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Anthony B Miller

Publications and source records attributed to Anthony B Miller.

At least 55 records · Page 3Linked to original sources
PubMed2003

Why is breast-cancer mortality declining?

Population statistics indicate that age-adjusted breast-cancer mortality rates began to decline during the early 1990s in many developed countries. For several decades before 1990, breast-cancer mortality rates in these countries had been either stable or increasing. Many investigators attribute the decline in mortality to mammography screening. However, randomised prospective trials indicate that there is a delay of 10 years before the effect of such screening can be seen in mortality statistics. In many developed countries, screening programmes were launched in the late 1980s and early 1990s, so the sudden decline in breast-cancer mortality in the early 1990s was much too soon to be attributable to mammography screening. In this review, we argue that although some of the decline in breast-cancer mortality is due to a reduction in breast-cancer risk, most of it can probably be attributed to adjuvant systemic therapy and the earlier detection of palpable tumours. We also explain why advances in the treatment of breast cancer might be outpacing the value of mammography screening. Since age-adjusted mortality rates are the most basic measure of progress in the treatment of breast cancer, we suggest that careful scrutiny of recent trends in breast-cancer mortality may provide important insights into the effectiveness of novel strategies for diagnosis and treatment.

Breast Neoplasms↗
PubMed2003

Primary and secondary prevention in colorectal cancer.

Colorectal cancer is an important public health problem: there are nearly one million cases of colorectal cancer diagnosed worldwide each year and half a million deaths. The geographic distribution of colorectal cancer follows the division between westernized versus developing countries, The highest rates are in North America, Australia and Europe. Rates in Africa and Asia are low, but are increasing in countries adopting western-style dietary habits. Given that the majority of cancers occur in older people, and with the ageing of the population in mind, this observation adds impetus to investigating prevention strategies to avoid some of this increase. High vegetable and fruit consumption has been associated with decreased risk of colorectal cancer in numerous observational studies, while high fibre intake seems to have a similar effect. Promising data have been obtained for aspirin and other non-steroidal anti-inflammatory drugs, and dietary calcium. A physically active lifestyle and maintenance of normal body weight are behavioural tools for prevention of colorectal cancer. Faecal occult blood testing has been shown to be effective in the prevention of about 20% of deaths from colorectal cancer, but few population-based screening programs have been initiated. Sigmoidoscopy and colonoscopy are potentially effective screening modalities; however, no randomized trial data have yet been reported. Overall, primary and secondary prevention, chemoprevention and screening research and implementation of these prevention strategies are priorities for reduction of colorectal cancer incidence and mortality.

Body Weight↗
PubMed2003

Quantity and quality of dietary fat, carbohydrate, and fiber intake in the German EPIC cohorts.

AIM: This evaluation aims to describe the quantity and quality of dietary fat, carbohydrate and fiber intake in both German cohorts participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS: Estimates are based on standardized computer-guided 24-hour dietary recalls from 1,078 women and 1,013 men in Heidelberg and 898 women and 1,032 men in Potsdam. In a subsample, plasma phospholipid (PL) fatty acids were analyzed as well. RESULTS: Adjusted mean dietary intake estimates demonstrated that the contribution of fat as well as n-6 and n-3 polyunsaturated fatty acids (PUFA) to the total daily energy intake was higher in both women and men of EPIC-Potsdam compared to EPIC-Heidelberg. Surprisingly, the dietary n-6/n-3 PUFA ratio was lower in the Potsdam cohort. These results were confirmed by means of the PL fatty acid pattern. Besides the higher contribution of polysaccharides to total energy intake in EPIC-Heidelberg, women of the Heidelberg cohort revealed a significantly lower contribution of mono- and disaccharides (sucrose) to total energy intake. Although total fiber intake data were similar in both cohorts, analysis by food groups showed differences in dietary fiber intake originating from the food groups cereals, fruits and potatoes. CONCLUSION: The results demonstrate distinct differences in the dietary fat, carbohydrate and fiber intake between both German EPIC cohorts, which contribute to the exposure variation in the whole of EPIC.

