Morphological evidence for an invasion-independent metastasis pathway exists in multiple human cancers

BACKGROUND: We have previously described an alternative invasion-independent pathway of cancer metastasis in a murine mammary tumor model. This pathway is initiated by intravasation of tumor nests enveloped by endothelial cells of sinusoidal vasculature within the tumor. In this study, we examined whether evidence for the invasion-independent pathway of metastasis is present in human cancers. METHODS: Archival specimens of 10 common types of human cancers were examined for the presence of sinusoidal vasculature enveloping tumor nests and subsequently generated endothelial-covered tumor emboli in efferent veins. RESULTS: A percentage of tumor emboli in all cancers was found to be enveloped by endothelial cells, but these structures were particularly prevalent in renal cell carcinomas, hepatocellular carcinomas and follicular thyroid carcinomas. A common feature of the vasculature in these tumors was the presence of dilated sinusoid-like structures surrounding tumor nests. A high mean vascular area within tumors, an indication of sinusoidal vascular development, was significantly related to the presence of endothelial-covered tumor emboli. CONCLUSIONS: These results suggest that an invasion-independent metastatic pathway is possible in a wide variety of human cancers. Further investigation of this phenomenon may present new therapeutic strategies for the amelioration of cancer metastasis

Childhood exposure due to the Chernobyl accident and thyroid cancer risk in contaminated areas of Belarus and Russia

The thyroid dose due to 131I releases during the Chernobyl accident was reconstructed for children and adolescents in two cities and 2122 settlements in Belarus, and in one city and 607 settlements in the Bryansk district of the Russian Federation. In this area, which covers the two high contamination spots in the two countries following the accident, data on thyroid cancer incidence during the period 1991-1995 were analysed in the light of possible increased thyroid surveillance. Two methods of risk analysis were applied: Poisson regression with results for the single settlements and Monte Carlo (MC) calculations for results in larger areas or sub-populations. Best estimates of both methods agreed well. Poisson regression estimates of 95% confidence intervals (CIs) were considerably smaller than the MC results, which allow for extra-Poisson uncertainties due to reconstructed doses and the background thyroid cancer incidence. The excess absolute risk per unit thyroid dose (EARPD) for the birth cohort 1971-1985 by the MC analysis was 2.1 (95% CI 1.0-4.5) cases per 10(4) person-year Gy. The point estimate is lower by a factor of two than that observed in a pooled study of thyroid cancer risk after external exposures. The excess relative risk per unit thyroid dose was 23 (95% CI 8.6-82) Gy(-1). No significant differences between countries or cities and rural areas were found. In the lowest dose group of the settlements with an average thyroid dose of 0.05 Gy the risk was statistically significantly elevated. Dependencies of risks on age-at-exposure and on gender are consistent with findings after external exposures

Das papilläre Schilddrüsenkarzinom. Prognose und prognostische Faktoren

89 folliculäre Schilddrüsencarcinome (von 1952 bis 1975) mit detaillierten histologischen Befunden, vollständigen klinischen Daten und Verlaufsangaben wurden nach verschiedenen Variablen, von denen eine prognostische Bedeutung erwartet werden konnte, aufgeschlüsselt. Die beobachteten Überlebenszeiten reichen von 0,08 bis 27,75 Jahren. Die beobachteten kumulativen und die erwarteten Überlebenszeiten wurden errechnet und statistisch ausgewertet. Die Abschätzung der individuellen Prognose erfordert naturgemäß die Kombination histologischer, makropathologischer und klinischer Daten: als wesentliche Parameter erweisen sich die lokale Tumorausbreitung, Kapsel- und Gefäßeinbrüche, Lymphknotenbefall und Fernmetastasen. Die einfache und prognostisch aussagekräftige Einteilung in intra- und extrathyreoidale Carcinome wird der T-Klassifikation der UICC vorgezogen

Follicular Adenoma and Carcinoma of the Thyroid Gland

Follicular neoplasms of the thyroid gland include benign follicular adenoma and follicular carcinoma. Currently, a follicular carcinoma cannot be distinguished from a follicular adenoma based on cytologic, sonographic, or clinical features alone. As a result, all patients with a follicular neoplasm should, at minimum, undergo a diagnostic thyroid lobectomy and isthmusectomy. A completion thyroidectomy is necessary for invasive follicular carcinoma. The overall ten-year survival for patients with minimally invasive follicular carcinoma is 98% compared with 80% in patients with invasive follicular carcinoma