Prevalence of thyroid cancer at a medical screening center: pathological features of screen-detected thyroid carcinomas

Survival Comparison of Incidentally Found versus Clinically Detected Thyroid Cancers: An Analysis of a Nationwide Cohort Study

BACKGRUOUND

The true benefit of thyroid cancer screening is incompletely understood. This study investigated the impact of ultrasound screening on thyroid cancer outcomes through a comparison with symptomatic thyroid cancer using data from a nationwide cohort study in Korea.

METHODS

Cox regression analysis was performed to assess the hazard ratios (HRs) for all-cause and thyroid cancer-specific mortality. Considering the possible bias arising from age, sex, year of thyroid cancer registration, and confounding factors for mortality (including smoking/drinking status, diabetes, and hypertension), all analyses were conducted with stabilized inverse probability of treatment weighting (IPTW) according to the route of detection.

RESULTS

Of 5,796 patients with thyroid cancer, 4,145 were included and 1,651 were excluded due to insufficient data. In comparison with the screening group, the clinical suspicion group was associated with large tumors (17.2±14.6 mm vs. 10.4±7.9 mm), advanced T stage (3-4) (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.09 to 1.41), extrathyroidal extension (OR, 1.16; 95% CI, 1.02 to 1.32), and advanced stage (III-IV) (OR, 1.16; 95% CI, 1.00 to 1.35). In IPTW-adjusted Cox regression analysis, the clinical suspicion group had significantly higher risks of all-cause mortality (HR, 1.43; 95% CI, 1.14 to 1.80) and thyroid cancer-specific mortality (HR, 3.07; 95% CI, 1.77 to 5.29). Mediation analysis showed that the presence of thyroid-specific symptoms was directly associated with a higher risk of cancer-specific mortality. Thyroid-specific symptoms also indirectly affected thyroid cancer-specific mortality, mediated by tumor size and advanced clinicopathologic status.

CONCLUSION

Our findings provide important evidence for the survival benefit of early detection of thyroid cancer compared to symptomatic thyroid cancer.

Lower Thyroid Cancer Mortality in Patients Detected by Screening: A Meta-Analysis

BACKGRUOUND

Thyroid cancer screening has contributed to the skyrocketing prevalence of thyroid cancer. However, the true benefit of thyroid cancer screening is not fully understood. This study aimed to evaluate the impact of screening on the clinical outcomes of thyroid cancer by comparing incidental thyroid cancer (ITC) with non-incidental thyroid cancer (NITC) through a meta-analysis.

METHODS

PubMed and Embase were searched from inception to September 2022. We estimated and compared the prevalence of high-risk features (aggressive histology of thyroid cancer, extrathyroidal extension, metastasis to regional lymph nodes or distant organs, and advanced tumor-node-metastasis [TNM] stage), thyroid cancer-specific death, and recurrence in the ITC and NITC groups. We also calculated pooled risks and 95% confidence intervals (CIs) of the outcomes derived from these two groups.

RESULTS

From 1,078 studies screened, 14 were included. In comparison to NITC, the ITC group had a lower incidence of aggressive histology (odds ratio [OR], 0.46; 95% CI, 0.31 to 0.7), smaller tumors (mean difference, -7.9 mm; 95% CI, -10.2 to -5.6), lymph node metastasis (OR, 0.64; 95% CI, 0.48 to 0.86), and distant metastasis (OR, 0.42; 95% CI, 0.23 to 0.77). The risks of recurrence and thyroid cancer-specific mortality were also lower in the ITC group (OR, 0.42; 95% CI, 0.25 to 0.71 and OR, 0.46; 95% CI, 0.28 to 0.74) than in the NITC group.

CONCLUSION

Our findings provide important evidence of a survival benefit from the early detection of thyroid cancer compared to symptomatic thyroid cancer.

