Well Differentiated Thyroid Cancer

Radioprotective Effects of Amifostine, L-Carnitine and Vitamin E in Preventing Early Salivary Gland Injury due to Radioactive Iodine Treatment

OBJECTIVE

Standard treatment of differentiated thyroid cancer includes total thyroidectomy and high-dose Radioactive Iodine Therapy (RIT) for ablation of remnant thyroid tissue. When administered systemically, RIT can cause radiation-induced damage in non-targeted normal tissues. The aim of the present study was to compare the protective effects of amifostine (AMI), LCarnitine (LC), and Vitamin E (EVIT) against high dose radioactive iodine treatment induced Salivary Gland (SG) damage using SG scintigraphy and histopathological examination.

METHODS

Forty adult guinea pigs were studied. Twenty guinea pigs receive 555-660 MBq 131Iodine intraperitoneally (IP) to ablate the thyroid and impair the parenchymal function of the SGs. The animals were divided into eight groups as follows: (1) Group 1 (control): 1 mL IP PS (physiological saline); (2) Group 2: single dose of 200 mg/kg IP AMI one hour prior to 1 mL IP PS; (3) Group 3: 200 mg/kg IP LC and 1 mL IP PS for 10 days; (4) Group 4: 40 mg/kg intramuscular (IM) EVITand 1 mL IP PS for 10 days; (5) Group 5: IP RIT after premedication; (6) Group 6: Single dose of 200 mg/kg IP AMI one hour prior to RIT and IP RIT after premedication; (7) Group 7: IP RIT after premedication and 200 mg/kg IP LC for 10 days starting one day before RIT; and (8) Group 8: IP RIT after premedication and 40 mg/kg IM EVIT for 10 days starting one day before RIT. Scintigraphy was performed 1 month after treatment. SGs were examined by light microscopy and a histopathological scoring system was used to assess the degree of SG damage.

RESULTS

There were significant differences in the body weight and thyroid hormone levels between the groups after treatment.

CONCLUSION

The individual use of AMI, LC and EVIT for radioprotection yield different levels of protection against radioactive iodine treatment injury in SGs; however, none of the agents could provide absolute protection at the doses administered in this experimental model.

The Value of Fine-Needle Aspiration Biopsy (FNAB) in Differential Diagnosis of Scintigraphic Cold Thyroid Nodule

INTRODUCTION

Pathology of thyroid nodules is present in all ages and it is frequently encountered in clinical practice. Thyroid nodules do not represent a single disease, but they are the clinical manifestation of a wide range of different thyroid diseases.

AIM

The objective of this study is to evaluate the frequency and localization of malignancy in solitary scintigraphic cold nodules, as well as the sensitivity, specificity and diagnostic accuracy of FNAB in comparison with histopathological findings.

METHODS

The study was included 49 patients with palpatory findings of the solitary nodule located in the both lobes or isthmus of thyroid gland. All subjects underwent the scintigraphy and FNAB, followed by a cytologic results that was compared to the final histopathological diagnosis, after surgery.

RESULTS

The study results show that the highest number of solitary nodules (81,6%) is localized in the lower pole of the both lobes of the thyroid gland. The cytologic results were benign 8 cases, malignant in 23 and indeterminate (follicular neoplasm) in 18 cases. The highest number of thyroid cancer is histopathologically confirmed in the patients with cytological diagnosis of follicular neoplasms, i.e. follicular cancer is found in 66.7% and papillary cancer is found in 33.3% of subjects. The most common cancer is papillary cancer found in 61,2%. Since the pathohistological diagnosis of all our patients responded to cancer, it was done indirect statistical evaluation of the diagnostic sensitivity of cytological method in the estimation of malignant thyroid lesion, which was 83,7%.

CONCLUSION

FNAB is a highly sensitive method in the diagnostics of malignant thyroid lesions with the sensitivity Se=83,7%. The highest number of thyroid cancer is histopathologically confirmed in the patients with cytological diagnosis of follicular neoplasm (66.7%). The highest number of patients had a cytological diagnosis of papillary cancer.

Association between prognostic factors and clinical outcome of well-differentiated thyroid carcinoma: A retrospective 10-year follow-up study

Differentiated thyroid carcinoma (DTC) is one of the most common metabolic disorders and accounts for 98% of all cases of thyroid cancer. Previously, a number of studies have investigated the prognostic factors associated with well-differentiated thyroid carcinoma (WDTC); however, these studies yielded conflicting results. The current study used a retrospective study design to collect data from WDTC patients who had received the same treatment regimen from the same institute, with a minimum follow-up of 10 years. The De Groot staging system was used to classify WDTC in a total of 320 patients (240 females and 80 males). Among the subjects, the pathological subtypes identified were as follows: Papillary carcinoma (240 cases, 75%), follicular carcinoma (67 cases, 21%) and Hürthle cell carcinoma (13 cases, 4%). Prognostic factors that significantly affected the clinical outcome of the disease were advanced age (P=0.001), tumor size (P=0.03), presence of thyroglobulin (P=0.001) and De Groot stage (P=0.005). The 10-year follow-up study revealed that WDTC is associated with a high survival rate of 96% (307/320 patients survived) and a low mortality rate (4%).

