Estimates of the worldwide incidence, mortality and prevalence of 26 cancers in the year 2002 are now available in the GLOBOCAN series of the International Agency for Research on Cancer. The results are presented here in summary form, including the geographic variation between 20 large "areas" of the world. Overall, there were 10.9 million new cases, 6.7 million deaths, and 24.6 million persons alive with cancer (within three years of diagnosis). The most commonly diagnosed cancers are lung (1.35 million), breast (1.15 million), and colorectal (1 million); the most common causes of cancer death are lung cancer (1.18 million deaths), stomach cancer (700,000 deaths), and liver cancer (598,000 deaths). The most prevalent cancer in the world is breast cancer (4.4 million survivors up to 5 years following diagnosis). There are striking variations in the risk of different cancers by geographic area. Most of the international variation is due to exposure to known or suspected risk factors related to lifestyle or environment, and provides a clear challenge to prevention.

https://acsjournals.onlinelibrary.wiley.com/doi/pdf/10.3322/canjclin.55.2.74

Global cancer statistics, 2002.

background The influence of excess body weight on the risk of death from cancer has not been fully characterized. methods In a prospectively studied population of more than 900,000 U.S. adults (404,576 men and 495,477 women) who were free of cancer at enrollment in 1982, there were 57,145 deaths from cancer during 16 years of follow-up. We examined the relation in men and women between the body-mass index in 1982 and the risk of death from all cancers and from cancers at individual sites, while controlling for other risk factors in multivariate proportional-hazards models. We calculated the proportion of all deaths from cancer that was attributable to overweight and obesity in the U.S. population on the basis of risk estimates from the current study and national estimates of the prevalence of overweight and obesity in the U.S. adult population. results The heaviest members of this cohort (those with a body-mass index [the weight in kilograms divided by the square of the height in meters] of at least 40) had death rates from all cancers combined that were 52 percent higher (for men) and 62 percent higher (for women) than the rates in men and women of normal weight. For men, the relative risk of death was 1.52 (95 percent confidence interval, 1.13 to 2.05); for women, the relative risk was 1.62 (95 percent confidence interval, 1.40 to 1.87). In both men and women, body-mass index was also significantly associated with higher rates of death due to cancer of the esophagus, colon and rectum, liver, gallbladder, pancreas, and kidney; the same was true for death due to non-Hodgkin’s lymphoma and multiple myeloma. Significant trends of increasing risk with higher body-mass-index values were observed for death from cancers of the stomach and prostate in men and for death from cancers of the breast, uterus, cervix, and ovary in women. On the basis of associations observed in this study, we estimate that current patterns of overweight and obesity in the United States could account for 14 percent of all deaths from cancer in men and 20 percent of those in women. conclusions Increased body weight was associated with increased death rates for all cancers combined and for cancers at multiple specific sites.

/pdf/overweight-obesity-and-mortality-from-cancer-in-a-3whc0l70ow.pdf

Overweight, obesity, and mortality from cancer in a prospectively studied cohort of U.S. adults.

The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

Harrison's Principles of Internal Medicine

Hepatocellular Carcinoma: Epidemiology and Molecular Carcinogenesis

CA : A Cancer Journal for Clinicians

Observational epidemiological studies almost invariably find a dose-dependent inverse association between frequency of fruit or vegetable intake and risk of epithelial cancers (1). The strength of this association is generally unimpressive, but since a sizeable and unavoidable exposure measurement error tends to bias any association towards the null, it has been assumed that the true effect is underestimated. Although adjustments for factors related to education, socioeconomic status and healthy lifestyle often attenuate the crude estimates, the inverse relationship usually persists after what could be considered adequate control for confounding. The consistency across studies and the plausibility*/largely hinged on an undisputable antioxidative action*/built a strong case for causality. Therefore, the total absence of any protection in three wellperformed large-scale randomized chemoprevention trials with the vitamins believed to be most responsible for the beneficial effects of fruits and vegetables (2 /4) came as a shock to the epidemiological community. While issues regarding doses and timing need some consideration, the discrepancy between observational data and the results from the randomized trials is most likely explained by either of two alternatives: 1) some constituent(s) other than the substances administered in the chemoprevention trials account for the anticarcinogenic action of fruits and vegetables; or 2) the seemingly protective effect in observational studies does not come from these foods, but comes from other factors that might be related to the general lifestyle of frequent consumers or to other components of their diet. The lesson to be learned from this major setback is that even the most evident causal relationship noted in observational studies could potentially be explained by confounding. As far-reaching campaigns are presently being launched in order to promote fruit and vegetable consumption (5)*/notwithstanding the chemoprevention failures*/and billions of Euros will be spent in the near future on programmes for distributing these foods to children and other targeted categories, it is difficult not to sympathize with the idea of making an appropriate assessment of their effect. And since confounding is the main concern, a randomized controlled trial is the method of choice. Provided that the study is large enough, randomization*/properly done*/will ensure that all factors causally related to the outcome, regardless of whether they are known or unknown, will be evenly distributed across the treatment arms. Hence, randomization safeguards against any known or unknown confounding. In this issue of Acta Oncologica , Mehr et al. propose a grand randomised, controlled trial in the Baltic countries aimed at providing valid and persuasive confirmation of the wholesome effects of fruit and vegetables (6). According to their appraisal, an almost unique window of opportunity will be open in these countries in the years to come. No doubt, such confirmation is needed. The question is whether the scheme is feasible and whether valid results will be obtained. Or in other words, will the huge investment that is required really be worthwhile? The authors behind the proposal are well aware of the complexity of such a trial, and some of the issues are touched upon in their thought-provoking article. Commendably, they recommend a multistage approach, with indepth preparation and feasibility studies preceding the main intervention study. This is a very sensible standpoint. Even with the best of intentions, interference with entrenched habits and social structures can produce unpredictable results*/a well-known fact among relief workers involved in aid to developing countries. Therefore, it is important to study the secondary effects of the intervention at the individual, group and community levels before the fullscale study is launched. The ideal design of any intervention study involves individual randomization. It is, however, evident that this will be impractical in the proposed study. First, it would be exceedingly expensive individually to deliver 1 500 /2 000 g of bulky food twice a week to 30 000 subjects scattered over large areas. Second, it would be virtually impossible to INVITED EDITORIAL