Adult↗
PubMed2002

The Canadian National Breast Screening Study-1: breast cancer mortality after 11 to 16 years of follow-up. A randomized screening trial of mammography in women age 40 to 49 years.

BACKGROUND: The efficacy of breast cancer screening in women age 40 to 49 years remains controversial. OBJECTIVE: To compare breast cancer mortality in 40- to 49-year-old women who received either 1) screening with annual mammography, breast physical examination, and instruction on breast self-examination on 4 or 5 occasions or 2) community care after a single breast physical examination and instruction on breast self-examination. DESIGN: Individually randomized, controlled trial. SETTING: 15 Canadian centers. PARTICIPANTS: 50 430 volunteers age 40 to 49 years, recruited from January 1980 to March 1985, who were not pregnant, had no previous breast cancer diagnosis, and had not had mammography in the preceding 12 months. INTERVENTIONS: Breast physical examination and instruction on breast self-examination preceded random assignment of 25 214 women to receive mammography and annual mammography, breast physical examination, and breast self-examination and 25 216 women to receive usual community care with annual follow-up. MEASUREMENTS: Verified breast cancer incidence and cohort mortality through 31 December 1993 and deaths from breast cancer through 30 June 1996. RESULTS: The 105 breast cancer deaths in the mammography group and 108 breast cancer deaths in the usual care group yielded a cumulative rate ratio, adjusted for mammography done outside the study, of 1.06 (95% CI, 0.80 to 1.40). A total of 592 cases of invasive breast cancer and 71 cases of in situ breast cancer were diagnosed by 31 December 1993 in the mammography group compared with 552 and 29 cases, respectively, in the usual care group. The expected proportions of nonpalpable and small invasive tumors were detected on mammography. CONCLUSION: After 11 to 16 years of follow-up, four or five annual screenings with mammography, breast physical examination, and breast self-examination had not reduced breast cancer mortality compared with usual community care after a single breast physical examination and instruction on breast self-examination. The study data show that true effects of 20% or greater are unlikely.

Adult↗
PubMed2002

Cigarette smoking and breast cancer risk: a long latency period?

The association between cigarette smoking and breast cancer risk remains unclear. Few studies have examined cigarette smoking of very long duration as there may not have been a sufficient number of long-term smokers in studies conducted before the 1980s. Therefore, we examined the association between smoking and breast cancer risk using data from participants in a randomized controlled trial of screening for breast cancer involving 89,835 women aged 40-59 years at recruitment and with up to 40 years of smoking duration at that time. Women with breast cancer diagnosed through 31 December 1993 were identified by linkage to the Canadian Cancer Database. Cox proportional hazards models were used to estimate rate ratios (RRs) and 95% confidence intervals (CIs). During an average of 10.6 years of follow-up, we observed 2,552 incident cases of breast cancer. We found a positive association between cigarette smoking and breast cancer risk, driven mainly by women who had smoked for several decades and who, therefore, had commenced smoking many years earlier. Relative to never-smokers, women who had smoked 40 years or more and 20 cigarettes/day or more were at the highest risk (RR = 1.83, 95% CI 1.29-2.61); for women who had commenced smoking 40 years or more before assessment (a measure of smoking latency rather than duration and intensity), the RR was 1.22 (95% CI 0.99-1.59). Our findings suggest that smoking of very long duration and high intensity may be associated with increased risk of breast cancer.

Age Factors↗
PubMed2002

Prospective cohort study of cigarette smoking and colorectal cancer risk in women.

Epidemiological studies have consistently found a positive association between cigarette smoking and risk of colorectal adenomas, so the absence of a clear association between smoking and colorectal cancer risk may seem paradoxical. However, if colorectal cancer develops only after an induction period of about 35 years, as has been proposed recently, then studies in which all subjects have fewer than about 35 years between smoking commencement and assessment of outcome would be unlikely to detect this association. Few studies have examined smoking of several decades' duration among women. Therefore, in the cohort study reported here, we used proportional hazards models to estimate hazard ratios relating cigarette smoking to colorectal cancer risk among 89,835 women aged 40-59 years at recruitment into the Canadian National Breast Screening Study, a randomized controlled trial of mammography screening for breast cancer. During an average 10.6 years of follow-up (936,433 person-years), a total of 527 women were diagnosed with incident colorectal cancer (363 colon and 164 rectal). We found that smoking was associated with increased risk of rectal cancer 30 years or more after commencement, and especially with smoking of 40 years' duration or longer (hazard ratio=3.14, 95% CI=1.33-7.42). There was little evidence for altered risk of colon cancer. These results, along with those of other recent studies, support the hypothesis that tobacco smoking is an initiator, rather than a promoter, of rectal cancer. However, the results do not support an association with colon cancer risk, even with smoking of very long duration and high intensity.

