CANCER MORTALITY AMONG JAPANESE ISSEI AND NISEI OF CALIFORNIA

Consumption of Grapes Modulates Gene Expression, Reduces Non-Alcoholic Fatty Liver Disease, and Extends Longevity in Female C57BL/6J Mice Provided with a High-Fat Western-Pattern Diet

A key objective of this study was to explore the potential of dietary grape consumption to modulate adverse effects caused by a high-fat (western-pattern) diet. Female C57BL/6J mice were purchased at six-weeks-of-age and placed on a standard (semi-synthetic) diet (STD). At 11 weeks-of-age, the mice were continued on the STD or placed on the STD supplemented with 5% standardized grape powder (STD5GP), a high-fat diet (HFD), or an HFD supplemented with 5% standardized grape powder (HFD5GP). After being provided with the respective diets for 13 additional weeks, the mice were euthanized, and liver was collected for biomarker analysis, determination of genetic expression (RNA-Seq), and histopathological examination. All four dietary groups demonstrated unique genetic expression patterns. Using pathway analysis tools (GO, KEGG and Reactome), relative to the STD group, differentially expressed genes of the STD5GP group were significantly enriched in RNA, mitochondria, and protein translation related pathways, as well as drug metabolism, glutathione, detoxification, and oxidative stress associated pathways. The expression of Gstp1 was confirmed to be upregulated by about five-fold (RT-qPCR), and, based on RNA-Seq data, the expression of additional genes associated with the reduction of oxidative stress and detoxification (Gpx4 and 8, Gss, Gpx7, Sod1) were enhanced by dietary grape supplementation. Cluster analysis of genetic expression patterns revealed the greatest divergence between the HFD5GP and HFD groups. In the HFD5GP group, relative to the HFD group, 14 genes responsible for the metabolism, transportation, hydrolysis, and sequestration of fatty acids were upregulated. Conversely, genes responsible for lipid content and cholesterol synthesis (Plin4, Acaa1b, Slc27a1) were downregulated. The two top classifications emerging as enriched in the HFD5GP group vs. the HFD group (KEGG pathway analysis) were Alzheimer's disease and nonalcoholic fatty liver disease (NAFLD), both of which have been reported in the literature to bear a causal relationship. In the current study, nonalcoholic steatohepatitis was indicated by histological observations that revealed archetype markers of fatty liver induced by the HFD. The adverse response was diminished by grape intervention. In addition to these studies, life-long survival was assessed with C57BL/6J mice. C57BL/6J mice were received at four-weeks-of-age and placed on the STD. At 14-weeks-of-age, the mice were divided into two groups (100 per group) and provided with the HFD or the HFD5GP. Relative to the HFD group, the survival time of the HFD5GP group was enhanced (log-rank test, p = 0.036). The respective hazard ratios were 0.715 (HFD5GP) and 1.397 (HFD). Greater body weight positively correlated with longevity; the highest body weight of the HFD5GP group was attained later in life than the HFD group (p = 0.141). These results suggest the potential of dietary grapes to modulate hepatic gene expression, prevent oxidative damage, induce fatty acid metabolism, ameliorate NAFLD, and increase longevity when co-administered with a high-fat diet.

Historical analysis of inverse correlation between soil-transmitted helminthiasis and pancreatic cancer

In this descriptive epidemiological study, the soil-transmitted helminth (STH) burden and pancreatic cancer (PC) mortality rates of different countries and peoples are compared to demonstrate an inverse correlation. Formerly ubiquitous helminth infection possibly played a significant role in defending the human host against PC until the advancement of modern hygiene, with helminth eradication in recent times in developed countries and urban centers. It is posited that a high rate of infection by STH in developing countries and rural areas protects the human host from the development of PC, possibly by immune modulation. This hypothesis is used to explain increased PC rates in minority groups in the United States who had decreased helminth exposure in the late 20th century.

Correlation between mouse age and human age in anti-tumor research: Significance and method establishment

Age is closely related with the occurrence and development of tumors, and with treatment outcomes. To improve the accuracy and rigor of preclinical studies, and to enhance consistency between the preclinical research and the clinical reality, the age of experimental animals used in preclinical studies is important. The mouse genome is 99% identical to the human genome, and mice have similar patterns with respect to organs and systemic physiology. Thus, mice have been the most widely used animals in anti-tumor research. However, most mice used in such studies are 6 to 8 weeks old, ignoring the fact that different tumors may often occur in various periods, with a particular tendency to occur in later stages of life. The great difference in age limits the success rate of clinical transformation. Therefore, it is very important to choose mice of suitable age for preclinical studies and to correlate ages of human and mice. Only a few related studies have been reported and there is a lack of consistency in the findings. This review points out that age is one of the important factors in anti-tumor research, and establishes a new method for calculating the age correlation between humans and mice. The equations obtained from the method can help researchers conveniently determine suitable aged mouse for their research, which will improve the rigor of their experimental results. Furthermore, this method can be used beyond anti-tumor research, in studies on other diseases that use mouse as an animal model.

