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Background: There is limited information about participation in organised population-wide screening programmes by people with disabilities.Methods: Data from the National Health Service routine screening programmes in England were linked to information on disability reported by the Million Women Study cohort participants.Results: Of the 473 185 women offered routine breast or bowel cancer screening, 23% reported some disability. Women with disabilities were less likely than other women to participate in breast cancer screening (RR=0.64, 95% CI: 0.62-0.65) and in bowel cancer screening (RR=0.75, 0.73-0.76). Difficulties with self-care or vision were associated with the greatest reduction in screening participation.Conclusion: Participation in routine cancer screening programmes in England is reduced in people with disabilities and participation varies by type of disability. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background:In 2006, the National Health Service Bowel Cancer Screening Programme in England (NHSBCSP) began offering routine population-based biennial faecal occult blood testing (FOBt) at ages 60-69. There is, however, limited information on how characteristics of individuals affect participation and outcomes of screening, and we studied this association by linking NHSBCSP data to a large prospective cohort of women.Methods:Electronic linkage of the NHSBCSP and Million Women Study records identified 899 166 women in the study cohort with at least one invitation for screening. NHSBCSP provided information on screening acceptance, FOBt results, screen-detected colorectal cancer and other outcomes. The Million Women Study provided prospectively collected information on personal and lifestyle factors. Multiple regression was used to estimate relative risks (RRs) of factors associated with acceptance and outcomes of screening.Results:Overall, 70% of women (628 976/899 166) accepted their first invitation for bowel cancer screening, of whom 9133 (1.5%) were FOBt-positive, 743 (0.1%) had screen-detected colorectal cancer and 3056 (0.5%) had screen-detected colorectal adenoma. Acceptance was lower in women from the most than the least deprived tertile, in South Asians and in Blacks than in Whites, in current than in never smokers and in obese than in normal weight women: adjusted RRs (95% confidence interval) for acceptance vs not, 0.90 (0.90-0.90); 0.77 (0.75-79); 0.94 (0.92-0.96); 0.78 (0.77-0.78); and 0.88 (0.88-0.89), respectively: P<0.001 for each. These factors were also associated with an increased risk of being FOBt-positive and of having screen-detected adenoma, but were not strongly associated with the risk of screen-detected colorectal cancer. Relative risks for screen-detected adenoma were 1.22 (1.12-1.34), 2.46 (1.75-3.45), 1.61 (1.05-2.48), 1.53 (1.38-1.68) and 1.77 (1.60-1.95), respectively (P<0.001 for all, except for Blacks vs Whites P=0.03). Use of hormone therapy for menopause was associated with reduced risk of screen-detected adenoma, RR ever vs never use, 0.87 (0.81-0.93), P<0.001 and colorectal cancer, 0.78 (0.68-0.91), P=0.001.Interpretation:Among women in England, socioeconomic and lifestyle factors strongly affect participation in routine bowel cancer screening, risk of being FOBt-positive and risk of having screen-detected colorectal adenoma. However, screen-detected colorectal cancer risk is not strongly related to these factors. [ABSTRACT FROM AUTHOR]

Background:Organically produced foods are less likely than conventionally produced foods to contain pesticide residues.Methods:We examined the hypothesis that eating organic food may reduce the risk of soft tissue sarcoma, breast cancer, non-Hodgkin lymphoma and other common cancers in a large prospective study of 623 080 middle-aged UK women. Women reported their consumption of organic food and were followed for cancer incidence over the next 9.3 years. Cox regression models were used to estimate adjusted relative risks for cancer incidence by the reported frequency of consumption of organic foods.Results:At baseline, 30%, 63% and 7% of women reported never, sometimes, or usually/always eating organic food, respectively. Consumption of organic food was not associated with a reduction in the incidence of all cancer (n=53 769 cases in total) (RR for usually/always vs never=1.03, 95% confidence interval (CI): 0.99-1.07), soft tissue sarcoma (RR=1.37, 95% CI: 0.82-2.27), or breast cancer (RR=1.09, 95% CI: 1.02-1.15), but was associated for non-Hodgkin lymphoma (RR=0.79, 95% CI: 0.65-0.96).Conclusions:In this large prospective study there was little or no decrease in the incidence of cancer associated with consumption of organic food, except possibly for non-Hodgkin lymphoma. [ABSTRACT FROM AUTHOR]

Background:Thyroid cancer incidence is increasing worldwide, but with large variations in incidence that may reflect either diagnostic bias or true ethnic differences. We sought to determine the effect of ethnicity on the incidence of thyroid cancer in England, a multiethnic population with a single health-care system.Methods:We analysed 11 263 thyroid cancer registrations with ethnicity obtained by linkage to the Hospital Episodes Statistics database. Incidence rate ratios (RRs) adjusted for age, sex and income were calculated for the six main non-White ethnic groups in England compared with Whites and to each other.Results:Thyroid cancer incidence was higher in all ethnic groups, except Indians, compared with Whites: in Pakistanis (RR 1.79, 99% floating confidence interval (FCI) 1.47-2.19); Bangladeshis (RR 1.99, 99% FCI 1.46-2.71); Black Africans (RR 1.69, 99% FCI 1.34-2.13); Black Caribbeans (RR 1.56, 99% FCI 1.25-1.93); and Chinese (RR 2.14, 99% FCI 1.63-2.80).Conclusion:The risk of thyroid cancer in England varies significantly by ethnicity. The elevated incidence in most ethnic minorities is unlikely to be due to diagnostic bias and warrants further investigation. [ABSTRACT FROM AUTHOR]

