Cancer Incidence In Population Research Articles

Reconciling Scientists' Beliefs about Radiation Risks and Social Norms: Explaining Preferred Radiation Protection Standards

Social scientists have argued about the role of political beliefs in highly charged policy debates among scientific experts. In debates about environmental hazards, the focus of contention is likely to rest on the appropriate scientific assumptions to inform safety standards. When scientific communities are polarized, one would expect to find systematic differences among combatants in the choice of appropriate assumptions, and variation in the application of "precaution" in standard setting. We test this proposition using an experiment applied in a mail survey format to groups of scientists from opposing sides of the nuclear policy debate. Questions were asked about the role of political, social, and epistemological beliefs in reaching scientific and policy judgments about the relationship between radiation dose and cancer incidence in human populations. We find that the precautionary tendency is pervasive regardless of whether the scientist is associated with a putatively pro- or anti-nuclear group. Using a multinomial logit model, we explain a modest percentage of the variation in the choice of preferred judgments about safety standards, but find that distinct sets of political and social values are significantly associated with policy positions among scientists. Implications for scientific advice to policymakers are discussed.

A Large Cohort Study of Long-Term Daily Use of Adult-Strength Aspirin and Cancer Incidence

Epidemiologic evidence indicates that aspirin use is associated with reduced risks of colon cancer and possibly several other cancers, including prostate and breast cancers. Recent results from the Women's Health Study randomized trial indicate that long-term use of low-dose aspirin (100 mg every other day) does not substantially reduce cancer risk. However, the potential effect of long-term daily use of higher doses of aspirin on cancer incidence remains uncertain. We examined associations between long-term daily use of adult-strength aspirin (> or = 325 mg/day) and both overall cancer incidence and incidence of 10 types of cancer among 69,810 men and 76,303 women participating in the Cancer Prevention Study II Nutrition Cohort, a relatively elderly population. Aspirin use was reported at enrollment in 1992-1993 and updated in 1997, 1999, and 2001. Multivariable Cox proportional hazards regression was used to calculate rate ratios (RRs). During follow-up through June 2003, 10,931 men and 7196 women were diagnosed with cancer. Long-term (> or = 5 years) daily use of adult-strength aspirin, compared with no use, was associated with lower overall cancer incidence in men (multivariable-adjusted RR = 0.84, 95% confidence interval [CI] = 0.76 to 0.93) and non-statistically significantly lower overall cancer incidence in women (multivariable-adjusted RR = 0.86, 95% CI = 0.73 to 1.03). Overall cancer incidence per 100,000 person-years (standardized to the age distributions of men and women in the study) with long-term daily aspirin use and no aspirin use was 1858 and 2163, respectively, among men and 1083 and 1169, respectively, among women. Long-term daily aspirin use was associated with lower incidence of colorectal cancer (RR = 0.68, 95% CI = 0.52 to 0.90 among men and women combined) and prostate cancer (RR = 0.81, 95% CI = 0.70 to 0.94) and a non-statistically significant lower risk of female breast cancer (RR = 0.83, 95% CI = 0.63 to 1.10). Long-term daily use of adult-strength aspirin may be associated with modestly reduced overall cancer incidence in populations among whom colorectal, prostate, and breast cancers are common.

Second primary cancers in patients with nasopharyngeal carcinoma: a pooled analysis of 13 cancer registries

To study the risk of second primary cancers in nasopharyngeal carcinoma (NPC) patients and the risk of NPC as second primary cancer. We used data from the cancer registries from Singapore and from 12 low-incidence areas, including a total of 8,947 first occurring NPC cases, and 167 second occurring cases. We calculated standardized incidence ratios (SIRs) by comparing the second cancer incidence in NPC patients to the first primary cancer incidence in non-cancer population. We also calculated SIRs of second NPC after other primaries. In Singapore, the risk of cancers of the lung (SIR=0.42), stomach (SIR=0.41), and colon (SIR=0.23) was significantly decreased after NPC, whereas that of cancer of the tongue (SIR=11.1) was significantly increased. In Australia, Canada, and Europe, the risk of non-Hodgkin's lymphoma (NHL) (SIR=3.06), tongue cancer (SIR=5.29), brain cancer (SIR=3.89), myeloid leukemia (SIR=3.85), and non-melanoma skin cancer (NMSC) (SIR=3.47) was significantly increased after NPC. Incidences of second occurring NPCs following various primary cancers were not significantly altered compared to the incidence of first occurring NPCs. Immune suppression (NHL, NMSC), shared genetic factors (lung cancer, NHL, myeloid leukemia), and shared environmental risk factors (tongue and brain cancers) might explain the associations. Except for NHL, there was no evidence of association with other Epstein-Barr virus-related cancers.