Global Epidemiology of Lung Cancer

While lung cancer has been the leading cause of cancer-related deaths for many years in the United States, incidence and mortality statistics - among other measures - vary widely worldwide. The aim of this study was to review the evidence on lung cancer epidemiology, including data of international scope with comparisons of economically, socially, and biologically different patient groups. In industrialized nations, evolving social and cultural smoking patterns have led to rising or plateauing rates of lung cancer in women, lagging the long-declining smoking and cancer incidence rates in men. In contrast, emerging economies vary widely in smoking practices and cancer incidence but commonly also harbor risks from environmental exposures, particularly widespread air pollution. Recent research has also revealed clinical, radiologic, and pathologic correlates, leading to greater knowledge in molecular profiling and targeted therapeutics, as well as an emphasis on the rising incidence of adenocarcinoma histology. Furthermore, emergent evidence about the benefits of lung cancer screening has led to efforts to identify high-risk smokers and development of prediction tools. This review also includes a discussion on the epidemiologic characteristics of special groups including women and nonsmokers. Varying trends in smoking largely dictate international patterns in lung cancer incidence and mortality. With declining smoking rates in developed countries and knowledge gains made through molecular profiling of tumors, the emergence of new risk factors and disease features will lead to changes in the landscape of lung cancer epidemiology.

Cancer incidence in South Asian migrants to England, 1986-2004: unraveling ethnic from socioeconomic differentials

Studies on cancer in migrants are informative about the relative influence of environmental and genetic factors on cancer risk. This study investigates trends in incidence from colorectal, lung, breast and prostate cancer in England among South Asians and examines the influence of deprivation, a key environmental exposure. South Asian ethnicity was assigned to patients recorded in the population-based National Cancer Registry of England during 1986-2004, using the computerized algorithm SANGRA: South Asian Names and Groups Recognition Algorithm. Population denominators were derived from population censuses. Multivariable flexible (splines) Poisson models were used to estimate trends and socioeconomic differentials in incidence in South Asians compared to non-South Asians. Overall, age-adjusted cancer incidence in South Asians was half that in non-South Asians but rose over time. Cancer-specific incidence trends and patterns by age and deprivation differed widely between the two ethnic groups. In contrast to non-South Asians, lung cancer incidence in South Asians did not fall. Colorectal and breast cancer incidence rose in both groups, more steeply in South Asians though remaining less common than in non-South Asians. The deprivation gaps in cancer-specific incidence were much less marked among South Asians, explaining some of the ethnic differences in overall incidence. Although still lower than in non-South Asians, cancer incidence is rising in South Asians, supporting the concept of transition in cancer incidence among South Asians living in England. Although these trends vary by cancer, they have important implications for both prevention and anticipating health-care demand.

Hypertension is positively associated with prostate cancer development in the TRAP transgenic rat model

Epidemiological data on the relationship between hypertension and prostate cancer development are conflicting. To cast light on this question, we performed animal experiments using hybrid rats generated by crossing the spontaneously hypertensive rat (SHR) or its normotensive control Wistar Kyoto (WKY) rat with a transgenic rat for adenocarcinoma of prostate (TRAP) that features development of adenocarcinoma at high incidence by 15 weeks of age. The number of adenocarcinomatous foci in the lateral prostate of hypertensive (TRAP × SHR)F1 rats was demonstrated to be significantly increased compared with those of normotensive (TRAP × WKY)F1 rats. In the ventral prostate, increase of carcinoma foci was also observed but did not reach significance. The number of cancer foci showing microinvasion in (TRAP × SHR)F1 rats was higher than that of (TRAP × WKY)F1 rats, but again without significance, while treatment with prazosin, an anti-hypertensive agent, tended to decrease microinvasive carcinoma foci in both the ventral and lateral prostate. In conclusion, the present study provided additional evidence that high blood pressure is associated with prostate cancer risk.

Global patterns of cancer incidence and mortality rates and trends

While incidence and mortality rates for most cancers (including lung, colorectum, female breast, and prostate) are decreasing in the United States and many other western countries, they are increasing in several less developed and economically transitioning countries because of adoption of unhealthy western lifestyles such as smoking and physical inactivity and consumption of calorie-dense food. Indeed, the rates for lung and colon cancers in a few of these countries have already surpassed those in the United States and other western countries. Most developing countries also continue to be disproportionately affected by cancers related to infectious agents, such as cervix, liver, and stomach cancers. The proportion of new cancer cases diagnosed in less developed countries is projected to increase from about 56% of the world total in 2008 to more than 60% in 2030 because of the increasing trends in cancer rates and expected increases in life expectancy and growth of the population. In this review, we describe these changing global incidence and mortality patterns for select common cancers and the opportunities for cancer prevention in developing countries.

Cancer mortality in ethnic South Asian migrants in England and Wales (1993-2003): patterns in the overall population and in first and subsequent generations

BACKGROUND

Cancer mortality has been examined among ethnic South Asian migrants in England and Wales, but not by generation of migration.

METHODS

Using South Asian mortality records, identified by a name-recognition algorithm, and census information, age-standardised rates among South Asians, and South Asian vs non-South Asian rate ratios, were calculated.

RESULTS AND CONCLUSIONS

All-cancer rates in ethnic South Asians were half of those in non-South Asians in first-generation (all-cancer-standardised mortality ratio (SMR) in males 0.51 and in females 0.56) and subsequent-generation South Asians (SMR in males 0.43 and in females 0.36). The higher mortality in first-generation South Asians for liver (both sexes), oral cavity and gallbladder cancer (females), particularly marked among Bangladeshis, was reduced in subsequent generations.

Incidence Rates of Cervical Carcinoma Among First- and Second-Generation Women of North African Origin in Israel

Objectives:

To evaluate the incidence rates of cervical cancer by ethnic origins and compare these rates between first- and second-generation women of North African origin.

