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Hay et al., Rochester, Minnesota, USA, report their 8 year experience with percutaneous ethanol
ablation (PEA) treatment in 22 selected patients with papillary thyroid carcinoma with 45
recurrent non-life-threatening neck nodal metastasis (NNM). All patients were initially treated
by total thyroidectomy, 20/22 had received radioiodine remnant ablation. Treatment discomfort
was minimal. At the time of this presentation 90% had post treatment exams with a mean follow-up
of 25 months. As compared to initial mean volume of nodal metastases, average volumes reduced
by 84% and 96% at 12 and 24 months respectively. (Comment: This is an interesting report.
Further follow-up however should give more definite answers, for instance if metastases will
vanish completely and if not, will that negatively influence prognosis of subjects.)
Sarkar et al., New York, New York, USA, performed thyroid imaging with I-131 and FDG
in 9 patients treated for Hurthle cell thyroid carcinoma over a period of 2-3 years. The patients
underwent a total of 12 sets of imaging studies. Both FDG and I-131 showed no metastasis in 4
patients. The remaining 5 patients had a total of 8 FDG studies that were positive for metastases
in lungs, lymph nodes, bone, and kidney. Serum TG was elevated in all these patients during high
TSH. I-131-imaging was positive only in 1 patient. These preliminary results suggest the
necessity of routine FDG-PET in this type of patients. Movshovich et al., New York, New York,
USA, analyzed I-131 whole body scans in 24 patients with metastatic Hurthle cell carcinoma and
found in 50% of these patients radioactive iodine avid metastasis on either diagnostic or
post-therapy whole body scanning. (Comment: I suggest that for the moment in thyroid Hurthle
cell carcinomas both I-131- and FDG-imaging may be necessary.) Sharaf et al., New York, New
York, USA, hypothesized that an isolated neck recurrence, especially in older patients, is not a
trivial event and is often followed by disease progression. They determined retrospectively
long-term clinical outcome in 59 patients with papillary thyroid carcinoma treated for an isolated
neck recurrence who were declared free of disease after initial treatment. After detection of
recurrence the median follow-up was 4 years (mean 7 years range 1-22 years). At the time of final
follow-up 54% of patients were again declared free of disease, 20% had persistent stable disease,
12% had locally progressive disease, and 14% had subsequently developed distant metastases.
From their analysis the authors found that in patients older than 45 years ultimate distant
metastases developed in 19% vs 9% when younger than 45 years (p = 0.004). (Comment: Thus it
seems that the presence of isolated lymph node metastasis in the neck in papillary carcinoma
is not that innocent after all!) Taguba et al., Cleveland, Ohio, USA, investigated the
sensitivity and specificity of TSH-receptor (TSHR) mRNA serum measurement in 38 patients with
well differentiated thyroid carcinoma, previously treated with near total thyroidectomy, and
compared results with Tg mRNA serum signals. No TSHR or Tg mRNA signals were detected in 10
controls and in 7/8 patients with benign thyroid disease. In the patients with treated carcinoma
they found the diagnostic sensitivity of TSHR- and Tg transcripts to be equal i.e. 67%.
Diagnostic specificity, positive and negative predictive values for TSHR mRNA signals were 97,
86, and 93% respectively, and for Tg mRNA signals 90, 67, ad 90% respectively. Overall
concordance with RAI scans for TSHR- and Tg mRNA were 89% and 84% respectively. (Comment: I
would not be surprised if a combination of these two tests would give even better results.
However the number of subjects in particular in the control groups is very small.) Chen et al.,
Washington DC, New York-New York, and Los Angeles, California, USA, determined if rhTSH testing
in patients with recurrent thyroid carcinoma would enhance clinical accuracy of measurement of
Tg mRNA. For this purpose 75 patients undergoing screening for recurrent thyroid carcinoma were
evaluated. Presence of thyroid tissue was defined as uptake on rhTSH I-131 scan, detectable
Tg immunoassay, positive post-therapy scan, and/or pathologic evidence of thyroid tissue.
Using a value of 1.6 Tg-18S as a cut-off, sensitivity and specificity were 75% and 74%
respectively and without rhTSH stimulation 50% and 72%.
