Diet and cancer prevention: where we are, where we are going

The European Prospective Investigation into Cancer and Nutrition (EPIC) was specifically designed to investigate the relationship between diet and cancer, with the aims of making a significant contribution to the accumulated scientific knowledge, trying to overcoming limitations of previous study. We present the most relevant results obtained so far for the most frequent cancer sites. EPIC is a multicenter prospective study carried out in 23 centers from 10 European countries: Denmark, France, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden, and the United Kingdom, including 519,978 subjects (366,521 women and 153,457 men), most aged 35-70 years. Consumption of fruit is negatively associated with cancer of the lung but probably not with prostate cancer and breast cancer. Consumption of vegetables, mainly onion and garlic, probably reduces the risk of the intestinal stomach cancer but probably is not associated with cancer of the lung, prostate, and breast cancer. Consumption of red and processed meat is positively associated with colorectal cancer and with non-cardia stomach cancer in those infected by Helicobacter pylori. Fish intake is negatively associated with colorectal cancer risk. High alcohol intake increases the risk of breast cancer. These first results from the EPIC study on main food groups and most frequent tumors have made a significant contribution to the already accumulated evidence and, in combination with data from other prospective studies, provide the scientific knowledge for appropriate public health strategies aimed at reducing the global cancer burden.     

Allergy,atopy, and cancer: a prospective study of the 1981 Busselton cohort

The associations among certain allergic disorders, atopy upon skin-prick testing, and specific cancers were evaluated in a prospective study. Information regarding history of asthma and hay fever was collected by questionnaire from 3,308 cancer-free participants in the 1981 Busselton Health Survey. A subset of 1,005 participants also underwent skin-prick testing. The cohort was followed for a new diagnosis of cancer or death until the end of 1999. Cox proportional hazards regression analysis was used to estimate adjusted hazard ratios (relative risks) for breast, prostate, colorectal, lung, and hematologic cancers and melanoma. Having a skin reaction to house dust mites nearly tripled the risk of prostate cancer (relative risk = 2.90, 95% confidence interval: 1.26, 6.68). History of asthma and hay fever were associated with a trend toward a reduced risk of colorectal cancer and increased risk of leukemia, but these results were not statistically significant. Hay fever was associated with melanoma risk in men but not in women. No association was found between breast and lung cancers and allergic disorders or atopy.     

Impact of lactose containing foods and the genetics of lactase on diseases: an analytical review of population data

Dairy foods (DFs) contain complex ingredients that could affect different diseases. The control of lactose digestion phenotypically divides populations into those who can [lactase persistent (LP)] and those who cannot [lactase nonpersistent (LNP)] assimilate lactose. LNP subjects, however, can adapt to lactose intolerance through intestinal bacteria. The DF/LNP status interactions may function as disease risk modifiers. We evaluated the relationship between DF and LNP with colorectal, breast, prostate, ovarian, lung, and stomach cancer and inflammatory bowel diseases (IBD; Crohn's disease and ulcerative colitis). Yearly per capita DF consumption, LNP national prevalence, cancer mortality, and incidence of IBD were obtained from several sources. A negative binomial regression model was used to derive incremental risks. There were statistically significant (P 相似文献   

Impact of Lactose Containing Foods and the Genetics of Lactase on Diseases: An Analytical Review of Population Data

Dairy foods (DFs) contain complex ingredients that could affect different diseases. The control of lactose digestion phenotypically divides populations into those who can [lactase persistent (LP)] and those who cannot [lactase nonpersistent (LNP)] assimilate lactose. LNP subjects, however, can adapt to lactose intolerance through intestinal bacteria. The DF/LNP status interactions may function as disease risk modifiers. We evaluated the relationship between DF and LNP with colorectal, breast, prostate, ovarian, lung, and stomach cancer and inflammatory bowel diseases (IBD; Crohn's disease and ulcerative colitis). Yearly per capita DF consumption, LNP national prevalence, cancer mortality, and incidence of IBD were obtained from several sources. A negative binomial regression model was used to derive incremental risks. There were statistically significant (P ≤ 0.05) increases in risk for colorectal and prostate cancer and ulcerative colitis with DFs and a statistically significant decreased risk for stomach cancer. There were trends (P < 0.1) for lung and ovarian cancers and Crohn's disease. As LNP prevalence increased, stomach cancer risk increased, whereas risks of all other conditions decreased (P < 0.01). In 3 cancers (prostate, ovarian, and breast), meta-analyses of case-based studies support ecological data. In colorectal cancer, on the contrary, meta-analyses of case-based studies suggest protection. The possible importance of distinguishing LNP/LP status in studies is discussed.     

