Isobel Barnes

Comparison of various characteristics of women who do and do not attend for breast cancer screening

BackgroundInformation regarding the characteristics and health of women who do and do not attend for breast cancer screening is limited and representative data are difficult to obtain.MethodsInformation on age, deprivation and prescriptions for various medications was obtained for all women at two UK general practices who were invited to breast cancer screening through the National Health Service Breast Screening Programme. The characteristics of women who attended and did not attend screening were compared.ResultsOf the 1064 women invited to screening from the two practices, 882 (83%) attended screening. Screening attenders were of a similar age to non-attenders but came from significantly less deprived areas (30% of attenders versus 50% of non-attenders came from the most deprived areas, P < 0.0001) and were more likely to have a current prescription for hormone replacement therapy (32% versus 19%, P < 0.0001). No significant differences in recent prescriptions of medication for hypertension, heart disease, hypercholesterolaemia, diabetes mellitus, asthma, thyroid disease or depression/anxiety were observed between attenders and non-attenders.ConclusionWomen who attend the National Health Service Breast Screening Programme come from less deprived areas and are more likely to have a current prescription for hormone replacement therapy than non-attenders, but do not differ in terms of age or recent prescriptions for various other medications.

Cancer incidence in British Indians and British whites in Leicester, 2001-2006.

Background:Incidence rates for many cancers are lower in India than in Britain and it is therefore of interest to compare rates in British Indians to British whites, as well as to rates in India. We present estimates for Leicester, which has the largest population of Indian origin in Britain, and also has virtually complete, self-assigned, ethnicity data.Methods:We obtained data on all cancer registrations from 2001 to 2006 for Leicester with ethnicity data obtained by linkage to the Hospital Episode Statistics database. Age-standardised incidence rates were calculated for British Indians and British whites as well as incidence rate ratios, adjusted for age and income.Results:Incidence rate ratios for British Indians compared with British whites were significantly less than 1.0 for all cancers combined (0.65) and for cancer of the breast (0.72), prostate (0.76), colon (0.46), lung (0.30), kidney (0.36), stomach (0.54), bladder (0.48) and oesophagus (0.64), but higher than 1.0 for liver cancer (1.95).Conclusion:These results are likely to be the most accurate estimate of cancer incidence in British Indians to date and confirm that cancer incidence in British Indians is lower than in British whites in Leicester, particularly for cancer of the breast, prostate, colon and lung (and other smoking-related cancers), but much higher than in India.

Incidence of gastrointestinal cancers by ethnic group in England, 2001–2007

Objective To compare the incidence of six gastrointestinal cancers (colorectal, oesophageal, gastric, liver, gallbladder and pancreatic) among the six main ‘non-White’ ethnic groups in England (Indian, Pakistani, Bangladeshi, Black African, Black Caribbean and Chinese) to each other and to Whites. Methods We analysed all 378 511 gastrointestinal cancer registrations from 2001–2007 in England. Ethnicity was obtained by linkage to the Hospital Episodes Statistics database and we used mid-year population estimates from 2001–2007. Incidence rate ratios adjusted for age, sex and income were calculated, comparing the six ethnic groups (and combined ‘South Asian’ and ‘Black’ groups) to Whites and to each other. Results There were significant differences in the incidence of all six cancers between the ethnic groups (all p<0.001). In general, the ‘non-White’ groups had a lower incidence of colorectal, oesophageal and pancreatic cancer compared to Whites and a higher incidence of liver and gallbladder cancer. Gastric cancer incidence was lower in South Asians but higher in Blacks and Chinese. There was strong evidence of differences in risk between Indians, Pakistanis and Bangladeshis for cancer of the oesophagus, stomach, liver and gallbladder (all p<0.001) and between Black Africans and Black Caribbeans for liver and gallbladder cancer (both p<0.001). Conclusions The risk of gastrointestinal cancers varies greatly by individual ethnic group, including within those groups that have traditionally been grouped together (South Asians and Blacks). Many of these differences are not readily explained by known risk factors and suggest that important, potentially modifiable causes of these cancers are still to be discovered.

Lifestyle and reproductive risk factors associated with anal cancer in women aged over 50 years.

