1,721,107 research outputs found

    Association between sonographic appearances of breast cancers and their histopathologic features and biomarkers.

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    Abstract PURPOSE: The purpose of this study was to investigate potential associations between invasive breast cancer sonographic (US) findings and histopathologic patterns and biomarkers. METHODS: One hundred consecutive women with invasive breast cancer treated in the Breast Diagnostic Center of Brotzu Hospital in Cagliari, Italy, from January to October 2013, were retrospectively evaluated. Two experienced breast radiologists independently evaluated hard copies of US examinations performed during the US-guided biopsy procedure. Tumor characteristics were assessed by using the BI-RADS US lexicon. For each patient, the results of histopathologic examination, tumor grading, hormone-receptor status, HER2, and Ki67 were considered. US characteristics were compared with histopathologic features and biomarkers. Statistical analysis was performed. RESULTS: Low-grade tumors were statistically significantly associated with spiculated margins (p = 0.002) and hyperechoic halos (p < 0.001). High-grade tumors were associated with abrupt interfaces, nonspiculated margins, and absence of posterior acoustic shadowing. Malignant breast masses with spiculated margins were significantly associated with hormone-receptor positivity (p = 0.009). The most frequent tumor grade was G3 in the HER2 + and triple-negative subgroups. Patients with G3 tumors were significantly younger than those with G1 or G2 disease (51.3 ± 9.5 years versus 58.7 ± 12.6 years; p = 0.004). CONCLUSIONS: Histopathologic patterns and breast cancer biomarkers determine differences in US imaging that can guide radiologists in better understanding the development of breast cancer and its prognosis. © 2015 Wiley Periodicals, Inc. J Clin Ultrasound 44:26-33, 2016

    How adverse selection affects the health insurance market

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    Adverse selection can be defined as strategic behavior by the more informed partner in a contract against the interest of the less informed partner(s). In the health insurance field, this manifests itself through healthy people choosing managed care and less healthy people choosing more generous plans. Drawing on theoretical literature on the problem of adverse selection in the health insurance market, the author synthesizes concepts developed piecemeal over more than 20 years, using two examples and revisiting the classical contribution of Rothschild and Stiglitz. He highlights key insights, especially from the literature on"equilibrium refinements"and on the theory of"second best."The government can correct spontaneous market dynamics in the health insurance market by directly subsidizing insurance or through regulation; the two forms of intervention provide different results. Providing partial public insurance, even supplemented by the possibility of opting out, can lead to second-best equilibria. The same result holds as long as the government can subsidize contracts with higher-than-average premium-benefit ratios and can tax contracts with lower-than-average premium-benefit ratios. The author analyzes the following policy options relating to the public provision of insurance: a) Full public insurance. b) Partial public insurance with or without the possibility of acquiring supplementary insurance and with or without the possibility of opting out. In recent plans implemented in Germany and the Netherlands, where competition among several health funds and insurance companies was promoted, a public fund was created to discourage risk screening practices by providing the necessary compensation across riks groups. But only"objective"risk adjusters (such as age, gender, and region) were used to decide which contracts to subsidize. Those criteria alone cannot correct the effects of adverse selection. Regulation can exacerbate the problem of adverse selection and lead to chronic market instability, so certain steps must be taken to prevent risk screening and preserve competition for the market. The author considers the following three policy options for regulating the private insurance market: 1) A standard contract with full coverage. 2) Imposition of a minimum insurance requirement. 3) Imposition of premium rate restrictions.Health Economics&Finance,Environmental Economics&Policies,Insurance&Risk Mitigation,Insurance Law,Financial Intermediation
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