Methods:

Data of all cervical carcinoma of Jewish women during 2000 to 2005 were obtained from the National Cancer Registry. Standardized incidence ratios for each ethnic origin category were calculated and compared using Poisson regression.

Results:

During the study period, 938 patients were examined. The standardized incidence ratios of North African-born women and of Israeli-born women of North African descent were significantly higher compared with those of women of other origins.

Conclusions:

The persistence of a higher risk of cervical cancer in Israeli Jewish women of North African descent compared with those of other origins may suggest that genetic factors are involved in the etiology of this neoplasm.

Stomach cancer mortality in two large cohorts of migrants from the Former Soviet Union to Israel and Germany: are there implications for prevention?

OBJECTIVES

Prevention and early detection are key elements for the reduction of stomach cancer mortality. To apply pertinent measures effectively, high-risk groups need to be identified. With this aim, we assessed stomach cancer mortality among migrants from the Former Soviet Union (FSU), a high-risk area, to Germany and Israel.

METHODS

We calculated standardized mortality ratios (SMRs) comparing stomach cancer mortality in two retrospective migrant cohorts from the FSU to Germany (n=34,393) and Israel (n=589,388) to that in the FSU and the host country. The study period ranges from 1990 to 2005 in Germany and from 1990 to 2003 in Israel. Vital status and cause of death were retrieved from municipal and state registries. To assess secular mortality trends, we calculated annual age-standardized mortality rates in the cohorts, the FSU, and the two host countries and conducted Poisson regression modeling.

RESULTS

SMRs (95% confidence intervals) for men in the German migrant cohort were 0.51 (0.36-0.70) compared with the FSU population and 1.44 (1.04-1.99) compared with the German population, respectively. For women, SMRs were 0.73 (0.49-1.03) compared with the FSU population and 1.40 (0.98-1.99) compared with the German population. SMRs for men in the Israeli migrant cohort were 0.49 (0.45-0.53) compared with the FSU population and 1.79 (1.65-1.94) compared with the Israeli population. SMRs for women in the Israeli cohort were 0.65 (0.59-0.72) compared with the FSU population and 1.82 (1.66-1.99) compared with the Israeli population. Poisson modeling showed a secular decrease in all populations with a time lag of 4-5 years between migrants and 'natives' in Germany and converging rates between migrants and the general population in Israel.

CONCLUSION

Stomach cancer mortality in migrants from the FSU remains elevated after migration to Germany and Israel but is much lower than in the FSU. Due to a secular decline, it can be expected that mortality among migrants from the FSU reaches within a few years levels similar to those of the host countries today. Therefore, migrant-specific prevention and early detection measures cannot be recommended. Detailed risk factor profiles, however, need to be obtained through further studies.

Cancer registry databases: an overview of techniques of statistical analysis and impact on cancer epidemiology

Cancer registries provide systematically collected information on cancer incidence, prevalence, mortality, and survival of different cancers. Aggregated and de-identified patient-level information on cancer is available for analysis from individual cancer registries, nationally from the Surveillance, Epidemiology, and End Results program, the Centers for Diseases Control and Prevention, the North American Association of Central Cancer Registries; and internationally from the International Association of Cancer Registries. Over the past few decades, the type and extent of cancer-related information captured by different cancer registries have been greatly expanded by linkage with other population-based information sources, such as the census data and the Centers for Medicare and Medicaid Services claims data. In addition, sophisticated statistical analytical techniques have been developed that have greatly expanded the traditional purview of cancer registries focused on descriptive epidemiology and disease quantification to a much broader analytical horizon ranging from study of cancer etiology; rare cancers in specific demographic groups; interaction of environmental and genetic factors in causation of cancer; impact of co-morbidities, race, geographic, socioeconomic, and provider-related factors on access, diagnosis, and treatment; outcomes and end results of cancer treatment; and cancer control initiatives to diverse areas of cancer care disparity, public health policy, public health education, and importantly, cost-effectiveness of cancer care. Thus, it is not surprising that cancer registries have increasingly become indispensable parts of local, national, and international cancer control programs, and it is certain that cancer registries will continue to be extraordinary resources of information for clinicians, researchers, scientists, policy makers, and the public in our fight against cancer.

Cancer occurrence

In this chapter, we describe the variability of cancer occurrence by using measures of incidence, mortality, prevalence, and survival, according to demographic characteristics such as age, sex, socioeconomic status, and race/ethnicity, as well as geographic location and time period. We also discuss the variability of cancer occurrence in relation to changes in risk factors, screening rates, and improved treatments. The variation according to risk factors provides strong evidence that much of cancer is caused by environmental factors and is potentially avoidable.

