Ethnic differences in breast cancer risk: a possible role for pregnancy levels of alpha-fetoprotein?

BACKGROUND: Breast cancer incidence rates are up to five times higher in white women in the United States compared with Asian women in China and Japan. A search for factors that modify estrogen's biological effect differentially between ethnic groups may add to the understanding of international variations in breast cancer risk. Recent evidence indicates that alpha-fetoprotein, a glycoprotein produced by the fetal liver, has important antiestrogenic properties. During pregnancy, alpha-fetoprotein reaches peak concentrations in maternal serum during the third trimester. METHODS: We compared pregnancy levels of alpha-fetoprotein in a population with high risk of breast cancer (Boston, MA) and low risk (Shanghai, China). Blood samples were collected around the 16th week and around the 27th week of gestation among women enrolled from March 1994 to October 1995. The number of specimens available for alpha-fetoprotein analysis was 1,033. RESULTS: Alpha-fetoprotein levels, adjusted for gestational length, were substantially higher in Shanghai compared with Boston women at both time points. When adjustments were made for prepregnancy weight, parity, offspring's sex and maternal age, alpha-fetoprotein levels remained 13% higher in Shanghai at 16 weeks of pregnancy but not at 27 weeks. CONCLUSIONS: These findings may explain, at least in part, the difference in breast cancer risk between Chinese and American women. On the population level, alpha-fetoprotein may influence risk by modifying the effect of biologically active estrogens both in the mother and in female offspring.     

Hormonal factors and risk of lung cancer among women?

BACKGROUND: Gender differences in the histological distribution of lung carcinoma and a possibly greater susceptibility of women than men to tobacco carcinogens, suggest a possible influence of sex-specific hormones. This study examines endocrine factors and risk of lung cancer among women by smoking status and histology. METHODS: We used data of a case-control study on lung cancer conducted from 1990 to 1996 in Germany, including 811 histologically confirmed female cases and 912 female population controls. Information on various menstrual and reproductive factors, use of oral contraceptives (OC), hormone replacement therapy (HRT), and smoking was gathered through personal interviews using a structured questionnaire. Odds ratios (OR) and 95% CI adjusted for age, region, smoking, and education were calculated via logistic regression. RESULTS: A reduction in lung cancer risk was observed with the use of OC (OR = 0.69; 95% CI: 0.51-0.92), but no trend in risk with increasing duration of use, age at first use, or calendar year of first use was present. A history of HRT was associated with a reduced risk (OR = 0.83; 95% CI: 0.64-1.09), particularly after long duration (>/=7 years) (OR = 0.59; 95% CI: 0.37-0.93). No clear association was found with regard to age at menarche, length of menstrual cycle, number of live-births, and age at menopause. Overall results did not differ much by histological cell subtype. The reduction in lung cancer risk associated with the use of exogenous hormones was primarily seen among smoking women. CONCLUSIONS: Our data provide evidence for a possible role of hormonal factors in the aetiology of lung cancer in women.     

Leanness and lung cancer risk: fact or artifact?

BACKGROUND: More than a dozen studies have examined the association between leanness and increased lung cancer risk. None of the prospective studies has been large enough to allow exclusion of smokers or persons with preexisting disease, two factors that cause both leanness and poor survival and thus may cause a spurious association between low body mass index and fatal lung cancer. METHODS: Using Cox proportional hazards models, we examined this issue in a cohort of 941,105 U.S. adults enrolled in an American Cancer Society prospective study in 1982. During 14 years of follow-up, 14,066 people died of lung cancer. RESULTS: In analyses restricted to lifelong nonsmokers who did not report preexisting disease, leanness was not substantially associated with lung cancer mortality in men (rate ratio = 0.9; 95% confidence interval = 0.3-3.1) or in women (rate ratio = 1.2; 95% confidence interval = 0.7-2.1). However, leanness was associated with increased lung cancer risk in analyses that attempted to control for, rather than exclude, smokers and persons with preexisting disease. CONCLUSIONS: These data suggest that the association between leanness and lung cancer mortality is not causal but rather is an artifact of the effects of smoking and preexisting disease.     

