Attitudes and impressions of participants in a study of the causes of childhood cancer.

Researchers and ethics committees are increasingly concerned about the perceived emotional impact on individuals following participation in epidemiologic studies. This attitudinal survey was designed to investigate this issue among 751 of the parents who had already given an interview in the UK Childhood Cancer Study (UKCCS), one of the largest case-control studies ever undertaken to investigate the aetiology of cancer in children. Information was collected by postal questionnaire on their reasons for agreeing to take part in the UKCCS, on whether questions had caused distress or difficulty and what their feelings were immediately after the interview and at the time of this survey. Parents were asked if they felt they had benefited in any way by taking part and control parents were asked if they would have taken part without prior consent of their doctor. 90% of both cases and controls felt glad to have taken part immediately after the interview and few reported any anxiety at having done so; 95% of both cases and controls felt satisfied that they had made a worthwhile contribution. Although 18% of cases felt tense and 14% felt unhappy after the interview, over 90% of them felt glad that they had taken part a few weeks later. Of particular interest is that 38% of cases and 24% of controls said they had positively benefited from taking part in the UKCCS and 96% of control mothers did not mind their family doctor giving permission for them to be contacted.

Effect of aspirin and non-steroidal anti-inflammatory drugs on colorectal adenomas: case-control study of subjects participating in the Nottingham faecal occult blood screening programme.

OBJECTIVE: To examine the relation between the use of aspirin and non-steroidal anti-inflammatory drugs and the presence of asymptomatic colorectal adenomas. DESIGN: Case-control study of subjects participating in a randomised controlled trial of faecal occult blood screening for colorectal cancer. Data on analgesics and other drugs were obtained from a questionnaire which was mainly concerned with diet and was administered by an interviewer. SETTING: Nottingham. SUBJECTS: 147 patients with positive results in faecal occult blood tests who were found to have colorectal adenomas (cases), 153 age and sex matched control subjects with negative results in such tests (negative controls), and 176 control subjects with positive results in the tests who were found not to have colorectal adenomas (positive controls). MAIN OUTCOME MEASURES: Relative risk of developing colorectal adenomas according to frequency and duration of use of analgesics. RESULTS: Cases reported taking less aspirin and non-steroidal anti-inflammatory drugs than the negative controls, with the estimated relative risk for any use being 0.49 (95% confidence interval 0.3 to 0.8). The inverse association was less strong when cases were compared with the positive controls (0.66 (0.4 to 1.1)). The association was specific for aspirin and non-steroidal anti-inflammatory drugs there being no association with paracetamol or other drugs. Prescribed use of non-steroidal anti-inflammatory drugs for longer than five years was associated with the lowest risk (0.21 (0.1 to 0.8)), although the numbers reporting prolonged prescribed use were small. CONCLUSIONS: These findings support the hypothesis that aspirin and non-steroidal anti-inflammatory drug use protects against the development of colorectal neoplasia.

Colorectal adenomas and diet: a case-control study of subjects participating in the Nottingham faecal occult blood screening programme.

Diets high in animal fat and protein and low in fibre and calcium are thought to be factors in the etiology of colorectal cancer. Intakes of these nutrients were determined in three groups participating in a randomised trial of faecal occult blood (FOB) screening. A diet history was obtained by interview from 147 patients with colorectal adenomas, 153 age and sex matched FOB-negative controls (a) and 176 FOB-positive controls without colorectal neoplasia (b). Unconditional logistic regression was used to estimate relative risks (RR) and 95% confidence limits (increases) adjusted for age, sex and social class. After adjustment for total energy intake, no associations were found with total, saturated or mono-unsaturated fat, or calcium intake. For total fibre intake there were non-linear relationships with both control groups with the crude RR for highest quintiles of total fibre intake compared to the lowest being 0.6, although this pattern was no longer apparent after adjustment for energy intake with group (a). In comparison with group (b) cereal fibre intake showed a more consistent inverse relationship with adenoma prevalence with the RR for ascending quintiles of intake being 1.0, 0.7 (0.3-1.6), 0.5 (0.3-1.1), 0.7 (0.4-1.4) and 0.3 (0.1-0.6) (trend chi 2 = 8.80, p = 0.003). In comparison with group (a), the adjusted RR for the highest quintile of cereal fibre intake compared with the lowest was 0.6, but no clear trend was apparent. There was an unexpected positive relationship between adenomas and polyunsaturated fat intake with the RR for having an adenoma being 1.0, 2.8 (1.3-6.1), 1.6 (0.7-3.4), 3.5 (1.6-7.5) and 2.3 (1.1-5.0) for ascending quintiles of polyunsaturated fat intakes (trend chi 2 = 4.8, P = 0.03) in comparison with group (a) only. Our data, while providing no support for the role of dietary animal fat or protein, do support the protective role of dietary cereal fibre in the etiology of colorectal adenomas.

Colorectal adenomas and energy intake, body size and physical activity: a case-control study of subjects participating in the Nottingham faecal occult blood screening programme.

Most case-control studies of colorectal cancer have shown a positive association with energy intake. In contrast studies which have considered physical activity have found the most active to have a lower risk of colonic cancer and obesity appears to be no more than weakly related to colorectal cancer. We therefore compared energy intake determined by a diet history interview, self-reported height and weight, together with measures of lifetime job activity levels and leisure activity in the year prior to interview in 147 cases with colorectal adenomas and two control groups (a) 153 age-sex matched FOB-negative subjects (b) 176 FOB-positive subjects in whom no adenoma or carcinoma was found. Unconditional logistic regression was used to estimate relative risks (RR) and 95% confidence intervals () adjusted for age, sex and social class. No association with weight or body mass index was found. The only association with physical activity found with both control groups was an inverse association with running or cycling for half an hour continuously at least once a week RR 0.46 (0.2-1.3) compared with control group (a), and RR = 0.32 (0.1-0.8) compared with (b), but few subjects engaged in such activity. There was an inverse association with energy intake (trend chi 2 = 5.3, P < 0.025) in the comparison with control group (a) only, a finding which is consistent with those of two previous studies of asymptomatic adenoma.