Lymphocytic infiltration in pediatric thyroid carcinomas

Thyroid Carcinoma Coexisting with Hashimoto's Thyreoiditis: Clinicopathological and Molecular Characteristics Clue up Pathogenesis

Thyroid cancer (TC) coexisting with Hashimoto’s thyroiditis (HT) presents with several characteristic features including multifocality and lower clinical stages compared to de novo carcinomas but its exact biology is still not understood. We reexamined clinico-pathological and molecular correlations between Hashimoto’s thyroditis and papillary thyroid cancer. A total of 262 patients with TC was evaluated who underwent thyroidectomy at the Surgical Department of the University of Debrecen. Clinical data, histology and molecular data were evaluated. Our cohort included 43 patients (16.4%) with (5 male, 38 female) and 219 (83.6%) patients without coexisting HT (48 male, 171 female). Hashimoto’s thyroiditis related thyroid cancer presented predominantly (93.0% of the cases) with the papillary histological type. Multifocality was observed more frequently with coexisting HT (16/40; 40.0%) compared to cases uninvolved (45/190; 23.7%)(p = 0.034). In contrast, lymphatic metastasis (pN1) with a significantly reduced frequency in patients with HT (4/11; 36.4%) then without HT (34/41 pN1; 82.9%)(p = 0.002). BRAF V600E mutation could be demonstrated at significantly lower rates in cases of PTC + HT (32.1 vs 60.7%, p < 0.005). High incidence, multifocality and papillary morphology strongly support a causal relation between TC and preexisting Hashimoto’s thyroiditis, the latter to be considered as a preneoplastic condition promoting thyroid carcinogenesis.

Prevalence and Significance of Thyroglobulin Antibodies in Pediatric Thyroid Cancer

CONTEXT

Circulating thyroglobulin antibodies (TgAb) can confound measurement of serum thyroglobulin and impair thyroid cancer surveillance. Few data exist on the significance of TgAb in pediatric thyroid cancer.

OBJECTIVE

To describe the prevalence, natural history, and clinical significance of TgAb in children with thyroid cancer.

DESIGN

Retrospective cohort study.

SETTING

Single academic pediatric center.

PATIENTS

Seventy-three consecutive children (≤18 years) with nonmedullary thyroid cancer who had serum TgAb measured within 6 months after diagnosis.

MAIN OUTCOME MEASURES

Prevalence and natural history of TgAb; association of TgAb status and resolution with patient and disease characteristics.

RESULTS

TgAb were detected in 41% of subjects (30 of 73) and were associated with lymph node metastasis (83% vs 53%, P = 0.01) but not distant metastasis. In patients with TgAb, resolution occurred in 44% (11 of 25) over a median follow-up of 3.8 years. Median time to clear TgAb was 10.7 months, and 10 of 11 patients who cleared (91%) did so within 2 years. Resolution of TgAb was associated with lower initial TgAb level (median 4.5 vs 76 normalized units, P = 0.003). TgAb positivity at diagnosis was not independently associated with persistent or recurrent disease (odds ratio 3.20, 95% confidence interval 0.95 to 10.80, P = 0.06).

CONCLUSIONS

TgAb are common at diagnosis in children with thyroid cancer but resolve in nearly half of patients within 1 to 2 years. TgAb are associated with the presence of lymph node metastasis at diagnosis, but the long-term prognostic significance remains to be determined.

The association between papillary thyroid carcinoma and histologically proven Hashimoto's thyroiditis: a meta-analysis

OBJECTIVE

No consensus exists on the association between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT). To resolve this controversy, this study aimed to evaluate the relationship between the two conditions using a meta-analysis.

METHODS

We searched relevant published studies using citation databases including PubMed, Embase, and ISI Web of Science. The effect sizes of clinicopathologic parameters were calculated by odds ratio (OR), weighted mean difference, or hazard ratio (HR). The effect sizes were combined using a random-effects model.

RESULTS

Thirty-eight eligible studies including 10 648 PTC cases were selected. Histologically proven HT was identified in 2471 (23.2%) PTCs. HT was more frequently observed in PTCs than in benign thyroid diseases and other carcinomas (OR=2.8 and 2.4; P<0.001). PTCs with coexisting HT were significantly related to female patients (OR=2.7; P<0.001), multifocal involvement (OR=1.5; P=0.010), no extrathyroidal extension (OR=1.3; P=0.002), and no lymph node metastasis (OR=1.3; P=0.041). Moreover, PTCs with HT were significantly associated with long recurrence-free survival (HR=0.6; P=0.001).

CONCLUSIONS

Our meta-analysis showed that PTC is significantly associated with pathologically confirmed HT. PTC patients with HT have favorable clinicopathologic characteristics compared with PTCs without HT. However, patients with HT need to be carefully monitored for the development of PTC.

The treatment of differentiated thyroid cancer in children: emphasis on surgical approach and radioactive iodine therapy

Pediatric thyroid cancer is a rare disease with an excellent prognosis. Compared with adults, epithelial-derived differentiated thyroid cancer (DTC), which includes papillary and follicular thyroid cancer, presents at more advanced stages in children and is associated with higher rates of recurrence. Because of its uncommon occurrence, randomized trials have not been applied to test best-care options in children. Even in adults that have a 10-fold or higher incidence of thyroid cancer than children, few prospective trials have been executed to compare treatment approaches. We recognize that treatment recommendations have changed over the past few decades and will continue to do so. Respecting the aggressiveness of pediatric thyroid cancer, high recurrence rates, and the problems associated with decades of long-term follow-up, a premium should be placed on treatments that minimize risk of recurrence and the adverse effects of treatments and facilitate follow-up. We recommend that total thyroidectomy and central compartment lymph node dissection is the surgical procedure of choice for children with DTC if it can be performed by a high-volume thyroid surgeon. We recommend radioactive iodine therapy for remnant ablation or residual disease for most children with DTC. We recommend long-term follow-up because disease can recur decades after initial diagnosis and therapy. Considering the complexity of DTC management and the potential complications associated with therapy, it is essential that pediatric DTC be managed by physicians with expertise in this area.