Background:Anal cancer incidence increases with age and is higher in women than men. Risk factors in this group other than high-risk human papillomavirus infection are unclear.Methods:In all, 1.3 million women were recruited in 1996–2001 and followed for incident anal cancer. Cox regression models were used to calculate relative risks (RRs) for anal cancer by various potential risk factors.Results:Five hundred and seventeen incident anal cancers were registered over 13 years of follow-up. The largest RR was associated with a history of cervical intraepithelial neoplasia grade 3 (CIN 3; RR=4.03, 95% CI 2.59–6.28). Other factors associated with significantly increased risks in multivariate analyses were: ever smoking (RR=1.49, 1.24–1.80); previous use of oral contraceptives (RR=1.51, 1.24–1.83); nulliparity (RR=1.61, 1.24–2.07); tubal ligation (RR=1.39, 1.13–1.70) and not living with a partner (RR=1.82, 1.40–2.38). The association with smoking was significantly greater for squamous cell carcinoma than adenocarcinoma of the anus (RR 1.66 vs 0.89, P for heterogeneity=0.04).Conclusions:History of CIN 3, smoking, past oral contraceptive use, nulliparity, tubal ligation and not living with a partner are risk factors for anal cancer in women. There was a significant increase in risk associated with smoking for squamous cell anal cancers but not adenocarcinomas.

Incidence of haematological malignancies by ethnic group in England, 2001-7.

The aetiology of most haematological malignancies is largely unknown. Studies of migrant populations can provide insights into the relative importance of genetic and environmental risk factors for these diseases. This study compares incidence rates in British Indians, Pakistanis, Bangladeshis, Black Africans, Black Caribbeans, Chinese and Whites in England from 2001 to 2007. We analysed 134 302 haematological cancer registrations with ethnicity obtained by linkage to the Hospital Episodes Statistics database. Mid‐year population estimates from 2001 to 2007 were used. Incidence rate ratios adjusted for age, sex and income were calculated, comparing the six ethnic groups to Whites and to each other. Whites had the highest rates for most subtypes. However, Blacks experienced more than double the incidence of plasma cell and mature T‐cell neoplasms compared to other ethnic groups. There were also significant differences in incidence between Indians, Pakistanis and Bangladeshis for Hodgkin lymphoma and mature B‐cell neoplasms and between Black African and Black Caribbeans for mature B‐cell and other lymphoid neoplasms (all P < 0·001). Our results show that the risk of haematological cancers varies greatly by ethnic group, including within those groups that have traditionally been grouped together (South Asians and Blacks) with many of these differences not explicable by known risk factors.

Tubal ligation and incidence of 26 site-specific cancers in the Million Women Study

Background:Tubal ligation is known to be associated with a reduction in ovarian cancer risk. Associations with breast, endometrial and cervical cancers have been suggested. We investigated associations for 26 site-specific cancers in a large UK cohort.Methods:Study participants completed a questionnaire on reproductive and lifestyle factors in 1996–2001, and were followed for cancer and death via national registries. Using Cox regression models, we estimated adjusted relative risks (RRs) for 26 site-specific cancers among women with vs without tubal ligation.Results:In 1 278 783 women without previous cancer, 167 430 incident cancers accrued during 13.8 years’ follow-up. Significantly reduced risks were found in women with tubal ligation for cancers of the ovary (RR=0.80, 95% CI: 0.76–0.85; P<0.001; n=8035), peritoneum (RR=0.81, 0.66–0.98; P=0.03; n=730), and fallopian tube (RR=0.60, 0.37–0.96; P=0.04; n=168). No significant associations were found for endometrial, breast, or cervical cancers.Conclusions:The reduced risks of ovarian, peritoneal and fallopian tube cancers are consistent with hypotheses of a common origin for many tumours at these sites, and with the suggestion that tubal ligation blocks cells, carcinogens or other agents from reaching the ovary, fallopian tubes and peritoneal cavity.

Incidence of breast and gynaecological cancers by ethnic group in England, 2001–2007: a descriptive study

BackgroundAlthough international comparisons reveal large geographical differences in the incidence of breast and gynaecological cancers, incidence data for ethnic groups in England remains scarce.MethodsWe compared the incidence of breast, ovarian, cervical and endometrial cancer in British Indians, Pakistanis, Bangladeshis, Black Africans, Black Caribbeans, Chinese and Whites between 2001 and 2007. We identified 357,476 cancer registrations from which incidence rates were calculated using mid-year population estimates from 2001 to 2007. Ethnicity was obtained through linkage to the Hospital Episodes Statistics database. Incidence rate ratios were calculated, comparing the 6 non-White ethnic groups to Whites, and were adjusted for age and income.ResultsWe found evidence of differences in the incidence of all 4 cancers by ethnic group (p < 0.001). Relative to Whites, South Asians had much lower rates of breast, ovarian and cervical cancer (IRRs of 0.68, 0.66 and 0.33 respectively), Blacks had lower rates of breast, ovarian and cervical cancer but higher rates of endometrial cancer (IRRs of 0.85, 0.62, 0.72 and 1.16 respectively), and Chinese had lower rates of breast and cervical cancer (IRRs of 0.72 and 0.68 respectively). There were also substantial intra-ethnic differences, particularly among South Asians, with Bangladeshis experiencing the lowest rates of all 4 cancers.ConclusionsOur study provides evidence that the risk of breast and gynaecological cancers varies by ethnic group and that those groups typically grouped together are not homogenous with regards to their cancer risk. Furthermore, several of our findings cannot be readily explained by known risk factors and therefore warrant further investigation.

