Is multifocality a risk factor in low-risk papillary thyroid cancer?

INTRODUCTION: Multifocality in papillary thyroid cancer (PTC) is a common event, ranging from 18% to 87%. Additional multiple foci are frequently very small and generally detected in pathology specimens. The mechanisms of intrathyroidal spread, and its correlation with age, gender, tumour size, and lymph node metastases remain unclear. Moreover, studies assessing the prognostic impact of PTC multifocality have yielded non-univocal results. We aimed to evaluate the following: a) the histopathological and clinical characteristics associated with multifocal PTC; and b) the impact of multifocality on the long-term outcome. MATERIAL AND METHODS: We analysed a consecutive series of 2814 PTC patients without evidence of microscopic extrathyroidal extension (T1a, T1b, and T2), all of whom had undergone total thyroidectomy and were followed-up (median 4.7 years) in our thyroid clinic. Females comprised 81.3% and males 18.7% (F/M = 4.4/1), with a median age at diagnosis of 45.0 years. Patients were subdivided into 2 groups: 72.7% unifocal tumour and 27.3% multifocal tumour. Post-surgical radioiodine ablation (RAI) (30-100 mCi of 131-I) was performed in 1425 (50.6%) patients. All patients were periodically followed with thyroglobulin and anti-thyroglobulin antibodies measurements and with neck ultrasonography under L-thyroxine therapy and subjected to additional radioiodine administration or another therapeutic measure if not cured. RESULTS: Patients in the multifocal group were older (median age 46.4 vs. 44.5 years, respectively, p < 0.05) and presented a lower F/M ratio (F/M = 3.7/1 and 4.7/1; p = 0.01). T1a and T1b tumours showed no significant difference in multifocality rate whereas T2 tumours were less frequently multifocal (14.2% vs. 10.9%, p < 0.05). Multifocal tumours were more frequent in N1b (11.3% vs. 7.8%, p < 0.01) and less frequent in Nx (50.5% vs. 56.8%, p < 0.01), with no difference between the N0 and N1a groups. The clinical outcome was similar in the 2 group of patients (88.2 % in the unifocal group vs. 90.2% in the multifocal group). CONCLUSIONS: Multifocality is more frequent in older and male patients, in smaller tumours, and in N1b. However, multifocality "per se" was not associated, in our study, with worse clinical outcome in PTC patients.

Combined use of sonographic and elastosonographic parameters can improve the diagnostic accuracy in thyroid nodules at risk of malignancy at cytological examination.

BACKGROUND: Thyroid nodules diagnosed as Thy3B at fine-needle aspiration biopsy have a relevant risk of malignancy (15-30%) and are usually addressed to surgery. However surgery will result unnecessary in most cases. The present study aims at evaluating the possible increase of diagnostic accuracy for predicting malignancy using novel sonographic and elastographic parameters. METHODS: In fifty patients undergoing thyroidectomy because of a Thy3B thyroid nodule, sonographic and elastosonographic evaluation was carried out by single operator before surgery. Five sonographic parameters (echogenicity, irregular margins, microcalcifications, intra-nodule blood flow and its irregularity) and two elastosonographic parameters (intra-nodule stiffness and its extension to adjacent tissue) were considered. After obtaining histological diagnosis, diagnostic accuracy was calculated. RESULTS: When the two procedures were analyzed separately, sensitivity, specificity, positive (PPV) and negative (NPV) predictive values were 100%, 85%, 63% and 100% for ultrasonography and 60%, 92.5%, 67%, 90% for elastrosonography, respectively. The newly introduced evaluation procedures increased sensitivity. When a combined sonographic and elastosonographic evaluation was introduced, diagnostic accuracy was significantly improved: when ≥4 out of the seven parameters indicated were present, the risk of malignancy was very high (sensitivity 100%, specificity 92.55%, PPV 77%, NPV 100%). CONCLUSIONS: A novel combined sonographic and elastosonographic parameter evaluation improved diagnostic accuracy for identifying thyroid nodules suspicious of malignancy.