Increased risk of differentiated thyroid carcinoma with combined effects of homologous recombination repair gene polymorphisms in an Iranian population

Homologous recombination (HR) repair has a crucial role to play in the prevention of chromosomal instability, and it is clear that defects in some HR repair genes are associated with many cancers. To evaluate the potential effect of some HR repair gene polymorphisms with differentiated thyroid carcinoma (DTC), we assessed Rad51 (135G>C), Rad52 (2259C>T), XRCC2 (R188H) and XRCC3 (T241M) polymorphisms in Iranian DTC patients and cancer-free controls. In addition, haplotype analysis and gene combination assessment were carried out. Genotyping of Rad51 (135G>C), Rad52 (2259C>T) and XRCC3 (T241M) polymorphisms was determined by PCR-RFLP and PCR-HRM analysis was carried out to evaluate XRCC2 (R188H) . Separately, Rad51, Rad52 and XRCC2 polymorphisms were not shown to be more significant in patients when compared to controls in crude, sex-adjusted and age-adjusted form. However, results indicated a significant difference in XRCC3 genotypes for patients when compared to controls (p value: 0.035). The GCTG haplotype demonstrated a significant difference (p value: 0.047). When compared to the wild type, the combined variant form of Rad52/XRCC2/XRCC3 revealed an elevated risk of DTC (p value: 0.007). It is recommended that Rad52 2259C>T, XRCC2 R188H and XRCC3 T241M polymorphisms should be simultaneously considered as contributing to a polygenic risk of differentiated thyroid carcinoma.

Measurement of radiation exposure in relatives of thyroid cancer patients treated with (131)I

This work evaluates the radiological risk that patients treated with I for differentiated thyroid cancer could present to relatives and occupationally exposed workers. Recently, the International Atomic Energy Agency issued document K9010241, which recommends that patient discharge from the hospital must be based on the particular status of each patient. This work measures effective dose received by caregivers of patients treated with I at the Instituto Nacional de Cancerología, Mexico City. Thermoluminescent dosimeters were carried during a 15-d period by 40 family caregivers after patient release from hospital. Relatives were classified into two groups, ambulatory and hospitalized, according to the release mode of the patient, and three categories according to the individual patient home and transport facilities. Categories A, B, and C were defined going from most to least adequate concerning public exposure risk. Measurements were performed for 20 family caregivers in each group. The effective dose received by all caregivers participating in this study was found to be less than 5 mSv, the recommended limit per event for caregivers suggested by ICRP 103. In addition, 70 and 90% of ambulatory and hospitalized groups, respectively, received doses lower than 1 mSv. Caregivers belonging to category C, with home situations that are not appropriate for immediate release, received the highest average doses; i.e., 2.2 ± 1.3 and 3.1 ± 1.0 mSv for hospitalized and ambulatory patients, respectively. Results of this work have shown that the proper implementation of radiation protection instructions for relatives and patients can reduce significantly the risk that differentiated thyroid cancer patients treated with I can represent for surrounding individuals. The results also stress the relevance of the patient's particular lifestyle and transport conditions as the prevailing factors related to the dose received by the caregiver. Therefore, the patient's status should be the criterion used to decide his/her release modality. This work provides support to recommend the implementation of the "patient specific release criteria" in accordance with ICRP 94, IAEA Safety Report No. 63, and IAE document K9010241 A for patients treated with radiopharmaceuticals.

p53 antibody: is it an indicator of dedifferentiated thyroid cancer?

AIM

Radioiodine is the most effective treatment modality in differentiated thyroid carcinoma, either in metastatic or residual thyroid tissue. However, sometimes dedifferentiation can develop and the effectiveness of radioactive I-131 decreases. The p53 is a tumor suppressor gene which plays an important role in controlling normal cell proliferation regulation. In the serum of healthy individuals, the presence of p53 autoantibodies is extremely rare. Mutations in this gene cause an accumulation of non-functional proteins and may lead to development of anti-p53 antibodies. The aim of the present study was to devise a simple blood test that could lead to early identification of patients with dedifferentiation. In this respect, we investigate whether the serum level of anti-p53 antibody is of diagnostic value in the follow-up of patients with high levels of thyroglobulin (Tg) and negative I-131 scan.

MATERIALS AND METHODS

Patients who were diagnosed with thyroid cancer, treated with total or near total thyroidectomy and referred for I-131 therapy or low dose I-131 whole body scan were included in our study. Blood samples were taken before the administration of I-131 orally in the group of patients. Besides, 28 healthy subjects were included. We quantified the presence of p53 autoantibodies from serums.

RESULTS

In the present study were enrolled 171 patients with a mean age of 47.7±13.5 years (range 16–80 years) and 28 healthy subjects with an age range of 18–52 years (mean 36.0±9.8 years). One hundred and forty-eight patients had papillary (86.5%), 7 (4.1%) follicular, 10 (5.8%) thyroid tumors of uncertain malignant potential, 2 (1.2%) Hürthle cell carcinoma, 3 (1.8%) poor differentiated, and 1 (0.6%) undifferentiated thyroid carcinoma. The p53 antibodies were positive in 16 (9.4%) patients and negative in 155 (90.6%). The p53 antibodies were positive in 3 (10.7%) healthy subjects, and negative in 25 (89.3%) healthy subjects. In five patients with high Tg level and negative radioiodine scan, who were accepted as dedifferentiated, p53 antibodies were also negative.

