Colorectal cancer case study

A case-control study was designed to explore risk factors for colorectal adenomas. Adenomas are precursors to 80-90% of all colorectal cancers. The study used 236 cases (with adenomas or polyps) and 409 controls (no adenomas) (Tseng ef aF., 1996) (Tabic 11,2). All subjects were patients receiving colonoscopy exams. The subjects were not recruited from the general public, A month or so after the exam, the subjects were asked to fill out a food choice questionnaire. 

The majority of previous immunohistochemical studies on the lymph node micrometastasis of gastric and colorectal cancers have only discussed the relationship between the presence or absence of micrometastasis and the prognosis. However, in their comparative study of lymph node micrometastasis between 10 recurrent and 9 nonrecurrent colorectal cancer cases in the pNO stage, Sasaki et al. revealed that the greater the numbers of lymph node metastases and the more distant the lymph node metastases, the higher the recurrence rate, and they proposed the introduction of a concept of... 

Carotenoids and urino-digestive cancers — On the whole, findings from epidemiological studies did not demonstrate a protective role of carotenoids against colorectal, gastric, and bladder cancers. Indeed, most prospective and case-control studies of colorectal cancer showed no association with dietary intake or plasma level of most carotenoids. - Only lycopene and lutein were shown to be protective against colorectal cancer. Otherwise, findings from the ATBC study s showed no effect of P-carotene supplementation on colorectal cancer. 

Tuyns, A. J., Kaaks, R., Haelterman, M., Colorectal cancer and the consumption of foods A case-control study in Belgium, Nutr Cancer, 11, 189, 1988. 

Bradbury et al. (2004), however, recently reanalyzed the relation between tamoxifen and cataracts and described it as a null association, They used a nested, matched, case-control study design and data collected in the General Practice Research Database. They identified all women 30-79 years old who were diagnosed with breast cancer and treated with tamoxifen within 6 months, or with bladder cancer, colorectal cancer, or nonmelanoma skin cancer between January 1991 and December i999. From this population they identified all newly diagnosed cases of cataract and matched four female controls to each case on age, index date, and study entry data. They assessed the risk of cataracts for current, past, and sometime users of tamoxifen... 

Kune GA, Kune S, Watson LF. Colorectal cancer risk, chronic illness, operations, and medications case control results from the Melbourne Colorectal Cancer Study. Cancer Res 1988 48 4399 1404. 

Xylene was mentioned as an exposure in four studies. Two were community-based case-control studies, one of which involved brain cancer and one involved several types of cancer. The two industry-based studies were configured as nested case-control studies, one of central nervous system tumours and one of several sites. In none of these studies was xylene the sole or predominant exposure. Cancers at most sites were not significantly associated with xylene exposure in any study. Incidence of colorectal cancer was significantly elevated in the Canadian case-control study, but no other study reported colorectal cancer results. Hodgkin s disease was elevated in one study non-Hodgkin lymphoma was elevated in one study, but not in another. Most results were based on small numbers. In... 

In a cohort study in 1848 British patients who received human pituitary-derived growth hormone from 1959 to 1985 (30 000 patient-years), there were two cases of colorectal cancer (0.25 expected) and two cases of Hodgkin s disease (0.85 expected) the standardized mortality ratios were 10.8 and 11.4 respectively (103). However, the number of cancers was small and the doses used were higher than typically today, and these results should be interpreted with caution. 

