Thyroid Cancer in Egypt: Histopathological Criteria, Correlation With Survival and Oestrogen Receptor Protein Expression

Oestrogen receptor alpha in papillary thyroid carcinoma: association with clinical features and BRAFV600E mutation

BACKGROUND

Papillary thyroid cancer cells can express oestrogen receptor alpha, which is encoded by the ESR1 gene and may bind to oestrogen to induce the occurrence and development of papillary thyroid cancer. The BRAFV600E mutation is also an important biomarker for the occurrence and progression of papillary thyroid cancer. However, the association between the BRAFV600E mutation and oestrogen receptor alpha expression has not been identified. This study aims to investigate the association between ESR1 expression and the BRAFV600E mutation and its clinical significance.

METHODS

Oestrogen receptor alpha and BRAFV600E proteins were detected by immunohistochemical staining of formalin-fixed paraffin-embedded thyroid tissues from 1105 patients with papillary thyroid cancer at our institution. Messenger RNA expression counts of ESR1 and clinicopathologic information were obtained from The Cancer Genome Atlas database.

RESULTS

Oestrogen receptor alpha protein expression was significantly associated with BRAFV600E protein. The positive rate of oestrogen receptor alpha protein in papillary thyroid cancer patients was significantly higher in males, younger patients and patients with the multifocal type. In papillary thyroid cancer patients with positive BRAFV600E protein, oestrogen receptor alpha expression was significantly correlated with central lymph node metastasis. Data from the The Cancer Genome Atlas database also suggested that the ESR1 messenger RNA level was associated with the BRAFV600E mutation. Furthermore, classification analysis performed according to a tree-based classification method demonstrated that higher ESR1 messenger RNA expression indicated poorer overall survival in papillary thyroid cancer patients with the BRAFV600E mutation.

CONCLUSIONS

The percentage of BRAFV600E mutations is increased in patients with higher ESR1 messenger RNA levels, and the BRAFV600E protein might be co-expressed with oestrogen receptor alpha, which could be an indicator of cervical lymph node metastasis and poor overall survival in patients with papillary thyroid cancer.

Decline in radioiodine use but not total thyroidectomy in thyroid cancer patients treated in the United Arab Emirates - A retrospective study

Objectives

To assess the trend of clinicopathological features and treatment modalities in patients with thyroid cancer (TC) in the largest oncology center in the United Arab Emirates (UAE).

Methods

A retrospective analysis of patients with TC presenting to a tertiary care hospital in Al Ain, UAE between September 2008 and December 2018 identified using ICD 9 & 10 codes was performed. Data on demographics, histopathology, surgical extent, and use of Radioiodine (RAI) were extracted. Exact logistic and ordinal logistic regressions were performed to analyze the annual trend in features and management of TC, and logistic regression analysis was performed to identify predictors of total thyroidectomy and RAI use.

Results

A total of 762 patients were included in the analysis (mean age: 39.6 ± 12.6 years, 45 (60%) women). The majority (92.2%) were diagnosed with papillary thyroid cancer (PTC) and 83.9% had tumor size of <4 cm. All patients underwent surgery (93.8% total thyroidectomy, 6.2% lobectomy) and 77.4% received RAI therapy overall with a significant (p < 0.001) decline from 100% in 2008 to 60% in 2018. In multivariate analysis, nationality, and lymph node (LN) involvement were significant predictors of total thyroidectomy, while nationality, LNs, year of diagnosis, and tumor size significantly predicted RAI use.

Conclusion

Most patients in our cohort were diagnosed with localized PTC with no significant change in the extent of surgical approach but a substantial decline in RAI therapy administration over time. Nationality and LN involvement were significant predictors of surgical extent and RAI use.

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This is the largest study evaluating clinicopathological features and treatment modalities in TC patients in the UAE.

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Most patients were diagnosed with localized PTC.

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A substantial decline in RAI therapy administration but not the extent of thyroidectomy was observed during the study period.

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Nationality and LN involvement were significant predictors of surgical extent and RAI use.

Thyroid cancer associated with Hashimoto thyroiditis: similarities and differences in an endemic area

BACKGROUND

Hashimoto thyroiditis (HT) is an autoimmune lymphocytic thyroiditis and is the most common form of thyroid inflammatory diseases. The association of HT with papillary thyroid carcinoma (PTC) has been described. PTC is the most common form of malignancy associated with HT. When papillary carcinoma develops on top of Hashimoto thyroiditis, the disease tends to be less aggressive and lymph node and extra-thyroidal invasion are infrequent.