Metastatic malignant struma ovarii with coexistence of Hashimoto's thyroiditis.

UNLABELLED: Struma ovarii is a rare ovarian teratoma characterized by the presence of thyroid tissue as the major component. Malignant transformation of the thyroidal component (malignant struma ovarii) has been reported in approximately 5% of struma ovarii. The management and follow-up of this unusual disease remain controversial. We report the case of a woman with a history of autoimmune thyroiditis and a previous resection of a benign struma ovarii that underwent hystero-annexiectomy for malignant struma ovarii with multiple papillary thyroid cancer foci and peritoneal involvement. Total thyroidectomy and subsequent radioiodine treatment lead to complete disease remission after 104 months of follow-up. The diagnosis and natural progression of malignant struma ovarii are difficult to discern, and relapses can occur several years after diagnosis. A multidisciplinary approach is mandatory; after surgical excision of malignant struma, thyroidectomy in combination with (131)I therapy should be considered after risk stratification in accordance with a standard approach in differentiated thyroid cancer patients. LEARNING POINTS: Malignant struma ovarii is a rare disease; diagnosis is difficult and management is not well defined.Predominant sites of metastasis are adjacent pelvic structures.Thyroidectomy and (131)I therapy should be considered after risk stratification in accordance with standard approaches in DTC patients.

The BRAF(V600E) mutation influences the short- and medium-term outcomes of classic papillary thyroid cancer, but is not an independent predictor of unfavorable outcome.

INTRODUCTION: The prognostic usefulness of BRAF(V600E) evaluation in papillary thyroid cancer (PTC) has been analyzed in many studies, with controversial conclusions. AIM: To analyze the clinical relevance of BRAF(V600E) measurement in a homogenous series of PTC patients followed in a single institution. METHODS: One hundred three classical variant PTC patients who underwent total thyroidectomy in the 3-year period between 2005 and 2008 were retrospectively selected, and BRAF(V600E) assessment was performed using paraffin-embedded archival specimens in 2013. All patients were actively followed at our medical center, with an average follow-up of 55±13 months. RESULTS: BRAF(V600E) mutation-positive cancers (55.3%) were more frequently associated with lymph node metastasis (p=0.01) and advanced TNM stage (III-IV) (p=0.03). These findings were also confirmed in the subset of 42 microcarcinomas. BRAF(V600E)-positive patients were also at a higher risk of persistent disease (OR 3.5 [95% confidence interval {CI} 1.2-10.3], p=0.03) in univariate but not multivariate analysis (OR 2.8 [CI 0.7-11.8], p=0.2). Lymph node involvement was an independent predictor of persistent disease (OR 30.9 [CI 6.0-159.0], p<0.0001). Kaplan-Meier curves confirmed a higher percentage of persistent/recurrent disease in BRAF(V600E)-positive patients (p=0.02). However, the BRAF(V600E) mutation did not change the recurrence rate of PTC in subgroup analyses on the basis of other established risk factors (p=0.2). CONCLUSIONS: BRAF(V600E)-positive tumors were at higher risk of developing more aggressive behavior and were associated with less favorable outcomes in the short and medium term, but the BRAF(V600E) mutation was not an independent predictor of unfavorable outcome. Therefore, its use as a prognostic marker in clinical practice is not advisable.

Descriptive epidemiology of human thyroid cancer: experience from a regional registry and the "volcanic factor".