Cancer incidence in the Hmong in California, 1988-2000

The Hmong represent a unique new Southeast Asian immigrant group to the U.S. Approximately 169,000 Hmong reside in the U.S., primarily in California, Minnesota, and Wisconsin. Previous studies of cancer in this population have indicated that Hmong experience an elevated risk of gastric, hepatic, cervical, and nasopharyngeal cancers and experience a reduced risk of breast, prostate, lung, and colorectal cancers. Approximately 65,000 Hmong live in California, where there has been a population-based cancer registry since 1988, and the authors used these data to calculate age-adjusted cancer incidence rates and to examine disease stage and tumor grade at diagnosis. Changes in rates during the period studied also were evaluated. These rates and proportions were compared with rates among the non-Hispanic white (NHW) and Asian/Pacific Islander (API) populations of California. Between 1988 and 2000, a total of 749 Hmong in California were diagnosed with invasive cancer, and the age-adjusted rate of cancer for the Hmong was 284 per 100,000 population, compared with 362.6 and 478 per 100,000 in the API and NHW populations, respectively. The age-adjusted incidence rates of cancer in the Hmong were elevated for hepatic, gastric, cervical, and nasopharyngeal cancers and for leukemia and non-Hodgkin lymphoma (NHL). Rates were lower in the Hmong for colorectal, lung, breast, and prostate cancers. For gastric cancer and lung cancer, age-adjusted rates increased between 1988 and 2000 in the Hmong, although breast cancer incidence declined. Cervical cancer incidence increased, rates of NHL were declining, and rates for colorectal cancer remained steady between 1988 and 2000. The Hmong experienced later disease stage at diagnosis than other API and generally poorer grade of disease at diagnosis. Hmong experienced lower overall invasive cancer incidence rates than API or NHW populations in California. However, they experienced higher rates of hepatic, gastric, cervical, and nasopharyngeal cancers; and, for most types of cancer, they were diagnosed in a later disease stage.

Cancer Surveillance Research: a Vital Subdiscipline of Cancer Epidemiology

Public health surveillance systems relevant to cancer, centered around population-based cancer registration, have produced extensive, high-quality data for evaluating the cancer burden. However, these resources are underutilized by the epidemiology community due, we postulate, to under-appreciation of their scope and of the methods and software for using them. To remedy these misperceptions, this paper defines cancer surveillance research, reviews selected prior contributions, describes current resources, and presents challenges to and recommendations for advancing the field. Cancer surveillance research, in which systematically collected patient and population data are analyzed to examine and test hypotheses about cancer predictors, incidence, and outcomes in geographically defined populations over time, has produced not only cancer statistics and etiologic hypotheses but also information for public health education and for cancer prevention and control. Data on cancer patients are now available for all US states and, within SEER, since 1973, and have been enhanced by linkage to other population-based resources. Appropriate statistical methods and sophisticated interactive analytic software are readily available. Yet, publication of papers, funding opportunities, and professional training for cancer surveillance research remain inadequate. Improvement is necessary in these realms to permit cancer surveillance research to realize its potential in resolving the growing cancer burden.

Colorectal cancer and the relationship between genes and the environment

Colorectal cancer (CRC) is a significant cause of morbidity and mortality in developed countries, with both genetic and environmental factors contributing to the etiology and progression of the disease. Several risk factors have been identified, including positive family history, red meat intake, smoking, and alcohol intake. Protective factors include vegetables, calcium, hormone replacement therapy, folate, nonsteroidal anti-inflammatory drugs, and physical activity. The interaction between these environmental factors, in particular diet and genes, is an area of growing interest. Currently, oncogenes, tumor suppressor genes, and mismatch repair genes are believed to play an essential role in colorectal carcinogenesis. When considering the genetics of CRC, only 10% of cases are inherited and only 2-6% can be ascribed to the highly penetrant genes, such as APC, hMLH and hMSH2. Lower penetrance genes combined with a Western-style diet contribute to the majority of sporadic CRCs. The purpose of this article is to give a brief overview of the epidemiologic studies that have been conducted and present the major findings. Here, we examine the molecular events in CRC, with particular focus on the interaction between genes and environment, and review the most current research in this area.

Correlation of dietary intake and colorectal cancer incidence among Mexican-American migrants: the multiethnic cohort study

Studies of migrants, along with geographic and temporal variations in incidence, indicate that colorectal cancer is especially sensitive to changes in environmental factors, including, most importantly, diet. The goal of this research was to examine the changes in dietary practices that may be consistent with the changing incidence of colorectal cancer in the Los Angeles Mexican-American population. Cancer incidence and dietary intake data were available for over 35,000 Latinos of Mexican national origin currently participating in the prospective Multiethnic Cohort Study, representing the largest sample of Mexican-origin Latinos of any such study in the United States. The dataset is unique in that changes in cancer rates and in dietary behaviors across three generations could be examined. Most of the change in colorectal cancer rates occurred between the first and second generations, and, correspondingly, nearly all the dietary change also occurred between the first and second generations. Although some food traditions were retained by Mexican Americans, the dietary changes due to acculturation were significant and support an association between colorectal cancer risk and certain dietary components, notably, alcohol as a risk factor and nonstarch polysaccharides and vegetables as protective factors.

The genetics and genomics of cancer

The past decade has seen great strides in our understanding of the genetic basis of human disease. Arguably, the most profound impact has been in the area of cancer genetics, where the explosion of genomic sequence and molecular profiling data has illustrated the complexity of human malignancies. In a tumor cell, dozens of different genes may be aberrant in structure or copy number, and hundreds or thousands of genes may be differentially expressed. A number of familial cancer genes with high-penetrance mutations have been identified, but the contribution of low-penetrance genetic variants or polymorphisms to the risk of sporadic cancer development remains unclear. Studies of the complex somatic genetic events that take place in the emerging cancer cell may aid the search for the more elusive germline variants that confer increased susceptibility. Insights into the molecular pathogenesis of cancer have provided new strategies for treatment, but a deeper understanding of this disease will require new statistical and computational approaches for analysis of the genetic and signaling networks that orchestrate individual cancer susceptibility and tumor behavior.

