| Zhang et al., Chicago, IL, USA, injected a replication defective adenovirus harboring the interleukin-2 gene in mice with medullary thyroid carcinoma. They noted up to 70% reduction of tumor in initially small tumors and stabilization of growth in initially large tumors. Histology revealed massive CD4+ and CD8+ cell infiltration in treated tumors, but not in untreated or control virus treated tumors. The data demonstrate an antitumor effect of interleukin-2. (Comment: This is an interesting study using gene therapy in experimental tumors in mice.) Activation of the ribonucleoprotein complex telomerase has been documented in various carcinomas. Saji et al., Baltimore, ML, USA, tested 34 thyroid nodules and 10 normal thyroids for gene expression of telomerase reverse transcriptase (TERT), the catalytic component of telomerase, using PCR reaction in 34 thyroid nodules and 10 normal thyroids. Gene expression was detected in 12/16 malignant nodules (3 follicular, 9 papillary) and only in 4/18 benign nodules. In all 4 benign nodules (1 follicular adenoma and 3 hyperplastic nodules) background lymphocytic thyroiditis was present. Gene expression was not found in the 10 normal thyroids. The authors conclude that in addition to cytology this test might be of help in differentiating malignant from benign thyroid nodules. Foster et al., Washington, DC, USA, retrospectively analyzed 237 patients for scintigraphically cold defects in the thyroid, occurring in 25 patients (11.4%). 13/25 were referred for surgery, 2/13 appeared to have papillary thyroid carcinoma. The authors conclude that cold defects in the thyroid occur in Graves’ disease and that about 50% of such patients have thyroid carcinoma. They state that thyroid scintigraphy should be performed initially in patients with Graves’disease and that cold defects should be examined further. (Comment: The prevalence of thyroid carcinoma in this patients group is less than 1% and from data available in the literature not higher then when clinically normal thyroids are examined histologically (see the classic study by Mortensen et al., J Clin Endocrinol Metab 15:1270,1955). The authors furthermore indicated that only 1 of the 2 found malignant nodules was palpable. No information at present is available about the malignant potential in the biological sense of non-palpable nodules that appear to be carcinomatous on histological examination. From the figures of this study I cannot endorse the advice given by these authors.) Vassilopoulou-Sellin et al., Houston, TX, USA, looked for the association between thyroid carcinoma and breast cancer in women. Among 18.931 women diagnosed with breast cancer since 1976, 11 developed differentiated thyroid carcinoma after two or more years. From control studies it appeared that the rate of carcinoma in this group is not abnormal. Among 1.013 women diagnosed with thyroid carcinoma since 1976, 24 patients developed breast cancer after two or more years. In this group the observed rate of breast cancer was significantly higher than expected from control studies. The authors conclude that breast cancer following thyroid carcinoma may point to a potential association. (Comment: More studies are necessary before any definite conclusion can be drawn.) Camargo et al., São Paulo, Brazil, classified thyroid nodules echographically in four grades: grade I benign cystic lesion, grade II benign isoechoic nodule, grade III doubtful hypoechoic nodule, and grade IV irregular hypoechoic nodule with microcalcifications suspicious for malignancy. Two hundred and seventy-seven patients presented as grade III or IV and underwent ultrasound-guided fine needle aspiration biopsy (FNAB). Twelve percent (32/277), were grade III nodules that were operated and 16/32 (50%) had thyroid carcinoma. Eleven percent (31/277) grade IV classified nodules, were operated and 30/31 (96.7%) had carcinoma. In addition, 12 nodules classified as grade I or II were operated and all were benign. The authors conclude that FNAB should only be performed in nodules with grade III or IV echographic characteristics and a diameter 1.0 cm. (Comment: These echographic findings are interesting and, if confirmed, of additional value in analysis of thyroid nodules.) Ringel et al., Los Angeles, CA, and Baltimore, ML, USA, did a preliminary study to assess the significance of qualitative RT-PCR measurement of thyroglobulin-mRNA in peripheral blood of patients with thyroid carcinoma during TSH suppressive thyroid hormone therapy. Measurements were done in 13 patients who also had antithyroglobulin antibodies in the circulation. Six/seven patients with recurrent or residual disease were identified using this reaction while 4/6 patients without disease had no detectable thyroglobulin-mRNA. TG-RIA detected 13/13 i.e. including those without clinical thyroid carcinoma and TG immunometric assay detected 2//7 patients tested, 1/4 with disease and 1/3 without disease. The authors conclude that quantitative TG RT-PCR may be an alternative marker of thyroid carcinoma in patients with anti-thyroglobulin antibodies. (Comment: This is a valuable observation and should be expanded to more patients to assess its ultimate significance.) Gardner et al., Washington, DC, USA, performed a retrospective study in 254 adult patients treated for papillary thyroid carcinoma since 1966 with a median follow-up of 6 years and assessed the significance of intra- and extrathyroidal vascular invasion with regard to the probability of metastases and recurrences. After reviewing of pathology reports, patients were separated into 3 groups i.e. without vascular invasion, with intrathyroidal vascular invasion, and with extrathyroidal vascular invasion. 5/225 patients without vascular invasion, 6/24 patients with intrathyroidal vascular invasion, and 2/5 with extrathyroidal vascular invasion had distant metastases at diagnosis. Patients with intrathyroidal vascular invasion and without vascular invasion had 16% vs. 5.2% local and 20% vs. 2.2% distant recurrence. (Comment: This study is important and I look forward to more data.) Pittas et al., New York, NY, USA, analyzed 146 patients from a database of over 1000 patients with thyroid carcinoma who had well documented bone metastases. Mean age at diagnosis of carcinoma was 55.4 years and 58.7 years at diagnosis of bone metastases. Eighty-four percent were differentiated thyroid carcinoma, 9% anaplastic, and 7% medullary carcinoma. Bone metastases were present in 47% at initial diagnosis. Common metastatic sites were vertebrae, pelvis, ribs, and femur. Overall survival rate from diagnosis of bone metastases at 5 and 10 years were 28 en 13% respectively. The longest survivals occurred in those who had only metastases in bone and not elsewhere and lesions that concentrated radioactive iodine. |