Adult↗
PubMed2002

Dietary intake of folic acid and colorectal cancer risk in a cohort of women.

Folate is crucial for normal DNA methylation, synthesis and repair, and deficiency of this nutrient is hypothesized to lead to cancer through disruption of these processes. There is some evidence to suggest that relatively high dietary folate intake might be associated with reduced colorectal cancer risk, especially among individuals with low methionine intake. A case-cohort analysis was undertaken within the cohort of 56,837 women who were enrolled in the Canadian National Breast Screening Study and who completed a self-administered dietary questionnaire. During follow-up to the end of 1993, a total of 389 women were diagnosed with colorectal cancer, identified by linkage to the Canadian Cancer Database. For comparative purposes, a subcohort of 5,681 women was randomly selected from the full dietary cohort at baseline. After exclusions for various reasons, the analyses were based on 295 cases and 5,334 non-cases. Folate intake was inversely associated with colorectal cancer risk (IRR = 0.6, 95% CI = 0.4-1.1, p for trend = 0.25). The inverse association was essentially similar among individuals with low and high methionine intake, and was similar for colon and rectal cancers when those endpoints were analyzed separately. Among individuals with low methionine intake, folate intake did not appear to lower the risk of rectal cancer, a finding that may be due, in part, to the low number of cases in the subgroup analysis. Overall, our data lend some support to the hypothesis that high folate intake is associated with a reduced risk of colorectal cancer.

Body Mass Index↗
PubMed2002

Quality assurance in screening strategies.

The pre-requisites for successful screening programmes include understanding and acceptance of the necessity for tests with achieved high coverage of those at risk for the disease, provision of screening tests, provision of facilities for treatment of abnormalities, and acceptance by women of the necessity for further investigation of abnormalities, all requiring attention to quality assurance. Screening programmes for cancer of the cervix have been very effective in many developed countries but in very few developing countries. In general, the failures in developing countries can be directly related to failure to achieve adequate quality in one or other component of a programme. Some of these failures occur at the level of the laboratory, but in several Latin American countries, there are superb laboratories, but overall the programme has failed to achieve the expected impact. In some countries this has led to alternatives to the cytology smear being evaluated, without recognition that it is not the test that has failed, but another essential component of an effective programme. The solution is attention to management and organisation at all levels, with quality assurance at each. This is required at the level of: definition of the target population, identification of the individual women in the target population, recruitment of the at risk woman to screening, administration of the screening test, laboratory examination of the test, communication of results from the laboratory to the woman and her physician, ensuring the woman attends for investigation and management of abnormal screening tests, ensuring adequate therapy of lesions identified by the diagnostic process, ensuring adequate follow-up of treated women, ensuring women with negative screening tests return for re-screening at the appropriate intervals, and monitoring and evaluation of the programme.

DNA, Viral↗
PubMed2002

A cohort study of dietary carotenoids and lung cancer risk in women (Canada).

OBJECTIVE: To investigate the association between dietary carotenoid intake and lung cancer risk in women. METHODS: A case-cohort study was undertaken in the Canadian National Breast Screening Study dietary cohort, which consists of 56,837 women who completed a self-administered dietary questionnaire. The cohort was recruited between 1980 and 1985, and during follow-up to the end of 1993 a total of 196 cohort members were diagnosed with incident lung cancer. For analysis, a subcohort consisting of a random sample of 5681 women was selected from the full dietary cohort. After exclusions for various reasons, the analyses were based on 155 cases and 5,361 non-cases. RESULTS: When compared to those in the lowest quartile level of intake, the adjusted incidence rate ratios (95% confidence intervals) for those in the highest quartile levels of alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein intake were 0.90 (0.51-1.58). 1.40 (0.76-2.59), 0.66 (0.33-1.32), 1.04 (0.61-1.76), and 1.26 (0.70-2.24), respectively; none of the associated tests for trend was statistically significant. CONCLUSION: These results suggest that there is no association between dietary carotenoid intake and lung cancer risk. at least for the range of intakes observed here.