Clinical and ultrasonography evaluation of thyroid tumor screening in symptomatic patient of Bajulmati primary care center, Banyuwangi, East Java, Indonesia

This study aims to assess the prevalence, clinical, and ultrasonography (US) in thyroid screening in healthy subjects with general symptoms of thyroid abnormality in low iodine intake in Bajulmati primary care center, East Java Indonesia. We retrospectively reviewed US thyroid examination of 74 subjects with symptoms of mass in the neck, shaky, sleep difficulties, over sweating, and chronic fatigue on September 15th, 2021. Following the WHO guidelines, subjects also underwent physical examination in which the result were classified into 3 categories, that is, no palpable nor visible goiter, palpable but no visible goiter, as well as palpable and visible goiter. We evaluate US thyroid characteristics following Korean Society of Thyroid Radiology guidelines. Image analysis was reviewed by 4 general radiologists with 2 to 13 years' experience. Categorical variables were compared using chi-squared or Fisher exact tests. Correlation between variables was measured with gamma statistics. Statistical analyses were conducted using IBM SPSS Statistics 23.0. A P-value < .05 was considered to indicate statistical significance. Of the 74 subjects, 32 (43.2%) show abnormalities. Statistical analysis showed no significant differences in the result of thyroid US in subjects with complaint fatigue (P = .464), insomnia (P = .777), over sweating (P = .158), and tremor (P = .778), but there were significant differences with the complaint of mass in the neck (P = .008). Furthermore, there was also a strong correlation between goiter palpation and US thyroid result (R = 0.773, P = .00). We conclude there were significant differences in US result of patients with and without complaint of mass in the neck. We also found a strong correlation between goiter palpation and US examination. Clinical findings, laboratory examination, cytology and molecular markers, patients' age, nodules size, and ultrasound features should be considered for the treatment planning.

Secondary and tertiary preventions of thyroid disease

INTRODUCTION

Secondary and tertiary preventions are concerned with the recognition of the disease process in a very early stage and delay in progression to complete disease and minimization of complications and the impact of illness.

METHODS

All articles related to secondary and tertiary prevention of thyroid diseases were reviewed. Using related key words, articles published between 2001 and 2015 were evaluated, categorized, and analyzed.

RESULTS

In secondary prevention, congenital hypothyroidism and subclinical hypo and hyperthyroidism are equally important. Routine screening of patients with multinodular goiter by either ultrasonography or calcitonin is a controversial issue, while calcitonin assessments in medullary cancer and RET in family members are recommended. Screening of thyroid disease in pregnancy is limited to those with risk factors. Views regarding the importance of thyroid autoimmunity in secondary prevention are also presented. In tertiary prevention, prescribing excessive doses of levothyroxine, in the elderly in particular and appropriate care of all patients to avoid progression and complications are the key issues.

CONCLUSION

Optimization of management of thyroid diseases requires timely screening, prevention of progression to more sever disease, optimal medical care, and avoidance of iatrogenic conditions.

Long-term survival of patients with thyroid cancer according to the methods of tumor detection: A nationwide cohort study in Korea

In this retrospective cohort study, we compared the survival of patients detected by screening with those detected based on symptoms, according to their tumor stages. After propensity score matching, 2,130 patients with papillary or follicular thyroid cancer, identified by screening detection (SD) and clinical detection (CD), were included. We compared the survival rates of patients identified by SD and CD in the early and advanced stages of thyroid cancer. Cox proportional hazard models were used to compare the hazard ratios (HRs) for mortality between the two groups. Of the 1,065 patients in each group, 12 (1.1%) died in the SD group, compared to 44 (4.1%) in the CD group, during an average 9.4 years (p<0.001). For early stage, there was no significant difference in all-cause and thyroid cancer-specific mortality between the two groups (p = 0.08, p = 0.0502). However, for advanced stage, the survival rates in the SD group were significantly higher than in the CD group (p<0.001, p = 0.004). Moreover, after adjusting for covariates, the HRs of all-cause mortality of the SD group was significantly lower than that of the CD group for the advanced stage patients (HRs: 0.37 [95% CIs: 0.17–0.80]), while no significant difference was observed in the early stage. While screening for thyroid cancer was not beneficial for early stage patients, our findings suggest that detection via screening is associated with better survival for patients with advanced stage cancer. However, the effects of selection bias and lead time bias could not be entirely excluded.

