International journal of cancer. Journal international du cancer
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Review Meta Analysis
Preoperative chemoradiation versus radiation alone for stage II and III resectable rectal cancer: a systematic review and meta-analysis.
Combining chemotherapy with preoperative radiotherapy (RT) has a sound radiobiological rationale. We performed a systematic review and meta-analysis of trials comparing preoperative RT with preoperative chemoradiation (CRT) in rectal cancer patients. The Cochrane Central Register of Controlled Trials, Web of Science, Embase and Medline (Pubmed) were searched from 1975 until June 2007. ⋯ Compared to preoperative RT alone, preoperative CRT improves local control in rectal cancer but is associated with a more pronounced treatment related toxicity. The addition of chemotherapy does not benefit sphincter preservation rate or long-term survival. Future trials should address improvements in the rate of distant metastasis and overall survival by incorporating more active chemotherapy.
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The cytosine analogues 5-azacytosine (azacytidine) and 2'-deoxy-5-azacytidine (decitabine) are the currently most advanced drugs for epigenetic cancer therapies. These compounds function as DNA methyltransferase inhibitors and have shown substantial potency in reactivating epigenetically silenced tumor suppressor genes in vitro. However, it has been difficult to define the mode of action of these drugs in patients and it appears that clinical responses are influenced both by epigenetic alterations and by apoptosis induction. ⋯ In this review, we examine the pharmacological properties of azanucleosides and their interactions with various cellular pathways. Because azacytidine and decitabine are prodrugs, an understanding of the cellular mechanisms mediating transmembrane transport and metabolic activation will be critically important for optimizing patient responses. We also discuss the mechanism of DNA methyltransferase inhibition and emphasize the need for the identification of predictive biomarkers for the further advancement of epigenetic therapies.
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This study aimed to estimate the mean sojourn time (MST) and sensitivity of asymptomatic lung cancer (ALC) detected by computed tomography (CT) or chest X-ray (CXR). Translation of early diagnosis into mortality reduction by 2 detection modalities and inter-screening interval was projected using a Markov model. On the basis of systematic literature review, data from 6 prospective CT screening studies were retrieved. ⋯ By simulating the scenario similar to NELSON study, CT screen may gain an extra of 0.019 year of life expectancy per person, yields 15% mortality reduction (relative risk (RR): 0.85, 95% confidence interval [95%CI: (0.58-1.01)]. Approximate 23% [RR: 0.77, 95%CI: (0.43-0.98)] mortality reduction would be achieved by annual CT screening program. The mortality findings in conjunction with higher sensitivity and shorter MST estimate given data on prevalent and incident (2nd) screen may provide a tentative evidence, suggesting that annual CT screening may be required in order to be effective in reducing mortality before the results of randomized controlled studies available.
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Sunscreen use is often proposed for sun protection because of their ability to block UV-induced sunburns (the sun protection factor--SPF). Among suntan seekers, however, risk of cutaneous melanoma may be increased because of extended sun exposure duration. We made a systematic review of the evidence linking sunscreen use to sun exposure duration. ⋯ One randomized trial in a holiday resort in France found a 3-13% increase in sun exposure duration with use of SPF 12 versus SPF 40 sunscreen. But, the SPF 12 groups used 3.6-4.2 more sunscreen than the SPF 40 group, and thus the actual SPF in the SPF 12 group was higher than in the SPF 40 groups. In conclusion, sunscreen use leads to longer duration of sun exposure when sun exposure is intentional, but not when sun exposure is non intentional.
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Sunscreen use is often proposed for sun protection because of their ability to block UV-induced sunburns (the sun protection factor--SPF). Among suntan seekers, however, risk of cutaneous melanoma may be increased because of extended sun exposure duration. We made a systematic review of the evidence linking sunscreen use to sun exposure duration. ⋯ One randomized trial in a holiday resort in France found a 3-13% increase in sun exposure duration with use of SPF 12 versus SPF 40 sunscreen. But, the SPF 12 groups used 3.6-4.2 more sunscreen than the SPF 40 group, and thus the actual SPF in the SPF 12 group was higher than in the SPF 40 groups. In conclusion, sunscreen use leads to longer duration of sun exposure when sun exposure is intentional, but not when sun exposure is non intentional.