Local control in differentiated thyroid carcinoma with extrathyroidal invasion

Surgical treatment of locally advanced thyroid cancer

Operations in this area are demanding and require special experience in endocrine, thoracic and vascular surgery, an experienced anaesthesiologist, as well as the interdisciplinary cooperation with other medical specialists (nuclear medicine, oncology, radiology, otolaryngology). A reliable system of surgical guidelines has been developed from a few individual publications with special impact.

Overexpression of long non-coding RNA NR_036575.1 contributes to the proliferation and migration of papillary thyroid cancer

Current evidence suggests that the human genome produces a large number of non-coding RNAs, including microRNAs and long non-coding RNAs (lncRNAs). Generally, lncRNAs are defined as RNA transcripts longer than 200 nucleotides that are not transcribed into proteins. In recent years, lncRNAs have been reported to play oncogenic roles in tumourigenesis. However, minimal research has been performed on the expression and clinicopathological significance of lncRNAs in papillary thyroid cancer (PTC). In the present study, we investigated not only the expression and clinicopathological significance of a novel lncRNA, NR_036575.1, in PTC tissues and adjacent non-cancerous tissues but also its potential function in TPC1 cells. The expression levels of the lncRNA NR_036575.1 in 83 pairs of PTC tissues and adjacent non-cancerous tissues were detected via quantitative real-time polymerase chain reaction. The relationships between the expression levels and clinicopathological characteristics of the lncRNA NR_036575.1 were analysed. In addition, we established two receiver operating characteristic (ROC) curves to assess the diagnostic value of NR_036575.1 expression. Cell Counting Kit-8 and transwell assays were used to assess cell proliferation and migration, respectively. The expression levels of the lncRNA NR_036575.1 were significantly higher in PTC tissues than in adjacent non-cancerous tissues. High NR_036575.1 expression was associated with extrathyroidal extension (ETE) (P = 0.011) and tumour size (P = 0.006). The ROC curves indicated that NR_036575.1 could potentially serve as a biomarker for identifying PTC and related, non-cancerous diseases (sensitivity, 80.7 %; specificity, 88 %), as well as for differentiating between PTC with or without ETE (sensitivity, 57.8 %; specificity, 86.7 %). NR_036575.1 knock-down significantly inhibited the proliferation and migration of TPC1 cells. Our findings are the first to describe lncRNA NR_036575.1 overexpression in PTC. NR_036575.1 expression was associated with both ETE and tumour size. In addition, NR_036575.1 modulation could regulate TPC1 cell proliferation and migration. The results of our study suggest that NR_036575.1 could be applied as a potential biomarker and a novel therapeutic target for PTC patients.

Soft tissue invasion of papillary thyroid carcinoma

Extrathyroidal extension (ETE) of papillary thyroid carcinoma (PTC) is common and clinical presentation can vary from minimal to extensive locoregional involvement. Although PTC is generally considered the most benign among all thyroid carcinomas, it may present with local invasion with poor prognosis. Our retrospective study involved 3267 PTC patients undergoing regular follow-up at Chang Gung Medical Center in Linkou, Taiwan. Among them, 269 were PTC cases with ETE, having tumors greater than 1 cm in size and treated with total or complete thyroidectomy with or without lymph node dissection for which the follow-up period was over 10 years. The mean age of 269 cases was 46.8 ± 15.1 (range 11-83 years) years. The number of females was 204 (75.8 %). Patients were categorized into minimal ETE (175 cases) and extensive ETE (94 cases) groups according to surgical findings and pathological reports. Mean follow-up period was 13.3 ± 5.5 (range 0.2-29.3) years, during which 28 (10.4 %) patients died of thyroid cancer; and 63 (23.4 %) of all-cause mortality. Multivariate analysis showed that age, gender, extensive ETE, and lymph node metastasis had a statistically significant effect on thyroid cancer mortality. Survival rates were significantly different between minimal ETE and extensive ETE groups (p < 0.0001). In conclusion, perithyroidal soft tissue involvement by PTC is an important factor that determines patient prognosis and a closer follow-up and more aggressive treatment is necessary for patients who are old, male, extensive ETE, and with lymph node involvement.