Evaluation of Diagnostic Performance of Screening Thyroid Ultrasonography and Imaging Findings of Screening-Detected Thyroid Cancer

Purpose

The purpose of this study was to evaluate the diagnostic performance and cost of screening thyroid ultrasonography (US) in an asymptomatic population and determine the US features of screening-detected thyroid cancer.

Materials and Methods

This study included 1,845 asymptomatic participants who underwent screening thyroid US between March and August 2012 at the screening center in our hospital. We evaluated the diagnostic performance of screening thyroid US for thyroid cancer and the average cost of diagnosis for each patient. We also determined the characteristic US features of screening-detected thyroid cancer.

Results

Of the 1,845 subjects, 661 showed no abnormalities, 1,155 exhibited benign thyroid nodules, and 29 exhibited thyroid cancer. Imaging features such as solid composition, hypoechogenicity, taller-than-wide axis, and ill-defined or spiculated margins of nodules were suggestive of malignancy. The rate of detection of cancer was 1.6% (29/1,845), and the sensitivity, specificity, and positive and negative predictive values were 100% (18/18), 98.7% (1,051/1,065), 56.3% (18/32), and 100% (1,051/1,051), respectively. Of 18 patients who underwent thyroidectomy, three (16.7%) had a pathological tumor staging of T3, and four (22.2%) had a pathological nodal staging of N1a. The average cost of diagnosis for each patient with cancer was $7,319.

Conclusion

Screening thyroid US exhibited a good diagnostic performance, with a feasible social cost of use. This modality demonstrated significant differences in sonographic features between screening-detected cancer and benign nodules.

Clinical and sonographic assessment of cervical lymph node metastasis in papillary thyroid carcinoma

The purpose of this study was to assess the differences in clinical and sonographic features of papillary thyroid carcinoma (PTC) between cervical lymph node metastatic (CLNM) and nonmetastatic groups. Clinical data of PTC patients (414 patients with 624 malignant nodules) who underwent a preoperative ultrasonography and surgery between June 2010 and March 2015 at Renmin Hospital of Wuhan University were retrospectively analyzed. Clinical factors, preoperative ultrasound features and the final pathological findings were obtained. The differences in the sonographic features of PTC between the CLNM group and the non-CLNM group were analyzed. There were 187 CLNM and 227 non-CLNM patients. The median age at the diagnosis of this cohort was 45.4 years old (ranging from 18 to 77 years). Ultrasonographic parameters that were significantly associated with CLNM [OR=2.569 (1.502, 4.393), P<0.001)] were as follows: the mulifocality of the nodules, size over 2 cm, the presence of microcalcifications, the distance ratio (DR) pattern showing the contact of the nodules with the thyroid capsule, and the extracapsular spread of the nodules. No significant differences in age, gender, thyroid stimulating hormone (TSH) levels and other ultrasonography parameters were found between the CLNM and the non-CLNM groups. Therefore, our results suggest that a larger size, microcalcifications, mulifocality, and the DR pattern showing the contact of the nodules with the thyroid capsule and extracapsular spread are significantly more indicative of CLNM in PTC.

VEGF-C Is a Thyroid Marker of Malignancy Superior to VEGF-A in the Differential Diagnostics of Thyroid Lesions

Introduction

Thyroid nodular goiter is one of the most common medical conditions affecting even over a half of adult population. The risk of malignancy is rather small but noticeable–estimated by numerous studies to be about 3–10%. The definite differentiation between benign and malignant ones is a vital issue in endocrine practice. The aim of the current study was to assess the expression of vascular endothelial growth factor A (VEGF-A) and VEGF-C on the mRNA level in FNAB washouts in case of benign and malignant thyroid nodules and to evaluate the diagnostic value of these markers of malignancy.

