48 research outputs found

    Cancer Stem Cell-Like Cells Derived from Malignant Peripheral Nerve Sheath Tumors

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    This study aims to examine whether or not cancer stem cells exist in malignant peripheral nerve sheath tumors (MPNST). Cells of established lines, primary cultures and freshly dissected tumors were cultured in serum free conditions supplemented with epidermal and fibroblast growth factors. From one established human MPNST cell line, S462, cells meeting the criteria for cancer stem cells were isolated. Clonal spheres were obtained, which could be passaged multiple times. Enrichment of stem cell-like cells in these spheres was also supported by increased expression of stem cell markers such as CD133, Oct4, Nestin and NGFR, and decreased expression of mature cell markers such as CD90 and NCAM. Furthermore, cells of these clonal S462 spheres differentiated into Schwann cells, smooth muscle/fibroblast and neurons-like cells under specific differentiation-inducing cultural conditions. Finally, subcutaneous injection of the spheres into immunodeficient nude mice led to tumor formation at a higher rate compared to the parental adherent cells (66% versus 10% at 2.5×105). These results provide evidence for the existence of cancer stem cell-like cells in malignant peripheral nerve sheath tumors

    Cost-effectiveness analysis of colorectal cancer screening in a low incidence country

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    Background: Colorectal cancer (CRC) screening is cost-effective in many Western countries, and many have successfully implemented CRC screening programs. For countries with a lower CRC incidence, like Saudi Arabia, the value of CRC screening is less evident and requires careful weighing of harms, benefits, and costs. Methods: We used the MISCAN-Colon microsimulation model to simulate a male and female cohort with life expectancy and CRC risk as observed in Saudi Arabia. For both cohorts, we evaluated strategies without screening, with annual or biennial faecal immunochemical testing (FIT), and with 10-yearly or once-only colonoscopy. We also considered different start and end ages of screening. For both cohorts, we estimated lifetime costs and effects of each strategy. We then ident

    Calculation of Stop Ages for Colorectal Cancer Screening Based on Comorbidities and Screening History

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    Background & Aims: Routine screening for colorectal cancer typically is recommended until age 74 years. Although it has been proposed that a screening stop age could be determined based on sex and comorbidity, less is known about the impact of screening history. We investigated the effects of screening history on the selection of an optimal age to stop screening. Methods: We used the Microsimulation Screening Analysis–Colon model to estimate the harms and benefits of screening with biennial fecal immunochemical tests by sex, comorbidity status, and screening history. The optimal screening stop age was determined based on the incremental number needed for 1 additional life-year per 1000 screened individuals compared with the threshold provided by stopping screening at 76 years in the average-health population with a perfect screening history (attended all required screening, diagnostic, and follow-up tests) to biennial fecal immunochemical testing from age 50 years. Results: For persons age 76 years, 157 women and 108 men with a perfect screening history would need to be screened to gain 1 life-year per 1000 screened individuals. Previously unscreened women with no comorbid conditions and no history of screening could undergo an initial screening through 90 years, whereas unscreened men could undergo initial screening through 88 years, before this balance is reached. As screening adherence improved or as comorbidities increased, the optimal age to stop screening decreased to a point that, regardless of sex, individuals with severe comorbidities and a perfect screening history should stop screening at age 66 years or younger. Conclusions: Based on the harm–benefit balance, the optimal stop age for colorectal cancer screening ranges from 66 years for unhealthy individuals with a perfect screening history to 90 years for healthy individuals without prior screening. These findings can be used to assist patients and clinicians in making decisions about screening participation

    Cost-Effectiveness of Personalized Screening for Colorectal Cancer Based on Polygenic Risk and Family History

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    BACKGROUND: There is growing evidence for personalizing colorectal cancer screening based on risk factors. We compared the cost-effectiveness of personalized colorectal cancer screening based on polygenic risk and family history to uniform screening. METHODS: Using the MISCAN-Colon model, we simulated a cohort of 100 million 40-year-olds, offering them uniform or personalized screening. Individuals were categorized based on polygenic risk and family history of colorectal cancer. We varied screening strategies by start age, interval and test and estimated costs, and quality-adjusted life years (QALY). In our analysis, we (i) assessed the cost-effectiveness of uniform screening; (ii) developed personalized screening scenarios based on optimal screening strategies by risk group; and (iii) compared the cost-effectiveness of both. RESULTS: At a willingness-to-pay threshold of 50,000/QALY,theoptimaluniformscreeningscenariowasannualfecalimmunochemicaltesting(FIT)fromages50to74years,whereasforpersonalizedscreeningtheoptimalscreeningscenarioconsistedofannualandbiennialFITscreeningexceptforthoseathighestriskwhowereoffered5yearlycolonoscopyfromage50years.AlthoughthesescenariosgainedthesamenumberofQALYs(17,887),personalizedscreeningwasnotcosteffective,costinganadditional50,000/QALY, the optimal uniform screening scenario was annual fecal immunochemical testing (FIT) from ages 50 to 74 years, whereas for personalized screening the optimal screening scenario consisted of annual and biennial FIT screening except for those at highest risk who were offered 5-yearly colonoscopy from age 50 years. Although these scenarios gained the same number of QALYs (17,887), personalized screening was not cost-effective, costing an additional 428,953 due to costs associated with determining risk (assumed to be 240perperson).Personalizedscreeningwascosteffectivewhenthesecostswerelessthan240 per person). Personalized screening was cost-effective when these costs were less than ∼48. CONCLUSIONS: Uniform colorectal cancer screening currently appears more cost-effective than personalized screening based on polygenic risk and family history. However, cost-effectiveness is highly dependent on the cost of determining risk. IMPACT: Personalized screening could become increasingly viable as costs for determining risk decrease
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