MicroRNA-663 suppresses cell invasion and migration by targeting transforming growth factor beta 1 in papillary thyroid carcinoma

MicroRNA-663 (miR-663) has been detected in a large variety of tumor types; however, it still holds both tumor suppressive and oncogenic roles in different tumor types. The miRNA-CHIP microarray assay revealed downregulation of miR-663 in papillary thyroid carcinoma (PTC); however, the effect of miR-663 on PTC cell invasion and migration remains unknown. Accordingly, this study aimed to investigate the potential involvement of miR-663 in PTC. In this study, miR-663 expression level was measured via quantitative real-time PCR in 91 pairs of human PTC and adjacent normal tissues and in two human PTC cell lines. The effect of miR-663 on PTC cell invasion and migration were studied by transwell and wound healing assays. In addition, the miR-663 target was searched and the underlying mechanism was clarified by reporter assay and rescue experiment. The current study confirmed that miR-663 expression was inhibited in PTC tissue samples and PTC cell lines. There were statistically significant differences in expression of miR-663 with regard to age and tumor size. Upregulation of miR-663 suppressed PTC cell invasion and migration. Further study showed that transforming growth factor beta 1 (TGFβ1) was the direct target of miR-663 and mediated the effect of miR-663 on PTC development. By targeting TGFβ1, miR-663 efficiently regulates the expression of epithelial-mesenchymal transition (EMT) markers and matrix metalloproteinases (MMPs). The data indicated that miR-663 may suppress tumor invasion and migration by targeting TGFβ1 and regulate EMT progress of PTC cells.

Patients Treated at Low-Volume Centers have Higher Rates of Incomplete Resection and Compromised Outcomes: Analysis of 31,129 Patients with Papillary Thyroid Cancer

BACKGROUND

Data on the importance of margin status after total thyroidectomy for papillary thyroid cancer (PTC) remain limited. This study sought to identify factors associated with positive margins and to determine the impact of positive margins on survival for patients with PTC.

METHODS

The National Cancer Data Base (1998-2006) was queried for patients with PTC who had undergone total thyroidectomy. The patients were divided into three groups based on margin status (negative, microscopically positive, and macroscopically positive). Patient demographic, clinical, and pathologic features were evaluated. A binary logistic regression model was developed to identify factors associated with positive margins. A Cox proportional hazards model was developed to identify factors associated with survival.

RESULTS

Of the 31,129 patients enrolled in the study, 91.3 % had negative margins, 8.1 % had microscopically positive margins, and 0.6 % had macroscopically positive margins. The patients with negative margins were younger and more likely to be female, white, covered by private insurance, and treated at an academic or high-volume center (p < 0.05). They had smaller tumors and were less likely to have advanced-stage disease. After multivariable adjustment, increasing patient age [odds ratio (OR) = 1.02; p < 0.01], government insurance (OR = 1.20; p < 0.01), and no insurance (OR = 1.34; p = 0.01) were associated with positive margins. Reception of surgery at a high-volume facility (OR = 0.72; p < 0.01) was protective. After multivariable adjustment, both microscopically [hazard ratio (HR), 1.49; p < 0.01] and macroscopically positive margins (HR = 2.38; p < 0.01) were associated with compromised survival.

CONCLUSIONS

Several vulnerable patient populations have a higher risk of incomplete resection after thyroidectomy for PTC. High-risk thyroid cancer patients should be referred to high-volume centers to optimize outcomes.