Furlan et al., Toronto, Canada, analyzed fine needle aspiration biopsy (FNAB) and frozen section (FS) test performance for well-differentiated thyroid carcinoma. Between 1998 and 2000, 268 patients underwent FNAB and FS for thyroid carcinoma and/or benign thyroid nodule. Test accuracy was 70.1% for FNAB and 65.7% for FS in thyroid carcinoma. FS sensitivity and specificity were 35% and 99.2%, and for FNAB these values were 82.1% and 57% respectively. Sievert et al., Meneola, New York, Chapel Hill, North Carolina, Jamaica, New York, Elmhurst, New York, USA, compared tumor recurrence and survival in patients undergoing extensive surgery, n = 27, and lobectomy, n = 18, for differentiated thyroid carcinoma in a retrospective study. Seventy-four percent and 72% respectively of patients received RAI. Patients were diagnosed between 1980 and 2000. Local recurrences were found in 6/27 (22%), and 3/18 (17%) respectively, being not significantly different. Neither was there any difference between the two groups with regard to Kaplan-Maier survival analysis using time to recurrence as an endpoint. (Comment: This study has several limitations: It is a retrospective study. It is not indicated on what basis patients were selected for lobectomy or extensive surgery. The number of patients is small and the follow-up time is limited. My personal opinion is that (near) total thyroidectomy should always be performed in patients with differentiated thyroid carcinoma irrespective of the expansion of the tumor as long as there is controversy about the necessary extensiveness of the operation.) Sheikh et al., New York, New York, USA, tested the efficacy of I-124 in estimating the radiation dose to individual lesions in patients selected for treatment with I-131. They did a pilot study in 5 patients and administered 148 MBq I-124 and obtained PET scans at 4, 20, and 44 hours. Patients were subsequently treated with I-131. There was a high concordance of individual lesions between I-124 diagnostic- and I-131 post therapeutic scans. The variation of predicted radiation dosis observed ranged widely between 0.003-0.85 cGy/MBq. From the results the authors conclude that I-124 is an important new agent in the evaluation of thyroid patients who are likely to receive a therapeutic dose of I-131 in that it can provide accurate estimates of the radiation dose to the individual lesions. McGriff et al., Bethesda, Maryland, USA, did a MEDLINE and EMBASE systematic literature search (1934-2001) concerning the question if T4 suppression therapy is beneficial in patients treated for thyroid carcinoma. They identified 24 clinical trials out of which only 9 studies met the inclusion criteria. Out of a combined cohort of 3060 patients, 2101 patients (69%) were reported as being on T4 suppressive therapy. The weighted average of the mean periods of follow-up for the combined cohort was 9.4 years. The analysis showed that the group of patients on T4 suppressive therapy had significantly less major adverse clinical events when compared to patients not being on T4 suppressive therapy (p = 0.001). (Comment: The authors consider their results still preliminary as they conclude that more large-scale studies, either prospective or derived from on-going registries are needed to better define the effect of T4 suppression on the clinical course.) D'Avanzo et al., San Francisco, California, USA, compared prognostic scoring systems including TNM, EORTC, AGES, AMES, and MACIS in a selected group of 86 patients with treated follicular thyroid carcinoma. A number of 19 out of 86 patients died from carcinoma with a mean follow-up period of 9 years. Kaplan-Meier analysis indicated that all scoring systems predicted survival time, but that the MACIS classification was the best predictor. Robbins et al., New York, New York, USA, retrospectively analyzed, in patients who underwent total thyroidectomy for thyroid carcinoma, the efficacy of thyroid remnant ablation after off T4 for 4-6 weeks following thyroidectomy or on T4 and receiving rhTSH in 45 and 37 patients respectively. Successful ablation was found in 38/45 (84.2%) and 32/37 (86.5%) of patients. The authors conclude that the choice of preparation for a remnant ablation should be made on considerations other than efficacy, such as quality of life, cost and convenience. Golger et al.. Toronto, Ontario, Canada, assessed the efficacy of a 3 weeks withdrawal of T4 suppression therapy in 146 patients treated for differentiated thyroid carcinoma. They found that in 128/146 (88%) of patients TSH was >20 mIU/L and in 87/146 (60%) >40 mIU/L. Assessment of quality of life showed that the degree of this disability was tolerated well by most patients. The authors suggest that 3 weeks of T4 withdrawal is a useful first line test and in those patients with insufficient TSH response, hrTSH stimulation may be considered. Baloch