Heterogeneity of colorectal cancer risk by tumour characteristics: Large prospective study of UK women

Associations between behavioural and other personal factors and colorectal cancer risk have been reported to vary by tumour characteristics, but evidence is inconsistent. In a large UK‐based prospective study we examined associations of 14 postulated risk factors with colorectal cancer risk overall, and across three anatomical sites and four morphological subtypes. Among 1.3 million women, 18,518 incident colorectal cancers were identified during 13.8 (SD 3.4) years follow‐up via record linkage to national cancer registry data. Cox regression yielded adjusted relative risks. Statistical significance was assessed using correction for multiple testing. Overall, colorectal cancer risk was significantly associated with height, body mass index (BMI), smoking, alcohol intake, physical activity, parity and menopausal hormone therapy use. For smoking there was substantial heterogeneity across morphological types; relative risks around two or greater were seen in current smokers both for signet ring cell and for neuroendocrine tumours. Obese women were also at higher risk for signet ring cell tumours. For adenocarcinomas, the large majority of colorectal cancers in the cohort, all risk factor associations were weak. There was little or no heterogeneity in risk between tumours of the right colon, left colon and rectum for any of the 14 factors examined. These epidemiological findings complement an emerging picture from molecular studies of possible different developmental pathways for different tumour types.

Past cervical intraepithelial neoplasia grade 3, obesity, and earlier menopause are associated with an increased risk of vulval cancer in postmenopausal women.

Background:Vulval cancer predominantly affects postmenopausal women. A smaller proportion of vulval cancers, particularly at older ages, are now thought to be associated with human papillomavirus infection than previously reported, but other risk factors have not been well examined in prospective cohort studies.Methods:A total of 1.3 million women aged 49–65 years were followed for incident vulval cancer (ICD-10 C51). Adjusted Cox regression models were used to examine the relationship between reproductive and lifestyle factors and risk of vulval cancer.Results:There were 898 vulval cancers registered in the cohort over an average of 14 years of follow-up; 70% were squamous cell carcinomas. Past registration of cervical carcinoma in situ (RR 2.68; 95% CI 1.71–4.18; P<0.001), obesity (RR 1.71; 95% CI 1.44–2.04; P<0.0001), and menopause before the age of 50 years (RR 1.52; 95% CI 1.22–1.89; P<0.001) were associated with a significantly increased risk of subsequent vulval cancer.Conclusion:Past cervical pre-cancer, obesity, and earlier age at menopause are associated with an increased risk of vulval cancer at older ages.

Incidence of prostate and urological cancers in England by ethnic group, 2001-2007: a descriptive study

BackgroundThe aetiology of urological cancers is poorly understood and variations in incidence by ethnic group may provide insights into the relative importance of genetic and environmental risk factors. Our objective was to compare the incidence of four urological cancers (kidney, bladder, prostate and testicular) among six ‘non-White’ ethnic groups in England (Indian, Pakistani, Bangladeshi, Black African, Black Caribbean and Chinese) to each other and to Whites.MethodsWe obtained Information on ethnicity for all urological cancer registrations from 2001 to 2007 (n = 329,524) by linkage to the Hospital Episodes Statistics database. We calculated incidence rate ratios adjusted for age, sex and income, comparing the six ethnic groups (and combined ‘South Asian’ and ‘Black’ groups) to Whites and to each other.ResultsThere were significant differences in the incidence of all four cancers between the ethnic groups (all p < 0.001). In general, ‘non-White’ groups had a lower incidence of urological cancers compared to Whites, except prostate cancer, which displayed a higher incidence in Blacks. (IRR 2.55) There was strong evidence of differences in risk between Indians, Pakistanis and Bangladeshis for kidney, bladder and prostate cancer (p < 0.001), and between Black Africans and Black Caribbeans for all four cancers (p < 0.001).ConclusionsThe risk of urological cancers in England varies greatly by ethnicity, including within groups that have traditionally been analysed together (South Asians and Blacks). In general, these differences are not readily explained by known risk factors, although the very high incidence of prostate cancer in both black Africans and Caribbeans suggests increased genetic susceptibility. g.