Linda Sharp

Rural and urban differences in stage at diagnosis of colorectal and lung cancers

There is evidence that patients living in outlying areas have poorer survival from cancer. This study set out to investigate whether they have more advanced disease at diagnosis. Case notes of 1323 patients in north and northeast Scotland who were diagnosed with lung or colorectal cancer in 1995 or 1996 were reviewed. Of patients with lung cancer, 42% (69/164) living 58 km or more from a cancer centre had disseminated disease at diagnosis compared to 33% (71/215) living within 5 km. For colorectal cancer the respective figures were 24% (38/161) and 16% (31/193). For both cancers combined, the adjusted odds ratio for disseminated disease at diagnosis in furthest group compared to the closest group was 1.59 (P = 0.037). Of 198 patients with non-small-cell lung cancer in the closest group, 56 (28%) had limited disease (stage I or II) at diagnosis compared to 23 of 165 (14%) of the furthest group (P = 0.002). The respective figures for Dukes A and B colorectal cancer were 101 of 196 (52%) and 67 of 172 (39%) (P = 0.025). These findings suggest that patients who live remote from cities and the associated cancer centres have poorer chances of survival from lung or colorectal cancer because of more advanced disease at diagnosis. This needs to be taken into account when planning investigation and treatment services.

Impact of deprivation and rural residence on treatment of colorectal and lung cancer.

For common cancers, survival is poorer for deprived and outlying, rural patients. This study investigated whether there were differences in treatment of colorectal and lung cancer in these groups. Case notes of 1314 patients in north and northeast Scotland who were diagnosed with lung or colorectal cancer in 1995 or 1996 were reviewed. On univariate analysis, the proportions of patients receiving surgery, chemotherapy and radiotherapy appeared similar in all socio-economic and rural categories. Adjusting for disease stage, age and other factors, there was less chemotherapy among deprived patients with lung cancer (odds ratio 0.39; 95% confidence intervals 0.16 to 0.96) and less radiotherapy among outlying patients with colorectal cancer (0.39; 0.19 to 0.82). The time between first referral and treatment also appeared similar in all socio-economic and rural groups. Adjusting for disease stage and other variables, times to lung cancer treatment remained similar, but colorectal cancer treatment was quicker for outlying patients (adjusted hazard ratio 1.30; 95% confidence intervals 1.03 to 1.64). These findings suggest that socio-economic status and rurality may have a minor impact on modalities of treatment for colorectal and lung cancer, but do not lead to delays between referral and treatment.

Psychological effects of a low-grade abnormal cervical smear test result: anxiety and associated factors

Receipt of an abnormal cervical smear result often generates fear and confusion and can have a negative impact on a womans well-being. Most previous studies have focussed on high-grade abnormal smears. This study describes the psychological and psychosocial effects, on women, of having received a low-grade abnormal smear result. Over 3500 women recruited to TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears) participated in this study. Anxiety was assessed using the Hospital Anxiety and Depression Scale (HADS) at recruitment. Socio-demographic and lifestyle factors, locus of control and factors associated with the psychosocial impact of the abnormal smear result were also assessed. Women reported anxiety levels consistent with those found in previous studies of women with high-grade smear results. Women at highest risk of anxiety were younger, had children, were current smokers, or had the highest levels of physical activity. Interventions that focus particularly on womens understanding of smear results and pre-cancer, and/or directly address their fears about cancer, treatment and fertility might provide the greatest opportunity to reduce the adverse psychosocial impact of receiving a low-grade abnormal cervical smear result.

Dietary flavonoid intake and colorectal cancer: a case-control study.

Diets rich in flavonoids may reduce the risk of developing colorectal cancer. Flavonoids are widely distributed in foods of plant origin, though in the UK tea is the main dietary source. Our objective was to evaluate any independent associations of total dietary and non-tea intake of four flavonoid subclasses and the risk of developing colorectal cancer in a tea-drinking population with a high colorectal cancer incidence. A population-based case-control study (264 cases with histologically confirmed incident colorectal cancer and 408 controls) was carried out. Dietary data gathered by FFQ were used to calculate flavonoid intake. Adjusted OR and 95 % CI were estimated by logistic regression. No linear association between risk of developing colorectal cancer and total dietary flavonol, procyanidin, flavon-3-ol or flavanone intakes was found, but non-tea flavonol intake was inversely associated with colorectal cancer risk (OR 0.6; 95 % CI 0.4, 1.0). Stratification by site of cancer and assessment of individual flavonols showed a reduced risk of developing colon but not rectal cancer with increasing non-tea quercetin intake (OR 0.5; 95 % CI 0.3, 0.8; P(trend) < 0.01). We concluded that flavonols, specifically quercetin, obtained from non-tea components of the diet may be linked with reduced risk of developing colon cancer.