Behavioral changes in observational and intervention studies

Changes of diet and other lifestyle factors are often highly recommended, but evidence for the effectiveness of behavioral changes in adult lives is limited. In the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study, we investigated the reasons for and the direction of dietary changes as well as factors that are associated with the self-report of a change in diet. About 47% of the 27,548 cohort members reported a dietary change within the first 2 y of the follow-up. Detailed analysis of the type of change showed that public health recommendations are clearly understood. More vegetables and fruit and less fat are the most reported changes. Investigations into the reasons for dietary changes showed that in most instances and in ever shorter intervals, dietary recommendations resulting from progress in science are reinforced or partly modified. The health-conscious individuals in a population try to put these health messages into practice by modifying their behavior; these are the individuals who are particularly attracted to participate in scientifically oriented prospective studies and therefore are likely to be recruited by and retained in these studies. Behavioral changes over time may indicate dietary changes that are related to health and weight problems. The consideration of dietary changes during prospective data collection, therefore, is an important issue in the design and analysis of longitudinal studies-both cohort and intervention studies. Cohort studies in which dietary changes are adequately measured can contribute substantially to the evidence for health benefits resulting from changes in diet.

Prostate cancer

It is a paradigm in cancer treatment that early detection and treatment improves survival. However, although screening measures lead to a higher rate of detection, for small bulk localised prostate cancer it remains unclear whether early detection and early treatment will lead to an overall decrease in mortality. The management options include surveillance, radiotherapy, and radical prostatectomy but there is no evidence base to evaluate the benefits of each approach. Advanced prostate cancer is managed by hormonal therapy. There have been major changes in treatment over the last two decades with the use of more humane treatment and developments in both chemotherapy and radiation. In this article we review the natural history and management of prostate cancer.

Biological mechanisms in breast cancer invasiveness: relevance to preventive interventions

Migration studies suggest that the high incidence of postmenopausal breast cancer in Western women is related mainly to epigenetic factors. Progression from ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) also appears to involve environmental rather than genetic factors, and a role has been postulated for metabolic-endocrine changes related to the Western lifestyle. Protein kinase C (PKC) is important in cell signal transduction, and laboratory studies show that PKC stimulates the activities of urokinase plasminogen activator, matrix metalloproteinases and cell adhesion molecules, all of which are known to increase invasiveness in human mammary cancer cell lines. In rodents, the activity of PKC in tissue cells is enhanced by insulin, and PKC isoenzymes have been shown to stimulate the development of hyperinsulinaemic insulin resistance in rodents. Clinically, hyperinsulinaemia and the concomitant increase in circulating levels of free oestradiol and bioactive insulin-like growth factor 1 (IGF1) are each confirmed markers of high risk for breast cancer in women. Lesions of DCIS show evidence of regression with mammary involution, but it is postulated that this may be opposed by the concomitants of hyperinsulinaemic insulin resistance. The prevalence of the latter is increasing in Western populations, and a combination of high IGF1 and low IGF-binding protein 3 concentrations has been associated with the presence of DCIS lesions in premenopausal women. Measures that enhance insulin sensitivity in such women may reduce the risk of progression in DCIS lesions, and a clinical trial is proposed to test the hypothesis.

Migration patterns and breast carcinoma

BACKGROUND

Many American Indian and Alaska Native women have lower incidence rates of breast carcinoma than other racial/ethnic groups in the United States. The rates in most areas, however, have increased in recent years. The author reviews the migration patterns and effects that might contribute to this change.

METHODS

A review of the literature on migration and breast carcinoma incidence was conducted.

RESULTS

Migration significantly impacts on breast carcinoma incidence in all groups of women studied.

CONCLUSIONS

Research must be designed that will explore the components of host, life-styles, and environment on breast carcinoma rates in American Indian and Alaska Native women to elucidate mechanisms of breast carcinoma etiology.

Molecular epidemiology, pathogenesis and prevention of gastric cancer

Cancer of the stomach is one of the most commonly diagnosed malignancies and remains an important cause of mortality world wide. This type of cancer is not uniformly distributed among populations but shows a marked variation in both incidence and mortality. Although gastric cancer is declining in many parts of the world, the reasons for this decline are not well understood and its etiology remains unclear. Several factors are suspected to play a role in gastric carcinogenesis, including the effects of diet, exogenous chemicals, intragastric synthesis of carcinogens, genetic factors, infectious agents and pathological conditions in the stomach (such as gastritis). A new look at the results of epidemiological and experimental studies is important for the establishment of strategies for control. Since cancer of the stomach has a very poor prognosis in its more advanced stages, such a control program must have its main focus on primary prevention. This review describes our knowledge about cancer of the stomach regarding epidemiology, pathogenesis and prevention.

Epidemiology and Prevention of Breast Cancer in the 21st Century

The incidence and mortality of breast cancer are high in Western industrialized and relatively low Japan and other Asian countries. In Japan the incidence and mortality of breast cancer have gradually been increasing. Marrying later, having fewer children, a larger intake of fat, dairy products and meats and a larger body mass index in menopausal women may be related to the increased incidence of breast cancer in Japan. A review of risk factors identified from recent epidemio-logical studies in Japan indicates that obesity after 50 years of age is an important risk factor for post-menopausal breast cancer. Future estimations of cancer mortality and incidence predict that breast cancer will further increase to become a leading cancer in Japan in the 21st century.

