Browsing by Subject "colon cancer"

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Open Access
Cost-effectiveness of adjuvant FOLFOX and 5FU/LV chemotherapy for patients with stage II colon cancer
(2013) Ayvaci, M.U.S.; Shi J.; Alagoz O.; Lubner, S.J.
Purpose. We evaluated the cost-effectiveness of adjuvant chemotherapy using 5-fluorouracil, leucovorin (5FU/LV), and oxaliplatin (FOLFOX) compared with 5FU/LV alone and 5FU/LV compared with observation alone for patients who had resected stage II colon cancer. Methods. We developed 2 Markov models to represent the adjuvant chemotherapy and follow-up periods and a single Markov model to represent the observation group. We used calibration to estimate the transition probabilities among different toxicity levels. The base case considered 60-year-old patients who had undergone an uncomplicated hemicolectomy for stage II colon cancer and were medically fit to receive 6 months of adjuvant chemotherapy. We measured health outcomes in quality-adjusted life-years (QALYs) and estimated costs using 2007 US dollars. Results. In the base case, adjuvant chemotherapy of the FOLFOX regimen had an incremental cost-effectiveness ratio (ICER) of $54,359/QALY compared with the 5FU/LV regimen, and the 5FU/LV regimen had an ICER of $14,584/QALY compared with the observation group from the third-party payer perspective. The ICER values were most sensitive to 5-year relapse probability, cost of adjuvant chemotherapy, and the discount rate for the FOLFOX arm, whereas the ICER value of 5FU/LV was most sensitive to the 5-year relapse probability, 5-year survival probability, and the relapse cost. The probabilistic sensitivity analysis indicates that the ICER of 5FU/LV is less than $50,000/QALY with a probability of 99.62%, and the ICER of FOLFOX as compared with 5FU/LV is less than $50,000/QALY and $100,000/QALY with a probability of 44.48% and 97.24%, respectively. Conclusion. Although adjuvant chemotherapy with 5FU/LV is cost-effective at all ages for patients who have undergone an uncomplicated hemicolectomy for stage II colon cancer, FOLFOX is not likely to be cost-effective as compared with 5FU/LV.
Open Access
Investigation of the effects of nicotine and levamisole on SW620 colon adenocarcinoma cells using a customized r-routine for automated microarray analysis
(2010) Üçal, Muammer
Nicotine, the addictive component of tobacco, shows proliferative and antiapoptotic activity in cancer cells. Levamisole, an antihelmintic, on the other hand, has been tested as an additive chemotherapeutic agent and in treatment of nephrotic syndrome. Nicotine and levamisole are both agonists of nicotinic acetylcholine receptors; effects of these two agents have not been studied in colon cancer transcriptome. In this study, nicotine and levamisole exposed SW620 colon cancer cells, at a dose of 1 μM for 7 days, were studied with respect to changes in expression using microarrays. For data analysis, a custom R-routine which makes extensive use of open source R-BioConductor Project and associated packages has been written; and it is composed of three modules: QualCont module performs quality controls supported with several visual
Open Access
Investigation of the effects of nicotine on the expression profile of SW620 colon adenocarcinoma cells using a functional genomics approach
(2009) Kaya, Onur
Colon cancer is the third most common form of cancer with approximately 655,000 deaths worldwide annually and the second principal cause of cancer-related death in the Western world. Studies focusing on genomic instability and cell culture in recent years have shown that there is a statistically significant link between tobacco smoking and colorectal cancer. Although nicotine is one of the most potent chemical in tobacco, it was not studied extensively in colorectal cancers. Nicotine works as an agonist of nicotinic acetylcholine receptors and modulates the intracellular calcium concentrations hence deregulating multiple signal transduction pathways (e.g., PI3K/AKT, MAPK, mTOR). It has been shown that nicotine accelerates cell proliferation while it increases cell migration, metastasis and angiogenesis, and inhibits apoptosis in lung and gastric cancers. The aim of this study was to give more insight into the association between nicotine and colon cancer by investigating the gene expression profiles of SW620 colon adenocarcinoma cells under 48h 1µM nicotine treatment at different serum levels to reflect molecular response to growth factor-induced and –depleted conditions (10% FBS or 0.1% FBS). We used multiple approaches including cell culture techniques, microarray technology, and gene-network analysis to assess the effects of nicotine on cell proliferation and transcriptome profile. Furthermore, the selected genes that are involved in cell cycle and apoptosis were used to confirm and evaluate the transcriptome analysis results with real time qRT-PCR and Western Blot techniques. In this project, our findings indicated that serum starvation of SW620 colon adenocarcinoma cell line resulted in decreased cell proliferation, which could be rescued by 1µM nicotine via deregulation of multiple pathways including cell cycle, apoptosis, Ca2+ signaling, and ribosomal protein expression. This study implicated that nicotine-, thus acetylcholine-mediated signaling may have an important role in tumor development and metastasis.