Treatment of thyroid follicular carcinoma

Differentiated thyroid carcinoma includes 2 different tumor types, papillary (PC) and follicular carcinoma (FC), and although similar, their prognosis is different. FC is uncommon, and this has led to it often being analyzed together with PC, and therefore the true reality of this tumor is difficult to know. As a result, the diagnostic and therapeutic management and the prognostic factors in differentiated carcinoma are more predictive of PC than FC. In this review we analyze the current state of many of the therapeutic aspects of this pathology. The best surgical technique and the usefulness of associated lymphadenectomy is also analyzed. Regarding post-surgical ablation with 131I, the indications, doses and usefulness are discussed. For the remaining therapies we analyze the few indications for radiotherapy and chemotherapy, and of new drugs such as tyrosine kinase inhibitors.

Characteristics and significance of minimal and maximal extrathyroidal extension in papillary thyroid carcinoma

OBJECTIVES

Maximal extrathyroidal extension (ETE) is known to be an important prognostic factor in papillary thyroid carcinoma (PTC). However, the significance of minimal ETE is controversial. The aim of this study was to investigate the clinicopathologic characteristics and prognostic significance of minimal vs maximal ETE in PTC.

MATERIALS AND METHODS

A group of 967 patients who underwent thyroidectomy for PTC in a tertiary hospital between January 2000 and December 2011 were studied retrospectively. Patients were classified into three groups: absence of ETE, and minimal and maximal ETE. The minimal ETE group was further categorized into two subgroups according to invasion of strap muscles or no invasion (STI+ and STI-).

RESULTS

Gender did not differ between the three groups of patients. The mean age of the patients with maximal ETE was significantly higher than in those belonging to the other groups. Tumor size, bilaterality, lymph node metastasis and stage increased significantly according to the degree of ETE. Recurrence and survival rates did not differ between the absence and minimal ETE groups, or between the STI- and STI+ subgroups of minimal ETE. However, the maximal ETE group had significantly higher recurrence and lower survival rates than the other groups (P<0.001).

CONCLUSION

Maximal ETE is a significant factor for poor prognosis. However, minimal ETE is not associated with increased recurrence or decreased survival in patients with PTC.

Impact of degree of extrathyroidal extension of disease on papillary thyroid cancer outcome

BACKGROUND

The clinical importance of extrathyroidal extension (ETE) on outcome of papillary thyroid cancer (PTC), particularly with respect to disease extending to the surgical margin is not well established. This study assessed the importance of surgical margin and extrathyroidal invasion relative to local control of disease and oncologic outcome.

METHODS

A retrospective analysis of a prospective institutional endocrine database was conducted on 276 patients with PTC treated between 1955 and 2004 to determine the impact of margin-negative resection (n=199, 72%), disease up to within 1 mm of surgical margin (n=19, 7%), microscopic (n=39, 14%), and gross (n=19, 7%) ETE. Data were compared with Fisher's exact test or analysis of variance (ANOVA).

RESULTS

Median follow-up was 3.1-6.8 years per study group (disease-free survival, range 1-37 years). The proportion of those with age >45 years, prior radiation exposure, distant metastasis at presentation, and those undergoing total thyroidectomy was not significantly different between groups. Tumor size and multifocality correlated with extent of local disease, which in turn was significantly associated with regional nodal disease at time of primary operation as well as prevalence of persistence of disease after multimodality therapy. Extent of local disease correlated significantly with subsequent clinical recurrence after a disease-free period (p=0.006); however, recurrence rates were not significantly different between negative and close (≤1 mm) margin resection.

CONCLUSION

Oncological outcome correlates with the extent of extrathyroidal invasion. Outcome is worse in patients with gross extrathyroidal disease extension than in those with microscopic local invasion apparent on histopathological assessment. However, the risk of clinical recurrence appears similar between patients undergoing margin-negative and "close margin" resection.

Association between the expression of four upregulated miRNAs and extrathyroidal invasion in papillary thyroid carcinoma

Background

MicroRNAs (miRNAs) are important diagnostic and prognostic markers in cancer. In the study reported here, we analyzed the potential relationship between miRNA expression and extrathyroidal invasion in papillary thyroid carcinoma (PTC).