Incidence and mortality due to cancer in Navarre, 1998-2002. Trends in the last 30 years

Between 1998-2002, 16,952 new cases of cancer were registered in Navarre. In men, the most frequently diagnosed cancers were in the following order: prostate, lung, colon and rectum, bladder and stomach, which accounted for 63.2%. In women, the sites were breast, colon and rectum, corpus uteri, stomach and ovary, which accounted for 57.6% of the cases. In the same period, 1998-2002, 4,127 men and 2,470 women died from cancer. Sixty percent of all deaths due to malign tumours in men were due to cancer of the lung, prostate, colon and rectum, stomach and bladder. In women this was due to cancers of colon and rectum, breast, stomach, pancreas and lung, which accounted for 49% of the cases. In men in Navarre there has been an increase in the incidence rates of cancer of the prostate, kidney and non-Hodgkin lymphoma. Avoidable cancers such as those related to smoking (lung, oral cavity and pharynx or pancreas) continue to rise, and represent a greater global risk of dying from cancer in the latest period studied than in the decades of the 1970s and 1980s. From 1995 up to the present, mortality due to cancer has moved from occupying the second place to become the first cause of death among men in Navarre. The global risk of death due to cancer in men is now equal to the first period studied, 1975-1977. Amongst women the global risk of death due to cancer fell by 25% between 1975 and 2002, basically at the cost of breast and stomach cancer. Tumours related to smoking increased both in mortality and in incidence and appear as a significant health problem amongst women in Navarre. Breast cancer has increased in incidence, with lower mortality figures than those of the first period 1975-1977. Invasive cancer of the cervix remains at very low rates in comparison with many European countries, including Spain. In both sexes colorectal and skin cancer has increased, while the incidence and mortality of stomach cancer continues to fall.     

Childhood dairy intake and adult cancer risk: 65-y follow-up of the Boyd Orr cohort

BACKGROUND: Dairy consumption affects biological pathways associated with carcinogenesis. Evidence for a link between cancer risk and dairy consumption in adulthood is increasing, but associations with childhood dairy consumption have not been studied adequately. OBJECTIVE: We investigated whether dairy consumption in childhood is associated with cancer incidence and mortality in adulthood. DESIGN: From 1937 through 1939, some 4,999 children living in England and Scotland participated in a study of family food consumption, assessed from 7-d household food inventories. The National Health Service central register was used to ascertain cancer registrations and deaths between 1948 and 2005 in the 4,383 traced cohort members. Per capita household intake estimates for dairy products and calcium were used as proxy for individual intake. RESULTS: During the follow-up period, 770 cancer registrations or cancer deaths occurred. High childhood total dairy intake was associated with a near-tripling in the odds of colorectal cancer [multivariate odds ratio: 2.90 (95% CI: 1.26, 6.65); 2-sided P for trend = 0.005] compared with low intake, independent of meat, fruit, and vegetable intakes and socioeconomic indicators. Milk intake showed a similar association with colorectal cancer risk. High milk intake was weakly inversely associated with prostate cancer risk (P for trend = 0.11). Childhood dairy intake was not associated with breast and stomach cancer risk; a positive association with lung cancer risk was confounded by smoking behavior during adulthood. CONCLUSIONS: A family diet rich in dairy products during childhood is associated with a greater risk of colorectal cancer in adulthood. Confirmation of possible underlying biological mechanisms is needed.     