CONCLUSION

The results of the present study suggested that the level of serum p53 antibody seems to be of limited value in the demonstration of dedifferentiation in thyroid cancer patients.

Prognostic significance of tumor multifocality in papillary thyroid carcinoma and its relationship with primary tumor size: a retrospective study of 2,309 consecutive patients

BACKGROUND

Tumor multifocality is frequently observed in papillary thyroid carcinoma (PTC), but its prognostic value is controversial. We investigated the prognostic significance of multifocality in PTCs larger than 1 cm and papillary thyroid microcarcinomas (PTMC).

METHODS

Medical records and pathologic results of 2,309 patients who received thyroidectomy and lymph node dissection for PTC were retrospectively reviewed. We identified 648 patients who had PTC with a primary tumor exceeding 1 cm, and 1,661 patients with PTMC. In each group, we compared patients with unifocal and multifocal disease. Cox regression analyses of disease persistence and recurrence were performed to identify the prognostic significance of multifocality.

RESULTS

The mean follow-up period was 5.6 years. In the analyses of PTCs larger than 1 cm, the multifocal group included more extensive thyroid surgeries (p = 0.039), radioactive iodine therapies with higher doses (p < 0.001), and significantly higher rates of disease persistence and recurrence (p = 0.001) compared with the unifocal group. In analogous analyses of patients with PTMC, disease persistence and recurrence did not differ significantly between the unifocal and multifocal groups. Cox regression analyses indicated that multifocality was an independent risk factor for disease persistence and recurrence in patients who had PTC with a tumor exceeding 1 cm, but not in patients with PTMC.

CONCLUSION

Tumor multifocality appears to be an important prognostic factor for PTCs larger than 1 cm, but may have little or no prognostic significance for PTMC.

The rate of operative success achieved with radioguided occult lesion localization and intraoperative ultrasonography in patients with recurrent papillary thyroid cancer

BACKGROUND

To investigate the rate of operative success in excision of nonpalpable lymph nodes with metastatic disease achieved with radioguided occult lesion localization (ROLL) and intraoperative ultrasonography (IOUS) in patients with papillary thyroid cancer (PTC).

METHODS

Twenty consecutive PTC patients with nonpalpable lymph nodes with metastatic disease localized in previously operated fields were randomized to receive ROLL (n = 11) or IOUS (n = 9). Nodes were excised along with adjacent soft tissue to accomplish a compartment-oriented dissection. The duration of operation, rate of postoperative complications, pre- and postoperative serum thyroglobulin (Tg) levels, and the findings of postoperative neck ultrasonography and postablation scan were recorded in all patients. Measures of operative success included a postoperative Tg level <50% of preoperative Tg level and no abnormal lesions on postoperative imaging.

RESULTS

Histopathologic examination confirmed the excision of all preoperatively identified metastatic nodes. Additional nodes also were excised (2.3 ± 3.3 per specimen in the ROLL group and 1.6 ± 1.8 per specimen in the IOUS group), 23% of which were metastatic. No postoperative complications occurred in either group. The duration of operation was similar in the 2 groups (P = .4). Postoperative imaging confirmed the clearance of suspicious nodes in all patients. The rate of operative success in ROLL and IOUS group were 100% and 89%, respectively.

CONCLUSION

In patients with recurrent PTC, a high rate of operative success in excision of nonpalpable metastatic lymph nodes was achieved by both ROLL and IOUS. We recommend compartment-oriented dissection; this approach may maximize the removal of metastatic nodes not identified by preoperative imaging.

Papillary thyroid carcinoma with lung metastasis arising from dyshormonogenetic goiter: a case report

Prior radiation exposure is the best known risk factor for thyroid cancers, and papillary thyroid carcinoma (PTC) may arise from dyshormonogenetic goiter. A 17-year-old female patient was admitted to the department of chest diseases with respiratory symptoms. The patient had undergone a thyroid surgery for goiter at the age of 9. A bilateral nodular opacity was detected by radiological examination. The histopathologic examination of the specimen obtained from computed tomography guided trucut biopsy was diagnosed as PTC. We present a very rare case of PTC with lung metastasis that had undergone subtotal thyroidectomy due to dyshormonogenetic goiter eight years ago.

On-site ultrasound-guided localization for impalpable nodal recurrences in papillary thyroid carcinoma patients

Purpose

The cervical lymph nodes are the most common sites of locoregional recurrence in patients with papillary thyroid carcinoma (PTC). Accurate tumor localization is important for the successful removal of impalpable recurrences in the cervical lymph nodes. We evaluated the benefits of ultrasound-guided localization (UGL) performed by a single surgeon on site.

Methods

Of 53 PTC patients who underwent reoperation for impalpable nodal recurrences, 32 (group 1) were assessed only using preoperative imaging, while 21 (group 2) were additionally evaluated by on-site UGL performed by the operating surgeon. Postoperative outcomes were compared between the two groups.