Cancer Incidence Before and After Kidney Transplantation

Immune suppression after organ transplantation is associated with a markedly increased risk of nonmelanoma skin cancer and a few virus-associated cancers. Although it is generally accepted that other cancers do not occur at increased rates, there have been few long-term population-based cohort studies performed. To compare the incidence of cancer in patients receiving immune suppression after kidney transplantation with incidence in the same population in 2 periods before receipt of immune suppression: during dialysis and during end-stage kidney disease before renal replacement therapy (RRT). A population-based cohort study of 28,855 patients with end-stage kidney disease who received RRT, with 273,407 person-years of follow-up. Incident cancers (1982-2003) were ascertained by record linkage between the Australia and New Zealand Dialysis and Transplant Registry and the Australian National Cancer Statistics Clearing House. Standardized incidence ratios (SIRs) of cancer, using age-specific, sex-specific, calendar year-specific, and state/territory-specific population cancer incidence rates. The overall incidence of cancer, excluding nonmelanoma skin cancer and those cancers known to frequently cause end-stage kidney disease, was markedly increased after transplantation (n = 1236; SIR, 3.27; 95% confidence interval [CI], 3.09-3.46). In contrast, cancer incidence was only slightly increased during dialysis (n = 870; SIR, 1.35; 95% CI, 1.27-1.45) and before RRT (n = 689; SIR, 1.16; 95% CI, 1.08-1.25). After transplantation, cancer occurred at significantly increased incidence at 25 sites, and risk exceeded 3-fold at 18 of these sites. Most of these cancers were of known or suspected viral etiology. Kidney transplantation is associated with a marked increase in cancer risk at a wide variety of sites. Because SIRs for most types of cancer were not increased before transplantation, immune suppression may be responsible for the increased risk. These data suggest a broader than previously appreciated role of the interaction between the immune system and common viral infections in the etiology of cancer.

Health risks of low photon energy imaging

The major health risk associated with low photon energy imaging is thought to be the induction of cancer as a consequence of the radiation exposure and this is the focus of this paper. Low photon energy imaging typically involves exposure to a low dose (<50 mGy) of low linear energy transfer (LET) radiation delivered at high dose-rate. Since epidemiologic data cannot provide an accurate assessment of risk at the doses used in imaging, risk estimates are currently made by fitting a linear response to intermediate and high dose data for cancer induction in radiation-exposed human populations. This method assumes a linear no-threshold (LNT) response and implies that no dose of radiation is safe. This assumption is not borne out by many laboratory studies of cancer-related endpoints that would suggest that the risk at low doses is much less than would be estimated from linear extrapolation from intermediate to high doses. It is also well recognised that the dose-response from many epidemiologic studies could equally well be fit by threshold models. Through the study of radiation-induced neoplastic transformation in vitro J-shaped dose-response curves for a variety of low LET radiations, including those used in low photon energy imaging, have been demonstrated. The relative risks calculated from this data compare remarkably well with those for breast cancer and leukemia incidence in radiation-exposed populations. From this it is concluded that the LNT hypothesis is likely to overestimate the risk of cancer induction by low photon energy imaging, at least for certain tumors.

Ethnic and geographic differences in mammographic density and their association with breast cancer incidence

