Integrated Therapeutic Strategies for Anaplastic Thyroid Carcinoma

Recombinant Human Thyrotropin (rhTSH) in the Follow-Up and Treatment of Patients with Thyroid Cancer

The follow-up of thyroid cancer is based on the detection of residual and recurrent thyroid carcinoma. This is traditionally done by means of measurements of serum thyroglobulin (Tg) combined with various imaging techniques (131I-whole body scan, ultrasound and other modalities). Tg serum levels and the uptake of 131I on a whole body scan (WBS) depend on TSH stimulation, which in thyroidectomized patients can be obtained either by withdrawal of thyroid hormone treatment (thyroxine) or by administration of exogenous TSH. At present exogenous human TSH is obtained by means of recombinant DNA technology, (recombinant human TSH (rhTSH), Thyrogen™). Even if the administration of rhTSH and withdrawal of thyroid hormone are not completely equivalent, the use of rhTSH has already entered the clinical routine (rhTSH Tg test and rhTSH WBS) because with rhTSH the morbidity and discomfort associated with the withdrawal of thyroid hormone can be avoided. At a recent International Consensus Conference on the follow-up of differentiated thyroid carcinoma it was proposed to carry out only Tg measurement after rhTSH stimulation; moreover, it was stated that 131I whole body scan has to be discouraged in patients submitted to radical surgery and radioiodine ablation with no clinical evidence of residual tumor and with undetectable levels of Tg during hormonal suppression of TSH. Similar strategies in this respect tend to eliminate the 131I WBS and propose only the rhTSH Tg test combined with head and neck ultrasound (US). This is still a matter of debate, also because it is not valid for all risk groups and not all patients undergo the same clinical management (radical surgery or not, thyroid ablation with 131I or not). However, the availability of rhTSH will definitely change the management of papillary and follicular thyroid carcinoma, also with regard to iodine treatment. In fact, rhTSH can be used during radioiodine treatment to enhance the 131I uptake by the cancer cells in particular groups of patients. Patients who could benefit from this approach can be divided into three subgroups: 1) patients in whom thyroxine withdrawal may be dangerous because of the effects of long-term TSH stimulation on the tumor mass (brain metastases, vertebral metastases, presence of neurological signs, heart diseases); 2) patients affected by tumors with marked biological aggressiveness and a low iodine uptake (variants of follicular carcinoma, insular carcinoma, tall and columnar cell variants of papillary thyroid carcinoma, Hürthle cell carcinoma); 3) patients with hypothalamic-pituitary alterations. The potential efficiency of rhTSH in radiometabolic treatment is an important issue that has been studied in a limited number of patients, but is worthy of further investigations in large perspective. A recent clinical prospective trial has been proposed by the Thyroid Cancer Study Group of the Istituto Nazionale Tumori and is now ongoing.

Epidemiology, clinical presentation, treatment and prognosis of a regional series of 26 anaplastic thyroid carcinomas (ATC). Comparison with the literature

OBJECTIVE

The aim of this study is to retrospectively describe the epidemiological and clinical features, therapeutic modalities, prognostic factors and survival figures in a population of patients with anaplastic thyroid carcinoma (ATC) observed in Auvergne, France. We compared these data with those in the literature.

MATERIAL AND METHODS

The analysis was conducted based on a computer database containing a regional register recorded by health professionals treating ATC.

RESULTS

Of the 1500 cancers observed over 16 years, 26 were identified as ATC. The male/female ratio was 1/2.7 and the average age: 72.1; 76.9% of the cases had thyroid medical history, average tumor size at diagnosis was 7.35 cm with N1 in the course of illness in 61.5% of cases, M1 in 34.6% of cases. Surgery was performed in 84.6% of cases, radiotherapy in 53.8% and chemotherapy in 19.2%. The average survival was 9 months, the survival median: 4 months.

CONCLUSION

Our results show that, in univariate analysis, age above 75, capsular invasion, lymph nodes metastasis, tumor residue after surgery and lack of multimodal treatment (particularly radiotherapy in patients without tumor residue) are factors of poor prognosis. In a multivariate analysis only age above 75, followed by node invasion, capsular invasion, and finally female gender are factors of poor prognosis.

Prognostic factors for Korean patients with anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid carcinoma (ATC), although rare, is one of the most aggressive human cancers, and patients with ATC have extremely poor prognoses despite various therapeutic measures. We wished to determine the prognostic factors of survival and effect of treatment on survival rate in patients with ATC.

METHODS

We retrospectively reviewed the medical records of the 121 patients (41 men and 80 women) diagnosed with ATC from January 1995 to June 2004 at 5 major referral centers in Korea.

RESULTS

Mean patient age at diagnosis was 64 +/- 11 years (range, 17-84 years). Of the 121 patients, 11 (9%) had intrathyroidal tumors, 69 (57%) had extrathyroidal tumors or lymph node involvement, 29 (24%) had distant metastases, and 12 had no data about staging (9%). The mean tumor diameter was 5.5 +/- 2.5 cm (range, 0.5-17.0 cm). At a median follow-up of 41 months (range, 26-122 months), 8 patients were alive. Median survival time was 5.1 months. The disease-specific survival rates were 42% at 6 months, 16% at 12 months, and 9% at 24 months. Sixteen patients (13%) received only supportive care, 25 (21%) received surgery alone, 20 (16%) received radiation treatment or chemotherapy without surgery, and 60 (50%) received surgery plus radiation treatment or chemotherapy. Multivariate analysis showed that age less than 60 years, tumor size less than 7 cm, and lesser extent of disease were independent predictors of lower disease-specific mortality.

CONCLUSIONS

Long-term survival is possible for ATC patients less than 60 years old and with small localized tumors. Although aggressive multimodal therapy, including surgery, radiation treatment, and chemotherapy, was not significantly associated with improved survival, we advocate aggressive multimodal therapy in selected ATC patients with good prognostic factors.

Inhibition of heat shock protein 90, a novel RET/PTC1-associated protein, increases radioiodide accumulation in thyroid cells

RET/PTC1 is a rearranged form of the RET tyrosine kinase commonly seen in papillary thyroid carcinomas. It has been shown that RET/PTC1 decreases expression of the sodium/iodide symporter (NIS), the molecule that mediates radioiodide therapy for thyroid cancer. Using proteomic analysis, we identify hsp90 and its co-chaperone p50cdc37 as novel proteins associated with RET/PTC1. Inhibition of hsp90 function with 17-allylamino-17-demothoxygeldanamycin (17-AAG) reduces RET/PTC1 protein levels. Furthermore, 17-AAG increases radioiodide accumulation in thyroid cells, mediated in part through a protein kinase A-independent mechanism. We show that 17-AAG does not increase the total amount of NIS protein or cell surface NIS localization. Instead, 17-AAG increases radioiodide accumulation by decreasing iodide efflux. Finally, the ability of 17-AAG to increase radioiodide accumulation is not restricted to thyroid cells expressing RET/PTC1. These findings suggest that 17-AAG may be useful as a chemotherapeutic agent, not only to inhibit proliferation but also to increase the efficacy of radioiodide therapy in patients with thyroid cancer.