CYP3A4 and VDR gene polymorphisms and the risk of prostate cancer in men with benign prostate hyperplasia.

Prostate cancer (PRCa) is one of the most common causes of cancer death in men and determinants of PRCa risk remain largely unidentified. Benign prostatic hyperplasia (BPH) is found in the majority of ageing men and has been associated with PRCa. Many candidate genes have been suggested to be involved in PRCa, such as those that are central to cellular growth and differentiation in the prostate gland. The vitamin D receptor (VDR) and CYP3A4 have been shown to be involved in the regulation of cell proliferation and differentiation in prostate cells. Genetic variations of these genes have been associated with PRCa in case–control studies and may be useful to detect BPH patients that have a higher risk of developing PRCa. The association between CYP3A4 and VDR TaqI SNPs and the risk of developing PRCa have been investigated in this study by determining the variant genotype frequencies of both SNPs in 400 patients with BPH who have been followed clinically for a median of 11 years. The results of this study showed that the incidence rate of PRCa was higher in BPH patients having CYP3A4 variant genotype compared to those with wild type (relative risk (RR)=2.7; 95% CI=0.77–7.66). No association between variant genotype and risk of developing PRCa was observed with the VDR TaqI variant genotype. In addition, the results of combined genotype analysis of these two SNPs showed a borderline significant association between CYP3A4 and VDR TaqI combined variant genotypes and PRCa risk (RR=3.43; 95% CI=0.99–11.77). While independent confirmation is required in further studies, these results provide a potential tool to assist prediction strategies for this important disease.

Polymorphisms in the methylenetetrahydrofolate reductase ( MTHFR ) gene, intakes of folate and related B vitamins and colorectal cancer: a case–control study in a population with relatively low folate intake

Folate is key in one-carbon metabolism, disruption of which can interfere with DNA synthesis, repair, and methylation. Efficient one-carbon metabolism requires other B vitamins and the optimal activity of enzymes including 5,10-methylenetetrahydrofolate reductase (MTHFR). We report a population-based case-control study of folate intake, related dietary factors and MTHFR polymorphisms (C677T, A1298C) and colorectal cancer in a population with relatively high colorectal cancer incidence and relatively low folate intake. A total of 264 cases with histologically confirmed incident colorectal cancer and 408 controls participated. There was no clear trend in risk with reported intakes of total, or dietary, folate, riboflavin, vitamin B12 or vitamin B6, nor were there interactions between folate intake and the other B vitamins or alcohol. For C677T, risk decreased with increasing variant alleles (multivariate OR for CT v. CC = 0.77 (95 % CI 0.52, 1.16); OR for TT v. CC = 0.62 (95 % CI 0.31, 1.24)), which, although not statistically significant, was consistent with previous studies. For A1298C, compared with AA subjects, CC subjects had modest, non-significant, reduced risk (multivariate OR = 0.81 (95 % CI 0.45, 1.49)). There were significant interactions between total folate and C677T (P = 0.029) and A1298C (P = 0.025), and total vitamin B6 and both polymorphisms (C677T, P = 0.016; A1298C, P = 0.033), although the patterns observed differed from previous studies. Seen against the setting of low folate intake, the results suggest that the role of folate metabolism in colorectal cancer aetiology may be more complex than previously thought. Investigation of particular folate vitamers (for example, tetrahydrofolate, 5,10-methylenetetrahydrofolate) may help clarify carcinogenesis pathways.

Colon Cancer and Genetic Variation in Folate Metabolism: The Clinical Bottom Line

So far, evidence for the relation between folate intake and colorectal cancer has been insufficient to lead to specific public health interventions. In principle, data on the relation between genetic variation in folate metabolism and colorectal neoplasia could be used to corroborate the data on the relation between folate intake or status and the disease, strengthening the evidence base for primary prevention. Issues in considering the relation between a health outcome and genetic variation in metabolism of nutrients or other food components include knowledge of gene function, linkage disequilibrium, population stratification, study size and quality, and gene-environment interaction. Overall homozygosity for MTHFR variant genotypes is associated with a reduced risk of colorectal cancer, the opposite of what might have been expected a priori. This has led investigators to place greater emphasis on the functions of folate and methylenetetrahydrofolate reductase in DNA synthesis. Folate and related nutrients may be important after adenoma formation. A challenge for the future is to characterize the effects of multiple genes influencing folate metabolism. Limited data for colorectal cancer suggest that the effect of a low folate diet overrides the effect of genotype, but two studies of adenomas suggested the opposite. Another potential role of information on genetic variation in folate metabolism is in the management of colorectal cancer but most studies have been small, have included selected patient groups, and have made limited adjustment for potentially important factors.