Results

Operation times were significantly shorter (P < 0.001) and the mean size of the resected lymph nodes were smaller (P = 0.013) for group 2 patients. More lymph nodes were identified and resected in group 1 (3.56 vs. 3.19), but the rate of positive lymph nodes was significantly higher in group 2 (P < 0.001). There were no differences between the two groups in terms of resection success rate, complication rate, and postoperative hospital stay. During a mean follow-up period of 27.6 months, 52 patients (98.1%) showed no evidence of recurrence on routine ultrasound, and serum thyroglobulin concentrations remained < 1 ng/mL in 49 patients (92.5%).

Conclusion

On-site UGL performed by the operating surgeon is useful for accurate resection of impalpable nodal recurrences in PTC patients.

Hemithyroidectomy increases the risk of disease recurrence in patients with ipsilateral multifocal papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is often clinically multifocal. In this study, the clinicopathological characteristics of a total of 347 PTC patients treated between 2006 and 2007 were investigated in order to assess the risk factors for tumor recurrence in patients with multifocal PTC. Of all the PTC cases reviewed, 35 (10%) were categorized as multifocal PTC. Patients with multifocal PTC were significantly more likely to have extrathyroidal extension, lymph node metastases and disease recurrence (P<0.05). Hemithyroidectomy resulted in a significantly higher incidence of tumor recurrence in patients with ipsilateral multifocal PTC compared with unifocal PTC patients (P<0.01). In conclusion, hemithyroidectomy was associated with tumor recurrence in patients with ipsilateral multifocal PTC but not those with unifocal PTC. Hemithyroidectomy should only be carried out after careful deliberation when involving patients with ipsilateral multifocal PTC.

Surgical extent of central lymph node dissection in clinically node-negative papillary thyroid cancer

BACKGROUND

The indications for elective bilateral central node dissection for patients with unilateral papillary thyroid carcinoma (PTC) who are clinically node negative are still not verified. We investigated the predictive factors of lymph node metastasis and formulated guidelines for surgical extent.

METHODS

From 2004 to 2009, 325 patients diagnosed with unilateral PTC who had undergone total thyroidectomy with bilateral central lymph node dissection (CLND) were enrolled retrospectively.

RESULTS

Central node metastasis was found in 45.2%, ipsilateral and contralateral lymph node metastasis was found in 40.0% and 16.0%, respectively. Tumor size larger than 1.0 cm and extrathyroidal extension were significant factors in predicting ipsilateral node metastasis (p = .004, < .001, respectively), and extrathyroidal extension and ipsilateral lymph node metastasis predicted contralateral node metastasis in multivariable analysis (p = .039, < .001, respectively).

CONCLUSION

Elective bilateral central node dissection may be considered in unilateral PTC with extrathyroidal extension or ipsilateral node metastasis.

Targeting the proteasome as a promising therapeutic strategy in thyroid cancer

BACKGROUND AND OBJECTIVES

Targeting the ubiquitin-proteasome system by using proteasome inhibitors represents a novel approach for cancer therapy. Anaplastic thyroid cancer (ATC), a subtype of thyroid cancer (TC), fails to respond to conventional TC treatment. Here we investigated the effects of bortezomib on TC in vitro. Further, the study aimed to evaluate its potential for TC treatment in vivo.

METHODS

Three anaplastic (Hth74, C643, Kat4), one follicular (FTC133), and one papillary (TPC1) TC cell lines were used. Antiproliferative, proapoptotic, and transcriptional effects of bortezomib treatment were analyzed in vitro and growth inhibition of ATC xenografts in vivo. Tumor samples were analyzed by Ki67, CD31, caspase-3, and NF-κB immunohistochemistry.

RESULTS

In vitro, bortezomib inhibited proliferation of TC cells (IC(50) 4-10 nM), increased caspase-3 activity and induced cell cycle arrest. NF-κB activity was affected differently. In vivo, bortezomib treatment was effective in reducing tumor volume (up to 74%), accompanied by reduced proliferation (Ki67) and 57% reduced tumor vascularity.

CONCLUSION

Proteasome inhibition is effective in reducing cell growth and inducing apoptosis of ATC in vitro and inhibiting tumor growth and vascularity in vivo. However, the impact on nuclear transcription remains controversial. Clinical evaluation of bortezomib treatment in ATC is warranted.

Tumor margin histology predicts tumor aggressiveness in papillary thyroid carcinoma: a study of 514 consecutive patients

Histologic patterns at tumor margins may be related to prognosis in several malignancies. We investigated tumor aggressiveness with respect to tumor margin histology in patients with papillary thyroid carcinoma (PTC). Five hundred fourteen consecutive patients who underwent surgery for primary PTC between January and July 2009 were assigned to two groups, one with an infiltrative pattern (I-type, n = 347) at tumor margins and one with an expanding pattern (E-type, n = 167). Tumor aggressiveness was assessed by analyzing relationships between these patterns and known prognostic factors. The analysis showed that unfavorable prognostic factors such as tumor multiplicity (P = 0.002), extrathyroidal extension (P < 0.001), lateral neck lymph node metastasis (P < 0.001) and advanced TNM stage (P = 0.001) were significantly more prevalent in patients with I-type PTC than in those with the E-type. Central neck node metastases were more prevalent without statistical significance in the I-type patients (P = 0.376). Tumor margin histology was not related to gender or tumor size. These results suggest that histologic patterns at tumor margins predict aggressiveness in PTC.