Decreased risk of prostate cancer after skin cancer diagnosis: a protective role of ultraviolet radiation?

Ultraviolet radiation causes skin cancer but may protect against prostate cancer. The authors hypothesized that skin cancer patients had a lower prostate cancer incidence than the general population. In the southeastern part of the Netherlands, a population-based cohort of male skin cancer patients diagnosed since 1970 (2,620 squamous cell carcinomas, 9,501 basal cell carcinomas, and 1,420 cutaneous malignant melanomas) was followed up for incidence of invasive prostate cancer until January 1, 2005, within the framework of the Eindhoven Cancer Registry. The incidence rates of prostate cancer among skin cancer patients were compared with those in the reference population, resulting in standardized incidence ratios. Skin cancer patients were at decreased risk of developing prostate cancer compared with the general population (standardized incidence ratio (SIR) = 0.89, 95% confidence interval (CI): 0.78, 0.99), especially shortly after diagnosis. The risk of advanced prostate cancer was significantly decreased (SIR = 0.73, 95% CI: 0.56, 0.94), indicating a possible antiprogression effect of ultraviolet radiation. Patients with a skin cancer in the chronically ultraviolet radiation-exposed head and neck area (SIR = 0.84, 95% CI: 0.73, 0.97) and those diagnosed after the age of 60 years (SIR = 0.86, 95% CI: 0.75, 0.97) had decreased prostate cancer incidence rates. These results support the hypothesis that ultraviolet radiation protects against prostate cancer.     

Vitamin D: a potential role in reducing suicide risk?

Suicide attempts are known to peak in the spring, overlapping with the time of year when 25-hydroxyvitamin D [25(OH)D] levels are at their nadir in the northern hemisphere because of negligible skin production of vitamin D owing to low levels of ultraviolet B radiation. Low levels of 25(OH)D, the vitamin D metabolite used to diagnose vitamin D deficiency, have been associated with certain pro-suicidal factors such as exacerbation of depression, anxiety, psychosis, and certain medical conditions. Therefore, we hypothesize that vitamin D deficiency could also be associated with increased risk of completed suicides. Here, we briefly review the literature on vitamin D, its deficiency, and its reported association with certain risk factors for suicide.     

Is the risk of lung cancer reduced among eczema patients?

Persons with a history of eczema have been shown to have a reduced risk of lung cancer, but the evidence has been inconclusive because of the small size of previous studies and their limited ability to control for confounding by smoking. The objective of this study was to determine the role of eczema in relation to lung cancer while overcoming the limitations of previous investigations. Study subjects included 2,854 cases and 3,116 population and hospital controls recruited during 1998-2001 from 16 areas in the Czech Republic, Hungary, Poland, Romania, Russia, Slovakia, and the United Kingdom. Odds ratios were calculated for self-reported history of eczema via multivariate logistic regression modeling. The odds ratio for a history of eczema was 0.61 (95% confidence interval: 0.48, 0.76) after control for age, sex, study center, and cumulative tobacco smoking. There was no heterogeneity in the results by sex or age at onset of eczema. Subjects reporting use of medication for eczema had a lower odds ratio than subjects not reporting such use. This study provides further evidence for an inverse association between history of eczema and lung cancer risk, which is unlikely to be due to chance, bias, or confounding.     

Lung cancer mortality in a cohort of workers in a petrochemical plant: occupational or residential risk?

The purpose of the present study is to examine the role of environmental (non occupational) exposures in lung cancer risk among petrochemical workers at a large petrochemical plant built on the Sicilian coast in the immediate vicinity of the town of Gela, Italy in 1960. The cohort included workers employed in the Gela petrochemical plant in 1960-1993. We looked at mortality rates for the period 1960-2002. An internal comparison was performed between two categories of workers with different likelihood of residence in Gela during the period of employment. The rate ratio of mortality from lung cancer comparing "probable residents" with "possible non residents," adjusted for age, calendar period, andjob classification (only blue collar, only white collar and both), was 1.66 (90% Confidence Interval 1.07-2.58). Although the information collected is quite sparse and no inferences can be made about risk sources, the results show a possible excess of residential/environmental risk from lung cancer mortality for those workers more likely to have been residents in Gela.     