Adult↗
PubMed2002

Dietary carotenoids and risk of breast cancer.

BACKGROUND: Many studies of fruit and vegetable consumption showed inverse associations with breast cancer risk, suggesting the potential importance of carotenoids (and other phytochemicals) contained in these foods. To date, however, only one prospective cohort study has examined dietary carotenoids other than beta-carotene in relation to breast cancer risk. OBJECTIVE: Our aim was to examine the relations between dietary intakes of beta-carotene, alpha-carotene, beta-cryptoxanthin, lycopene, and lutein + zeaxanthin and breast cancer risk in a large cohort study of Canadian women. DESIGN: A case-cohort analysis was undertaken in a cohort of 56 837 women who were enrolled in the Canadian National Breast Screening Study and who completed a self-administered dietary questionnaire. During follow-up to the end of 1993 a total of 1589 women were diagnosed with biopsy-confirmed incident breast cancer. For comparison, a subcohort of 5681 women was randomly selected. After exclusions for various reasons, the analyses were based on 1452 cases and 5239 noncases. RESULTS: We found no clear association between intakes of any of the studied carotenoids and breast cancer risk in the study population as a whole or in subgroups defined by smoking status; relative body weight (assessed by body mass index); intakes of total fat, energy, alcohol, or folic acid; family history of breast cancer; or menopausal status. CONCLUSIONS: Our data do not support any association between dietary intakes of the studied carotenoids and breast cancer risk. However, prospective cohort studies of carotenoids in relation to breast cancer are scarce and further studies are warranted.

Breast Neoplasms↗
PubMed2002

Meat and dairy food consumption and breast cancer: a pooled analysis of cohort studies.

BACKGROUND: More than 20 studies have investigated the relation between meat and dairy food consumption and breast cancer risk with conflicting results. Our objective was to evaluate the risk of breast cancer associated with meat and dairy food consumption and to assess whether non-dietary risk factors modify the relation. METHODS: We combined the primary data from eight prospective cohort studies from North America and Western Europe with at least 200 incident breast cancer cases, assessment of usual food and nutrient intakes, and a validation study of the dietary assessment instrument. The pooled database included 351,041 women, 7379 of whom were diagnosed with invasive breast cancer during up to 15 years of follow-up. RESULTS: We found no significant association between intakes of total meat, red meat, white meat, total dairy fluids, or total dairy solids and breast cancer risk. Categorical analyses suggested a J-shaped association for egg consumption where, compared to women who did not eat eggs, breast cancer risk was slightly decreased among women who consumed < 2 eggs per week but slightly increased among women who consumed > or = 1 egg per day. CONCLUSIONS: We found no significant associations between intake of meat or dairy products and risk of breast cancer. An inconsistent relation between egg consumption and risk of breast cancer merits further investigation.

Animals↗
PubMed2002

Dietary carotenoid intake and colorectal cancer risk.

Several studies have found inverse associations between fruit and vegetable consumption and colorectal cancer risk, suggesting the potential etiological importance of carotenoids (and other phytochemicals) contained in these foods. However, only one study (a case-control study) has examined the association between dietary carotenoids other than beta-carotene and colorectal cancer risk. In the study reported here, we examined the relationships between dietary intakes of beta-carotene, alpha-carotene, lycopene, lutein, and beta-cryptoxanthin and colorectal cancer risk in a large cohort study of Canadian women. A case-cohort analysis was undertaken within the cohort of 56,837 women who were enrolled in the Canadian National Breast Screening Study and who completed a self-administered dietary questionnaire. During follow-up to the end of 1993, a total of 388 women were diagnosed with colorectal cancer. For comparative purposes, a subcohort of 5,681 women was randomly selected. After exclusions for various reasons, the analyses were based on 295 cases and 5,334 noncases. We did not find any clear association between intake of any of the studied carotenoids and colorectal cancer risk in the study population as a whole or in subgroups defined by smoking status, relative body weight (body mass index), intakes of total fat, energy, alcohol, and folic acid, or menopausal status. Our data do not support any association between dietary intakes of the studied carotenoids and colorectal cancer risk. However, given that this is the first prospective cohort study of carotenoids in relation to colorectal cancer, further studies are warranted.