Background:In the United Kingdom, breast cancer incidence is lower in South Asian and Black women than in White women, but the extent to which this is due to known risk factors is unknown. In a large prospective study, we describe breast cancer incidence by ethnicity, before and after adjustment for known risk factors for the disease.Methods:Women were recruited into the Million Women Study in 1996-2001, when information on reproductive and lifestyle factors known to influence the risk of breast cancer was obtained. Ethnicity was determined from study questionnaires and hospital admission data. Cox regression models were used to calculate adjusted relative risks (RR) for incident breast cancer in South Asians and Blacks compared with Whites.Results:Analyses included 5877 South Asian, 4919 Black, and 1 038 144 White women in England. The prevalence of 8 out of the 9 risk factors for breast cancer examined, differed substantially by ethnicity (P<0.001 for each), such that South Asian and Black women were at a lower risk of the disease than White women. During 12.2 years of follow-up incident breast cancer occurred in 217 South Asians, 180 Blacks, and 45 191 Whites. As expected, breast cancer incidence was lower in South Asians (RR=0.82, 95% CI 0.72-0.94) and Blacks (RR=0.85, 0.73-0.98) than in Whites when the analyses were adjusted only for age and region of residence. However, after additional adjustment for the known risk factors for the disease, breast cancer incidence was similar to that of Whites, both in South Asians (0.95, 0.83-1.09) and in Blacks (0.91, 0.78-1.05).Conclusion:South Asian and Black women in England have lower incidence rates of breast cancer than White women, but this is largely, if not wholly, because of differences in known risk factors for the disease. [ABSTRACT FROM AUTHOR]

Background:Greater adiposity and height have been associated with increased risk of haematological malignancies. Associations for disease subtypes are uncertain.Methods:A cohort of 1.3 million middle-aged UK women was recruited in 1996-2001 and followed for 10 years on average. Potential risk factors were assessed by questionnaire. Death, emigration, and incident cancer were ascertained by linkage to national registers. Adjusted relative risks were estimated by Cox regression.Results:During follow-up, 9162 participants were diagnosed with lymphatic or haematopoietic cancers. Each 10 kg m−2 increase in body mass index was associated with relative risk of 1.20 (95% confidence interval: 1.13-1.28) for lymphoid and 1.37 (1.22-1.53) for myeloid malignancy (P=0.06 for heterogeneity); similarly, Hodgkin lymphoma 1.64 (1.21-2.21), diffuse large B-cell lymphoma 1.36 (1.17-1.58), plasma cell neoplasms 1.21 (1.06-1.39), acute myeloid leukaemia 1.47 (1.19-1.81), and myeloproliferative/myelodysplastic syndromes 1.32 (1.15-1.52). Each 10 cm increase in height was associated with relative risk of 1.21 (1.16-1.27) for lymphoid and 1.11 (1.02-1.21) for myeloid malignancy (P=0.07 for heterogeneity); similarly, mature T-cell malignancies 1.36 (1.03-1.79), diffuse large B-cell lymphoma 1.28 (1.14-1.43), follicular lymphoma 1.28 (1.13-1.44), plasma cell neoplasms 1.12 (1.01-1.24), chronic lymphocytic leukaemia/small lymphocytic lymphoma 1.23 (1.08-1.40), and acute myeloid leukaemia 1.22 (1.04-1.42). There was no significant heterogeneity between subtypes.Conclusion:In middle-aged women, greater body mass index and height were associated with modestly increased risks of many subtypes of haematological malignancy. [ABSTRACT FROM AUTHOR]

Objective:To explore the long-term effects of women's childbearing patterns on their body mass index.Design:Cross-sectional analysis.Setting:Population-based study of UK women.Participants:740 628 postmenopausal participants in the Million Women Study who reported their height, weight, reproductive histories and other relevant factors.Main Outcome Measures:Standardized mean BMI (kg m−2) in groups defined by their parity and breastfeeding history.Results:Women were aged 57.5 (s.d. 4) years on average, and had a mean BMI of 26.2 kg m−2 (s.d. 5); 88% were parous, with 2.1 (s.d. 1.2) children on average. The standardised mean BMI increased progressively with the number of births from 25.6 kg m−2 (95% confidence interval (CI): 25.5-25.6) in nulliparous women up to 27.2 kg m−2 (CI: 27.2-27.3) for women with four or more births, a difference of 1.7 kg m−2 (CI: 1.6-1.7). Among the parous women 70% had ever breastfed and their average total duration of breastfeeding was 7.7 (s.d. 8.8) months. At every parity level the standardised mean BMI was significantly lower among women who had breastfed than those who had not, decreasing by 0.22 kg m−2 (CI: 0.21-0.22) for every 6 months of breastfeeding, that is, women's mean BMI was 1% lower for every 6 months that they had breastfed. These associations were highly statistically significant (P<0.0001) and independent of the effects of socioeconomic group, region of residence, smoking and physical activity.Conclusions:Childbearing patterns have a persistent effect on adiposity in this population. The reduction in BMI associated with just 6 months breastfeeding in UK women could importantly reduce their risk of obesity-related disease as they age. [ABSTRACT FROM AUTHOR]

Background:Previous research suggests associations of lower alcohol intake and higher tobacco consumption with increased risks of haematological malignancy. The prospective Million Women Study provides sufficient power for reliable estimates of subtype-specific associations in women.Methods:Approximately 1.3 million middle-aged women were recruited in the United Kingdom during 1996-2001 and followed for death, emigration and cancer registration until 2009 (mean 10.3 years per woman); potential risk factors were assessed by questionnaire. Adjusted relative risks were estimated by Cox regression.Results:During follow-up, 9162 incident cases of haematological malignancy were recorded, including 7047 lymphoid and 2072 myeloid cancers. Among predominantly moderate alcohol drinkers, higher intake was associated with lower risk of lymphoid malignancies, in particular diffuse large B-cell lymphoma (relative risk 0.85 per 10 g alcohol per day (95% confidence interval 0.75-0.96)), follicular lymphoma (0.86 (0.76-0.98)) and plasma cell neoplasms (0.86 (0.77-0.96)). Among never- and current smokers, higher cigarette consumption was associated with increased risk of Hodgkin lymphoma (1.45 per 10 cigarettes per day (1.22-1.72)), mature T-cell malignancies (1.38 (1.10-1.73)) and myeloproliferative/myelodysplastic disease (1.42 (1.31-1.55)).Conclusion:These findings confirm and extend existing evidence for associations of subtypes of haematological malignancy with two common exposures in women. [ABSTRACT FROM AUTHOR]