Incidence and mortality of cancer in Navarra, 1993-1997. Tendencies in the last 25 years

Between 1993-1997, there were 14,023 new cases of cancer registered in Navarra. In men, the most frequently diagnosed cancers were in the following order: lung, prostate, colon and rectum, stomach and bladder, which accounted for 60% of all the cancer cases. In women the sites of breast, colon and rectum, body of uterus, stomach and ovary accounted for 57% of the total number of cases. In the same period, 1993-1997, 3,875 men and 2,332 women died of cancer. 60% of all the deaths caused by malignant tumours in men were due to the sites of lung, colon and rectum, prostate, stomach and bladder. In women the sites of breast, colon and rectum, stomach, pancreas and liver, accounted for 51% of deaths from cancer. Amongst men in Navarra there has been an important increase in the last two decades of the rates of incidence and mortality of cancers related to the habit of smoking (lung, oral cavity and pharynx or pancreas). The global risk of dying from cancer was higher in the late 90s than in the 70s and 80s. From 1995 onwards, cancer mortality advanced from second place to occupy the first place as the cause of death amongst men in Navarra. Amongst women, cardiovascular diseases continue to be the first cause of death. Amongst women the global risk of death from cancer fell by 20% between 1975 and 1997, due principally to a fall in cases of stomach cancer. Tumours related to the habit of smoking have not so far shown substantial increases amongst women in Navarra. Breast cancer has increased in recent years, although its incidence and mortality amongst women in Navarra continues to be somewhat lower than the average in the European Union and the United States. Invasive cervical cancer remains at very low rates with respect to many European countries, including Spain. In both sexes there has been an increase in colorectal cancer and melanoma, while the incidence and mortality of stomach cancer continues to fall.     

Garlic consumption and cancer prevention: meta-analyses of colorectal and stomach cancers

BACKGROUND: Animal and in vitro studies have provided evidence of an anticarcinogenic effect of active ingredients in garlic. OBJECTIVE: The objective was to conduct meta-analyses of the epidemiologic literature on the association between garlic consumption and risk of stomach, colon, head and neck, lung, breast, and prostate cancers. DESIGN: Meta-analyses were conducted for all cancers mutually and separately for colorectal and stomach cancers in relation to consumption of exclusively raw garlic, cooked garlic, or both (RC garlic). Eighteen studies reported a relative risk estimate for RC garlic consumption and cancer risk. RESULTS: In the meta-analyses of colorectal and stomach cancer, the reference categories ranged from no consumption to consumption of 3.5 g/wk, whereas the highest categories ranged from any consumption to >28.8 g/wk. The average difference between the highest and lowest categories was 16 g/wk. The random-effects relative risk (RR) estimate of colorectal cancer and RC garlic consumption, excluding garlic supplements, was 0.69 (95% CI: 0.55, 0.89). For stomach cancer, the random-effects RR estimate was 0.53 (95% CI: 0.31, 0.92). The heterogeneity among studies for the latter outcome (P: = 0.0002) indicates the questionableness of the generalizability of this summary estimate. An indication of publication bias for all cancers combined is evident from a funnel plot of RC garlic consumption and cancer risk and from the results of the Begg and Mazumdar test (P: = 0.049). CONCLUSIONS: High intake of RC garlic may be associated with a protective effect against stomach and colorectal cancers. Heterogeneity of effect estimates, differences in dose estimation, publication bias, and possible alternative hypotheses (eg, confounding by total vegetable consumption) preclude sole reliance on summary effect estimates.     