The objective of this pooled analysis was to compare differences in dense areas and percent mammographic densities to breast cancer incidence in populations at different breast cancer risk. The data set included 1,327 women aged 40-80: Caucasians from Norway, Arizona, and Hawaii, Japanese from Hawaii and Japan, Latina from Arizona, and Native Hawaiians from Hawaii. One reader performed computer-assisted quantitative density assessment for all mammographic films. Multiple linear regression models evaluated the influence of the covariates on breast density. Spearman correlation coefficients (r (s)) estimated the association between breast density and breast cancer incidence for the seven populations. After adjustment for covariates, ethnicity, but not location, was significantly associated with breast density. In the full model, 19% of the variation in the dense areas and 46% in the variation of percent densities were explained by measured risk factors. Native Hawaiians had the largest dense areas and women in Japan the smallest, whereas percent densities were highest among Native Hawaiians and Japanese in Hawaii and lowest among Norwegian women. The mean age-adjusted dense area had the strongest association with breast cancer incidence (r (s) = 0.93, P = 0.003); the relation with percent density was considerably weaker (r (s) = 0.32, P = 0.48). The correlation between age-adjusted dense area and breast cancer incidence remained strong after selectively removing individual data points. This comparison of mammographic densities suggests that, on a group level, age-adjusted dense areas may reflect breast cancer incidence better than percent densities.

Colorectal cancer in a population with endemic Schistosoma mansoni: is this an at-risk population?

Chronic infection with schistosomiasis has been clearly associated with the development of bladder cancer, and infestation is associated with a high incidence of colorectal cancer in endemic populations. Despite this association, the potential role of alterations in tumor suppressor genes colorectal cancers has never been evaluated in an endemically infected population. The aim of this paper was to compare histopathologic and genetic changes in schistosomal colitis-associated colorectal cancer (SCC) with colorectal cancer in a group of patients from the same population not affected by the disease (NDCC). Sixty patients were included in this study: SCC-40, NDCC-20. Data collected included age, sex, clinical presentation, presence of synchronous tumors, histopathology, and clinical stage. p53, DCC (deleted in colorectal cancer gene), and mismatch repair genes (MLH1 and MSH2) were studied using immunohistochemical staining. Patients with SCC were significantly younger than the NDCC group (34.52+/-11.22 years vs 50.73+/-12.75 years, p=0.02). Mucinous adenocarcinoma occurred significantly more frequently in SCC (35 vs 10%, p=0.02). SCC tumors were more frequently stage III or IV, and significantly more synchronous tumors were present in the affected group (SCC-8/40 vs NDCC-1/20, p=0.05). p53 staining was far more frequent in SCC (SCC-32/40 vs NDCC-8/20, p=0.006). DCC expression was similar in two groups. There were only four cases, three in SCC and one in NDCC, that showed microsatellite instability. The data suggest that schistosomal colitis is more commonly associated with earlier onset of multicentric colorectal cancer, high percentage of mucinous adenocarcinoma, and presents at an advanced stage. The identification of a higher incidence of altered p53 expression in the SCC group raises the possibility of an association between schistosomiasis and alterations in p53 activation as an inciting event in colorectal cancer development.

Effets biologiques des anti-oxydants : les données de l’étude SU.VI.MAX

The SU.VI.MAX study is a double blind, randomised, placebo-controlled trial testing, for 8 years, the effect of a combination of antioxidant vitamins and minerals, at doses considered to be nutritional (120 mg vitamin C, 30 mg vitamin E, 6mg beta-carotene, 100 lg selenium and 20 mg zinc) in reducing cancer and ischaemic vascular disease incidence in a general population (12,741 middleaged). After 7.5 years, low-dose antioxidant supplementation had no effect on vascular disease incidence. This dose lowered, however, total cancer incidence in men, but not in women. With regard to contradictory results of observational and interventional studies published for the last decades, we can consider that the effect of antioxidant on cancer may depend on the doses (nutritional versus pharmacological), baseline antioxidant status (different between gender and/or nutritional status) and health status of subjects (healthy versus cancer high-risk subjects). Antioxidant supplementation may have a beneficial effect on cancer incidence only in healthy subjects who are not exposed to cancer risk, and with a particularly low baseline status. Finally, antioxidants as well as free radicals appear to be ambiguous nutrients with a wide range of benefits and toxicity. High doses of antioxidant supplements may be deleterious in high-risk subjects without any clinical symptoms in whom the initial phase of cancer development has already started.