Excision efficiency of radioguided occult lesion localization in reoperative thyroid and parathyroid surgery

BACKGROUND

The purpose of this study was to investigate the efficiency of a radioguided occult lesion localization technique in reoperative thyroid and parathyroid procedures in patients who had undergone previous neck exploration for thyroid or parathyroid disease.

METHODS

Twenty-one consecutive patients who were scheduled for reoperative thyroid or parathyroid surgery were studied. The indication for reoperation was recurrent papillary thyroid cancer (PTC) in eight patients, completion thyroidectomy for PTC in eight patients who had previously undergone a bilateral subtotal thyroidectomy, recurrent goiter in two patients, primary hyperparathyroidism in two patients, and recurrent parathyroid cancer in one patient. Ninety minutes before surgery, 0.1 mL of Technetium-99m (0.2 mCi)-labeled macroaggregated albumin was injected directly into the lesion under ultrasonographic guidance. During surgery, a handheld gamma probe was used to localize and excise the lesions. The background and postexcisional site radioactivities were compared to confirm the completeness of each procedure. The radiation dose in the operating room environment, duration of surgery, and postoperative complication rates were evaluated in all patients. In patients with PTC, the change in serum thyroglobulin (Tg) following surgery was noted.

RESULTS

Thirty lesions were marked and excised. The postexcisional bed gamma counts (610 ± 141) were markedly decreased compared with the pre-excisional site counts (21,415.8 ± 4993.4; p = 0.0001). The ratio of the postexcisional and background counts (4.6 ± 4.3) was significantly lower than the ratio of the pre-excisional and background counts (173.7 ± 156.4; p = 0.0001). The mean operation duration was 53.3 ± 7.5 minutes. The dose absorbed by the hands of the surgeon was estimated as 0.07 ± 0.02 and 0.15 ± 0.05 millisievert/h when one or three lesions were marked, respectively. One patient developed postoperative transient hypoparathyroidism. After surgery, serum Tg levels dropped to <2 ng/mL in 86% (6/7) of the patients with PTC whose preoperative serum Tg was elevated.

CONCLUSIONS

The radioguided occult lesion localization technique was efficient in the perioperative identification of thyroid and parathyroid tumors in patients who were undergoing reoperation for PTC and hyperparathyroidism.

Familial nonmedullary thyroid carcinoma-clinical relevance and prognosis. A European multicenter study. ESES Vienna presentation

PURPOSE

Approximately 5% of differentiated thyroid carcinomas are of familial origin. These familial nonmedullary thyroid carcinomas (FNMTC) have an increased risk of multifocal disease and lymph node involvement. Consequently, higher recurrence rates and decreased disease-specific survival rates are described. The best surgical approach is discussed controversially.

PATIENTS AND METHODS

A survey among the international members of the German Society of Endocrine Surgeons revealed 20 families with two or more first-degree relatives with FNMTC. The mean age of the 41 patients (30 female, 11 male) with FNMTC was 40.6 years (18-73 years).

RESULTS

Total thyroidectomy was performed in 31 of 41 patients (76%). Ninety-five percent of the tumors were papillary carcinomas. Two of 41 patients had follicular carcinomas. Ten patients (24%) with papillary carcinomas were diagnosed with Hashimoto's thyroiditis. The mean tumor size was 1.45 cm. FNMTC was multifocal in 12 patients (29%). A systematic lymph node dissection was performed in 21 of 41 patients (51%). Lymph nodes metastases were found in seven of these 21 patients. Twenty-eight of the patients (68%) underwent postoperative radioiodine ablation. After a mean follow-up of 7.2 years, 39 patients (95%) were disease free. One patient developed local recurrence and lung metastases, 10 and 25 years, respectively, after initial diagnosis. Another patient died 2 years postoperatively from advanced metastatic disease.

CONCLUSIONS

FNMTC is associated with an early onset of small, mostly papillary thyroid carcinomas and an increased risk of multifocality and lymph node involvement. Total thyroidectomy and systematic neck dissection are recommended together with radioiodine ablation. Screening for first-degree relatives should start at age 18 years.

Expression and secretion of endostatin in thyroid cancer

BACKGROUND

In thyroid cancer (TC) endostatin was identified as a powerful negative regulator of tumor angiogenesis in vitro. It is currently being evaluated in phase I trials for antiangiogenic therapy in various solid tumors. The aim of this study was to evaluate endostatin expression in archival TC specimens and its secretion following stimulation with thyrotropin (TSH) and epidermal growth factor (EGF) in TC cell lines.

METHODS

Tissue microarrays of 44 differentiated and 7 anaplastic TC and their metastasis were immunostained for endostatin protein expression and compared with corresponding non-neoplastic thyroid tissue (NT). In vitro, six differentiated (FTC133, FTC236, HTC, HTC-TSHr, XTC, and TPC1) and three anaplastic (C643, Hth74, Kat4.0) TC cell lines were evaluated for basal as well as TSH (1-100 mU/ml) and EGF stimulated (1-100 ng/ml) endostatin.