Trends in incidence of cancer in southeast North Brabant and North Limburg during 1975-1986; report from the IKZ/SOOZ cancer registration (Integrated Cancer Center South/Cooperative Organization Oncology Hospitals)

Trends in the incidence of cancer have been determined in the Southeast of the Netherlands from 1975 to 1986 inclusive by means of the regional SOOZ cancer registry. Age-adjusted registration rates of cancer in males rose rather steeply from more than 371 per 10(5) men-years to 424 in 1982-3 and fell thereafter to 407 per 10(5) in 1986. A similar changing pattern was seen in cancer of the lung, larynx, prostate and kidney and possibly also in cancer of the head and neck. The incidence of colorectal cancer had skin melanoma increased while that of cancer of the stomach fell. Age-adjusted incidence of cancer in females rose steadily from 266 to 290 per 10(5) woman-years. A steady increase was observed for cancer of the lung, breast, bladder and melanoma and temporarily for cancer of the kidney. The incidence of cancer of the stomach and gallbladder fell continuously. These changes in incidence generally corresponded with trends in cancer mortality as registered with the Central Bureau of Statistics. Bias from changes in data collection and coding appears to be negligible, but a certain influence on the registration rates from the markedly increased number of consultants managing cancer patients is likely. Contrasting trends in male and female rates of cancer of the airways illustrate the marked changes in smoking patterns since the sixties.     

Folate levels and cancer morbidity and mortality: prospective cohort study from Busselton, Western Australia

PURPOSE: To test a community population for the hypothesis that carcinogenesis is related to blood folate levels. METHODS: Prospective analysis of cancer mortality data for a cohort of 964 men (person-time follow up: 20,254 years) and 1024 women (person-time follow up: 24,970 years) and morbidity data for a subcohort, all of whom participated in the 1969 Busselton (Western Australia) Health survey. Outcome measures were adjusted hazard ratios according to baseline folate levels for total cancer mortality and morbidity and site specific mortality and morbidity for colorectal, lung, breast, and prostate cancers. RESULTS: In total, there were 278 cancer deaths--45 from colorectal cancer, 44 from lung cancer, 15 from breast cancer, and 31 from prostate cancer. Decreased serum folate levels showed an independent association with increased prostate cancer mortality risk, the adjusted hazard ratio per decrease of 2 microg/L was 1.56 (CI: 1.05, 2.38), men whose levels were in the lowest quartile had an adjusted hazard ratio of 4.79 (CI: 1.56, 14.43) for subsequent death from prostate cancer. The morbidity subcohort data showed that decreased red blood-cell folate was significantly associated with increased events due to breast cancer, the adjusted hazard ratio per decrease of 100 mug/L was 1.96 (CI: 1.22, 3.12), women in the lowest quartile of red cell folate levels had an adjusted hazard ratio of 6.46 (CI: 1.19, 35.07) for a subsequent breast cancer event. Mortality and morbidity from colorectal or lung cancers were not associated with folate levels. CONCLUSIONS: Independent associations, assessed over periods greater than 20 years, were demonstrated between decreased folate levels and increased risks of prostate cancer mortality and breast cancer morbidity.     

Is the rate of biological aging,as measured by age at diagnosis of cancer,socioeconomically patterned?

STUDY OBJECTIVE: To investigate the hypothesis that biological aging, as measured by age at diagnosis of some common cancers, is socioeconomically patterned. DESIGN: A cross sectional analysis of the association between an area based measure of material deprivation and age at diagnosis of four common cancers (breast, prostate, colorectal, and lung cancers). A further analysis, restricted to breast and colorectal cancer, adjusted for stage and grade of cancer at diagnosis. SETTING: The Northern and Yorkshire cancer registry and information service, Northern and Yorkshire region, UK. PARTICIPANTS: All people living in the Northern and Yorkshire region diagnosed with breast, prostate, colorectal, or lung cancer in 1986-1995. All people living in the Northern and Yorkshire region diagnosed with breast or colorectal cancer in 1998-2000 with data on stage and grade of cancer at diagnosis. MAIN RESULTS: There was evidence that greater material deprivation was associated with younger age at diagnosis of cancer in prostate (beta coefficient -0.073), colorectal (women: -0.042; men: -0.063), and lung cancer (women: -0.214; men: -0.161). The opposite association was found in women with breast cancer (0.149). Adjusting for stage and grade at incidence, where possible, had little effect on the magnitude of the beta coefficients. CONCLUSIONS: Age at diagnosis of some common cancers seems to be socioeconomically patterned with people from more deprived areas being diagnosed with prostate, colorectal, and lung cancers earlier in life. The opposite was seen in women with breast cancer. Further work is required to investigate the socioeconomic distribution of more accurate measures of biological aging.     