Trends in Incidence of Colorectal Cancer in Jewish and Arab Populations in Central Israel

Background/Aims: To compare the current differences with our earlier findings on the incidence and locations of colorectal cancer (CRC) among Israeli-born Jews and Arabs living within the same central coastal region in Israel. Methods: Data on demographics and the incidence and locations of malignancies were retrieved from hospital files of pathology-diagnosed patients with CRC throughout 1997–2003 and compared with equivalent data from 1988 to 1996. Results: Of the 624 patients recently diagnosed as having CRC, 562 (90.1%) were Jews and 62 (9.9%) were Arabs (p < 0.001). The average age of the entire cohort was significantly lower since our earlier study (72.9 ± 12.5 compared to 67.9 ± 12.7 years, p < 0.0001). The Jewish patients were significantly younger (p < 0.0001) but the Arab patients were not. The percentage of the adenocarcinoma being located in the right colon was significantly lower (p < 0.0006) and significantly higher in the rectum (p < 0.008). The reverse was true among the Jewish patients, but not significantly. Conclusions: Both study groups were younger than those in our earlier study. The lower incidence of CRC among the Arab patients persisted over time, but the location of their adenocarcinoma changed significantly. The increased incidence of CRC in ‘westernized’ countries is reflected in the Jewish but not the Arab community.

Oxidative DNA modifications

Oxidative DNA modifications are frequent in mammalian DNA and have been suggested an important mechanism in carcinogenesis, diabetes and ageing. The foundations for this suggestion are: Evidence for the importance of oxidative DNA modifications in cancer development is: high levels of oxidative lesions in cancer tissue; highly conserved and specific DNA repair systems targeting oxidative lesions; high levels of oxidative DNA lesions in oxidative DNA repair knock-out animals; defective repair of oxidative lesions in cancer-prone progeria syndromes; reduced cancer incidence in populations with high dietary antioxidant intake; and increased oxidative stress to DNA in tobacco smokers. Conflicting evidence for a relation between oxidative stress to DNA and cancer is: disagreement about the true levels and occurrence of the oxidative lesions in vivo; failure to identify the localization of oxidative lesions in important genes, e.g. tumor suppressor and oncogenes; lack of evidence that the oxidative lesions induce mutations in vivo; no cancer development in animals knocked-out for specific DNA repair enzymes in spite of high tissue levels of oxidative lesions; and unchanged cancer rates after antioxidant interventions in large clinical controlled and randomized trials. The rate of DNA oxidation has been estimated from urinary excretion of repair products and it is evident that if these lesions were not repaired, a large part of DNA would be oxidized to a degree not compatible with living. The methodologies by which oxidative DNA modifications are measured cover a wide and different range, advantages and disadvantages will be presented. One particular problem is artificial oxidation, and methods to prevent such artifacts will be presented together with results from a large interlaboratory standardization program. The methodology by which the lesions can be measured is complicated and prone to artifacts during DNA isolation, digestion, derivatization and maybe even during the separation procedure proper prior to detection. A large effort from 20+ laboratories supported by a grant from the EU has reduced artifacts considerably and work towards interlaboratory standardization of the methodology is in progress. The presently agreed “normal” levels of the most frequent known lesion 8-oxodG is about 5 per million dG's in DNA. A comprehensive evaluation of the evidence, from chemistry to clinical and epidemiological trials, linking oxidative modifications to cancer will be given. Finally, an estimate of the quantitative role oxidative DNA modifications play among the multiplicity of other insults is given. While there is no question that all of these oxidative mechanisms do exist, quantitative data on their importance for the human situation do not exist. Prospective human studies that can provide such quantitative data on different mechanisms are underway.