Offering a prognosis in lung cancer: when is a team of experts an expert team?

The outlook for patients with lung cancer is poor, so an accurate estimation of prognosis will underpin treatment decisions and allow patients to make personal plans for the future. However, evidence suggests that there is a variation between doctors in their predictions of outcomes and also they tend to be over-optimistic. Two main questions are addressed in this study: whether multidisciplinary team discussion changes prognostic accuracy of individual clinicians; and whether team discussion improves the accuracy of the team's aggregated prediction. A real-time study of 50 newly diagnosed patients discussed by a regional lung cancer team was undertaken. A case pro-forma informed the completion of a pre-discussion questionnaire by each team member, seeking prognostic predictions at specific time points. This was repeated after team discussion. Medical notes were reviewed at 6 months to establish actual survival status. Group discussion did not significantly change the accuracy of survival predictions for any one clinician, but the team as a whole performed better after case discussion. Predictions which the clinicians were more confident about were found to be no more accurate than those where they were less confident. There is a wide variation in the range and accuracy of prognostic predictions made by individual clinicians, with no consistent improvement after team discussion. As such predictions are integral to decision making, further research on decision-making processes of clinical teams is required.     

Is there a role for carbohydrate restriction in the treatment and prevention of cancer?

Background

Aflatoxin B1 (AFB1) is potent hepatotoxic and hepatocarcinogenic agent. In aflatoxicosis, oxidative stress is a common mechanism contributing to initiation and progression of hepatic damage. The aim of this work was to evaluate the hepatoprotective effect of cactus cladode extract (CCE) on aflatoxin B1-induced liver damage in mice by measuring malondialdehyde (MDA) level, the protein carbonyls generation and the heat shock proteins Hsp 70 and Hsp 27 expressions in liver. We also looked for an eventual protective effect against AFB1-induced genotoxicity as determined by chromosome aberrations test, SOS Chromotest and DNA fragmentation assay. We further evaluated the modulation of p53, bax and bcl2 protein expressions in liver.

Methods

Adult, healthy balbC (20-25 g) male mice were pre-treated by intraperitonial administration of CCE (50 mg/Kg.b.w) for 2 weeks. Control animals were treated 3 days a week for 4 weeks by intraperitonial administration of 250 μg/Kg.b.w AFB1. Animals treated by AFB1 and CCE were divided into two groups: the first group was administrated CCE 2 hours before each treatment with AFB1 3 days a week for 4 weeks. The second group was administrated without pre-treatment with CCE but this extract was administrated 24 hours after each treatment with AFB1 3 days a week for 4 weeks.

Results

Our results clearly showed that AFB1 induced significant alterations in oxidative stress markers. In addition, it has a genotoxic potential and it increased the expression of pro apoptotic proteins p53 and bax and decreased the expression of bcl2. The treatment of CCE before or after treatment with AFB1, showed (i) a total reduction of AFB1 induced oxidative damage markers, (ii) an anti-genotoxic effect resulting in an efficient prevention of chromosomal aberrations and DNA fragmentation compared to the group treated with AFB1 alone (iii) restriction of the effect of AFB1 by differential modulation of the expression of p53 which decreased as well as its associated genes such as bax and bcl2.

Conclusion

We concluded that CCE might have a hepatoprotective effect against aflatoxicosis in mice, probably acting by promoting the antioxidant defence systems.     