Colorectal cancer and genetic polymorphisms of CYP1A1, GSTM1 and GSTT1: A case‐control study in the Grampian region of Scotland

Cytochrome P‐450 CYP1A1 is involved in the metabolism of polycyclic aromatic hydrocarbons (PAHs) that are derived from meat intake and tobacco smoking. Expression of the CYP1A1 gene is induced by compounds present in cruciferous vegetables. The glutathione S‐transferases play a central role in the detoxification of carcinogens, including PAHs. We investigated the association between colorectal cancer and three variants (CYP1A1*2A, CYP1A1*2C, CYP1A1*4) of the CYP1A1 gene, and homozygosity for the null deletion of the GSTM1 and GSTT1 genes, and the joint effects of these genotypes and smoking, meat intake and intake of green leafy vegetables in a population‐based study of 264 cases and 408 controls in Northeast Scotland. There was an inverse association with the CYP1A1*4 (m4) variant (OR 0.3, 95% CI 0.13–0.70). The OR for the CYP1A1*2C (m2) variant was 1.3 (95% CI 0.59–2.91), which is similar to a combined estimate for previous studies (OR 1.2, 95% CI 0.95–1.41). We observed no association with the CYP1A1*2A (m1) variant, or the GSTM1 and GSTT1 polymorphisms. Significant interactions between all 3 CYP1A1 variants and meat intake, and between the m1 and m2 variants and intake of green leafy vegetables, were observed. There was no evidence of interaction between CYP1A1 and smoking, and no evidence of interaction between the GSTM1 or GSTT1 polymorphisms and smoking, meat intake, green leafy vegetable intake, CYP1A1 variants or each other.

Lifestyle and socio-demographic factors associated with high-risk HPV infection in UK women

The world age-standardised prevalence of high-risk HPV (hrHPV) infection among 5038 UK women aged 20–59 years, with a low-grade smear during 1999–2002, assessed for eligibility for TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears) was 34.2%. High-risk HPV prevalence decreased with increasing age, from 61% at ages 20–24 years to 14–15% in those over 50 years. The age-standardised prevalence was 15.1, 30.7 and 52.7%, respectively, in women with a current normal, borderline nuclear abnormalities (BNA) and mild smear. In overall multivariate analyses, tertiary education, previous pregnancy and childbirth were associated with reduced hrHPV infection risk. Risk of infection was increased in non-white women, women not married/cohabiting, hormonal contraceptives users and current smokers. In stratified analyses, current smear status and age remained associated with hrHPV infection. Data of this type are relevant to the debate on human papillomavirus (HPV) testing in screening and development of HPV vaccination programmes.

Developing a questionnaire to measure the psychosocial impact of an abnormal cervical smear result and its subsequent management: the TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears) trial

This paper describes the process of developing and testing a new questionnaire, Process Outcome Specific Measure (POSM), including an assessment of its content validity and reliability. The questionnaire was developed within the context of Trial Of Management of Borderline and Other Low-grade Abnormal smears (TOMBOLA) to assess the psychosocial impact of a low-grade abnormal cervical smear result and the subsequent management. A literature search, focus groups and thorough pre-testing involving experts and patients resulted in a short (15-item), easily completed and understood questionnaire. Questions address issues including cancer, health, fertility and sexual concerns. Repeatability was assessed in 110 TOMBOLA recruits using weighted κ; all but one of the questions showed levels of reliability near to, or above, 0.5. Cronbach’s standardised α was 0.73, indicating acceptable internal consistency. Each POSM item was correlated with the anxiety and depression sub-scales of the Hospital Anxiety Depression Scale (HADS). All except one of the questions correlated more highly with the total POSM score than with the HADS sub-scales thus indicating discriminant validity. The POSM will enable comparison of the alternative management policies for low-grade cervical smears in terms of the benefits (or otherwise) perceived by the women managed by these policies.