RESULTS

Endostatin was detected in all TC and more than half of the NT. Endostatin expression was more frequent and intense in differentiated as compared to anaplastic TC. In vitro, basal endostatin secretion varied between 33 +/- 5 pg/ml (FTC236) and 549 +/- 65 pg/ml (TPC1) and was doubled in FTC, when the "primary" (FTC133) was compared with the metastasis (FTC236). Some cell lines showed TSH-induced (e.g., 60% in XTC) or EGF-induced (e.g., 120% in TPC1) upregulation of endostatin secretion, while others did not, despite documented receptor expression.

CONCLUSION

This study demonstrates endostatin expression in TC, metastasis and--less frequently and intensely--in NT, suggesting a possible association to tumor progression. In vitro, endostatin secretion of some cell lines is regulated by TSH and EGF, however the individual differences deserve further functional studies. These results support rather tumor-specific than histotype-specific expression and regulation of endostatin in TC.

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

Total thyroidectomy is the treatment of choice for clinically significant papillary thyroid cancer (PTC); however, 10-15% develop palpable local recurrence in the cervical lymph nodes. Metastases in the cervical lymph nodes account for 75% of loco-regional recurrence and up to 50% of these patients eventually die of their disease. It is generally accepted that surgical excision of grossly involved lymph node disease should be carried out. The role of routine lymph node dissection, however, is greeted with far more controversy. Regional lymph node metastases have been shown to be associated with more frequent tumour recurrence. Not only is recurrence associated with increased disease-related mortality, but recent data have shown that the presence of involved lymph nodes is associated with adverse survival. Additionally, there have been significant changes to the way patients are managed after treatment for PTC in recent years. Surveillance previously relied on clinical assessment and radioiodine scans whereas now the use of serum thyroglobulin and high-resolution ultrasound are the standard as evidenced by recommendations by the American Thyroid Association. These techniques have greater sensitivity and subsequently lymph node metastases are being detected earlier and more frequently. This has led to a paradigm shift in the aims of treatment of PTC, from a focus on survival data to a focus on disease-free status. Routine central neck lymph node dissection can be carried out with no increased morbidity and can achieve lower 6-month stimulated thyroglobulin levels when compared with total thyroidectomy alone. Routine ipsilateral level VI lymph node dissection in addition to total thyroidectomy should be carried out for the management of clinically significant PTC.

Differential effects of cetuximab and AEE 788 on epidermal growth factor receptor (EGF-R) and vascular endothelial growth factor receptor (VEGF-R) in thyroid cancer cell lines

This study evaluated the role of EGF and the effects of EGF-targeting drugs (Cetuximab, AEE 788) on growth, apoptosis, and autocrine VEGF-secretion of thyroid cancer (TC) cells. Autocrine activation of the epidermal growth factor receptor (EGF-R) is commonly regarded to contribute to the malignant phenotype of TC cells and may therefore represent a rational therapeutic target. Out of a number of TC cell lines two anaplastic (Hth74, C643), one follicular (FTC133), and one papillary thyroid cancer cell line (TPC1) were analyzed in depth for VEGF-R-and EGF-R-expression, basal and EGF-stimulated (1-100 ng/ml) VEGF protein secretion and proliferation. Subsequently the antiprolifereative and antiangiogenic effect of cetuximab (Erbitux), a monoclonal antibody that blocks the EGF-R and AEE 788, a novel dual-kinase inhibitor of EGF-R and VEGF-R were assessed, and the downstream EGF-R signal transduction was analyzed by means of detecting phosphorylated pEGF-R, pVEGF-R, pAkt, and p-MAPK. EGF stimulated VEGF-mRNA expression and protein secretion in all TC cell lines. The EGF-R antagonist Cetuximab consistently decreased VEGF secretion in all TC cell lines (min. 15%, n.s. in C643 cells and max. 90% in Hth74 cells, P < 0.05), but did not affect tumor cell proliferation in vitro. In contrast, the EGF-R- and VEGF-R-kinase inhibitor AEE 788 not only reduced VEGF secretion (min. 55%, P < 0.05 in C643 and max. 75%, P < 0.05, in FTC133), but also exhibited a dose-dependent inhibition of tumor cell proliferation (min. 75%, P < 0.05 in C643 and max. 95%, P < 0.05 in Hth74) and was a potent inductor of apoptosis in two of four TC cell lines. These effects were always accompanied by reduced levels of pEGF-R, pVEGF-R, pAkt, and pMAPK. Although inhibition of the EGF-receptor by Cetuximab potently disrupts autocrine secretion of VEGF, only the concurrent inhibition of the VEGF- and EGF receptor, e.g., by AEE 788 induces reduced proliferation and apoptosis in vitro. This suggests a particular rationale for the use of tyrosine kinase inhibitors with dual modes of action such as AEE 788 in thyroid cancer.