Methods

Samples from 91 patients with PTC were collected from January 2008 to April 2012 at our hospital. To detect the levels of miRNA expression in fresh frozen tissues from patients with extrathyroidal invasion (n = 3) and non-extrathyroidal invasion (n = 3), miRNA array was carried out. The upregulated miRNAs between the two groups were confirmed by using real-time reverse transcriptase polymerase chain reaction.

Results

The levels of miR-146b, miR-221, miR-222, and miR-135b were significantly higher in the extrathyroidal invasion group than in the non-extrathyroidal invasion group (P = 0.001, 0.019, 0.004, and 0.006, respectively). In addition, the miR-146b expression level was significantly higher in the massive extrathyroidal invasion group than in the minimal extrathyroidal invasion group (P = 0.016). The expression levels of miR-146b, miR-222, and miR-135b were significantly associated with tumor size (P = 0.018, 0.008, and 0.024, respectively). The upregulation of miR-146b and miR-222 was significantly associated with higher tumor-node-metastasis stage (P = 0.004 and 0.0001, respectively). The expression level of miR-222 was also correlated with age and sex (P = 0.048 and 0.002, respectively).

Conclusion

Our results reveal that the expression of four miRNAs correlated with extrathyroidal invasion and other clinicopathologic features in PTCs, which may support their potential clinical value as prognostic biomarkers for PTCs.

Parathyroid involvement in thyroid cancer: an unforeseen event

Background

Parathyroid metastatic disease from thyroid cancer has not been studied extensively, mainly due to the need for parathyroid preservation during thyroid surgery.

Methods

We reviewed files from 1,770 patients with thyroid cancer followed up in our department and 10 patients with parathyroid metastases (0.5%) were identified. Patient and tumor characteristics were recorded.

Results

Six out of ten patients had metastases from papillary thyroid cancer, three from follicular thyroid cancer and one from anaplastic thyroid cancer. In nine patients parathyroid infiltration from thyroid cancer was found in direct contact with the thyroid cancer, and in one patient metastatic foci were observed not in continuity with the thyroid cancer.

Conclusions

Parathyroid involvement, although infrequent, may occur in thyroid cancer independently of patient age and tumor size. The clinical significance of such event is not clear. The influence on disease outcome remains to be elucidated.

Gender-Specific Variation in the Prognosis of Papillary Thyroid Cancer TNM Stages II to IV

To investigate the correlation between gender and the clinical presentation of papillary thyroid cancer and the long-term followup results, 435 patients who underwent total or near-total thyroidectomy were enrolled in this study. Among these papillary thyroid cancer patients, 12.2% showed lymph node metastases and a higher incidence of male patients in the N1b group. There were 65 from 316 female (20.6%) and 49 from 120 male (40.8%) patients who had a postoperative disease progression. A total of 55 (12.6%) patients died of thyroid cancer. Male patients showed a higher thyroid cancer mortality than the females. Multiple regression analysis showed that male gender was an independent risk factor for cancer recurrence and mortality. Male patients with TNM stages II to IV of papillary thyroid cancer need to adopt aggressive surgical and postoperative (131)I therapy.

Old and new insights in the treatment of thyroid carcinoma

Thyroid cancer is the endocrine tumor that bears the highest incidence with 33 550 new cases per year. It bears an excellent prognosis with a mortality of 1530 patients per year (Jemal et al.; 2007). We have been treating patients with thyroid carcinoma during many years without many innovations. Recently, we have assisted to the development of new agents for the treatment of this disease with unexpected good results. Here we present a review with the old and new methods for the treatment of this disease.