Background:Sleep disturbance, a correlate of which is daytime napping, has been hypothesised to be associated with risk of breast and other cancers.Methods:We estimated relative risks (RR) of breast and other invasive cancers by the reported frequency of daytime napping in a large prospective cohort of middle-aged women in the UK.Results:During an average of 7.4 years of follow-up, 20 058 breast cancers and 31 856 other cancers were diagnosed. Over the first 4 years of follow-up, daytime napping (sometimes/usually vs rarely/never) was associated with slightly increased risks of breast cancer (RR=1.10, 95% CI 1.06-1.15) and of other cancers (RR=1.12, 1.08-1.15), but the RRs decreased significantly with increasing follow-up time (P=0.001 and P=0.01, respectively, for trend). Four or more years after baseline, there was no elevated risk of breast cancer (RR=1.00, 0.96-1.05), and only marginally greater risk of other cancers (RR=1.04, 1.01-1.07).Conclusion:The effect of pre-clinical disease is a likely explanation for the short-term increased risk of breast and other cancers associated with daytime napping. [ABSTRACT FROM AUTHOR]

Background:Greater adiposity in early life has been linked to increased endometrial cancer risk in later life, but the extent to which this association is mediated through adiposity in later life is unclear.Methods:Among postmenopausal women who had never used menopausal hormone therapies and reported not having had a hysterectomy, adjusted relative risks (RRs) of endometrial cancer were estimated using Cox regression.Results:Among 249 791 postmenopausal women with 7.3 years of follow-up on average (1.8 million person-years), endometrial cancer risk (n=1410 cases) was strongly associated with current body mass index (BMI) at baseline (RR=1.87 per 5 kg m−2 increase in BMI, 95% confidence interval (CI): 1.77-1.96). Compared with women thinner than average at age 10, the increased risk among women plumper at age 10 (RR=1.27, 95% CI: 1.09-1.49) disappeared after adjustment for current BMI (RR=0.90, 95% CI: 0.77-1.06). Similarly, compared with women with clothes size 12 or less at age 20, the increased risk among women with clothes size 16 or larger (RR=1.87, 95% CI: 1.61-2.18) was not significant after adjustment for current BMI (RR=1.03, 95% CI: 0.88-1.22).Conclusion:Among women who have never used hormone therapy for menopause, the association between body size in early life and endometrial cancer risk in postmenopausal women can be largely explained by women's current BMI. [ABSTRACT FROM AUTHOR]

Background:Hormonal factors may influence risk for upper gastrointestinal cancers in women. We examined risk of oesophageal and gastric cancers in relation to reproductive factors in a large UK cohort, the Million Women Study.Methods:Among 1 319 409 women aged on average 56 years at recruitment, 1186 incident cancers of the oesophagus and 1194 of the stomach were registered during 11.9 million person-years' observation. Adjusted relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models.Results:Risks of both oesophageal and gastric cancer were significantly higher in postmenopausal than in pre- or peri-menopausal women (RRs 1.46, 1.07-2.00 and 1.59, 1.15-2.20, respectively; P0.01 for both); and, among postmenopausal women, risk was higher the younger women were at menopause (RR, 95% CI per 5 years younger at menopause 1.18, 1.05-1.34 for oesophageal cancer and 1.18, 1.04-1.34 for stomach cancer, Ptrend=0.01 for both). For factors relating to childbearing, including women's age at first birth, their number of children, and breastfeeding history, the only significant association was a higher risk of oesophageal cancer in nulliparous, compared with parous, women (RR 1.31, 1.11-1.55; P=0.002). When risks for squamous cell and adenocarcinomas of the oesophagus were compared, most did not differ significantly, but statistical power was limited.Conclusion:Both oesophageal and gastric cancer risks appeared to be related to menopausal status and age at menopause, but there was little consistent evidence for associations with factors related to childbearing. [ABSTRACT FROM AUTHOR]

Background: It has been suggested that the apparent protective effect of alcohol intake on renal cell carcinoma may be due to the diluting effect of carcinogens by a high total fluid intake. We assessed the association between intakes of total fluids and of specific beverages on the risk of renal cell carcinoma in a large prospective cohort of UK women.Methods: Information on beverage consumption was obtained from a questionnaire sent ∼3 years after recruitment into the Million Women Study. Cox proportional hazards models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for renal cell carcinoma associated with beverage consumption adjusted for age, region of residence, socioeconomic status, smoking, and body mass index.Results: After an average of 5.2 years of follow-up, 588 cases of renal cell carcinoma were identified among 779,369 women. While alcohol intake was associated with a reduced risk of renal cell carcinoma (RR for ≥ 2 vs <1 drink per day: 0.76; 95% CI: 0.61-0.96; P for trend=0.02), there was no association with total fluid intake (RR for ≥ 12 vs <7 drinks per day: 1.15; 95% CI: 0.91-1.45; P for trend=0.3) or with intakes of specific beverages.Conclusions: The apparent protective effect of alcohol on the risk of renal cell carcinoma is unlikely to be related to a high fluid intake. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objectives: To examine the effect of reproductive history and use of hormonal therapies on the risk of hip and knee joint replacement for osteoarthritis. Methods: A prospective study of 1.3 million women aged on average 56 years at recruitment and followed-up through linkage to routinely collected hospital admission records was conducted. The adjusted relative risk (RR) of hip and knee replacement for osteoarthritis was examined in relation to parity, age at menarche, menopausal status, age at menopause and use of hormonal therapies. Results: Over a mean of 6.1 person-years of follow-up, 12 124 women had a hip replacement and 9977 a knee replacement. The risk of joint replacement increased with increasing parity and the effect was greater for the knee than the hip: increase in RR of 2% (95% CI 1 to 4%) per birth for hip replacement and 8% (95% CI 6 to 10%) for knee replacement. An early age at menarche slightly increased the risk of hip and knee replacement (relative risk for menarche ⩽11 years versus 12 years, 1.09 (95% CI 1.03 to 1.16) and 1.15 (95% CI 1.08 to 1.22), respectively). Menopausal status and age at menopause were not clearly associated with risk. Current use of postmenopausal hormone therapy was associated with a significant increase in the incidence of hip and knee replacement (RR 1.38 (95% CI 1.30 to 1.46) and RR 1.58 (95% CI 1.48 to 1.69), respectively) while previous use of oral contraceptives was not (RR 1.02 (95% CI 0.98 to 1.06) and RR 1.00 (95% CI 0.96 to 1.04) for hip and knee, respectively). Conclusions: Hormonal and reproductive factors affect the risk of hip and knee replacement, more so for the knee than the hip. The reasons for this are unclear. [ABSTRACT FROM PUBLISHER]