Welche Effekte hat k?rperliche Bewegung auf das Krebsrisiko und auf den Krankheitsverlauf nach einer Krebsdiagnose?

Numerous epidemiologic studies have demonstrated that regular physical activity convincingly reduces risk for colon cancer, probably for endometrium and postmenopausal breast cancer, and possibly for premenopausal breast, prostate, lung, and pancreas cancer. Relative risk reductions range from 10-30%. On the absolute scale about 9-19% of the most frequent cancers can be attributed to a lack of sufficient physical activity. Thus, exercise, as a modifiable health behavior, has a strong potential for primary cancer prevention. Current recommendations call for at least 30-60 min of moderate to vigorous activity daily. Physical activity is also increasingly gaining importance in cancer treatment and is now considered to be feasible, safe, and even recommended in almost all stages of disease. Randomized-controlled trials show that disease- and treatment-related symptoms, such as fatigue, sleep disorders, and depression which sometimes limit quality of life in cancer patients over years, can be reduced by physical activity. For disease-specific and total mortality, clinical studies are not yet available. However, preliminary observational studies with breast, colon, and prostate cancer patients show risk reductions.     

Nutrition and cancer: causative, protective and therapeutic aspects]

In prospective cohort studies an association between fat consumption and breast and colon cancer was not confirmed. Alcoholic beverages enhance the risk of cancer of the oral cavity, pharynx, larynx and oesophagus, while the relation is less well established for cancer in the stomach, pancreas, colon, rectum and breast. Consumption of vegetables and fruits reduces the risk of lung, oesophagus, stomach and pancreatic cancer. Which food components are responsible for this observation is unclear, but beta-carotene does not appear to be responsible. Clinical depletion in cancer patients is a result of metabolic disturbances as a consequence of the cancer and has negative effects on the course of the disease and on the treatment. Altered eating behaviour, food aversion, decreased food intake and loss of body weight may indicate the presence of clinical depletion. Positive effects of (artificial) nutrition as an adjunct to chemoor radiation therapy are very limited, larger but still limited as an adjunct to surgical therapy. It is not justified to allow insufficient food intake to continue during treatment of cancer; early (artificial) nutritional intervention is warranted in those cases. Food requirements of cancer patients and healthy persons apparently do not differ. A well balanced normal diet providing adequate amounts of energy, proteins, vegetables and fruits is therefore advised. Alternative diets, such as the Moerman or Houtsmuller diet, may provide the necessary energy and other specific food components as long as animal proteins (milk, meat, fish) are not omitted completely. There is no evidence that these diets will alter the disease course in a positive way; patients may benefit from the idea that they are contributing to their own health, however. If the physician doubts whether the alternative diet is used voluntarily, or if there are negative effects (social isolation, financial burden) he or she should advise against its continuation.     

Incidence of cancer in Navarra in the year 1998

This report brings the latest statistics available in the Cancer Register of Navarra on the incidence of cancer in this autonomous community in the year 1998. 3,018 incident cases of cancer were registered, 57.5% in men. Excluding nonmelanoma skin tumours, the crude incidence rate was 518 and 358 per 100,000 in men and women, and the rates adjusted to the world population were 296 and 199 per 100,000 respectively. 55.4% of all the cases of cancer diagnosed in men during 1998 occurred in the following sites: prostate, lung, colorectal, and bladder. In women breast, colorectal, body of uterus and stomach sites made up 53.6% of the cases. With respect to the five year period 1993-97, for the first time the adjusted incidence rate for all sites combined showed a decline of 1.1% amongst men, while amongst women the rising tendency was upheld. Notable were the decline of tumours related to smoking amongst men and of stomach cancer in both sexes. The data for women seem to indicate that some sites which traditionally showed extremely low rates in Navarra, tumours related to smoking and the cervix, have begun to increase in recent years, probably in relation to changes of life style. In both sexes there was an increase of non-Hodgkin's lymphomas and, continuing the tendency begun in previous years, the rate of incidence of breast cancer in women and prostate cancer in men continued to increase. The decline in the incidence of some cancers, particularly for the sites related to smoking observed amongst men in Navarra, is a hopeful fact, which will need confirmation in coming years.     