Cancer incidence in Kyrgyzstan

9699 Background: To study age, sex, geographic, site specific and ethnic cancer incidence in Kyrgyzstan. Methods: Calculated the incidence of cancer between 1997 and 1999 in all population. Estimated population relative risk for main tumours in urban and rural areas. Detailed population figures from census are available from National Center of Statistics. The population figures and cancer incidence rates were provided in for each age, ethnic and sex groups. Counted crude, age-standardised rates (ASR) per 100 000. Results: There were 4896 males and 5034 females registered with new diagnoses of cancer. Male-female proportion - 1,03. Histologically verified cases 80,5%. ASR annual incidence was in males 201.2 and females 137.9 (total 169.55)The most frequent diagnostic groups in males were tumours of the stomach (44.65), lung (41.0), skin (27.8), oesophagus (11.65), haemoblastoses (8.6), bladder (6.6) colon (5.9), and prostate (5.9); in females - skin (23.5), breast (19.1), stomach (16.2), cervical cancer (15.5), ovary (6.7), lung (5.9), corpus uteri (5.5), oesophagus (5.4), blood and lymph (5.2). Cancer incidence was significantly higher in urban (255.5-male, 161.9-female) than rural (161.8-male, 118.5-female) regions. However, in some tumours (oesophagus, stomach in males and cervical cancer in females) incidence rate was slightly higher in rural areas. Incidence was significantly higher in the Slavic ethnic groups (Russians, with an ASR of 263.8 cases per 100 000, Ukrainians 239.8, Byelorussians 185.0) compared with 65.7 for Kyrgyzs, 52.5 for Uzbeks and 61.5 for Kazakhs people. Excess relative risk (RR) was higher among Russians in tumours of skin (6,6), endometrial cancer (2,5), breast cancer (2,2), and lung cancer (1,7). However, oesophagus, cervix of uteri, stomach cancer incidence in native ethnic people was significantly higher than Russians and other Slavic groups. Cancer incidence in the mountain areas was differing. High incidence registered in low altitude (650 - 1500 m. above level sea), with ASR 205.9, middle altitude (1500 - 2500 m.), with ASR 118.7, than high altitude (2500 - 3500 m.) regions, with ASR 60.8. Conclusions: Cancer incidence in Kyrgyzstan is low and similar to those reported from some Asian developing countries. No significant financial relationships to disclose.

What Is the Role of Diet in the Development of Cancer in American Indian and Alaska Native Populations?

The associations between diet and cancer in American Indian and Alaska Native (AIAN) populations are not well understood. I review current knowledge of the associations between diet and cancer. Studies of diet and cancer are inconsistent. Underlying characteristics of populations could contribute to observed differences. Dietary patterns and energy balance may importantly relate to cancer in AIAN populations. Given the differences in cancer incidence and mortality rates in AIAN populations, it is reasonable that diet and lifestyle patterns could contribute to these differences, although we can only speculate as to specific dietary factors in cancer etiology.

Cancer incidence in the south Asian population of California, 1988–2000

BackgroundAlthough South Asians (SA) form a large majority of the Asian population of U.S., very little is known about cancer in this immigrant population. SAs comprise people having origins mainly in India, Pakistan, Bangladesh and Sri Lanka. We calculated age-adjusted incidence and time trends of cancer in the SA population of California (state with the largest concentration of SAs) between 1988–2000 and compared these rates to rates in native Asian Indians as well as to those experienced by the Asian/Pacific Islander (API) and White, non-Hispanic population (NHW) population of California.MethodsAge adjusted incidence rates observed among the SA population of California during the time period 1988–2000 were calculated. To correctly identify the ethnicity of cancer cases, 'Nam Pehchan' (British developed software) was used to identify numerator cases of SA origin from the population-based cancer registry in California (CCR). Denominators were obtained from the U.S. Census Bureau. Incidence rates in SAs were calculated and a time trend analysis was also performed. Comparison data on the API and the NHW population of California were also obtained from CCR and rates from Globocan 2002 were used to determine rates in India.ResultsBetween 1988–2000, 5192 cancers were diagnosed in SAs of California.Compared to rates in native Asian Indians, rates of cancer in SAs in California were higher for all sites except oropharyngeal, oesophageal and cervical cancers. Compared to APIs of California, SA population experienced more cancers of oesophagus, gall bladder, prostate, breast, ovary and uterus, as well as lymphomas, leukemias and multiple myelomas. Compared to NHW population of California, SAs experienced more cancers of the stomach, liver and bile duct, gall bladder, cervix and multiple myelomas. Significantly increasing time trends were observed in colon and breast cancer incidence.ConclusionSA population of California experiences unique patterns of cancer incidence most likely associated with acculturation, screening and tobacco habits. There is need for early diagnosis of leading cancers in SA. If necessary steps are not taken to curb the growth of breast, colon and lung cancer, rates in SA will soon approximate those of the NHW population of California.

