Small Cell Carcinoma: a Rare Subtype of Thyroid Cancer with Unanticipated Prognosis.

The prognosis of small cell thyroid carcinoma (SCTC) in a large cohort has not been well reported in the literature. In this study, we analyzed the mortality of SCTC, in comparison to medullary thyroid cancer (MTC) and anaplastic thyroid cancer (ATC), based on the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute, to determine the prognosis of SCTC. Information regarding patients with a diagnosis of MTC, ATC, or SCTC, between 2004 and 2013, was acquired from the SEER database. Patient survival curves were assessed by Cox proportional hazards regression analyses, Kaplan-Meier analyses, and log-rank tests. In a Kaplan-Meier analysis of the entire cohort of thyroid cancer patients, cancer-specific survival declined sharply for patients with SCTC, but it declined more modestly for patients with MTC. The cancer-specific survival was not significantly different between SCTC and ATC. Unadjusted Cox regression analysis showed that SCTC had a higher cancer-specific mortality than MTC but a similar prognosis as ATC. SCTC showed a higher cancer-specific mortality than MTC and ATC after adjustments for various confounding factors. SCTC was found to have a more highly lethal clinical course than MTC and had a similar death rate to ATC. Therefore, we recommend that aggressive, radical treatment like surgery or radiation should be performed for these patients.

Treatment for papillary thyroid microcarcinoma.

AIM OF THE STUDY: The treatment for papillary thyroid microcarcinoma (PTMC), which is a tumor measuring less than 1 cm, is still a subject of controversy. The aim of this study is to retrospectively evaluate the patients diagnosed with PTMC in terms of their clinical and histopathological features. MATERIAL AND METHODS: A total of 153 consecutive patients with PTMC were treated, and their clinical and histopathological characteristics were reviewed. The tumor diameter was observed to range from 1.0 mm to 10 mm (mean of 5.8 mm). Histologically, 138 (90.2%) cases of classical papillary carcinoma and 15 (9.8%) cases of the follicular variant were noted. Multicentric tumors were found in 37 (24.2%) patients, of whom 12 (7.8%) had more than one PTMC on the same side and 25 (16.3%) displayed bilateral PTMC. RESULTS: The proportions of capsular invasion and lymph node metastasis were 11.8% (18/153) and 48.1% (39/81), respectively. One patient showed distant metastasis during follow-up and died fifteen months after the operation. PTMC showed a high incidence of multifocality and lymph node metastasis in the level VI central compartment. The optimal surgical strategy for PTMC was total thyroidectomy and central compartment node dissection. CONCLUSIONS: Frozen tissue sections should be made for the prompt diagnosis of PTMC in all the thyroid nodules, except when the malignant diagnosis was already confirmed by cytology.

[Fusion expression and purification of recombinant ricin A-chain].

AIM: To prepare recombinant ricin A-chain(RTA) protein with high biological activity. METHODS: RTA gene containing KDEL sequence at the carboxyl terminal was cloned in pET32a vector, which was fused with thioredoxin. Furthermore, the constructed recombinant plasmid was transformed into the competent cell BL21, and induced with low concentration of IPTG (0.4 mmol/L) under low temperature (20 degrees Celsius). After binding to Co2+ chelating column, the expressed supernatants were eluted by applying imidazole solutions with the concentration from 20 to 100 mmol/L. The purified protein was identified with SDS-PAGE and Western blot analysis and was used to cleave supercoiled dsDNA. RESULTS: About 60 mg fusion proteins were obtained from 1,000 mL cultures , with purity above 90% and M(r) 45,000. The cleavage of supercoiled dsDNA demonstrated that RTA-Trx fusion proteins could significantly cleave supercoiled dsDNA as native RTA. CONCLUSION: The pET32a vector expression system can be used to produce a mass of soluble RTA-Trx fusion proteins with high biological activity.