Influence of surgical and postoperative treatment on survival in differentiated thyroid cancer

Background

The extent of thyroidectomy in patients with differentiated thyroid cancer (DTC) remains controversial. The aim of this study was to identify how surgical technique and postoperative treatments influence survival and locoregional recurrence in DTC.

Methods

A nested case-control study was conducted in a cohort of 5123 patients diagnosed with DTC in Sweden between 1958 and 1987. One matched control subject was selected randomly for each patient who died from DTC. Details regarding surgery and postoperative treatments were obtained from medical records. The effect of treatment on survival was estimated by conditional logistic regression.

Results

Patients not treated surgically had a poorer prognosis, but the risk of death from DTC was not affected by the choice of surgical technique. The extent of surgery influenced survival only in patients with TNM stage III disease. Locoregional recurrence resulted in a fivefold increased risk of death. Postoperative treatment was not associated with improved survival.

Conclusion

In operated patients, the most important prognostic factor was complete removal of the tumour. The extent of removal of remaining thyroid tissue was of prognostic importance in stage III disease only. Adjuvant postoperative treatment did not influence the prognosis favourably.

Hook needle-guided excision of recurrent differentiated thyroid cancer in previously operated neck compartments: a safe technique for small, nonpalpable recurrent disease

CONTEXT

As a result of more sensitive techniques to detect recurrent thyroid cancer, the number of patients presenting with small, nonpalpable recurrent thyroid cancer in cervical lymph nodes is increasing. Surgical excision of nonpalpable recurrent thyroid cancer can be difficult, particularly in a previously operated area.

OBJECTIVE

The objective of this study was to investigate whether preoperative insertion of a hook needle under ultrasound guidance is useful in neck reoperations for recurrent thyroid cancer.

PATIENTS

Ten consecutive patients presenting over a 4-month period with nonpalpable, ultrasound-visible, fine needle biopsy-proven recurrent thyroid cancer in previously operated neck compartment(s) were studied.

MAIN OUTCOME MEASURES

We measured whether it was technically possible to insert a hook needle preoperatively, rate of negative neck exploration, and complication rate.

RESULTS

The hook needle was inserted in seven patients. In three patients, the hook needle was not inserted; one patient had palpable disease 4 months after the preoperative clinic visit, one patient had a tumor too close to the carotid artery, and one patient had multiple bilateral foci of recurrent disease in the central neck. One patient had bleeding after insertion of the needle due to a penetration of an anterior jugular vein that was easily managed at neck reexploration. No other complication occurred during the hook needle insertion, and the only surgical complication was a transient recurrent nerve palsy. All pathology reports showed malignant disease.

CONCLUSION

Hook needle-guided excision of recurrent thyroid cancer is feasible and appears to be a promising tool for safe and successful reoperation of patients with small recurrent thyroid cancer in cervical lymph nodes.

Papillary thyroid cancer

Papillary thyroid cancer (PTC), the most common thyroid malignancy, is associated with an excellent prognosis. Overall survival is more than 90%. The first-line treatment is surgical excision, and although the debate continues as to whether a total thyroidectomy or thyroid lobectomy should be recommended, most patients at the University of California, San Francisco are treated with a total thyroidectomy. Not only has this been shown to be superior for overall survival in select patient populations, but local recurrence is also significantly lower with this approach. Total thyroidectomy also optimizes the adjuvant treatment options that are unique to "differentiated" thyroid cancer because these malignant cells retain many of the features of the native thyroid follicular cell. These cellular features are used for specialized investigations and treatment options in patients with PTC. For example, PTC cells retain the ability to produce thyroglobulin, to be stimulated by thyroid-stimulating hormone (TSH), and to take up iodine. These features are vital and separate differentiated thyroid cancer from other epithelial malignancies because such features can be used in clinical follow-up (monitoring serum thyroglobulin levels, whole body radioactive iodine scans) and in the treatment of patients with PTC (TSH suppression, radioactive iodine ablation of thyroid remnant, local recurrences, and regional or distant metastases). In summary, the wide array of treatment options for patients with PTC includes surgery, radioactive iodine, thyroid hormone suppression of TSH, external beam radiation (less commonly), and rarely, chemotherapy. This continues to be an area of exciting research for emerging therapy, much of which concentrates on enhancing or re-establishing the differentiated features of the thyroid cancer cell, in an effort to optimize the adjuvant treatment options. The treatment options that are chosen depend on patient factors, disease factors, and the decisions of the patient and treatment team.

Selective modified radical neck dissection for papillary thyroid cancer-is level I, II and V dissection always necessary?

BACKGROUND

There is ongoing controversy as to the indications for and extent of lateral cervical lymphadenectomy for patients with papillary thyroid cancer (PTC). While most now agree that prophylactic lymph node dissections (LND) play no role, at the University of California, San Francisco (UCSF) we limit LND selectively on a level by level basis, and resect only the levels thought to harbor disease or to be at increased risk of metastases. This initial 'selective LND' usually includes levels III and IV (due to the well-documented increased likelihood of metastases to these levels) and levels I, II, and V are included when there is clinical or radiological evidence of disease or increased risk of it.