Clinical significance of extrathyroid extension to the parathyroid gland of papillary thyroid carcinoma

Extrathyroid extension is a prominent prognostic factor of papillary thyroid carcinoma (PTC). In the UICC TNM classification, minimal extension to the sternothyroid muscle and perithyroid soft tissue is classified as T3 and further massive extension is classified as T4, the highest T grade. However, there have been few studies on the clinical significance of extension to the parathyroid gland in a large case series. In this study, we investigated the prognosis of PTC with extension to the parathyroid gland in a series of 3208 patients who underwent initial surgery between 1997 and 2004. Of these patients, 51 (1.6%) showed extension to the parathyroid gland on pathological examination. Twenty-one of these patients had massive extrathyroid extension to other adjacent organs corresponding to pT4. The remaining 30 were enrolled in this study. The disease-free survival (DFS) of these 30 patients was significantly better (p<0.0001) than that of pT4 patients and did not differ from that of patients showing minimal extrathyroid extension without extension to the parathyroid gland (p = 0.6264). Furthermore, none of these 30 patients died of carcinoma. Taken together, it is appropriate that extension to the parathyroid gland of PTC is graded as minimal extrathyroid extension (pT3), but not massive extension (pT4). Since minimal extension did not affect patient prognosis in our series, it is suggested that extension to the parathyroid gland has little clinical significance in PTC.

Papillary thyroid carcinoma with distant metastases: survival predictors and the importance of local control

BACKGROUND

The presence of distant metastases is the most important predictive factor of poor outcomes in patients with papillary thyroid carcinoma (PTC). Some patients have very slow-growing distant metastases with relatively favorable outcomes, so predicting prognosis is not easy. Furthermore, many patients with distant metastases show locally advanced disease, and no consensus is available for operative control of cervical tumor in this situation.

METHODS

Among 1023 patients with PTC who underwent primary thyroidectomy from 1976 to 2002, 42 patients displayed distant metastases at initial presentation and 44 patients developed distant metastases during follow-up. We reviewed the records retrospectively of these 86 patients. Mean duration of follow-up after detection of distant metastases was 7 years. Our treatment approach for patients with locally advanced neoplasms was radical resection including extensive neck dissection and extended resection of the involved organs, even when distant metastases were present.

RESULTS

Disease-specific survival of the 86 patients with distant metastases at 5 and 10 years was 65% and 45%, respectively. Using multivariate analysis, older age at time of distant metastases detection, distant metastases involving sites other than the lung, distant metastases diameter > or = 2 cm, presence of large nodal metastases (> or = 3 cm), and a primary neoplasm with poorly differentiated components were all predictive of worse prognosis. Our aggressive approach allowed curative resection in all but 1 patient, and only 5 patients (6%) succumbed to local disease. Patients with cervical recurrences displayed worse prognosis than those without.

CONCLUSIONS

Although the currently employed modalities of therapy for distant metastases do not have definitive impact on survival, some PTC patients with distant metastases, including younger patients with well-differentiated, small lung metastases appear to have relatively favorable outcomes. Local operative control of PTC is important even in patients with distant metastases, particularly when the distant metastases appear to be slow-growing.

Parathyroid invasion, nodal recurrence, and lung metastasis by papillary carcinoma of the thyroid

AIMS

Parathyroid invasion by papillary thyroid carcinoma (PTC) is found in a small proportion of surgical specimens, but the clinicopathological relevance of this phenomenon is not well understood. This study investigated the possible prognostic relevance of parathyroid invasion in PTC.

METHOD

Parathyroid involvement was seen in 14 patients with PTC, and the clinicopathological characteristics and follow up data of these patients were analysed and compared with 164 patients without parathyroid involvement, in whom histological parathyroid examination had been undertaken, and 177 other patients without parathyroid examination (341 patients without parathyroid involvement in total).

RESULTS

Parathyroid invasion was found in older patients and there were more male patients in this group than in those without parathyroid invasion. These patients had more extrathyroid extension and were frequently in an advanced stage of disease. Lung metastasis was seen in two of the 14 patients, which was significantly more than that seen in control cases. Moreover, male patients with parathyroid invasion and those who were older than 55 years had reduced disease free survival compared with those without parathyroid invasion.

CONCLUSION

Parathyroid invasion seen in thyroid carcinoma may be an important histological feature indicating a greater chance of nodal recurrence and lung metastasis.