Objective To investigate any long term effects on mortality in participants in experimental research related to chemical warfare agents from 1941 to 1989. Design Historical cohort study. Data source Archive of UK government research facility at Portori Down, UK military personnel records, and national death and cancer records. Participants 18 276 male members of the UK armed forces who had spent one or more short periods (median 4 days between first and last test) at Porton Down and a al comparison group of 17 600 non-Porton Down veterans followed to 31 December 2004. Main outcome measures Mortality rate ratio of Porton Down compared with non-Porton Down veterans and standardised mortality ratio of each veteran group compared with the general population. Both ratios adjusted for age group and calendar period. Results Porton Down veterans were similar to non-Porton Down veterans in year of enlistment (median 1951) but had longer military service (median 6.2 v 5.0 years). After a median follow-up of 43 years, 40% (7306) of Porton Down and 39% (6900) of non-Porton Down veterans had died. All cause mortality was slightly greater in Porton Down veterans (rate ratio 1.06, 95% confidence interval 1.03 to 1.10, P<0.001), more so for deaths outside the UK (1.26,1.09 to 1.46). Of 12 cause specific groups examined, rate ratios in.Porton Down veterans were increased for deaths attributed to infectious and parasitic (1.57,1.07 to 2.29), genitourinary (1.46,1.04 to 2.04), circulatory (1.07,1.01 to 1.12), and external (non- . medical) (1.17,1.00 to 1.37) causes and decreased for deaths attributed to in situ, benign, and unspecified neoplasms (0.60, 0.37 to 0.99). There was no clear relation between type of chemical exposure and cause specific mortality. The mortality in both groups of veterans was lower than that in the general population (standardised mortality ratio 0.88, 0.85 to 0.90; 0.82, 0.80 to 0.84). Conclusions Mortality was slightly higher in Porton Down ( than non-Porton Down veterans. With lack of information on other important factors, such as smoking or service overseas, it is not possible to attribute the small excess mortality to chemical exposures at Porton Down. [ABSTRACT FROM AUTHOR]

Objective To determine cancer morbidity in members of the armed forces who took part in tests of chemical warfare agents from 1941 to 1989. Design Historical cohort study, with cohort members followed up to December 2004. Data source Archive of UK government research facility at Porton Down, UK military personnel records, and national death and cancer records. Participants All veterans included in the cohort study of mortality, excluding those known to have died or been lost to follow-up before 1 January 1971 when the UK cancer registration system commenced: 17 013 male members of the UK armed forces who took part in tests (Porton Down veterans) and a similar group of 16 520 men who did not (non-Porton Down veterans). Main outcome measures Cancer morbidity in each group of veterans; rate ratios, with 95% confidence intervals, adjusted for age group and calendar period. Results 3457 cancers were reported in the Porton Down veterans compared with 3380 cancers in the non-Porton Down veterans. While overall- cancer morbidity was the same in both groups (rate ratio 1.00, 95% confidence interval 0.95 to 1.05), Porton Down veterans had higher rates of.ill defined malignant neoplasms (1.12,1.02 to 1.22), in situ neoplasms (1.45,1.06 to 2.00), and those of uncertain or unknown behaviour (1.32,1.01 to 1.73). Conclusion Overall cancer morbidity in Porton Down veterans was no different from that in non-Porton Down veterans. [ABSTRACT FROM AUTHOR]

Little is known about how reproductive factors affect the risk of breast cancers of different histology. In an analysis of prospective data on 1.2 million middle-aged UK women, we used proportional hazards models to estimate the relative risks of six histological types in relation to menarche, childbearing and menopause. During 8.7 million person-years of follow-up, 17 923 ductal, 3332 lobular, 1062 tubular, 944 mixed ductal lobular, 330 mucinous and 117 medullary cancers were diagnosed. The effect of both age at menarche and age at first birth was greatest for lobular tumours; relative risks per 5-year increase in age at menarche for ductal, lobular, and tubular cancers were 0.93 (0.87-0.99), 0.65 (0.56-0.76), and 0.75 (0.57-0.98), respectively (P-value for heterogeneity=0.0001); and the relative risks per 5-year increase in age at first birth were 1.10 (1.07-1.12), 1.23 (1.17-1.29), and 1.13 (1.03-1.23), respectively (P-value for heterogeneity=0.0006). Increasing parity reduced the risk of each tumour type, except medullary cancers, but the reduction in risk was greater for mucinous cancers than for any other subtype considered (P<0.05 for comparison with each other subtype in turn). The effect of menopause did not vary significantly by tumour histology. Meta-analysis of published results on the effects of age at menarche and age at first birth on ductal and lobular cancers were in keeping with our findings. [ABSTRACT FROM AUTHOR]

The separate and joint effects of alcohol and smoking on incidences of liver cirrhosis and gallbladder disease were examined in a prospective study of 1,290,413 United Kingdom women (mean age, 56 years) recruited during 1996-2001. After a mean follow-up of 6.1 years (1996-2005), incidence rates of cirrhosis and gallbladder disease were 1.3 per 1,000 persons (n = 2,105) and 15 per 1,000 persons (n = 23,989), respectively, over 5 years. Cirrhosis risk increased with increasing alcohol consumption, while the risk of gallbladder disease decreased (P(trend) < 0.0001 for each). Comparing women who drank > or =15 units/week with those who drank 1-2 units/week, the relative risk was 4.32 (95% confidence interval (CI): 3.71, 5.03)) for cirrhosis and 0.59 (95% CI: 0.55, 0.64) for gallbladder disease. Increasing numbers of cigarettes smoked daily increased the risk of both conditions (P(trend) < 0.0001 for each). Comparing current smokers of > or =20 cigarettes/day with never smokers, the relative risk was 3.76 (95% CI: 3.25, 4.34) for cirrhosis and 1.29 (95% CI: 1.22, 1.37) for gallbladder disease. Effects of alcohol and smoking were more than multiplicative for cirrhosis (P(interaction) = 0.02) but not for gallbladder disease (P(interaction) = 0.4). Findings indicate that alcohol and smoking affect the risks of the 2 conditions in different ways. For cirrhosis, alcohol and smoking separately increase risk, and their joint effects are particularly hazardous. For gallbladder disease, alcohol reduces risk and smoking results in a small risk increase. [ABSTRACT FROM AUTHOR]