Patterns of milk consumption and risk of cancer

The reported milk consumption habits of 3,334 cancer patients and 1,300 comparable control subjects seen at Roswell Park Memorial Institute were studied. The cancer patient group included persons diagnosed with cancers of the oral cavity, stomach, colon, rectum, lung, breast, uterus, cervix, prostate, or bladder. Data were obtained by means of a standardized admissions questionnaire. As a group, control patients were more likely to report never drinking whole milk; cancer patients more often reported frequent consumption of whole milk. Relative risks of different patterns of milk consumption for specific cancer diagnoses, adjusted for sex, age, smoking history, education, and county of residence, were calculated with multiple logistic regression analysis. Elevated risks for frequent consumption of whole milk relative to not drinking milk were observed for cancers of the oral cavity, stomach, colon, rectum, lung, bladder, breast, and cervix. Reduced risks for frequent consumption of 2% milk relative to not drinking milk were observed for cancers of the oral cavity, stomach, rectum, lung, and cervix. Preference for exclusive consumption of reduced-fat milk was linked to significant risk reduction for oral and cervical cancers, and drinking only whole milk was linked to significant risk increases for cancers of the oral cavity, stomach, rectum, lung, and breast. Some associations were observed for a computed index of milk fat intake, but the overall pattern of effects was not fully explained by variations in fat content. The effects observed for some sites may be confounded by other dietary or nondietary correlates of risk.     

某高校教职工恶性肿瘤173例调查分析

目的探讨某高校教职工恶性肿瘤的患病与构成情况,为肿瘤的预防与控制提供依据。方法回顾性调查某高校2005—2010年173例教职工新发恶性肿瘤的病史资料,统计分析恶性肿瘤的发病率、发病年龄与时间趋势、肿瘤的构成与患病因素。结果该高校教职工近6年来恶性肿瘤的发病率呈上升趋势,肠癌的发病率逐年增高。男性恶性肿瘤的发病率高于女性,前5位恶性肿瘤依次为:肠癌、肺癌、前列腺癌、胃癌、乳腺癌,肿瘤的发病谱基本兼具发达国家和发展中国家癌谱特征。人口老龄化、精神压力大、不良生活方式等是肿瘤的易患因素。结论应在教职工中积极开展肿瘤预防的健康教育和对高发肿瘤危险因素的干预,进一步提高教职工的自我保健意识和能力,加强对肠癌和肺癌的防控。     

Family history of cancer and incidence of acute leukemia in adults

Family history of cancer may represent shared genetic and environmental risk factors for leukemia. The authors examined associations of first-degree family history of cancer with adult acute leukemia incidence by using data on 811 patients (or their proxies) identified at diagnosis and 637 population-based controls in the United States and Canada during 1986-1990. For proxy-interviewed patients, relative risks were elevated for family history of any cancer (relative risk = 1.7, 95% confidence interval (CI): 1.3, 2.4), hematopoietic cancer (relative risk = 1.8, 95% CI: 1.1, 3.0), leukemia (relative risk = 2.4, 95% CI: 1.3, 4.6), and breast cancer (relative risk = 1.7, 95% CI: 1.0, 3.0) but not for colorectal, prostate, or lung cancer. For self-interviewed patients, family history of hematopoietic cancer was inversely associated with leukemia incidence (relative risk = 0.6, 95% CI: 0.4, 1.1). Regardless of patient interview type, history of breast cancer in sisters was positively associated with adult acute leukemia, whereas history of breast cancer in mothers was not. The role of family history of cancer in leukemia etiology is unclear because of differential reporting by patients and proxies. Specifically, self-interviewed patients may underreport cancer in their first-degree relatives. Associations between family history of breast cancer and leukemia incidence may be the result of unmeasured, shared etiologies specific to these cancers.     