Materials and Methods

Patients undergoing fine-needle aspiration biopsy (FNAB) in our department between January 2013 and May 2014 were included. In case of all patients who gave the written consent, after ultrasonography (US) and fine-needle aspiration biopsy (FNAB) performed as routine medical procedure the needle was flushed with RNA Later solution, the washouts were frozen in -80 Celsius degrees. Expression of VEGF-A and VEGF-C and GADPH (reference gene) was assessed in washouts on the mRNA level using the real-time PCR technique. Probes of patients who underwent subsequent thyroidectomy and were diagnosed with differentiated thyroid cancer (DTC; proved by post-surgical histopathology) were analyzed. Similar number of patients with benign cytology were randomly selected to be a control group.

Results

Thirty one DTCs and 28 benign thyroid lesions were analyzed. Expression of VEGF-A was insignificantly higher in patients with DTCs (p = 0.13). Expression of VEGF-C was significantly higher in patients with DTC. The relative expression of VEGF-C (in comparison with GAPDH) was 0.0049 for DTCs and 0.00070 for benign lesions, medians – 0.0036 and 0.000024 respectively (p<0.0001).

Conclusions

Measurement of expression VEGF-C on the mRNA level in washouts from FNAB is more useful than more commonly investigated VEGF-A. Measurement of VEGF-C in FNAB washouts do not allow for fully reliable differentiation of benign and malignant thyroid nodules and should be interpreted carefully. Further studies on larger groups are indicated. However, measurement of VEGF-C on mRNA level can bring important information without exposing patient for additional risk and invasive procedures.

[Health education in radiology service: orientations for breast and thyroid aspiration puncture]

This is a convergent care research developed in a school hospital's radiology service whose purpose is to learn about the concerns and expectations of clients submitted to breast and thyroid Fine Needle Aspiration Puncture. Data collection was conducted from September 2010 to April 2011, through 10 educational meetings in the waiting room interviewing 88 clients. The results show: clients' perception of the test, cancer as a stigma and healthcare education as a confrontation strategy. In addition, they revealed fear of both the procedure and the diagnosis of cancer. Educational practice in the waiting room is a space to decrease anxiety and allows the exchange of experiences and knowledge between professional and client, it also fosters a support network among clients. It is characterized as important space of action to the nurse within radiology service.

Comparison of diagnostic value of conventional ultrasonography and shear wave elastography in the prediction of thyroid lesions malignancy

INTRODUCTION

Thyroid nodular disease (TND) is a very common disorder. However, since the rate of malignancy is reported to be 3-10%, only a minority of patients require aggressive surgical treatment. As a result, there is a need for diagnostic tools which would allow for a reliable differentiation between benign and malignant nodules. Although a number of conventional ultrasonographic (US) features are proved to be markers of malignancy, Shear Wave Elastography (SWE) is considered to be an improvement of conventional US. The aim of this study was to compare conventional US markers and SWE diagnostic values in the differentiation of benign and malignant thyroid nodules.

MATERIALS AND METHODS

All patients referred for thyroidectomy, irrespective of the indications, underwent a US thyroid examination prospectively. Patients with TND were included into the study. Results of the US and SWE examinations were compared with post-surgical histopathology.

RESULTS

One hundred and twenty two patients with 393 thyroid nodules were included into the study. Twenty two patients were diagnosed with cancer. SWE turned out to be a predictor of malignancy superior to any other conventional US markers (OR=54.5 using qualitative scales and 40.8 using quantitative data on maximal stiffness with a threshold of 50 kPa).

CONCLUSIONS

Although most conventional US markers of malignancy prove to be significant, none of them are characterized by both high sensitivity and specificity. SWE seems to be an important step forward, allowing for a more reliable distinction of benign and malignant thyroid nodules. Our study, assessing SWE properties on the highest number of thyroid lesions at the time of publication, confirms the high diagnostic value of this technique. It also indicates that a quantitative evaluation of thyroid lesions is not superior to simpler qualitative methods.