RESULTS

We retrospectively examined the pathological features of our patients who were diagnosed with concomitant HT and thyroid cancer. In Egyptian patients, PTC was the main type of malignancy associated with HT (96.2%) and was often multifocal (46.2%). In contrast to the published literature, lymph node invasion and extra-thyroidal extension were as frequent in association with HT as in other cancer cohorts. We also observed the frequent occurrence of Hürthle cell metaplasia (23.1%) and the appreciable incidence of aggressive histological types of PTC (32%).

CONCLUSION

Thyroid carcinoma with HT may have some aggressive features in areas with endemic goiter background.

Signaling Complexity Measured by Shannon Entropy and Its Application in Personalized Medicine

Traditional approaches to cancer therapy seek common molecular targets in tumors from different patients. However, molecular profiles differ between patients, and most tumors exhibit inherent heterogeneity. Hence, imprecise targeting commonly results in side effects, reduced efficacy, and drug resistance. By contrast, personalized medicine aims to establish a molecular diagnosis specific to each patient, which is currently feasible due to the progress achieved with high-throughput technologies. In this report, we explored data from human RNA-seq and protein–protein interaction (PPI) networks using bioinformatics to investigate the relationship between tumor entropy and aggressiveness. To compare PPI subnetworks of different sizes, we calculated the Shannon entropy associated with vertex connections of differentially expressed genes comparing tumor samples with their paired control tissues. We found that the inhibition of up-regulated connectivity hubs led to a higher reduction of subnetwork entropy compared to that obtained with the inhibition of targets selected at random. Furthermore, these hubs were described to be participating in tumor processes. We also found a significant negative correlation between subnetwork entropies of tumors and the respective 5-year survival rates of the corresponding cancer types. This correlation was also observed considering patients with lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD) based on the clinical data from The Cancer Genome Atlas database (TCGA). Thus, network entropy increases in parallel with tumor aggressiveness but does not correlate with PPI subnetwork size. This correlation is consistent with previous reports and allowed us to assess the number of hubs to be inhibited for therapy to be effective, in the context of precision medicine, by reference to the 100% patient survival rate 5 years after diagnosis. Large standard deviations of subnetwork entropies and variations in target numbers per patient among tumor types characterize tumor heterogeneity.

The Emerging Role of Estrogens in Thyroid Redox Homeostasis and Carcinogenesis

Reactive oxygen species (ROS) are the most critical class of free radicals or reactive metabolites produced by all living organisms. ROS regulate several cellular functions through redox-dependent mechanisms, including proliferation, differentiation, hormone synthesis, and stress defense response. However, ROS overproduction or lack of appropriate detoxification is harmful to cells and can be linked to the development of several diseases, such as cancer. Oxidative damage in cellular components, especially in DNA, can promote the malignant transformation that has already been described in thyroid tissue. In thyrocyte physiology, NADPH oxidase enzymes produce large amounts of ROS that are necessary for hormone biosynthesis and might contribute to the high spontaneous mutation rate found in this tissue. Thyroid cancer is the most common endocrine malignancy, and its incidence is significantly higher in women than in men. Several lines of evidence suggest the sex hormone estrogen as a risk factor for thyroid cancer development. Estrogen in turn, besides being a potent growth factor for both normal and tumor thyroid cells, regulates different mechanisms of ROS generation. Our group demonstrated that the thyroid gland of adult female rats exhibits higher hydrogen peroxide (H₂O₂) production and lower enzymatic antioxidant defense in comparison with male glands. In this review, we discuss the possible involvement of thyroid redox homeostasis and estrogen in the development of thyroid carcinogenesis.

Estrogen and thyroid cancer is a stem affair: A preliminary study

Gender influences Papillary Thyroid Cancer (PTC) with an incidence of 3:1 when comparing women to men with different aggressiveness. This gender discrepancy suggests some role of sex hormones in favoring the malignant progression of thyroid tissue to cancer. Estrogens are known to promote Stem Cell self-renewal and, therefore, may be involved in tumor initiation. The goals of these studies are to investigate the underlying causes of gender differences in PTC by studying the specific role of estrogens on tumor cells and their involvement within the Cancer Stem Cell (CSC) compartment. Exposure to 1nmoll^-1 Estradiol for 24h promotes growth and maintenance of PTC Stem Cells, while inducing dose-dependent cellular proliferation and differentiation following Estradiol administration. Whereas mimicking a condition of hormonal imbalance led to an opposite phenotype compared to a continuous treatment. In vivo we find that Estradiol promotes motility and tumorigenicity of CSCs. Estradiol-treated mice inoculated with Thyroid Cancer Stem Cell-enriched cells developed larger tumor masses than control mice. Furthermore, Estradiol-pretreated Cancer Stem cells migrated to distant organs, while untreated cells remained circumscribed. We also find that the biological response elicited by estrogens on Papillary Thyroid Cancer in women differed from men in pathways mediated. This could explain the gender imbalance in tumor incidence and development and could be useful to develop gender specific treatment of (PTC).