Fat and dietary fiber intake and colon cancer mortality: a chronological comparison between Japan and the United States

To estimate the role of dietary fiber (DF) and fat in the striking growth of colon cancer mortality in Japan after World War II, we analyzed relations between the above variables in comparison with those in the United States. In the United States, fat intake grew by only one-third over the past 70 years (from 124 g in 1909-1913 to 166 g in 1984), whereas colon cancer mortality increased fourfold (from 5 to 20 per 100,000). In Japan, although fat intake roughly doubled during the 40 years after World War II (from 20 to 38 g), colon cancer mortality grew 5.5-fold (from 2 to 11 per 100,000). It is difficult to give a consistent explanation for the growth patterns of colon cancer mortality in both countries on the basis of fat consumption as a cancer promoter. In the United States, DF intake continuously dwindled at a level always less than in Japan throughout this century. DF intake in Japan also declined rather steadily, except for war time, over the past 80 years. However, with regard to the growth pattern of colon cancer mortality, it began rising steeply around the period when the daily DF intake diminished below 20 g, suggesting the presence of a threshold level in this neighborhood in preventing the development of colon cancer.

Association between breast and colorectal cancers

BACKGROUND

The risk of breast and colorectal cancers in immigrants from non-industrialised countries is sharply increased when they adopt a Western lifestyle. In addition, epidemiological studies on Western populations show an association between the two tumours, both in the same individual and also in close relatives. Most studies agree that high energy intake, obesity and inadequate physical exercise are associated with an increased risk of both tumours.

METHODS

Risk markers for each cancer are examined in order to identify causative nutritional factors or metabolic-endocrine dysfunction. The role of steroid hormones and other possible carcinogenic mechanisms is discussed, concentrating on evidence of a role for insulin and insulin-like growth factors (IGFs) in the promotion of carcinogenesis in both organs.

RESULTS

Individuals with a genetic susceptibility to insulin resistance show triggering of hyperinsulinaemia following excessive weight gain or long-term diet high in saturated fat. Case-control studies show an association between hyperinsulinaemia and evidence of breast or colorectal carcinoma. Multiple laboratory studies show that increased activity of IGFs can stimulate the growth of human breast and colorectal cancer cells.

CONCLUSION

It is postulated that either insulin resistance and its concomitants promote the development of breast and colorectal cancers, or that they share common risk factors. Sex steroid metabolism and organ specificity may explain age and sex differences between the tumours in relation to the role of obesity. Recent research suggests that a diet high in n-3 polyunsaturated fatty acids may reduce the risk of developing insulin resistance. This observation may be applied to test the hypothesis that an effect on hyperinsulinaemia may modify the risk of developing breast or colorectal cancer.

Annual changes in colorectal carcinoma incidence in Japan. Analysis of survey data on incidence in Aomori Prefecture

BACKGROUND

In recent years, the mortality rate for colorectal carcinoma in Japan has rapidly been increasing, and there are indications that it may surpass that of gastric carcinoma, with colorectal carcinoma fast becoming one of the main targets of cancer treatment in Japan.

METHODS

Eight thousand three hundred and eighty-six case records of colorectal carcinoma (4479 males and 3907 females; 4691 colon carcinoma cases and 3695 rectal carcinoma cases), diagnosed over 18 years from 1974 to 1991 in Aomori Prefecture, were analyzed.

RESULTS

Age-adjusted incidence for colorectal carcinoma per 100,000 population were 12.6 and 8.7 for males and females, respectively, in 1974. The corresponding rates were 20 and 13.6, respectively, in 1980, and 42.5 and 25.6, respectively, in 1991. Among patients with colon carcinoma, a higher proportion have sigmoid colon carcinoma. The degree of increase in the incidence of sigmoid colon carcinoma was almost the same as that of right-sided colon carcinoma. By birth cohort analysis, among those born in 1934 or earlier, the incidence at the same age was higher in the younger population.

CONCLUSION

It is possible that the age-adjusted incidence of colorectal carcinoma in Japan will soon resemble that of the white population in the United States, in a manner similar to that of Japanese-Americans.

Lifestyle changes during adolescence and risk of breast cancer: an ecologic study of the effect of World War II in Norway

There are biologic reasons to believe that the period between the larche and the first full-term pregnancy is a particularly sensitive period in a woman's life regarding the development of breast cancer. In this ecologic study, data provided by the Norwegian Cancer Registry were analyzed to compare risk of breast cancer among women who experienced this sensitive period before, during, or after World War II. An ordinary age-cohort model and a model where the cohort was described by exposure by calendar period and sensitivity to this exposure at different ages, were fitted to the data. The incidence of breast cancer was lower than expected among women who experienced puberty during the war. The estimated configuration of the exposure variable showed an increase in exposure up to the start of WWII to twice the level in 1916, dropped by 13 percent during the war, and increased again after the war. The level in 1975 was approximately 2.7 times higher than the level in 1916. The results indicate that one or more lifestyle factors that changed among adolescent women during the war, influenced their risk of breast cancer. Dietary intake of energy, fat, meat, milk, fish, fresh vegetables, and potatoes, in addition to physical activity level and height, are important factors to consider in relation to breast cancer risk.