Previous studies have reported inconsistent results on the effect of anthropometric and lifestyle factors on the risk of developing glioma or meningioma tumours. A prospective cohort of 1.3 million middle-aged women was used to examine these relationships. During 7.7 million women-years of follow-up, a total of 1563 women were diagnosed with a primary incident central nervous system tumour: 646 tumours were classified as glioma and 390 as meningioma. Our results show that height is related to the incidence of all central nervous system tumours with a risk of about 20% per 10 cm increase in height (relative risk=1.19, 95% CI=1.10-1.30 per 10 cm increase in height, P<0.001): the risks did not differ significantly between specified glioma and meningioma. Body mass index (BMI) was also related to central nervous system tumour incidence, with a risk of about 20% per 10 kg m(-2) increase in BMI (relative risk=1.17, 95% CI=1.03-1.34 per 10 kg m(-2) increase in BMI, P=0.02). Smoking status, alcohol intake, socioeconomic level, parity, age at first birth, and oral contraceptive use were not associated with the risk of glioma or meningioma tumours. In conclusion, for women in the United Kingdom, the incidence of glioma or meningioma tumours increases with increasing height and increasing BMI. [ABSTRACT FROM AUTHOR]

Active smoking has little or no effect on breast cancer risk but some investigators have suggested that passive smoking and its interaction with active smoking may be associated with an increased risk. In a population based case-control study of breast cancer in women aged 36-45 years at diagnosis, information on active smoking, passive smoking in the home, and other factors, was collected at interview from 639 cases and 640 controls. Women were categorised jointly by their active and passive smoking exposure. Among never smoking controls, women who also reported no passive smoking exposure were significantly more likely to be nulliparous and to be recent users of oral contraceptives. Among those never exposed to passive smoking, there was no significant association between active smoking and breast cancer, relative risk (RR) of 1.12 (95% confidence interval (CI) 0.72-1.73) for past smokers and RR of 1.19 (95% CI 0.72-1.95) for current smokers, nor was there an association with age started, duration or intensity of active smoking. Compared with women who were never active nor passive smokers, there was no significant association between passive smoking in the home and breast cancer risk in never smokers, RR of 0.89 (95% CI 0.64-1.25), in past smokers, RR of 1.09 (95% CI 0.75-1.56), or in current smokers, RR of 0.93 (95% CI 0.67-1.30). There was no trend with increasing duration of passive smoking and there was no heterogeneity among any of the subgroups examined. In this study, there was no evidence of an association between either active smoking or passive smoking in the home and risk of breast cancer. [ABSTRACT FROM AUTHOR]

Antibody titres against Kaposi's sarcoma associated herpesvirus (KSHV or human herpesvirus 8 (HHV-8)) and Epstein–Barr virus (EBV) were examined in people who subsequently developed Kaposi's sarcoma and non-Hodgkin's lymphoma, within randomised controlled trials of antiretroviral therapy in adults infected with the human immunodeficiency virus-1 (HIV). For each case of Kaposi's sarcoma (n=189) and each case of non-Hodgkin's lymphoma (n=67), which developed after randomisation, one control was randomly selected from other trial participants, after matching for age, sex, ethnicity, mode of HIV transmission, type of treatment received and period of follow-up. Using sera taken an average of two and a half years before the diagnosis of cancer, titres of antibodies against KSHV latent (LANA) and lytic (K8.1) antigens and against EBV (VCA) antigens were investigated in relation to subsequent risks of cancer by calculating odds ratios (OR) using conditional logistic regression. Latent antibodies against KSHV were detectable among 38% (72 out of 189) of Kaposi's sarcoma cases and 12% (23 out of 189) of their controls (OR=4.4, 95% confidence intervals (CI) 2.3–8.3, P<0.001). The OR for Kaposi's sarcoma increased with increasing antilatent KSHV antibody titre (χ21 for trend=32.2, P<0.001). Lytic antibodies against KSHV were detectable among 33% (61 out of 187) of Kaposi's sarcoma cases and 19% (36 out of 187) of their controls (OR=2.0, 95% CI 1.2–3.4, P=0.003) and the OR for Kaposi's sarcoma increased with increasing antilytic KSHV antibody titre (χ21 for trend=6.2, P=0.02). Virtually, all cases and controls had anti-EBV antibodies detected and the OR for non-Hodgkin's lymphoma associated with a doubling of the anti-EBV antibody titre was estimated to increase by a multiplicative factor of 1.3 (95% CI 0.9–1.7, P=0.1). Kaposi's sarcoma was not associated with antibody levels against EBV (P=0.4) and non-Hodgkin's lymphoma was not associated with antibodies against KSHV (latent P=0.3; lytic P=0.5). Adjustment for CD4 count at the time of sample collection made no material difference to any of the results. In conclusion, among human immunodeficiency virus infected people, high levels of antibodies against KSHV latent and lytic antigens are strongly associated with subsequent risk of Kaposi's sarcoma but not non-Hodgkin's lymphoma. Antibody titre to EBV does not appear to be strongly associated with subsequent risk of Kaposi's sarcoma or non-Hodgkin's lymphoma in HIV infected people.British Journal of Cancer (2006) 94, 1504–1509. doi:10.1038/sj.bjc.6603100 www.bjcancer.com [ABSTRACT FROM AUTHOR]