et al., Philadelphia, Pennsylvania, USA, compared inter-institutional results (i.e. outhouse diagnosis of referred patients with in-house diagnosis) of thyroid fine needle aspiration biopsies (FNAB) in 183 patients. In 28/183 (26%) patients significant disagreements were noted. In 16/183 (15%) the diagnosis was changed from benign to malignant and in 12/183 (11%) the reverse was the case. Histologic follow-up was available in 109/183 cases and overall accuracy of outside diagnosis was 73% and of inside diagnosis 85%. (Comment: This is not de first publication on discrepancies between cytological diagnoses. Obviously many factors may explain differences, probably one of the most important being the grade of experience of the cyto-pathologist. Maybe the solution to this problem is to create national centers for cytologic diagnosis instead of having this done in one's own hospital.) Fatemi et al., Los Angeles, California, USA, analyzed long-term recurrence risk in 44 patients treated (near total thyroidectomy, I-131 remnant ablation and absence of Tg antibodies) for papillary thyroid carcinoma. At the end of a median follow-up of 7.6 years patients were classified as disease free or recurrent/persistent disease. In this study the question was asked whether the long-term risk for recurrence or persistence was different in patients with stimulated serum Tg values <1.0 ng/ml vs values between 1-10 ng/ml. The results showed that risk for recurrence or persistence did not differ in both groups. (Comment: I consider these results as preliminary mainly because the follow up period is relatively short for a tumor that generally grows so slowly.) Bhala et al., Rochester, Minnesota, USA, studied 23 patients with Cowden disease (19 females), mean age at diagnosis 44 years. Cowden disease is a benign/malignant tumor predisposition syndrome of multiple organs, due to mutations of the PTEN gene. Twenty-one out of 23 (91%) patients had evidence of thyroid disease and in 17/21 the thyroid diagnosis predated the diagnosis of Cowden disease. Twenty/twenty-one patients underwent thyroidectomy. Pathologic diagnosis revealed 6/20 multinodular goiter, 10/20 follicular adenoma, and 4/20 thyroid carcinoma. Tuttle et al., New York, New York, and Washington, DC, USA, tested the hypothesis that vascular endothelial growth factor (VEGF) would be higher in patients with recurrent or persistent thyroid carcinoma than those cured after treatment and also that TSH would stimulate VEGF levels further in patients with recurrent/persistent disease. Their study comprised 69 patients with differentiated carcinoma including 21 patients with no evidence of disease and 48 patients with local or distant metastases. They found that serum VEGF is significantly elevated in patients with metastatic differentiated carcinoma, but not in those with poorly differentiated thyroid cancer metastases. TSH did not appear to stimulate VEGF in any group of patients. (Comment: The mean level of VEGF in patients with metastatic disease was substantially higher (416 ± 62 pg/ml) than in patients without disease (185 ± 25 pg/ml) suggesting little overlap.) Robbins et al., New York, New York, USA, measured the clinical accuracy of rhTSH stimulated Tg in a group of 368 patients with low risk recurrence for differentiated thyroid carcinoma. Patients who had not had a remnant ablation, those with TSH-suppressed Tg levels >2 ng/ml, those with distant metastases, all with TNM stage III or IV and all with aggressive histology, were eliminated from the study. Of the remaining 114 "low-risk" patients 91/114 had stimulated Tg levels <2 ng/ml, 85/91 a negative diagnostic WBS that was positive in 6/91. It was noted that these 6 patients also prior had an abnormal diagnostic WBS. From their results the authors conclude that when prior diagnostic WBS is negative in low-risk patients, Tg response to rhTSH is sufficient to monitor for residual disease. Fatourechi et al., Rochester, Minnesota, USA, determined the effect of RAI therapy in 20 patients who were Tg-positive, but diagnostic scan-negative after initial treatment (thyroidectomy and RAI remnant ablation) for follicular cell derived thyroid carcinoma. Two groups could be discerned, one group showing macro-metastases (n = 13) and another group showing only micro-metastases (diameter <1 cm) (n = 7). Follow-up of the total group was 33 months. In patients with macro-metastases, tumor mass progressed substantially during follow-up as did serum Tg. However, in the group with micro-metastases patients remained stable both on tumor mass and serum Tg. (Comment: Although follow-up is really short in these patients and the number of patients small, these preliminary results suggest that in patients with micro-metastases tumor cells remain dormant or at least grow at a non detectable rate for the time of observation.) |