Epidemiology of and risk factors for pancreatic cancer

In the United States, incidence of and mortality from pancreatic cancer increased for several decades earlier in this century but have tended to level off in recent years. Rates increase with age and are higher in blacks than in whites and higher in males than in females. No consistent differences by socioeconomic status or by geographic location in the United States have been identified, although international variation and differences in migrants have been observed. Thus, both genetic and environmental factors may be playing significant roles in the development of pancreatic cancer. Cigarette smoking increases the risk of pancreatic cancer, but the strength of this association is much less than for lung cancer or other smoking-related cancers. Epidemiologic studies of the effect of alcohol consumption on pancreatic cancer largely show no relationship, and the results for coffee consumption indicate little, if any, association. Human studies have suggested positive associations with meat consumption and carbohydrate intake and a protective effect of dietary fiber and consumption of fruits and vegetables. Results of a number of occupational studies are suggestive of increased risk associated with some exposures but are not fully consistent. Thus, much progress has been made in the last two decades in identifying risk factors, but much epidemiologic work is needed to identify and reduce putative exposures.

Epidemiology of Breast Cancer in Japan

The mortality and incidence of breast cancer are high in Western industrialized countries and relatively low in developing countries in Asia and other parts of the world. In Japan the mortality of breast cancer has gradually been increasing, but is still much lower compared with those of Western countries. Within Japan the mortality of breast caner is higher in urban areas than in non-urban areas. The future estimation of cancer incidence in Japan predicts that breast cancer will become a leading cancer in the near future. From the present review of epidemiology of breast cancer it is recommended that excess intake of fat and calories, especially of animal fat, be avoided.

Epidemiology of breast cancer in Japan

The mortality and incidence of breast cancer are high in Western industrialized countries and relatively low in developing countries in Asia and other parts of the world. In Japan the mortality of breast cancer has gradually been increasing, but is still much lower compared with that of Western countries. Within Japan the mortality of breast cancer is higher in urban areas than in non-urban areas. The future estimation of cancer incidence in Japan predicts that breast cancer will become a leading cancer in the near future.

Aetiology of pancreatic cancer

Curative surgery is possible in only a small minority of patients with pancreatic cancer and, to date, responses to chemotherapy and radiotherapy have been disappointing. To make any impact on the incidence of the disease a clearer understanding of its aetiology is required. This review explores present knowledge of the aetiology and epidemiology of pancreatic cancer.

Gastric cancer: an epidemiological review

An attempt is made to synthesize the epidemiological literature and identify salient factors from the multitude of potential antecedents of gastric cancer, factors which to a greater or lesser degree create nonrandom variations in the distribution of the disease. Implicit in this approach is the notion that observation of spatial variations in the incidence of gastric cancer may lead to hypotheses relating to the biological, personal and physical environmental factors. An extensive bibliography accompanies the text.

Simultaneous gastric cancer in monozygotic twins

Monozygotic twins developed gastric cancers that were found almost simultaneously. A 47-year-old man complained of nausea and vomiting; an upper gastrointestinal series and endoscopy revealed advanced gastric cancer invading the serosa. Palliative subtotal gastrectomy was performed. In his asymptomatic twin a gastric polyp was detected during a screening examination, and this was observed for 2 years. After the former twin had undergone surgery, the latter twin was given a detailed endoscopic examination, and biopsy revealed gastric cancer limited to within the mucosa. Curative subtotal gastrectomy was performed. The noncancerous gastric mucosa of the former twin showed severe intestinal metaplasia, but that in the latter showed only spotty metaplasia. They had lived together for 40 years, but the former was a heavy smoker and drank alcohol, while the latter did not. These differences in taste might have contributed to the observed difference in intestinal metaplasia, which indicates chronic mucosal damage.

Cross-cultural correlations of childhood growth and adult breast cancer

International differences in breast cancer incidence and mortality, and studies on Japanese migrants to the United States, point to the importance of environmental factors, including diet and nutrition, in the etiology of breast cancer. Some studies have suggested that dietary patterns in early life are important to the long-term risk of breast cancer. Given that human growth is partially a function of early dietary intake, cross-cultural correlations between breast cancer rates and anthropometric variables measured at different times in childhood provide additional information about the association of early nutrition and cancer. In this study, the associations between food consumption and anthropometric variables, and childhood growth patterns (attained size at age) and adult breast cancer rates, were considered. Data from cross-sectional growth studies conducted during the years 1956-1971 on children aged 6-18 years were obtained for age-specific stature, sitting height, weight, triceps skinfold thickness, arm and chest circumferences, and biacromial and biiliac diameters. National food consumption data were obtained from the United Nations Food and Agriculture Organization (FAO) and socioeconomic status indicators from the United Nations Children's Fund (UNICEF). Cancer incidence data for the years 1972-1977 were obtained from regional cancer registries reported by the International Agency for Research on Cancer (IARC), and mortality data for 1978 were obtained from national cancer registries around the world. Significant correlations were seen between national food consumption data and childhood growth (attained size at age); between cancer incidence and age-specific stature (r = 0.68), weight (r = 0.59), triceps skinfold thickness (r = 0.78), and biacromial width (r = 0.84); and between mortality and age-specific stature (r = 0.77), weight (r = 0.75), and biacromial width (r = 0.78). In general, the correlation coefficients of the observed anthropometric variables with breast cancer increase with increasing age and become highly significant at ages 13-14 years, reflecting cumulative childhood nutritional intake.