Tea consumption and lung cancer risk: A meta-analysis of case–control and cohort studies

ObjectiveRecent epidemiologic studies, especially cohort and case–control studies, have yielded inconsistent findings regarding the association between tea consumption and risk for lung cancer. The aim of this study was to assess a potential relationship between tea consumption and the incidence of lung cancer worldwide.MethodsA systematic literature search of PubMed, Web of Science, the Cochrane Library, Google Scholar, the Chinese Biomedical Database, and Wanfang Database was conducted from 1966 to January 2014 by two investigators. All cohort studies and case–control studies that evaluated the association of tea and lung cancer were included. Summary relative risks (RR) and the corresponding 95% confidence intervals (CIs) were calculated using a random-effects model. Quality assessments were performed using the Newcastle–Ottawa Scale. Heterogeneity was assessed using the Q and I² tests, and the source of heterogeneity was detected by meta-regression analysis. Publication bias was evaluated with Egger's regression symmetry test. Subgroup analyses and sensitivity analysis were performed.ResultsThirty-eight lung cancer studies (26 case–control studies and 12 cohort studies) with 59,041 cases and 396,664 controls were included. Overall tea consumption was significantly associated with decreased risk for lung cancer (RR, 0.78; 95% CI, 0.70–0.87). Subgroup analyses showed that tea consumption was associated with reduced risk for lung cancer in women (RR, 0.76; 95% CI, 0.62–0.93), case–control studies (RR 0.72; 95% CI 0.63–0.83), Western studies (RR, 0.85; 95% CI, 0.75–0.97), and studies in China and Japan (RR, 0.74; 95% CI, 0.62–0.88). Both green tea (RR, 0.75; 95% CI, 0.62–0.91) and black tea (RR, 0.82; 95% CI, 0.71–0.94) were significantly associated with reduced lung cancer risk. No significant association was found in men or in cohort studies.ConclusionTea consumption may offer some protection against lung cancer.     

Consumption of alcohol and risk of cancer among men: a 30 year cohort study in Lithuania

Studies have indicated hazardous consumption of large quantities of alcohol among adults in Lithuania. We assessed the associations of alcohol consumption at baseline with cancer incidence among men in a population-based cohort study, using Cox models adjusted for smoking, education and body mass index. Attained age was used as a time-scale. During follow-up (1978–2008) 1,698 men developed cancer. A higher amount of alcohol consumption (≥140.1 g/week vs. 0.1–10.0 g/week) was positively associated with increased risk of total cancer [hazard ratio (HR) = 1.36, 95 % confidence interval (95 % CI) 1.11, 1.65], upper aerodigestive tract cancer (HR = 2.79, 95 % CI 1.23, 6.34) and alcohol-related cancers (i.e. oral cavity, pharynx, larynx, oesophagus, colorectal and liver cancer) (HR = 1.88, 95 % CI 1.25, 2.85). Compared to occasional drinkers (a few times/year), drinkers 2–7 times/week showed an increased risk of total (HR = 1.45, 95 % CI 1.16, 1.83), alcohol-related (HR = 1.83 95 % CI 1.14, 2.93) and other cancers (HR = 1.35, 95 % CI 1.04, 1.76). Our results showed no statistically significant associations between quantity of alcohol intake per one occasion and risk of cancer. About 13 % of total, 35 % of upper aerodigestive tract, 22 % of alcohol-related and 10 % of other cancer cases were due to alcohol consumption in this cohort of men.     

Dietary and alcohol intake,smoking pattern,occupational risk,and family history in lung cancer patients: Results of a case‐control study in males

In a case‐control study of 71 consecutive new male cases of lung cancer and 71 male hospital control patients, previous dietary and alcohol intake, smoking pattern, occupation, dust exposure, and family history of lung cancer were investigated. The cases and controls were similar in age, country of origin, area of residence, and marital status. Using a frequency‐based assessment of previous dietary intake, broad food groups were similar for cases and controls. Cases had a significantly lower intake offish than controls did (odds ratio = 0.5, confidence interval = 0.2–1.0, p = 0.05). A protective effect for fish consumption in lung cancer has not been previously reported. The dietary intake of foods containing retinol and ß‐carotene and the intake of alcohol were not significantly different between cases and controls. For cases, smoking duration was longer and the time since cessation for exsmokers was shorter, cigarette pack years were longer, and the number of cigarettes smoked per day was greater. The factors of occupation, dust exposure, and family history of cancer (including lung cancer) were similarly distributed between cases and controls.