TEORA Collection: Onkologi

Meat, vegetables and genetic polymorphisms and the risk of colorectal carcinomas and adenomas

Tue, 18 Dec 2007 22:58:59 GMT

Title: Meat, vegetables and genetic polymorphisms and the risk of colorectal carcinomas and adenomas

Authors: Skjelbred, Camilla Furu; Sæbø, Mona; Hjartåker, Anette; Grotmol, Tom; Hansteen, Inger-Lise; Tveit, Kjell M.; Hoff, Geir; Kure, Elin H.

Abstract: BACKGROUND: The risk of sporadic colorectal cancer (CRC) is mainly associated with lifestyle factors, particularly dietary factors. Diets high in red meat and fat and low in fruit and vegetables are associated with an increased risk of CRC. The dietary effects may be modulated by genetic polymorphisms in biotransformation genes. In this study we aimed to evaluate the role of dietary factors in combination with genetic factors in the different stages of colorectal carcinogenesis in a Norwegian population. METHODS: We used a case-control study design (234 carcinomas, 229 high-risk adenomas, 762 low-risk adenomas and 400 controls) to test the association between dietary factors (meat versus fruit, berries and vegetables) genetic polymorphisms in biotransformation genes (GSTM1, GSTT1, GSTP1 Ile105Val, EPHX1 Tyr113His and EPHX1 His139Arg), and risk of colorectal carcinomas and adenomas. Odds ratio (OR) and 95% confidence interval (95% CI) were estimated by binary logistic regression. RESULTS: A higher ratio of total meat to total fruit, berry and vegetable intake was positively associated with both high and low-risk adenomas, with approximately twice the higher risk in the 2nd quartile compared to the lowest quartile. For the high-risk adenomas this positive association was more obvious for the common allele (Tyr allele) of the EPHX1 codon 113 polymorphism. An association was also observed for the EPHX1 codon 113 polymorphism in the low-risk adenomas, although not as obvious. CONCLUSION: Although, the majority of the comparison groups are not significant, our results suggest an increased risk of colorectal adenomas in individuals for some of the higher ratios of total meat to total fruit, berry and vegetable intake. In addition the study supports the notion that the biotransformation enzymes GSTM1, GSTP1 and EPHX1 may modify the effect of dietary factors on the risk of developing colorectal carcinoma and adenoma.

Expression of NDRG2 is down-regulated in high-risk adenomas and colorectal carcinoma

Thu, 11 Oct 2007 22:58:59 GMT

Title: Expression of NDRG2 is down-regulated in high-risk adenomas and colorectal carcinoma

Authors: Lorentzen, Anders; Vogel, Lotte K.; Lewinsky, Rikke H.; Sæbø, Mona; Skjelbred, Camilla Furu; Godiksen, Sine; Hoff, Geir; Lothe, Inger Marie Bowitz; Ikdahl, Tone; Kure, Elin H.; Mitchelmore, Cathy

Abstract: BACKGROUND: It has recently been shown that NDRG2 mRNA is down-regulated or undetectable in several human cancers and cancer cell-lines. Although the function of NDRG2 is unknown, high NDRG2 expression correlates with improved prognosis in high-grade gliomas. The aim of this study has been to examine NDRG2 mRNA expression in colon cancer. By examining affected and normal tissue from individuals with colorectal adenomas and carcinomas, as well as in healthy individuals, we aim to determine whether and at which stages NDRG2 down-regulation occurs during colonic carcinogenesis. METHODS: Using quantitative RT-PCR, we have determined the mRNA levels for NDRG2 in low-risk (n = 15) and high-risk adenomas (n = 57), colorectal carcinomas (n = 50) and corresponding normal tissue, as well as control tissue from healthy individuals (n = 15). NDRG2 levels were normalised to β-actin. RESULTS: NDRG2 mRNA levels were lower in colorectal carcinomas compared to normal tissue from the control group (p < 0.001). When comparing adenomas/carcinomas with adjacent normal tissue from the same individual, NDRG2 expression levels were significantly reduced in both high-risk adenoma (p < 0.001) and in colorectal carcinoma (p < 0.001). There was a trend for NDRG2 levels to decrease with increasing Dukes' stage (p < 0.05). CONCLUSION: Our results demonstrate that expression of NDRG2 is down-regulated at a late stage during colorectal carcinogensis. Future studies are needed to address whether NDRG2 down-regulation is a cause or consequence of the progression of colorectal adenomas to carcinoma.

Use of a disposable sheath system for flexible sigmoidoscopy in decentralized colorectal cancer screening

Mon, 29 Oct 2001 22:58:59 GMT

Title: Use of a disposable sheath system for flexible sigmoidoscopy in decentralized colorectal cancer screening

Authors: Bretthauer, Michael; Hoff, Geir; Thiis-Evensen, Espen; Grotmol, Tom; Larsen, Inger K.; Kjellevold, Øystein; Skovlund, Eva

Abstract: Background and Study Aims: To prevent transmission of infectious agents and to reduce instrument reprocessing time, the use of disposable sheath systems instead of conventionally reprocessed endoscopes has been promoted for flexible sigmoidoscopy. This trial primarily investigated the feasibility of a disposable sheath system for flexible sigmoidoscopy in decentralized colorectal cancer screening.Patients and Methods: In an ongoing colorectal cancer screening trial, 226 consecutive participants were randomly allocated to have their flexible sigmoidoscopy performed with either a fiberoptic sigmoidoscope covered with a disposable sheath (“EndoSheath group”) or a conventional video colonoscope (“standard colonoscope group”). All examinations were performed at a temporary screening center. The patients' experience was documented using a questionnaire. The feasibility of running temporary screening units was evaluated.Results: Examinations beyond the 60-cm level were excluded. Thus, 113 patients (examined with the disposable instrument) and 87 (standard instrument) were eligible for analysis. When the sheathed system was used, all the devices needed could be satisfactorily transported. A screening center could be set up within a few hours. No differences were observed in patient discomfort. Fewer patients with polyps were observed in the EndoSheath group (48 [42 %]), compared with 55 (63 %) in the standard colonoscope group; P = 0.005). No significant differences were observed for polyps larger than 5 mm (14 [12 %] in the EndoSheath group, 13 [15 %] in the standard colonoscope group; P = 0.6).Conclusions: Using the disposable system, decentralized colorectal cancer screening was easily established. However, fewer polyps were found, possibly due to the fiberoptic nature of the instrument. Sheathed video instruments are desirable and may increase the diagnostic yield.

Med åpent blikk utenfor egen institusjon

Sun, 29 Oct 2000 22:58:59 GMT

Title: Med åpent blikk utenfor egen institusjon

Authors: Hoff, Geir

Abstract: Even in a country like Norway, with a poor reputation for investment in medical research, some studies may materialise against all odds. This is the story about the difficult start and first few years of flexible sigmoidoscopy screening studies in Norway. It started in the peripheral county of Telemark with the Telemark Polyp Study no. I (TPS-I) in 1983. We now see the success of the Norwegian Colorectal Cancer Prevention (NORCCAP) study, which is an on-going large-scale version of the TPS-I study comprising 21,000 men and women to be offered flexible sigmoidoscopy screening in Oslo and Telemark after randomised invitation from the population registry.