Background: Infections with certain human herpesviruses have been established as risk factors for some cancer types. For example, Epstein-Barr Virus is considered a cause of Burkitt's lymphoma and other immunosuppression related lymphomas, Hodgkin lymphoma, and nasopharyngeal cancer. Several other human herpesviruses have been linked to cancers but the totality of evidence is inconclusive. Methods: We conducted a systematic sub-study from within an ongoing case control study of adult black South Africans to investigate the relationship between antibodies to six human herpesviruses and seven cancer groups that may be caused by infectious agents. Subjects had incident cancers of the oral cavity(n = 88), the cervix(n = 53), the prostate(n = 66), Hodgkin lymphoma(n = 83), non-Hodgkin lymphoma(n = 80), multiple myeloma(n = 94) or leukaemia(n = 203). For comparison, patients with other cancers(n = 95) or cardiovascular disease(n = 101) were randomly selected from within the study. Patients were interviewed and their blood was tested for IgG antibodies against HSV-1, HSV-2, VZV, EBVEBNA, CMV and HHV-6 using enzyme linked immunosorbent assays. Because these viruses are highly prevalent in this population, optical density results from the assays were used as an indirect, quantitative measure of antibody level. Results: There was significant variation in the mean log antibody measures for HSV-2, VZV, CMV and HHV-6 between the disease groups. However, none of the specific cancer groups had significantly higher mean log antibody measures for any of the viruses compared to either control group. In a more detailed examination of seven associations between cancers and herpesviruses for which there had been prior reports, two statistically significant associations were found: a decreasing risk of myeloid leukaemia and an increasing risk of oral cancer with increasing tertiles of antibodies against HHV-6 compared to all other patients (p-trend = 0.03 and 0.02, respectively). Odds ratios for the top tertile compared to the bottom tertile were 0.58 (95%CI 0.3 – 1.0) for myeloid leukaemia and 2.21 (95% CI 1.1 – 4.3) for oral cancer. Conclusion: In this population, using these tests for IgG, neither mean antibody measure nor high antibody measure against human herpesviruses 1–6 was strongly associated with any of the seven cancer groups. However, we may not have had sufficient power to detect weak associations or associations with a sub-type of cancer if they were present. [ABSTRACT FROM AUTHOR]

We examined the relationship between body fatness, sports participation and breast cancer risk in 1560 premenopausal cases and 1548 controls, from three related population-based case–control studies in the UK. Half of the women with breast cancer were aged less than 36 years at diagnosis. Women who perceived themselves as plump at age 10 years had a relative risk of 0.83 (95% confidence interval 0.69–0.99, P=0.03) as compared with those who perceived themselves as thin. Self-reported obesity compared with leanness at diagnosis was associated with a relative risk of 0.78 (95% confidence interval 0.56–1.06, P=0.11). Women who reported having been plump at age 10 years and overweight or obese at diagnosis had a relative risk of 0.75 (95% confidence interval 0.56–1.01, P=0.06) as compared with those who reported being thin at age 10 years and at diagnosis. Findings for three related measures of body fatness suggested that obesity is associated with a reduced risk of premenopausal breast cancer. There was no association between sports participation and breast cancer risk in these premenopausal women. The relative risk for spending an average of more than 1 h per week in sports compared with less from ages 12 to 30 years was 1.00 (95% CI 0.86–1.16, P=0.98).British Journal of Cancer (2005) 93, 817–824. doi:10.1038/sj.bjc.6602758 www.bjcancer.com Published online 13 September 2005 [ABSTRACT FROM AUTHOR]

Objectives: To assess the short- and long-term reproducibility of a short food group questionnaire, and to compare its performance for estimating nutrient intakes in comparison with a 7-day diet diary.Design: Participants for the reproducibility study completed the food group questionnaire at two time points, up to 2 years apart. Participants for the performance study completed both the food group questionnaire and a 7-day diet diary a few months apart. Reproducibility was assessed by kappa statistics and percentage change between the two questionnaires; performance was assessed by kappa statistics, rank correlations and percentages of participants classified into the same and opposite thirds of intake.Setting: A random sample of participants in the Million Women Study, a population-based prospective study in the UK.Subjects: In total, 12 221 women aged 50-64 years.Results: In the reproducibility study, 75% of the food group items showed at least moderate agreement for all four time-point comparisons. Items showing fair agreement or worse tended to be those where few respondents reported eating them more than once a week, those consumed in small amounts and those relating to types of fat consumed. Compared with the diet diary, the food group questionnaire showed consistently reasonable performance for the nutrients carbohydrate, saturated fat, cholesterol, total sugars, alcohol, fibre, calcium, riboflavin, folate and vitamin C.Conclusions: The short food group questionnaire used in this study has been shown to be reproducible over time and to perform reasonably well for the assessment of a number of dietary nutrients. [ABSTRACT FROM AUTHOR]

K. Canfell, W. Gray, P. Snijders, C. Murray, S. Tipper, K. Drinkwater and V. BeralFactors predicting successful DNA recovery from archival cervical smear samplesPolymerase chain reaction (PCR)-based DNA testing of archival cervical smear slides is a useful method of retrospectively establishing the presence of the human papillomavirus (HPV) in cervical cells. A cellular DNA recovery test is performed in parallel to HPV DNA testing to ensure that sufficient cells are present and purification of sample DNA has been successfully performed. Previous studies have not comprehensively assessed DNA recovery rates in slides older than 13 years. We undertook a study to determine the factors impacting DNA recovery in 436 UK slides dating from 11 to 33 years prior to testing. Overall, a low cellular DNA recovery success rate of 29% was obtained but a strong trend was observed with increasing recovery rates the older the slides (P < 0.001). Recovery rates increased from 22% in the most recent slides collected from 1988 to 1992, to 61% in the oldest slides, collected in 1970–72. It is likely that fixation compounds incorporating acetic acid, introduced in the UK through the 1980s, have compromised subsequent attempts at PCR amplification. These findings emphasize the importance of the original fixation method in the success of DNA recovery from archival smear samples. [ABSTRACT FROM AUTHOR]