Very high prevalence of ultrasound thyroid scan abnormalities in healthy volunteers in Modena, Italy

BACKGROUND

Italy is characterized by high prevalence of goiter. To date, only limited data about the prevalence of goiter in the Italian adult population are available.

AIM

To investigate the prevalence of thyroid ultrasound abnormalities in adults unaware of any thyroid disease and evaluate the rate of differentiated thyroid cancer (DTC) obtained by this intervention.

METHODS

Ultrasound (US) thyroid scan was performed in adult volunteers recruited by advertisement in Modena, Italy. One hundred and thirty-five women and 66 men (no.= 201), unaware of any thyroid disease (mean age of 46 ± 10.7 yr) underwent their first thyroid US scan.

RESULTS

US thyroid abnormalities were found in 101 subjects (50.3%): 91 nodular goiters (45.2%) and 13 US-thyroiditis (6.5%) associated with positive auto-antibodies in 11 of them. Seventeen subjects (18%) with nodules underwent US-fine needle aspiration biopsy with the following cytological class (C) outcome: 14 patients C2 (82%), 1 patient C3 (6%), 2 patients had C4 (12%), the latter received histological confirmation.

CONCLUSIONS

The prevalence of thyroid abnormalities is very high in subjects unaware of any thyroid disease. DTC was found in 1% of subjects and in 2% of those affected by nodular goiter. Compared to the detection rate of the well-established screening programs for breast (0.45%) and colorectal (0.27%) cancer, the prevalence of DTC seems to be much higher. Thyroid US screening could allow the detection of DTC in asymptomatic subjects and this diagnosis often includes DTC at an advanced stage. Thus, US screening not necessarily results in the over-diagnosis of clinically not relevant thyroid diseases.

Annual increase in the frequency of papillary thyroid carcinoma as diagnosed by fine-needle aspiration at a cytology unit in Sicily

OBJECTIVE

An increased frequency of papillary thyroid carcinoma (PTC) has been reported in the literature, including studies based on fine-needle aspiration cytology (FNAC).

DESIGN

To substantiate our own ascertainment of such an increase, we retrieved all the diagnoses of ultrasound-guided FNAC which was performed on 11,389 patients referred for cytological evaluation of a single or dominant thyroid nodule from 1988 to 2010. FNAC yielded 11,258 adequate specimens.

RESULTS

The number of patients with PTC was 200 (age 10-83 yrs) and increased significantly from 1988 to 2010 (r= 0.916, P<0.001). Expressing data as percent of FNAC in any given year, PTC and colloid goiter increased, while adenomatous goiter, follicular lesions and anaplastic or medullary thyroid cancer decreased. PTC accounted for 0% of all FNAC diagnoses in 1988 but for 2% in 2010, with a peak of 2.6% in 2006. Of interest, chronic lymphocytic thyroiditis (CLT) also increased, preceding the increase of PTC by 5-6 years.

CONCLUSION

We conclude that in the regions on either side of the Strait of Messina (Italy), PTC has become progressively more frequent during the 23-year period between 1988 and 2010 and that this increase lagged behind the increase of CLT.

The BRAF(V600E) mutation is associated with malignant ultrasonographic features in thyroid nodules

CONTEXT

Several ultrasonographic (US) features of thyroid nodules have been reported to predict malignancy. The BRAF(V600E) mutation is a useful diagnostic marker for differentiating papillary thyroid carcinoma from benign thyroid nodules, especially in BRAF(V600E) -prevalent populations such as in Korea.

OBJECTIVE

To evaluate the association of BRAF(V600E) mutation with US features of thyroid nodules in predicting the malignancy of thyroid nodules in Korean patients.