Influence of lymphocitic thyroiditis on prognostic outcome differentiated thyroid carcinoma

Backgraund/aim. Thyroid carcinoma is rare malignant tumors. They are typically presented with slow progression and clinical course. Lymphocytic infiltration, including fagocytosis of neoplastic cells by macrophage plays an important role in preventing development of distant metastases. This paper sets the following objectives: Establish whether presence or absence of Hashimoto thyroiditis in differentiated thyroid carcinoma (DTC) is a favourable prognostic factor. Methods. The group under examination here are all newly diagnosed patients with differentiated thyroid carcinoma surgically treated at the Surgery Clinic in Podgorica from 2003. to 2010. A total of 125 patients, aged 11 to 79, were included in this research. The patients were divided in two groups, those with and those without lymphocytic infiltration. Both groups were mutually compared for their prognostic factors. For the identification of T and B lymphocytes, anti-CD 3 and anti-CD 20 antibodies were used. Student t-test was used for comparison of clinical and pathological parameters among groups, Hi square test for comparison of frequency, and Coxs regression model for time dependant variables as frequency of recurrence among groups with various stages of disease. Survival curve (Kaplan-Meier) is used for comparison of time dependant variables (survival, recurrence, death). The follow-up time ranges from 10 to 70 months in both groups of patients. Results are as follows: presence of lymphocytic infiltration in thyroid tissue in patients with differentiated thyroid carcinoma is significant prognostic factor (P<0.0001). But, absence of lymphocytic infiltration is a poor prognostic factor in patients with invasive extra thyroid tumours (P<0.0001). Also, absence of lymphocytic infiltration is a poor prognostic factor for development of lymphogenic and hematogenic metastases. The presence of T or B lymphocytes and varying degree of their presence is not a significant prognostic factor (P<0.0046). Patients without lymphocytic infiltration are significantly more numerous in the fourth stage of disease (P<0.0001). There is no statistically significant difference in terms of the presence of T or B lymphocytes in the tissue. Chronic lymphocytic thyroidis hahshimoto is a favourable prognostic factor in our examined group (P<0.0001). Local invasiveness and extrathyroid expansion is significantly smaller in the group of patients with the presence of lymphocytic infiltration (P<0.0001). By means of univariate analysis, we found that factors with a significant impact on survival rate include age (P<0.0001), size of tumour (P<0.018), extrathyroid invasiveness (P<0.0001), hematogenic metastases (P<0.049). Lymphocytic infiltration is present in 81% of patients in their thyroid gland, and in 19% patients there are no lymphocytes in tissue. Limphocitic infiltration has a favourable influence on tumor variables. Conclusion.This research has shown that lymphocytes in tissue as part of Hashimoto thzroiditis have an effect on certain prognostic factors of differentiated thyroid carcinoma as size, smaller invasiveness and extrathyroid tumour growth and incidence of hematogenic metastases.

A radiation-induced gene signature distinguishes post-Chernobyl from sporadic papillary thyroid cancers

We investigated selected gene targets to differentiate radiation-induced papillary thyroid cancers (PTCs) from other etiologies. Total RNA was isolated from 11 post-Chernobyl PTCs and 41 sporadic PTCs characterized by a more aggressive tumor type and lacking a radiation exposure history. RNA from 10 tumor samples from both groups was pooled and hybridized separately on a whole genome microarray for screening. Then 92 selected gene targets were examined quantitatively on each tumor sample using an RTQ-PCR-based low-density array (LDA). Screening for more than fivefold differences in gene expression between the groups by microarray detected 646 up-regulated and 677 down-regulated genes. Categorization of these genes revealed a significant (P < 0.0006) over-representation of the number of up-regulated genes coding for oxidoreductases, G-proteins and growth factors, while the number of genes coding for immunoglobulin appeared to be significantly down-regulated. With the LDA, seven genes (SFRP1, MMP1, ESM1, KRTAP2-1, COL13A1, BAALC and PAGE1) made a complete differentiation between the groups possible. Gene expression patterns known to be associated with a more aggressive tumor type in older patients appeared to be more pronounced in post-Chernobyl PTC, thus underlining the known aggressiveness of radiation-induced PTC. Seven genes were found that completely distinguished post-Chernobyl (PTC) from sporadic PTC.

Thyroid cancer and the immune system: a model for effective immune surveillance

Differentiated thyroid cancers, including papillary and follicular variants, are a useful model with which to examine interactions between cancer and the immune system. Differentiated thyroid cancers are detected in only 20,000 individuals annually in the USA, but thyroid microcarcinomas (< 1 cm in diameter) are far more common. This suggests that the immune system might restrain the growth of these microcarcinomas. On the clinical level, patients with lymphocytes that infiltrate into papillary thyroid cancer have improved survival, supporting the notion that immune system activation might improve this. Together, these observations suggest that the growth and distant spread of thyroid carcinoma are suppressed by mechanisms of immune surveillance, possibly involving lymphocytes, macrophages and their secreted products. In this review, we examine the general hypothesis of immune surveillance and the data pertaining to the roles of lymphocytes, dendritic cells and cytokines in the immune response against thyroid cancers.