A novel classification system for patients with PTC: addition of the new variables of large (3 cm or greater) nodal metastases and reclassification during the follow-up period

BACKGROUND

Several factors have been proven to be useful for classifying patients with papillary thyroid carcinoma (PTC) into either low- or high-risk groups. However, the relative importance of prognostic factors, including lymph nodal metastasis, remains unclear.

METHODS

A total of 604 patients who underwent initial surgery for PTC (diameter of tumor>1 cm) were analyzed. The mean duration of follow-up was 10.7 years.

RESULTS

By multivariate analysis for disease-specific survival, distant metastasis was the only significant risk factor (risk ratio=65.1) for younger patients (age<50). For older patients (age> or =50), distant metastasis (risk ratio=6.7), extrathyroidal invasion (risk ratio=2.4), and large nodal metastasis (> or =3 cm; risk ratio=5.3) had relative importance. From the results, younger patients with distant metastasis and older patients with any of the 3 factors were defined as at high risk, whereas the other patients were defined as at low risk. Overall, 106 patients at high risk (18%) and 498 patients at low risk (83%) had 10-year survival rates of 69% and 99%, respectively. Only 3 patients of the low-risk group died from the disease. Among postoperative factors, recurrence within 3 years after initial surgery was the most important risk factor for cancer death. Of the high-risk group, patients with a disease-free interval of >3 years showed an excellent outcome (96% of a 10-year survival rate), similar to patients in the low-risk group.

CONCLUSIONS

A novel classification system, in which large nodal metastases and postoperative reclassification were added, was devised. This was useful for choosing proper therapeutic strategies, offering rational information, and determining adequate postoperative follow-up schemes for individual patients with PTC.

Recombinant TSH-stimulated, radioguided differentiated thyroid carcinoma surgery

A novel approach to locating and surgically resecting occult metastatic foci in a 25-year-old female with a history of total thyroidectomy for differentiated thyroid carcinoma was attempted. Two iodine-131 (131I) body scans were performed: one after the patient underwent a 2-3 week thyroxine withdrawal, and another the following week utilizing recombinant TSH-stimulation. Then the patient was treated with 151 mCi of 131I, and 2 weeks later, without further hormonal manipulation, she had radioguided surgery. The two diagnostic 131I body scans were negative, but the post-therapy scan was positive. Two weeks later after pre-operative skin marking, radioguided surgery localized metastatic foci in the central compartment neck just dorsal to the suprasternal notch. No other foci were identified with the probe at surgery. At pathology, 2 of the 12 nodes were positive, as well as a 1 mm metastatic focus in the fat. Provocative imaging protocols, aggressive radioiodine therapy, and the novel use of radioguided surgery to attempt a cure in an 131I image-negative metastatic thyroid carcinoma patient was performed. No other cases using these combined diagnostic and therapeutic efforts have been reported in the literature.

Parathyroid gland involvement by papillary carcinoma of the thyroid gland

OBJECTIVE

To describe the phenomenon of parathyroid gland involvement by thyroid carcinoma and to explore its clinicopathologic significance.

DESIGN

We reviewed the clinicopathologic features and described the histopathologic characteristics of 20 cases of parathyroid involvement found in a series of 911 papillary thyroid carcinomas.

RESULTS

Parathyroid involvement occurred in 3 patterns: (1) direct invasion from the main tumor with an infiltrative growth, (2) invasion of the parathyroid gland with an expansive growth and formation of a pseudocapsule between the carcinoma and the parathyroid gland, and (3) metastatic deposition within the parathyroid gland itself. Among the 20 cases, 6 (30%) had primary tumors measuring 1 cm or less, and 14 (70%) had primary tumors measuring more than 1 cm. The cases with smaller primary tumors had a comparatively lower rate of nodal metastasis (50% vs 100%, P =.02). Furthermore, none of the cases with smaller primary tumors had invasion of extrathyroid structures other than parathyroid gland, but such invasion was common among the cases with larger primary tumors (0% vs 71%, P =.01).

CONCLUSION

To the best of our knowledge, this is the first report showing that parathyroid involvement occurs in papillary thyroid carcinomas even in the early stage of the disease.