Overview of national guidelines for infrastructure and staffing of radiotherapy. ESTRO-QUARTS: Work package 1

Background and purposeThe aim of this study was to collect the available guidelines for infrastructure and staffing throughout Europe and to develop general guidelines. Materials and methodsQuestionnaires were sent to representatives in all European countries. Countries were divided into three groups, based on the GDP per capita (low, medium and high resource countries). Based on the results, general guidelines were developed. Results41 countries (93.2%), representing over 99% of the European population responded. Guidelines for the number of linear accelerators and personnel were available in about 40% of the countries. For accelerators, the average was 1 per 183,000 inhabitants in the high, 1 per 284,000 in the medium and 1 per 500,000 in the low resource countries. For radiation oncologists, it varied between 1 per 150–400 patients (average: 250) and there was no clear difference between high, medium and low resource countries. For physicists, the average was 1 per 530 patients for high and 1 per 610 for medium or low resource countries. Guidelines for other equipment and staffing are highly dependent on local habits and complexity of the treatments. ConclusionAn accurate overview of existing guidelines for radiotherapy infrastructure and staffing is obtained. It is suggested to have one linear accelerator per 450 patients, one radiation oncologist per 200–250 patients and one physicist per 450–500 patients (or one per linac). It should be stressed, however, that these are only crude guidelines and that the actual needs heavily depend on population structure, cancer incidence and treatment strategies, which differ between the various countries.

State-of-the-Art of High-Resolution Anoscopy as a Tool to Manage Patients at Risk for Anal Cancer

Anal cancer is increasing in incidence in urban populations worldwide and particularly in HIV-positive men who have sex with men (MSM). The etiologic relationship of both anal and cervical cancer to human papillomavirus (HPV) is well established. The incidence of cervical cancer has decreased significantly as a result of an effective screening program. Women with abnormal cervical cytology are referred for colposcopy, which is used to identify and eradicate the cervical cancer precursors, cervical high-grade squamous intraepithelial lesions (HSIL). High-resolution anoscopy (HRA) or colposcopy of the anus and perianal area is a powerful tool to find and treat the precursors to anal cancer, anal HSIL. The approach to management and treatment of anal HSIL at the UCSF Anal Dysplasia Clinic using HRA in conjunction with anal cytology and digital rectal examination (DRE) is presented as a means to prevent anal cancer and to facilitate the early diagnosis of anal cancer. Principles of HRA, how to perform HRA, findings during HRA, and the use of HRA in the operating room are described. HRA coupled with DRE is an effective way to manage patients at risk for anal cancer. Several cases are described illustrating the practical application of HRA in managing patients with anal HSIL and diagnosing anal cancer. Increased awareness and, at the very least, performance of regular DRE in patients at risk and training more providers in HRA may help to decrease the incidence of anal cancer in populations at risk.

Cancer statistics: everything you wanted to know about the cancer registry data but were too afraid to ask

Australia and New Zealand (ANZ) have had complete population cancer incidence registration for decades and are beginning to develop clinical data systems to collect details of staging and treatment. Sadly, this bounty of statistical data is often under utilized and occasionally abused. Many are unaware of the data and statistical services available from their local cancer registry. To promote the use of ANZ population cancer data, the following paper describes the principal statistics that are available and identifies common problems with their use.

Liver cancer screening in a high-risk population in China fails to reduce mortality

Question Does liver cancer screening reduce mortality from the disease in a high-risk Chinese population? Study design Cluster randomised controlled trial. Main results In people at high risk of liver cancer, screening did not significantly reduce the incidence of primary liver cancer or risk of death compared with no screening (see Table 1), despite earlier detection of the disease (see notes). Table 1 Primary liver cancer incidence and mortality rates in a high-risk Chinese population. Screened ( N=3712) Not screened ( N=1869) p value Number of primary liver cancer cases 257 (7%) 117 (6%) Incidence rate † 1341 1195 0.30 Deaths from primary liver cancer 218 (6%) 109 (6%) Mortality rate † 1138 1113 0.86 †Per 100,000 person years. Authors’ conclusions Liver cancer screening in a high-risk population in China does not reduce mortality from the disease.

