kaplan-Meyer survival curve was constructed, and comparative stratification for various parameters was performed.

RESULTS

During 47 surgeries, the following lesions were resected from mid-mediastinum/hila, 17; lung parenchyma, 12; skeleton, 14; kidneys, 2; and brain, 2. All patients received multiple radioiodine (RAI) treatments. External-beam radiotherapy, chemotherapy and other palliative measures were used in selected patients. Six patients (21%) died within 74.7 +/- 54.7 months after the first distant metastasectomy. The outcome of the remaining patients was as follows: complete remission, 3; partial remission, 10; and 10: progressive disease, 10, with a follow-up of 175 patient-years. Metastasectomy led to a decrease of 38% in thyroglobulin levels in 23 patients. Cumulative survival rates were 78.5 +/- 8.4% at 5 years and 50.2 +/- 12.5% at 10 years (mean +/-SEM) after initial distant metastasectomy.

CONCLUSIONS

Our data show that extensive targeted metastasectomy in the setting of a tertiary center can be beneficial to patients with disseminated ThyrCa with persistent or recurrent distant disease, when used in conjunction with nonsurgical treatment modalities.

Prognostic Factors in Mortality and Morbidity in Patients with differentiated Thyroid Cancer

We attempted to determine if women younger than 45 years of age who have isolated papillary thyroid cancer and whose tumors are smaller than 4 cm (T2N0M0) are at low risk for mortality and morbidity following thyroid lobectomy. To this end, we analyzed information on both women and men obtained from our review of the literature, and we integrated it with data compiled in the Delaware Cancer Registry. We performed a secondary analysis to determine if the risk of death and recurrence can be predicted on the basis of age, tumor size, sex, histology, and the type of operation. We found that among patients who had undergone either thyroid lobectomy or total thyroidectomy, mortality rates were 1.3% for those younger than 45 years of age and 15.6% for those 45 years and older (p< 0.0001). With respect to tumor size, patients whose masses were smaller than 4 cm had significantly lower mortality (3.0%) and recurrence (11.1%) rates than did those whose tumors were 4 cm or larger (16.8 and 33.3%, respectively; p< 0.0001). Other significant risk factors for death were male sex and the presence of follicular thyroid cancer (as opposed to papillary thyroid cancer). The risk of permanent hypocalcemia was significant among patients who had undergone total thyroidectomy, but not among those who had been treated with lobectomy. The subgroup of patients who had the lowest risk of mortality and morbidity was made up of women younger than 45 years who had a papillary thyroid tumor smaller than 4 cm that was limited to one lobe and who had undergone lobectomy. On the other hand, we found that lobectomy might carry a higher risk of recurrence (from a micrometastasis in the cervical lymph node) than does total thyroidectomy. Experienced surgeons whose rates of hypocalcemia and recurrent laryngeal nerve paralysis following total thyroidectomy are low offer their patients the unambiguous advantage of superior follow-up with thyroglobulin and radioactive iodine.

Therapeutic strategies and long-term results in differentiated thyroid cancer

Differentiated thyroid carcinoma (DTC) is usually an indolent tumor associated with a low mortality. However, DTC, particularly papillary thyroid carcinoma, happens to be a multicentric tumor and tends to spread to the regional lymph nodes in the early stage of the disease; some patients with DTC do die from metastatic or recurrent disease. Despite the small number of these patients, therapeutic strategies designed to prevent such outcomes should be pursued. In this review, we attempt to evaluate the impact of different therapeutic strategies on survival and recurrence. Consequently, we conclude that the surgical approach to DIC should be individualized on the basis of the biologic behavior of the tumor, rather than on the extent of cancer involvement in the thyroid and regional lymph nodes. It is mandatory to expand our efforts to identify high-risk patients more accurately, thereby facilitating more rational approaches to treatment.

Modified neck dissection in the treatment of differentiated thyroid carcinoma

The prognosis of differentiated carcinoma of the thyroid has been reported to be extremely favourable. Previous studies have concluded that lymph node metastasis do not affect survival rates in patients with differentiated thyroid carcinoma. Therefore, nodal metastasis has not been evaluated as a prognostic factor in recent definitions of risk groups. To determine the significance of nodal disease, we reviewed 219 consecutive patients with differentiated thyroid cancer (191 papillary, 14 follicular and 14 Hurtle cell carcinomas). Fifty-five patients were treated with modified neck dissection and all of them received adjuvant radioiodine. There were recurrences in 25 patients (11.4%), with follow-up ranging from 6 months to 14 years. Systemic disease occurred synchronously in two patients, and four patients died of thyroid carcinoma.

Overexpression of p53 protein and DNA content are important biologic prognostic factors for thyroid cancer

BACKGROUND

Many factors gave been reported to be of prognostic importance for thyroid cancer. Biologic aggressiveness may influence postoperative recurrences and the prognosis of thyroid cancer. Immunohistochemical staining for the p53 protein and DNA content are novel factors that suggest biologic aggressiveness.

METHODS

Retrospective study of the survival rate after operation of differentiated thyroid cancer was undertaken at Osaka Police Hospital. Age, gender operative method, extent of lymph node dissection, use of radioiodine, primary or recurrent tumor, tumor size and invasion, lymph node involvement, presence of distant metastases, DNA ploidy, percentage of S phase and G2M phase fractions, positive staining for the p53 protein, and histologic type and subtype were evaluated as possible prognostic factors by univariate and multivariate analyses of survival.

RESULTS

Positive staining for the p53 protein was related to postoperative local recurrence, and DNA ploidy was related to distant metastatic recurrence. Univariate analysis suggested that age, tumor size and invasion, lymph node involvement, presence of distant metastases, percentage of S phase fraction, histologic subtype, DNA ploidy, and positive staining for the p53 protein were significant prognostic factors. Multivariate analysis suggested that positive staining of the protein and DNA ploidy were independent prognostic factors for overall survival.

CONCLUSIONS

Both positive staining for the p53 protein and DNA ploidy, which suggest biologic aggressiveness, are independent prognostic factors for overall survival of patients with thyroid cancer, Examination of these biologic factors may provide new information regarding postoperative recurrences and the prognosis of thyroid cancer.

Risk of bilateral cervical lymph node metastases in papillary thyroid cancer

We evaluated the risk of bilateral or contralateral cervical lymph node metastases in 135 patients with papillary thyroid cancer who underwent bilateral neck dissection. We confirmed that bilateral jugular lymph node metastases were frequent in patients with obvious carcinoma in both lobes of the gland, in those with cancers arising in the isthmus, in those with clinically detectable bilateral lymphadenopathy, and in those with recurrent thyroid cancer. However, only 24% of the patients who had cancer clinically confined to one lobe with no bilateral or contralateral lymphadenopathy had histologically detected bilateral or contralateral jugular lymph node metastases. But the occurrence of contralateral jugular lymph node metastases was significantly correlated with both clinical lymphadenopathy in the ipsilateral neck and contralateral paratracheal lymph node metastases. Bilateral lymph dissection might be beneficial for these patients.