In 2003, the National Health Service Cervical Screening Programme (NHSCSP) announced that its screening interval would be reduced to 3 years in women aged 25-49 and fixed at 5 years in those aged 50-64, and that women under 25 years will no longer be invited for screening. In order to assess these and possible further changes to cervical screening practice in the UK, we constructed a mathematical model of cervical HPV infection, cervical intraepithelial neoplasia and invasive cervical cancer, and of UK age-specific screening coverage rates, screening intervals and treatment efficacy. The predicted cumulative lifetime incidence of invasive cervical cancer in the UK is 1.70% in the absence of screening and 0.77% with pre-2003 screening practice. A reduction in lifetime incidence to 0.63% is predicted following the implementation of the 2003 NHSCSP recommendations, which represents a 63% reduction compared to incidence rates in the UK population if it were unscreened. The model suggests that, after the implementation of the 2003 recommendations, increasing the sensitivity of the screening test regime from its current average value of 56 to 90% would further reduce the cumulative lifetime incidence of invasive cervical cancer to 0.46%. Alternatively, extending screening to women aged 65-79 years would further reduce the lifetime incidence to 0.56%. Screening women aged 20-25 years would have minimal impact, with the cumulative lifetime incidence decreasing from 0.63 to 0.61%. In conclusion, the study supports the 2003 recommendations for changes to cervical screening intervals. [ABSTRACT FROM AUTHOR]

We report results on risk factors for invasive squamous cell and adenocarcinomas of the cervix in women aged 20-44 years from the UK National Case-Control Study of Cervical Cancer, including 180 women with adenocarcinoma, 391 women with squamous cell carcinoma and 923 population controls. The risk of both squamous cell and adenocarcinoma was strongly related to the lifetime number of sexual partners, and, independently, to age at first intercourse. The risk of both types of cervical cancer increased with increasing duration of use of oral contraceptives, and this effect was most marked in current and recent users of oral contraceptives. The risk of squamous cell carcinoma was associated with high parity and the risk of both squamous cell and adenocarcinoma increased with early age at first birth. Long duration smoking (20 or more years) was associated with a two-fold increase in the risk of squamous cell carcinoma, but smoking was not associated with the risk of adenocarcinoma. Further studies are needed to confirm the suggestion from this and other studies of differences in risk related to smoking between squamous cell and adenocarcinomas of the cervix. [ABSTRACT FROM AUTHOR]

Human papillomavirus (HPV) infection is thought to be a necessary but not sufficient cause of most cases of cervical cancer. Since oral contraceptive use for long durations is associated with an increased risk of cervical cancer, it is important to know whether HPV infection is more common in oral contraceptive users. We present a systematic review of 19 epidemiological studies of the risk of genital HPV infection and oral contraceptive use. There was no evidence for a strong positive or negative association between HPV positivity and ever use or long duration use of oral contraceptives. The limited data available, the presence of heterogeneity between studies and the possibility of bias and confounding mean, however, that these results must be interpreted cautiously. Further studies are needed to confirm these findings and to investigate possible relations between oral contraceptive use and the persistence and detectability of cervical HPV infection. [ABSTRACT FROM AUTHOR]

The United Kingdom Childhood Cancer Study, a population-based case-control study covering the whole of Great Britain, incorporated a pilot study measuring electric fields. Measurements were made in the homes of 473 children who were diagnosed with a malignant neoplasm between 1992 and 1996 and who were aged 0-14 at diagnosis, together with 453 controls matched on age, sex and geographical location. Exposure assessments comprised resultant spot measurements in the child's bedroom and the family living-room. Temporal stability of bedroom fields was investigated through continuous logging of the 48-h vertical component at the child's bedside supported by repeat spot measurements. The principal exposure metric used was the mean of the pillow and bed centre measurements. For the 273 cases and 276 controls with fully validated measures, comparing those with a measured electric field exposure >/=20 V m(-1) to those in a reference category of exposure <10 V m(-1), odds ratios of 1.31 (95% confidence interval 0.68-2.54) for acute lymphoblastic leukaemia, 1.32 (95% confidence interval 0.73-2.39) for total leukaemia, 2.12 (95% confidence interval 0.78-5.78) for central nervous system cancers and 1.26 (95% confidence interval 0.77-2.07) for all malignancies were obtained. When considering the 426 cases and 419 controls with no invalid measures, the corresponding odds ratios were 0.86 (95% confidence interval 0.49-1.51) for acute lymphoblastic leukaemia, 0.93 (95% confidence interval 0.56-1.54) for total leukaemia, 1.43 (95% confidence interval 0.68-3.02) for central nervous system cancers and 0.90 (95% confidence interval 0.59-1.35) for all malignancies. With exposure modelled as a continuous variable, odds ratios for an increase in the principal metric of 10 V m(-1) were close to unity for all disease categories, never differing significantly from one. [ABSTRACT FROM AUTHOR]

As part of a larger investigation of cancer in Uganda, we conducted a case-control study of conjunctival squamous cell carcinoma in adults presenting at hospitals in Kampala. Participants were interviewed about social and lifestyle factors and had blood tested for antibodies to HIV, KSHV and HPV-16, -18 and -45. The odds of each factor among 60 people with conjunctival cancer was compared to that among 1214 controls with other cancer sites or types, using odds ratios, estimated with unconditional logistic regression. Conjunctival cancer was associated with HIV infection (OR 10.1, 95% confidence intervals [CI] 5.2-19.4; P<0.001), and was less common in those with a higher personal income (OR=0.4, 95% CI 0.3-0.7; P<0.001)[corrected]. The risk of conjunctival cancer increased with increasing time spent in cultivation and therefore in direct sunlight (chi2 trend=3.9, P=0.05), but decreased with decreasing age at leaving home (chi2 trend=3.9, P=0.05), perhaps reflecting less exposure to sunlight consequent to working in towns, although both results were of borderline statistical significance. To reduce confounding, sexual and reproductive variables were examined among HIV seropositive individuals only. Cases were more likely than controls to report that they had given or received gifts for sex (OR 3.5, 95% CI 1.2-10.4; P=0.03), but this may have been a chance finding as no other sexual or reproductive variable was associated with conjunctival cancer, including the number of self-reported lifetime sexual partners (P=0.4). The seroprevalence of antibodies against HPV-18 and -45 was too low to make reliable conclusions. The presence of anti-HPV-16 antibodies was not significantly associated with squamous cell carcinoma of the conjunctiva (OR 1.5, 95% CI 0.5-4.3; P=0.5) and nor were anti-KSHV antibodies (OR 0.9, 95% CI 0.4-2.1; P=0.8). The 10-fold increased risk of conjunctival cancer in HIV infected individuals is similar to results from other studies. The role of other oncogenic viral infections is unclear. [ABSTRACT FROM AUTHOR]