Cervical cancer among Hmong women in California, 1988 to 2000

Background The Hmong immigrated to the United States from Laos after the Vietnam conflict ended. Hmong encounter numerous readjustment issues, including health care. Traditional Hmong health beliefs and practices encompass more spiritual than biological etiologies. Hmong usually seek the first course of treatment from traditional healers, as they had in Laos. This practice delays early diagnosis and treatment of disease because biomedicine is used only as a last resort. This study examined cervical cancer incidence, mortality, and other tumor characteristics in the Hmong female population of California between 1988 and 2000. Methods Data from the California Cancer Registry were used to calculate annual average incidence, mortality, and age-specific rates for Hmong women diagnosed with cervical cancer. The population at risk was estimated with linear interpolation using data from the 1990 and 2000 censuses. Results Hmong women experienced incidence and mortality rates three and four times higher than Asian/Pacific Islander and non-Hispanic white women, respectively. Fifty-one percent of Hmong women chose no treatment, compared to 5.8% for Asian/Pacific Islander women and 4.8% for non-Hispanic white women. Hmong women aged ≥40 years carried an unequal burden of cervical cancer. They were more likely to be diagnosed with cervical cancer at later stages and poorer histologic grades, and had a lower survival rate than younger Hmong females. Conclusions Cervical cancer is clearly a public health issue that threatens the health and well-being of Hmong women. Culturally sensitive screening and prevention programs need to be developed to target older Hmong women using bilingual and bicultural Hmong women health educators using verbal communication.

Les traitements par β-bloquants pourraient-ils être associés à une diminution du risque de cancer ?

The relationship between the use of anti-hypertensive drugs and cancer risk remains controversial. The main objective of this study was to assess the potential effect of beta-blocker use on cancer risk. In a cohort of 839 patients with cardiovascular disease, followed up prospectively for an average period of 10 years, cancer occurrence was recorded according to the exposure to beta-blockers. The relative risk of cancer associated with beta-blocker use was estimated using a Cox model adjusted on gender and age. Ever- vs never-use of beta-blockers and duration of exposure to the drug were analyzed as time-dependent variables. In addition, the standardized incidence ratios (SIR) were calculated using the corresponding age- and gender-adjusted cancer incidences in the French general population. A total of 326 beta-blocker users and 513 users of other treatments were included in the cohort. During the follow-up period, representing 8,466 person-years, incident cancer cases were 15 and 59 in beta-blocker ever-users versus never-users, respectively. Using the Cox model, the overall relative risk of cancer was 0.51 (95% confidence interval [95% CI]: 0.29-0.90) in the beta-blocker ever-users versus never-users (p=0.02), with a 6% decrease per year of use (95% CI: 1%-12%; p=0.03). The corresponding SIR ratio between these two groups was 0.44 (95% CI: 0.24-0.76). In this cohort, the beta-blocker treatments appeared to decrease the cancer risk significantly. However, this result should be considered with caution; further work is needed, as some sources of bias associated with this type of epidemiological study cannot be totally excluded.

Phytoestrogenic Isoflavones Daidzein and Genistein Reduce Glucose‐Toxicity‐Induced Cardiac Contractile Dysfunction in Ventricular Myocytes

Epidemiological evidence suggests a reduction in the incidence of coronary heart disease, cancer and osteoporosis in populations with a high dietary intake of plant estrogen or phytoestrogen. The clinical benefit of phytoestrogens in cereals, vegetables and medicinal plants is attracting increasing attention for the general public. In the present study, we examined the effect of phytoestrogenic isoflavones daidzein and genistein on glucose toxicity‐induced cardiac mechanical malfunction simulating diabetic cardiomyopathy. Adult rat ventricular myocytes were isolated and maintained for 24 hours in normal (NG, 5.5 mM) or high glucose (HG, 25.5 mM) medium in the absence or presence of isoflavones daidzein (50 µM) or genistein (20 µM). Cardiac contractile indices were evaluated using an IonOptix® MyoCam system including peak shortening (PS), maximal velocity of shortening/relengthening (± dL/dt), time‐to‐PS (TPS) and time‐to‐90% relengthening (TR90). Myocytes maintained in HG medium displayed altered mechanical function simulating in vivo diabetes including reduced PS, ± dL/dt and prolonged TR90 associated with normal TPS compared to those from NG myocytes. Interestingly, these HG‐induced mechanical dysfunctions were abolished by co‐incubation of daidzein or genistein. However, daidzein but not genistein itself depressed PS in NG myocytes. Neither daidzein nor genistein affected any other mechanical parameters tested in NG myocytes. Collectively, these data suggest that the phytoestrogenic isoflavones daidzein and genistein may reduce glucose toxicity‐induced cardiac mechanical dysfunction and thus possess therapeutic potential against diabetes‐associated cardiac defects.