METHODS

A retrospective review of the clinical charts and hospital records of 106 consecutive patients who had metastatic PTC and who underwent at least one lateral cervical LND at UCSF between January 1995 and December 2003 was carried out. Data were collected to assess which patients had levels I, II, and/or V included in their initial ipsilateral and/or contralateral LND and to determine the recurrence rates at these levels if they had previously been excised compared with if they had not. Chi-squared and Fisher exact tests were utilized for statistical comparison, where appropriate.

RESULTS

A total of 140 initial lateral LND were performed: 104 ipsilateral and 36 contralateral. In these initial LND, 3.9%, 72.5%, and 18.6% of patients had levels I, II, and V resected on the ipsilateral side, and 2.9%, 60.0%, and 37.1% of patients had levels I, II, and V resected on the contralateral side. Recurrence at levels I and V was uncommon in all patient populations. Recurrence at level II was 19% ipsilaterally and 10% contralaterally when the level was previously resected and 21% ipsilaterally and 14% contralaterally when the level was not previously resected. There was no statistically significant difference in recurrence at level II when the level had previously been resected compared with when it had not.

CONCLUSIONS

If utilized in the appropriate patient population, a selective approach to lateral cervical LND for PTC can be a successful alternative to the routine modified radical LND. Levels I and V do not require resection unless there is clinical or radiological evidence of disease. Guidelines for which patients may be considered for this less aggressive approach to level II nodal metastases are suggested.

Targeting the EGF/VEGF-R system by tyrosine-kinase inhibitors--a novel antiproliferative/antiangiogenic strategy in thyroid cancer

AIM

In thyroid cancer (TC), endothelial growth factor (EGF) has been associated with dedifferentiation, tumor cell proliferation, and angiogenesis. Vascular endothelial growth factor (VEGF) has been documented to be the main stimulator of angiogenesis in the thyroid gland. Patients with undifferentiated thyroid cancer are in desperate need of new therapeutic strategies because common protocols of therapy usually fail. The aim of this study, therefore, was to evaluate two tyrosine-kinase inhibitors (TKI, ZD 1839 gefitinib and ZD 6474 vandetanib), directed against the EGF/VEGF receptor for possible antitumor therapy in thyroid cancer.

METHODS

EGF/VEGF-R was documented in anaplastic (Hth74, C643), follicular (FTC133), and papillary (TPC1) thyroid cancer cell lines by Western blot analysis. The antiproliferative effect of two TKI (0.1-10 microM) on thyroid cancer cell lines in vitro was quantified by MTT assay, the antiangiogenic effect by assessing secretion of VEGF by enzyme-linked immunosorbent assay (R&D Systems). ZD 1839 is mainly directed against EGF-R and ZD 6474 against VEGF-R (AstraZeneca, UK), single applications and combinations of compounds were evaluated.

RESULTS

EGF-R and VEGF-R as well as the phosphorylated receptor were documented in all of the cell lines. Administration of ZD1839 led to an up to 90% reduction of cell number in Hth74, 80% in C643, 50% in FTC133, and 90% in TPC1 (p < 0.05). ZD1839 induced a decrease of VEGF secretion between 30% in C643 and 90% in Hth74. Administration of ZD6474 led to an up to 95% reduction of cell number in Hth74, 85% in C643, 90% in FTC133, and 90% in TPC1 (p < 0.05). The ZD6474 induced decrease of VEGF secretion ranged between 20% (FTC133) and 60% (TPC1). Combinations of IC50 concentrations of TKI showed synergistic effects, resulting in additional inhibition of proliferation between 50 and 90% compared to single drug administration.

CONCLUSION

The EGF/EGF-R system resembles a powerful VEGF-stimulating pathway in all histiotypes of TC and can be inhibited by TKI. TKI directed against EGF-R as well as VEGF-R inhibit tumor cell proliferation and VEGF secretion in vitro. Combinations of TKI are more effective than strategies using single agents. It is suggested that targeting EGF-R/VEGF-R-mediated pathways may have therapeutic potential in some undifferentiated thyroid cancers.

Papillary thyroid cancer: surgical management of lymph node metastases

Papillary thyroid cancer (PTC), the most common thyroid malignancy, is associated with cervical lymph node metastases in 30% to 90% of patients. While surgery is the primary treatment modality for PTC, radioactive iodine and thyroid hormone suppression often complement the treatment plan. Although thyroid hormone suppression may decrease the incidence of recurrent disease and radioactive iodine may diagnose and treat metastases, lymph node dissection (LND) is the mainstay treatment for clinically evident cervical lymph node metastases. The surgical treatment options published in the literature include the traditional radical LND, the modified radical LND, the selective LND (compartment-based resection based on documented lymph node metastases), and a 'berry picking' resection (in which only the grossly abnormal lymph nodes are excised). At the University of California, San Francisco, we prefer the modified radical LND with preservation of the cervical sensory nerves for the first lymph node dissection with the 'berry picking' procedure limited to surgical treatment of recurrent nodal metastases in previously resected lymph node basins. Some centers are evaluating the potential role of sentinel lymph node biopsies for PTC. While the extent of lymphadenectomy is debated, most physicians treating patients with PTC agree that clinical evidence of lymphatic metastases should be surgically exercised and there is no role for prophylactic LND.