Meat and Fish Consumption and Cancer in Canada

In this study, we examined the association between meat and fish intake and the risk of various cancers. Mailed questionnaires were completed by 19,732 incident, histologically confirmed cases of cancer of the stomach, colon, rectum, pancreas, lung, breast, ovary, prostate, testis, kidney, bladder, brain, non-Hodgkin's lymphomas (NHL), and leukemia and 5,039 population controls between 1994 and 1997 in 8 Canadian provinces. Measurement included information on socioeconomic status, lifestyle habits, and diet. A 69-item food frequency questionnaire provided data on eating habits 2 yr before data collection. Odds ratios and 95% confidence intervals were derived through unconditional logistic regression. Total meat and processed meat were directly related to the risk of stomach, colon, rectum, pancreas, lung, breast (mainly postmenopausal), prostate, testis, kidney, bladder, and leukemia. Red meat was significantly associated with colon, lung (mainly in men), and bladder cancer. No relation was observed for cancer of the ovary, brain, and NHL. No consistent excess risk emerged for fish and poultry, which were inversely related to the risk of a number of cancer sites. These findings add further evidence that meat, specifically red and processed meat, plays an unfavorable role in the risk of several cancers. Fish and poultry appear to be favorable diet indicators.     

Nutrition and immunity in cancer

The purpose of this article is to give a general overview of the effects of nutrition on the development of cancer as well as part of a therapeutic approach. There is much evidence that diet and lifestyle can alter the risk of cancer development as is the case for many other chronic diseases. This may be through a direct action on the immune system, either by enhancing or suppressing it, as well as on the development of the tumour itself, by modulating gene expression or by antioxidant activity. Protective effects can be achieved by adequate intakes of vitamins A and C, beta-carotene, selenium and n-3 fatty acids among others, while negative effects are found mainly with high intakes of n-6 and saturated fatty acids. Weight gain, obesity and lack of regular physical activity have also been associated with an increased risk of cancer. The protective effects are best observed when adequate diet and lifestyle are present together. With respect to the therapeutic role of nutrition in cancer, it has been observed that the use of pre- or post-operative enteral or parenteral nutrition may improve patients' survival rates and quality of life; however, more research is needed in this particular area. Breast, colon, rectum, prostate, stomach and lung are the types of cancer most commonly associated with diet or dietary components.     

Associations of race, education, and patterns of preventive service use with stage of cancer at time of diagnosis

OBJECTIVE: To go beyond the documentation of disparities by race and SES by analyzing health behaviors regarding preventive and cancer screening services and determining if these behaviors are associated with stage of cancer when first diagnosed. DATA: Stage of cancer for Medicare patients diagnosed in 1995 with breast, colorectal, uterine, ovarian, prostate, bladder, or stomach cancer; and use of influenza and pneumonia immunization, mammography, pap smear, colon cancer screening, and the prostate specific antigen test during the two years preceding diagnosis of cancer. STUDY DESIGN: Hypothesis tested: health behaviors regarding use of preventive and cancer screening services are associated with stage of cancer when first diagnosed. DATA COLLECTION/EXTRACTION METHODS: Information was extracted from the database formed by the linkage of Surveillance, Epidemiology, and End Results (SEER) cancer registries with Medicare files. PRINCIPAL FINDINGS: Black and white patients (of higher and lower SES) who used more of the preventive and cancer screening services were at a lower risk of having late stage cancer for six cancers studied (breast, colorectal [male and female], prostate, uterine, and male bladder cancer) than their counterparts who used fewer of these services. CONCLUSIONS: The use of preventive and cancer screening services is a health behavior associated with better health outcomes for the elderly diagnosed with cancer. The lack of preventive service use can serve as a marker for identifying persons at risk of late stage cancer when first diagnosed. Strategies that encourage the use of preventive services by low users of these services are likely to reinforce a range of healthy behaviors that help to ameliorate disparities in health outcomes.