Cancer risk, decrease

Colorectal Cancer. Colorectal cancer occurs frequently in the UK population but is historically rare in Asia. Rates in Japan have, however, increased rapidly in recent years.Interestingly, there appears to be an association between oestrogen exposure and colon cancer risk has been shown to increase in women with increasing age of first live birth, and to decrease with increasing parity (number of children). In addition, many colon tumours express sex hormone receptors, and this is thought to play a part in development of the tumours. "... 

Dietary and pharmacologic agents influence the risk of colon cancer. Diets high in fat and low in fiber are associated with increased colon cancer risk, whereas the regular use of aspirin (and other NSAIDs) and calcium supplementation may decrease the risk of colon cancer. 

The degree of colorectal cancer risk reduction associated with increased consumption of vegetables and fruit is variable but generally modest and has ranged from no difference to a 25% decrease in cancer risk in prospective studies.9,10... 

Numerous studies demonstrated that lipid peroxidation significantly decreased in cancer cells and tissues (Ref. [176] and references therein). It has been proposed that this can be a consequence of a decrease in the content of highly unsaturated fatty acids, the concentration of cytochrome p-450, and the contents of NADPH, SOD, and catalase in tumors. Cheeseman et al. [176] suggested that the reduction of lipid peroxidation in tumors may depend on both the expression of malignant transformation and cell division. It should be mentioned that Boyd and McGuire [177] demonstrated that there is a correlation between lipid peroxidation and breast cancer risk in premenopausal women. 

Raloxifene (like tamoxifen) is associated with decreased breast cancer risk. Raloxifene is associated with decreases in total and low-density lipoprotein cholesterol, neutral effects on high-density lipoprotein cholesterol, but slight increases in triglycerides no beneficial cardiovascular effects have yet been demonstrated. 

There is still debate about the side-effects of the pill. The general consensus is that, although the risk of thrombosis and breast cancer is increased, the risk of endometrial or ovarian cancer is decreased. 

By contrast, other compounds in food may decrease cancer risk (Table 21.7). Free radical scavengers such as the antioxidants, vitamins E and C, carotenoids and fla-venoids have anti-cancer activity, while vitamins A and D and other retinoids may encourage a cell to differentiate rather than proliferate (Box 21.4). Plant oestrogens in soya prodncts may be protective since they compete with human oestrogens for the oestrogen receptors in breast and ovary bnt elicit no response. 

Whether long-term treatment can reduce prostate cancer risk is unknown decreases prostate-specific antigen (PSA)... 

Arsenic exposure contributes to cancer risk and has been associated with decreased ERCCl expression in isolated lymphocytes at the mRNA and protein levels (51). Along the same lines, increased expression of defense genes, like ERCCl, has been observed in premalignant lesions, such as colorectal adenomas (52). In early-stage NSCLC, high ERCC 1 expression has been observed in almost half of the patients, indicating both a lower risk of relapse and a lower probability of benefit from adjuvant cisplatin-based chemotherapy. 

The level of NAT therefore influences the cancer risk, with low NAT2 being associated with an increased risk of bladder, liver, breast, and lung cancer, but decreased risk of colon cancer. Conversely, low NAT1 is associated with an increased risk of bladder and colon cancer but decreased lung cancer. 

To complicate further the relationship between ALA and prostate cancer risk, Mannisto et al. (2003) reported that prostate cancer risk and ALA decrease when smokers were included in the model. This suggests that factors other than diet need to be considered in the models for determining causative relationships. Case-controlled studies also provide conflicting conclusions regarding the role of ALA in prostate cancer. For a complete review of these studies, see Bougnoux and Chajes (2003). 

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