The authors used data collected from 1995 to 1999, from an on-going cancer case-control study in greater Johannesburg, to estimate the importance of tobacco and alcohol consumption and other suspected risk factors with respect to cancer of the oesophagus (267 men and 138 women), lung (105 men and 41 women), oral cavity (87 men and 37 women), and larynx (51 men). Cancers not associated with tobacco or alcohol consumption were used as controls (804 men and 1370 women). Tobacco smoking was found to be the major risk factor for all of these cancers with odds ratios ranging from 2.6 (95% CI 1.5-4.5) for oesophageal cancer in female ex-smokers to 50.9 (95% CI 12.6-204.6) for lung cancer in women, and 23.9 (95% CI 9.5-60.3) for lung cancer and 23.6 (95% CI 4.6-121.2) for laryngeal cancer in men who smoked 15 or more grams of tobacco a day. This is the first time an association between smoking and oral and laryngeal cancers has been shown in subSaharan Africa. Long-term residence in the Transkei region in the southeast of the country continues to be a risk factor for oesophageal cancer, especially in women (odds ratio = 14.7, 95% CI 4.7-46.0), possibly due to nutritional factors. There was a slight increase in lung cancer (odds ratio = 2.9, 95% CI 1.1-7.5) in men working in 'potentially noxious' industries. 'Frequent' alcohol consumption, on its own, caused a marginally elevated risk for oesophageal cancer (odds ratio = 1.7, 95% CI 1.0-2.9, for women and odds ratio = 1.8, 95% CI 1.2-2.8, for men). The risks for oesophageal cancer in relation to alcohol consumption increased significantly in male and female smokers (odds ratio = 4.7, 95% CI = 2.8-7.9 in males and odds ratio = 4.8, 95% CI 3.2-6.1 in females). The above results are broadly in line with international findings. [ABSTRACT FROM AUTHOR]

BACKGROUND: Little is known about the factors influencing the risk of recall for assessment, invasive diagnostic procedures, and early rescreening after screening mammography. METHODS: From June 1996 to March 1998 women attending screening at 10 National Health Service Breast Screening Programme (NHSBSP) centres completed a self administered questionnaire and were followed up for their screening outcome. RESULTS: 1969 (3.3%) out of 60 443 women aged 50–64 who had never used hormone replacement therapy (HRT) were recalled for assessment but were not diagnosed with breast cancer (defined here as false positive recall). After adjustment for the variation between centres, false positive recall was decreased significantly among women who were likely to have had a previous NHSBSP mammogram (odds ratio (OR) 0.49, 95% confidence interval (95% CI) 0.38 to 0.63 for likely versus unlikely), who were postmenopausal (OR 0.65, 95% CI 0.56 to 0.76 for postmenopausal v premenopausal) and increased significantly for women reporting previous breast surgery (OR 1.64, 95% CI 1.42 to 1.89). Although false positive recall decreased significantly with parity and increasing body mass index, these effects were not large and no significant variation was found with age, education, family history of breast cancer, oral contraceptive use, sterilisation, exercise, smoking, or alcohol consumption. Altogether 655 (1.1%) women had an invasive diagnostic procedure; no personal characteristics were predictive of this outcome, 286(0.5%) were referred for early rescreening, and this was increased significantly by nulliparity and a family history of breast cancer. INTERPRETATION: Premenopausal women, those without a previous NHSBSP mammogram, and women with previous breast surgery have an increased risk of false positive recall by the NHSBSP. [ABSTRACT FROM AUTHOR]

Investigates the primary infertility risk of employees in the nuclear industry in Great Britain. Percentage of employees with primary infertility; Amount of ionizing radiation detected in the employees; Prevalence of infertility among women.

The association between soya foods and breast cancer risk was investigated in a prospective study of 34 759 women in Hiroshima and Nagasaki, Japan. Women completed dietary questionnaires in 1969-1970 and/or in 1979-1981 and were followed for incident breast cancer until 1993. The analysis involved 427 cases of primary breast cancer in 488 989 person-years of observation. The risk for breast cancer was not significantly associated with consumption of soya foods: for tofu, relative risks adjusted for attained age, calendar period, city, age at time of bombings and radiation dose to the breast were 0.99 (95% CI 0.80-1.24) for consumption two to four times per week and 1.07 (0.78-1.47) for consumption five or more times per week, relative to consumption once a week or less; for miso soup, relative risks were 1.03 (0.81-1.31) for consumption two to four times per week and 0.87 (0.68-1.12) for consumption five or more times per week, relative to consumption once a week or less. These results were not materially altered by further adjustments for reproductive variables and were similar in women diagnosed before age 50 and at ages 50 and above. Among 17 other foods and drinks examined only dried fish (decrease in relative risk with increasing consumption) and pickled vegetables (higher relative risk with higher consumption) were significantly related to breast cancer risk; these associations were not prior hypotheses and, because of the large number of comparisons made, they may be due to chance. [ABSTRACT FROM AUTHOR]

Because routinely collected survival data for cancer patients in England and Wales do not typically specify cause of death, conventional estimates of survival in cancer patients based on such data are a measure of their mortality from all causes rather than their mortality due to cancer. As a result, trends in survival over time are difficult to interpret because changes in overall survival may well reflect changes in the risk of death from other causes, rather than from the cancer of interest. One way of overcoming this problem is to use some form of 'relative survival' defined as a measure of survival corrected for the effect of other independent causes of death. Since this concept was first introduced, various methods for calculating relative survival have been proposed and this had led to some confusion as to the most appropriate choice of estimate. This paper aims to provide an introduction to the concept of relative survival and reviews some of the suggested methods of estimation. In addition, a particularly simple, but robust approach, is highlighted based on expected and observed mortality. This method is illustrated using preliminary data from the Office for National Statistics on cancer survival in patients born after 1939 and diagnosed with cancer during 1972-84. The examples presented, although limited to analyses on a small number of selected sites, highlight some encouraging trends in survival in people aged under 35 diagnosed with leukaemia, Hodgkin's disease and testicular cancer during this period. [ABSTRACT FROM AUTHOR]