DESIGN

A total of 991 thyroid nodules from 823 patients in fine-needle aspiration biopsy (FNAB) specimens were investigated. The relationship between US features and the presence of BRAF(V600E) mutation by pyrosequencing method was prospectively analysed.

RESULTS

The BRAF(V600E) mutation was associated with the following US features: solid composition [odds ratio (OR) 20·338; 95% confidence interval (CI): 4·952-83·532; P < 0·001], marked hypoechogenicity (OR 30·744; 95% CI: 15·951-59·255; P < 0·001), irregular margin (OR 9·889; 95% CI: 7·005-13·859; P < 0·001), taller-than-wide shape (OR 6·031; 95% CI: 4·343-8·376; P < 0·001) and the presence of microcalcifications (OR 6·664; 95% CI: 4·604-9·648; P < 0·001). The BRAF(V600E) mutation with malignant US features in FNAB enhanced the diagnostic accuracy compared with cytologic diagnosis alone (94·3%vs 69·7%).

CONCLUSION

The BRAF(V600E) mutation is significantly associated with malignant US features, such as solid composition, marked hypoechogenicity, irregular margin, taller-than-wide shape and the presence of microcalcifications. The application of BRAF(V600E) mutation analysis in US-guided FNAB can improve the diagnostic accuracy of thyroid nodules.

Ultrasonographic screening for occult thyroid cancer

BACKGROUND

It has been shown that occult thyroid carcinoma can be identified in about 10% of thyroid glands in autopsy. The purpose of this study was to evaluate the prevalence of asymptomatic thyroid carcinoma in the Hong Kong Chinese population by ultrasonographic screening.

METHODS

Volunteer subjects without symptoms of thyroid disease were recruited for ultrasonographic screening for thyroid cancer. A total of 1140 subjects were recruited in this study.

RESULTS

Thyroid nodules were found in 45% subjects (511 of 1140); the mean age was 48 years. Ultrasonographic-guided aspiration cytology was performed in 258 subjects. Twenty-six subjects (2.3%) had cytologic findings suspicious of malignancy. Fourteen subjects (1.2%) had pathologic diagnosis of thyroid cancer, including 13 papillary carcinomas and 1 follicular carcinoma.

CONCLUSION

A high incidence of occult thyroid cancer could be identified on ultrasonographic screening. Subjects could benefit with early diagnosis with either early intervention or close monitoring.

Tumor size and presence of calcifications on ultrasonography are pre-operative predictors of lymph node metastases in patients with papillary thyroid cancer

BACKGROUND AND OBJECTIVES

Lymph node metastases in papillary thyroid cancer (PTC) are common and their presence can significantly alter the treatment for patients with PTC. We therefore sought to identify pre-operative predictors of lymph node metastases in patients with PTC.

METHODS

A thyroid tumor database was queried to identify patients with a pre-operative diagnosis of PTC and underwent thyroidectomy between January 2006 and August 2009. One hundred and three patients who had a pre-operative ultrasound and had lymph nodes surgically resected were identified. Clinical factors and tumor ultrasound characteristics were recorded. The pre-operative ultrasound results, type of operation, and final pathology results were also recorded.

RESULTS

Of the 103 patients, 74 (72%) were women and 29 (28%) were men with an age range of 15-78 years (median age of 43). Of the ultrasound characteristics evaluated only calcifications (P = 0.007) and size (P = 0.003) were statistically associated with positive cervical lymph nodes. None of the other demographic or clinical factors were significantly associated with lymph node metastases.

CONCLUSIONS

Thyroid nodule size and presence of calcifications on ultrasound were found to have a statistically significant association with lymph node metastases in patients with PTC. This information could be used to guide the surgical management of these patients.

The thyroid nodule: fine-needle aspiration biopsy technique

The initial portion of this article includes general comments regarding thyroid nodules, reference to 2 recent articles delineating guidelines for management of thyroid nodules, and discussion of several areas of disagreement with these articles and expansion of recommendations in areas not covered by the published guidelines. The main body of the article provides a detailed discussion of our technique for fine-needle aspiration biopsy of a thyroid nodule.