In the study on colorectal cancer (Table 20.4), a reduced risk was found for increasing intake of anthocyanidins (OR, 0.67 for the highest versus the lowest quintile,p-trend, 0.001), flavonols (OR, 0.64,p-trend < 0.001), flavones (OR, 0.78, p-trend, 0.004), and isoflavones (OR, 0.76, p-trend, 0.001). [Rossi et al., 2006], The estimates did not substantially differ for colon and rectal cancers. After allowance for fruit and vegetable consumption, for dietary fiber, or for micronutrients previously associated to this tumor including vitamin C, the associations with flavonoids did not change by more than 10%. A recent case-control study of 1456 pairs of cases and controls conducted in Sweden confirmed a significant decrease in risk of colorectal cancer for intake of anthocyanidins and flavonols [Theodoratou et al., 2007], but there was no relation for isoflavones and flavones. However, the results on isoflavones and flavones are questionable due to the unusually and generally low intakes of the populations studied. In the Italian population, anthocyanidins were derived mainly from wine, red fruit, and onions, and flavonols from apples or pears, wine, and mixed salads. 

Theodoratou E, McNeill G, Cetnarskyj R, Farrington SM, Tenesa A, Barnetson R, Porteous M, Dunlop M, Campbell H. 2007. Dietary fatty acids and colorectal cancer A case-control study. Am J Epidemiol 166 181-195. 

Levamisole was first synthesized for the treatment of parasitic infections. Later studies suggested that it increases the magnitude of delayed hypersensitivity or T cell-mediated immunity in humans. In immunodeficiency associated with Hodgkin s disease, levamisole has been noted to increase the number of T cells in vitro and to enhance skin test reactivity. Levamisole has also been widely tested in rheumatoid arthritis and found to have some efficacy. However, it has induced severe agranulocytosis (mainly in HLA-B27-positive patients), which required discontinuation of its use. The drug may also potentiate the action of fluorouracil (5-FU) in adjuvant therapy of colorectal cancer, and this combination has been approved for clinical use in the treatment of Dukes class C colorectal cancer after surgery. Its use in these cases reduces recurrences, and the mechanism... 

Case study level 2 - Treatment of advanced colorectal cancer... 

Case study level 1 - Non-small cell lung cancer 171 Case study level 2 - Treatment of advanced colorectal cancer 173 Case study level 3 - Treatment of metastatic breast cancer and its complications 175... 

Benito, E., Obrador, A., Stiggelbout, A., Bosch, F.X. Mulct, M., Munoz, N., and Kaldor, J., A population-based case-control study of colorectal cancer in Majorca. I. Dietary factors, Int. J. Cancer, 45, 69-76, 1990. 

Okano, K., Yamamoto, X, Kosuge, T., Yamamoto, S., Sakamoto, M., Nakanishi, Y., Hirohashi, S. Fibrous pseudocapsule of metastatic liver tumors from colorectal carcinoma - clinicopathologic study of 152 first resection cases. Cancer 2000 89 267-275... 

In cases of inflammatory bowel disease, no overall increased incidence of cancer was noted after a median of 9 years follow-up in 755 patients who had taken less than 2 mg/kg/day of azathioprine over a median period of 12.5 years (69). Only colorectal cancers (mostly adenocarcinoma) were more frequent, but their incidence was also increased in chronic inflammatory bowel diseases. More specifically, there was no excess of non-Hodgkin s lymphoma, but the power of the study to detect an increased risk of this disorder was low. 

Acquavella JF, Owen CV, Bird G, et al. An adenomatous polyp case-control study to assess occupational risks following a workplace colorectal cancer duster. Am J Epidemiol 1991 133(4) 357-67. 

Selby JV, Friedman GD, Quesenberry CP, Weiss NS. A case-control study of screening sigmoidoscopy and mortality from colorectal cancer. N Engl J Med 1992 326 653-657. 

Interestingly, Cryptosporidium infection has been related to carcinogenesis. The association of cryptosporidiosis and colonic adenocarcinoma was speculated in the case of a Spanish patient carrying both, who died rapidly after the onset of symptoms (Izquierdo et al. 1988). More recently, an epidemiological study in Poland reported a high frequency of cryptosporidiosis in patients with colorectal cancer (Sulzyc-Bielicka et al. 2007). However, in these reports it was unclear if Cryptosporidium sp. behaved as a carcinogenesis factor or simply as an opportunistic agent whose development was enhanced by host immunosuppression. 

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