The use of epidemiology, scientific data, and regulatory authority to determine risk factors in cancers of some organs of the digestive system. 6. Pancreatic cancer

The etiology of pancreatic cancer remains elusive. It predominates in males and in certain ethnic populations (i.e., Polynesians and blacks). Primarily a disease of aging, it is rare in individuals under 40. Genetics is believed to play a very small part if any. While diabetics have higher than expected incidence and mortality rates, several recent studies have indicated that in most cases the diabetes is an early sign of pancreatic cancer rather than a predisposing condition. Other conditions have been infrequently reported in association with pancreatic cancer. None of them have shown a definitive associative pattern and are believed to represent coincidental occurrences. Migrant studies of Japanese immigrants implicate some type of environmental etiology, since pancreatic cancer rates increase dramatically within one to two generations. Studies on atom bomb survivors have demonstrated no link between a single intense dose of radiation and subsequent development of this disease. Workers exposed to low-level radiation have shown an increase in pancreatic cancer, but this result may reflect methodologic problems. Many chemicals have been shown to cause pancreatic cancer in animals, and chemists exhibit higher pancreatic cancer rates than expected. However, the human cases have not been traced to any specific chemical. Many other occupations besides chemistry have shown increased pancreatic cancer rates, but the common factor in these occupations is not obvious. Studies analyzing the relationship of alcohol consumption to pancreatic cancer yield conflicting results. This may be explained if the observed effects are due to a confounder, such as cigarette smoking; to an ingredient other than alcohol contained in alcoholic beverages, such as nitrosamines; or to the immunosuppressive effects of chronic excessive alcohol consumption. Smoking is the risk factor showing the most definitive and consistent results. There is little doubt that it plays an etiologic role, and it probably accounts for the higher incidence of the disease in males. Most other research does not support MacMahon's reported association between coffee drinking and pancreatic cancer. Recent studies have indicated a generally increased fluid intake in pancreatic cancer patients due to a disease-induced disturbance in glucose tolerance function. Such increased fluid intake would tend to manifest itself in the most popular beverage of the country (i.e., coffee in the United States and tea in the United Kingdom). Animal studies have indicated a link between pancreatic cancer and high fat and/or high protein diets as well as raw soybean consumption.(ABSTRACT TRUNCATED AT 400 WORDS)

Comparison of the fecal microflora in rural Japanese and urban Canadians

The fecal microflora of nine rural healthy Japanese and eight urban healthy Canadians was examined. The two populations ate typical Japanese and western diets, respectively. The numbers of eubacteria (P less than 0.01), bifidobacteria (P less than 0.05), bacilli (P less than 0.01), lactobacilli and veillonellae and the frequency of occurrence of bifidobacteria were higher in the Japanese than in the Canadians. Higher numbers of bacteroides and lecithinase-negative clostridia were found in the Canadians. Twenty-three genera and over 75 species or biovars were isolated from the feces of Japanese and 18 genera and over 66 species or biovars from the Canadians. The numbers of Bacteroides vulgatus (P less than 0.05), Clostridium coccides (P less than 0.001), and C. tertium (P less than 0.05) and the incidence of B. uniformis (P less than 0.01), C. innocuum (P less than 0.05), and Bacillus spp. (P less than 0.01) were significantly lower in the Japanese than in the Canadians. In contrast, the numbers of Eubacterium aerofaciens (P less than 0.001), and the incidence of Bifidobacterium adolescentis biovar b (P less than 0.01) and Bacillus subtilis (P less than 0.01) were significantly higher in the Japanese than in the Canadians. These findings suggest that significant reductions in anaerobic gram-positive bacilli and increased numbers of bacteroides and clostridia in the feces were induced by the intake of a western diet.

Mortality from cancer of the stomach, colon and rectum in the city of Naples and the provinces of Campania

Utilizing data on deaths from 1951 to 1981, this study attempts to verify a time trend for stomach, colon and rectum cancer in the city of Naples. Time trend analysis and cohort analysis have shown an increase of colon rectum cancer mortality affecting cohorts born after 1871 and a decrease of stomach cancer mortality for those born after 1886. A comparison of mortality rates in three geographical areas shows that, while there is not any difference for stomach cancer, the mortality curves relating to cancer of the colon and rectum are higher in the city of Naples than in the province of Naples and the other provinces of Campania.

A case-control study of stomach cancer in a coal mining region of Pennsylvania

Historically coal mining populations have been reported to have elevated stomach cancer incidence rates. To identify which factors might be associated with cases who reside in these high risk areas, and specifically if particulate exposures from coal mining and coal utilization are associated with risk, a mining area of western Pennsylvania was defined for a retrospective case-control study. One hundred seventy-eight resident cases, identified from certificates of death, were compared to three controls: digestive cancer deaths, arteriosclerotic heart disease deaths, and neighborhood (living) controls. Controls were matched to each case on age, race, sex, and residence. Interviews were conducted during 1981 and 1982. Excess risks were shown for foreign born and eastern Europeans. Coal mining was not shown to be a risk factor for males, while an association was seen for female cases whose husbands were miners. Farming was a risk factor for males and females. Marked decreased risks were shown for gas heating and cooking fuels, with elevated risks for coal, wood and oil heating fuels, and wood cooking fuel. These findings are associated with lower socioeconomic status, and suggest environmental exposures or lifestyles that are directly and indirectly related to these risks factors. The marked inverse relationship between stomach cancer and use of gas heating and cooking fuel may be of important etiologic significance, especially in association with dietary changes. Further evaluation of prior use of various types of heating and cooking fuels needs to be considered especially using incident rather than case deaths.