Estimation of the Release Time from Isolation for Patients with Differentiated Thyroid Cancer Treated with High-dose I-131

PURPOSE

Patients receiving high-dose I-131 to treat differentiated thyroid cancer are isolated from visitors to limit radiation exposure to reasonable levels. The appropriate isolation time is unclear and has not been reported in Korea. The purpose of this study was to estimate the isolation time and investigate the possibility of earlier release from isolation.

METHODS

This study was a retrospective analysis of data from 71 patients (10 men and 61 women; mean age, 49 ± 11.1 y) who received 3.7 GBq (47 patients), 5.55 GBq (23 patients), or 7.4 GBq (1 patient) of I-131 between January 2008 and December 2008. The radiation dose was measured with a fixed probe placed inside the isolation room. The total estimated dose equivalent (TEDE) to family members, the time required for the external dose rate to become <0.07 mSv/h, and the time required for whole-body retention to become <1.2 GBq were calculated.

RESULTS

By the TEDE criterion (<5 mSv), 70 of 71 patients (98.6%) could have been released without isolation. By the external dose rate criterion, 10 of 71 (14.1%) and 60 of 71 patients (84.5%) could have been released without isolation and within 24 h, respectively. With whole-body retention criterion, 19 of 71 (26.8%) and 48 of 71 patients (67.6%) could have been released within 24 h and within 48 h, respectively.

CONCLUSIONS

Appropriate release times were estimated and compared using different criteria. Most patients could have been released without isolation or within 24 h of radiation treatment.

[Thyroid cancers in Madagascar]

This is a retrospective study, conducted on thyroid cancer observed for 13 months (from June 1(st) 2004 to June 30(th) 2005). Data were collected from four main surgical pathology laboratories in Antananarivo, Madagascar. Among 6,036 surgical samples, 179 were of thyroid gland, a rate that is near 3% of the total. Among them were found 40 cases of thyroid cancer, which is 0.66% of all screened samples, and 22.32% of all examined thyroid samples. In the studied population was observed a female preponderance (82%) with a mean age of 43.9 years when diagnosis was confirmed. It was evidenced a 50 % of papillary carcinoma and 45% of follicular carcinoma, with a rate of 2.5% respectively for the medullar and anaplastic carcinoma. Metastases were seen in 20%, originated from papillary type for the lymph node involvement and from the follicular type for the bone involvement. In Antananarivo, thyroid cancer is seen mainly in people from the surrounding Highlands, supposed to be sites of endemic goiter related to iodine deficiency. Despite its limits, this study may be used as reference about thyroid cancer in Madagascar. Further studies are required to find out other factors involved in the development of this disease.

Identification of differentially expressed genes in papillary thyroid cancers

PURPOSE

Techniques designed to identify differentially expressed genes (DEGs) in tumors have become important in modern pathology. Genefishing technique using the annealing control primer (ACP) system has recently been developed to screen for DEG transcripts. We tried to identify DEGs involved in papillary thyroid cancer (PTC) by using Genefishing technique.

MATERIALS AND METHODS

We utilized a new differential display method, designated with Genefishing technique, to analyze DEGs in 21 cases of PTCs.

RESULTS

Comparing the gene expression profiles between PTC and normal thyroid, we detected 17 genes that were differentially expressed in PTCs and performed cloning with sequencing in 10 genes. We confirmed the expression patterns of 2 DEGs by RT-PCR assay and identified the same results in 17 out of 21 (81%) PTCs. The 2 DEGs over-expressed in PTCs were identified as DC-STAMP and type I collagen A1. They are novel genes identified first in PTCs.

CONCLUSION

We confirmed 2 DEGs in PTCs as DC-STAMP and type I collagen A1 by using Genefishing technique. Although the detailed functions of those 2 genes and their products remain to be determined, the genes will provide insights into mechanisms of carcinogenesis or tumor progression in PTCs.