Thyroid cancer (TC), the most common endocrine tumor, has steadily increased worldwide due to the increase of the papillary histotype. The reasons for this spread have not been established. In addition to more sensitive thyroid nodule screening, the effect of environmental factors cannot be excluded. Because high incidences of TC were found in volcanic areas (Hawaii and Iceland), a volcanic environment may play a role in the pathogenesis of TC. In January 2002, the Regional Register for TC was instituted in Sicily. With a population of approximately five million inhabitants with similar genetic and lifestyle features, the coexistence in Sicily of rural, urban, industrial, moderate-to-low iodine intake, and volcanic areas provides a conducive setting for assessing the environmental influences on the etiology of TC. In Sicily, between 2002 and 2004, 1,950 new cases of TC were identified, with an age-standardized rate (world) ASR(w) = 17.8/10(5) in females and 3.7/10(5) in males and a high female/male ratio (4.3:1.0). The incidence of TC was heterogeneous within Sicily. There were 2.3 times more cases in the Catania province (where most of the inhabitants live in the volcanic area of Mt. Etna): ASR(w) = 31.7/10(5) in females and 6.4/10(5) in males vs. 14.1 in females and 3.0 in males in the rest of Sicily. Multivariate analysis documented that residents in the volcanic area of Mt. Etna had a higher risk of TC, compared to the residents in urban, industrial, and iodine deficient areas of Sicily. An abnormally high concentration of several chemicals was found in the drinking water of the Mt. Etna aquifer, which provides water to most of the residents in the Catania province. Our data suggest that environmental carcinogen(s) of volcanic origin may promote papillary TC. Additional analyses, including cancer biological and molecular features, will allow a better understanding of risk factors and etiopathogenetic mechanisms.

Increased mortality in patients with differentiated thyroid cancer associated with Graves' disease.

CONTEXT: We previously reported that differentiated thyroid cancer (DTC) has higher aggressiveness and poorer prognosis in patients with Graves' disease (GD) than DTC in euthyroid control patients. Subsequent studies on this issue reached controversial conclusions. Genetic and environmental factors, as well as the lack of appropriate control subjects and/or inadequate patient follow-up, may account for these discrepancies. OBJECTIVE: The aim of this study was to investigate the long-term disease-specific mortality of nonoccult DTCs occurring in patients with GD compared with DTCs in matched euthyroid control patients. PATIENTS AND DESIGN: The previously described cohorts of nonoccult DTCs occurring in either patients with GD (DTC-GD, n = 21) or matched euthyroid DTC control patients (n = 70) were compared again after a longer follow-up (50-363.6 months; median, 165.6 months) to compare the major clinical endpoints of persistent/recurrent disease and overall survival. Both cohorts were recruited in 1982-1994 at a single institution. All patients had undergone total thyroidectomy and were followed up according to a standardized protocol. RESULTS: Persistent/recurrent disease was more frequent in DTC-GD patients than in control patients (P = .0119). Disease-specific mortality was also significantly higher in DTC-GD patients (6 of 21, 28.6%) than in euthyroid control patients (2 of 70, 2.9%) (P = .0001). At the last visit, the percentage of disease-free patients was 57.1% (12 of 21) in the DTC-GD group vs 87.1% (61 of 70) in the control group (P = .0025). CONCLUSIONS: Nonoccult DTCs occurring in patients with GD cause increased disease-specific mortality compared with DTCs in matched euthyroid control patients. These findings emphasize the need for early diagnosis and aggressive treatment of nonoccult DTCs in patients with GD.

Update on thyroid cancer treatment.

Surgery and radioiodine therapy are usually effective for most patients with differentiated thyroid cancer. However, poorly differentiated and anaplastic thyroid carcinomas represent a challenge to physicians on the basis of the current cancer treatment modalities. These cancer subtypes are often lethal and refractory to radioiodine therapy as well as most of the common chemotherapy drugs. Several kinase inhibitors are promising targeted therapies for these malignancies; however, clinical trials involving these drugs have provided controversial results and their clinical use is still under debate. Advanced medullary thyroid carcinomas may also be refractory to conventional therapies and novel kinase inhibitors may also be useful to control tumor progression in certain patients. Novel evidence is emerging that thyroid cancer is a stem cell disease, thereby implying that the driving force of thyroid cancers is a subset of undifferentiated cells (thyroid cancer stem cells) with unlimited growth potential and resistance to conventional therapeutic regimens. Thyroid cancer stem cells have been proposed as responsible for tumor invasiveness, metastasis, relapse and differentiation. Therefore, drugs that selectively target these cells could serve as a cornerstone in the treatment of poorly differentiated thyroid cancer.