Adult↗
PubMed2002

Dietary fat and risk of lung cancer in a pooled analysis of prospective studies.

Lung cancer rates are highest in countries with the greatest fat intakes. In several case-control studies, positive associations have been observed between lung cancer and intakes of total and saturated fat, particularly among nonsmokers. We analyzed the association between fat and cholesterol intakes and lung cancer risk in eight prospective cohort studies that met predefined criteria. Among the 280,419 female and 149,862 male participants who were followed for up to 6-16 years, 3,188 lung cancer cases were documented. Using the Cox proportional hazards model, we calculated study-specific relative risks that were adjusted for smoking history and other potential risk factors. Pooled relative risks were computed using a random effects model. Fat intake was not associated with lung cancer risk. For an increment of 5% of energy from fat, the pooled multivariate relative risks were 1.01 [95% confidence interval (CI), 0.98-1.05] for total, 1.03 (95% CI, 0.96-1.11) for saturated, 1.01 (95% CI, 0.93-1.10) for monounsaturated, and 0.99 (95% CI, 0.90-1.10) for polyunsaturated fat. No associations were observed between intakes of total or specific types of fat and lung cancer risk among never, past, or current smokers. Dietary cholesterol was not associated with lung cancer incidence [for a 100-mg/day increment, the pooled multivariate relative risk was 1.01 (95% CI, 0.97-1.05)]. There was no statistically significant heterogeneity among studies or by sex. These data do not support an important relation between fat or cholesterol intakes and lung cancer risk. The means to prevent this important disease remains avoidance of smoking.

Case-Control Studies↗
PubMed2002

Plasma 7beta-hydroxycholesterol as a possible predictor of lung cancer risk.

Epidemiological data suggests a role of dietary cholesterol in the etiology of lung cancer without having a clear biological hypothesis. Although smoking as the outstanding risk factor for lung cancer may enhance lipid peroxidation reactions, this study was planned to assess smoking-independent associations between the extent of cholesterol oxidation and the risk for lung cancer. In the frame of a nested case-control study in European Prospective Investigation on Cancer-Heidelberg, six cholesterol oxidation products (COPs) were determined in plasma samples of 20 incident lung cancer patients obtained 1.9 +/- 0.6 years before diagnosis and in 40 matched (including smoking habits) controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by conditional logistic regression. Among all COP compounds tested, plasma 7beta-hydroxycholesterol was associated with lung cancer risk. The high crude risk estimate (OR approximately equals 5) became significant after adjustment for sports activity (OR = 6.83, CI = 1.08-43.01, 3rd versus 1st tertile). For the independent effect of 7beta-hydroxycholesterol, i.e., adjusted for other COP compounds, an OR of 8.08 (CI = 1.12-58.54, 3rd versus 1st tertile) was calculated (P = 0.04 for trend). Lung cancer risk adjusted for sports activity significantly increased by 26% (CI = 1.050-1.506, P = 0.01) per unit (1 nmol/mmol plasma cholesterol) of 7beta-hydroxycholesterol. No dietary factor had a significant effect in the regression model, but the dietary intake of meat, eggs, animal fat, cholesterol, and fruits (inversely) correlated with plasma COP concentrations. In this small study, plasma 7beta-hydroxycholesterol appeared to be a smoking-independent predictor of lung cancer risk and might therefore be used as a biomarker. Because of the rather high-risk estimate, research on possible intrinsic biological effects of this compound should be encouraged.

Adenocarcinoma↗