Israel Medical Association Journal

Background: Radiation exposure is a well-known risk factor for well-differentiated thyroid cancer (WDTC). However, disease characteristics, optimal treatment, time from exposure to disease appearance, and the effect on outcome of age at initial exposure have yet to be determined. 

Objectives: To identify the characteristics of radiation-induced thyroid carcinoma.

Methods: We retrieved the charts of all patients previously exposed to radiation who were diagnosed with WDTC between the years 1985 and 2013 in a tertiary referral center. 

Results: Forty-four patients were reviewed. Median time from radiation exposure to diagnosis was 23 years. These patients had higher rates of aerodigestive symptoms and distant metastases on presentation than seen in non-radiated patients. Patients who were exposed to radiation before age 15 years tended to develop the disease at a younger age but had a longer latency period (34.7 ± 15.3 vs. 16.3 ± 10 years, P < 0.001) and none had significantly higher rates of vocal cord palsy, hoarseness on presentation, or aggressive variants on histology compared to patients exposed to radiation at an older age. Disease-specific survival (DSS) was the same for both groups and were similar to that seen in the general population (95% 20 year DSS).

Conclusions: Radiation-induced thyroid cancer has a more aggressive presentation and the age at exposure affects the presentation of disease. Nonetheless, appropriate treatment leads to a favorable prognosis.

 

Background: Treatment guidelines for well-differentiated papillary thyroid carcinoma (PTC) are based on retrospective studies and vary among different professional thyroid associations.

Objectives: To evaluate physician adherence to guidelines, overall and by specialty.

Methods: Questionnaires on the approach to low risk PTC were distributed among 51 surgeons and endocrinologists treating patients with PTC in tertiary medical centers.

Results: A wide range of answers was recorded among physicians regarding the danger posed by low risk PTC to the patient’s life, urgency with which treatment should be administered, type of treatment, and risks associated with this treatment. There was a significant between-group difference in treatment preference: endocrinologists chose total thyroidectomy with radioactive iodine, while surgeons favored hemithyroidectomy alone.

Conclusions: There is a wide difference in treatment recommendations between treating physicians and different specialties with regard to low risk PTC. The wide variation within and between specialties may be explained by biases. 

Background: Matrix metalloproteinases are proteolytic enzymes that degrade extracellular matrix components. Numerous studies have demonstrated that individual MMPs[1] play a crucial role in tumor invasion and metastasis.

Objective: To examine the expression of MMPs and their inhibitor TIMP-2 in neoplastic and normal thyroid tissues.

Methods: We examined 33 cases of thyroid tumor (papillary, follicular and medullary carcinoma, follicular adenoma and multinodular goiter). MMP protein content and activity were measured by enzyme-linked immunosorbent assay and gel zymography. Immunohistochemistry was also performed.

Results: The thyroid tissues examined secreted MMP-2 and 9 as well as TIMP-2, but only MMP-2 was significantly higher in papillary carcinoma cases compared to the adjacent normal tissue or to the other tumor entities. Increased MMP-2 immunohistochemical staining was demonstrated in the neoplastic papillary epithelial component. No significant difference was seen between papillary carcinomas with lymph node metastases and those without.

Conclusions: Increased MMP-2 expression may be useful as a diagnostic marker to differentiate papillary carcinoma from other thyroid neoplasms, but it cannot serve as a useful prognostic marker.