On the long and winding road to an evidence-based diet.

In order to establish time trends in surgical rates for peptic ulcer disease, we sent a questionnaire to every surgical department in Sweden. Eighty-two per cent of the departments responded. Since 1956 there was a marked and steady decline in elective procedures (− 83%) and to a much lesser extent also in emergency procedures for perforations (− 30%). The decline was most pronounced for duodenal ulcer in men. In 1986, the incidence was 1. 2 and 0. 65 operations per 10 000 inhabitants for elective and emergency operations, respectively. In the future, the few patients needing elective surgery for peptic ulcer may have to be served by a small number of specialized centers.

https://www.tandfonline.com/doi/pdf/10.3109/03009738809178537

Time trends in peptic ulcer surgery in Sweden. A preliminary report of a nation-wide survey.

Introduction: Migrant studies may provide valuable clues to the etiology of chronic diseases such as cancer. We conducted a migrant study to examine cancer incidence among Iranian immigrants in Sweden. Methods: A cohort of Iranian immigrants in Sweden in 1960-2004 was followed through record linkages with Swedish registers of cancer, death, and migration. We compared Age-Standardized Incidence Rates (ASRs) with corresponding ASRs in Tehran and Sweden and estimated Standard Rate Ratios with 95% confidence intervals (CI). In addition, ASRs were stratified by follow-up time. Results: In total 1,041 cancers occurred among 60,718 Iranian immigrants. The ASRs for all cancers combined were 182.3 and 175.5 per 100,000 person-years among men and women, respectively. For men, this rate was slightly and non-significantly higher than in Iran, while for women the excess (24%) was statistically significant. However, their ASRs were significantly lower than those for native Swedes: men had 37% (95% CI 27-47%) and women 35% (95% CI 33-37%) lower ASRs.  Compared to male Iranians living in Tehran, ASRs of esophageal and gastric cancer were lower while ASRs of colorectal and prostate cancer were higher, and both of the latter increased with time since immigration. In women, the ASR of non-melanoma skin cancer was lower and that of breast cancer higher and increasing. Conclusion: In male first-generation immigrants, incidence rates of esophageal, gastric, colorectal, and prostate cancer change in the direction of prevailing rates in Sweden, likely due to changes in exposure to environmental risk factors. A similar adjustment occurs for breast and non-melanoma skin cancer among female immigrants.

/pdf/cancer-incidence-rates-among-iranian-immigrants-in-sweden-a-4rk2mrcbkk.pdf

Cancer Incidence Rates among Iranian immigrants in Sweden, a Population-Based Retrospective Cohort Study

In clinical epidemiology, modern statistical and epidemiological methods are used to answer questions that arise in clinical practice. The study designs can be either observational or experimental. With its roots in analytical epidemiology which is based mainly on observational methods, clinical epidemiology has inherited its mother discipline’s concern with methodological issues. Special attention is paid to threats to the external and internal validity of the studies. Particularly, clinical epidemiology regularly uses methods developed to accommodate the influence of confounding factors and other cofactors which cannot be controlled by the investigator.

Olof Nyrén

Papers

On the long and winding road to an evidence-based diet.

Time trends in peptic ulcer surgery in Sweden. A preliminary report of a nation-wide survey.

Cancer Incidence Rates among Iranian immigrants in Sweden, a Population-Based Retrospective Cohort Study

The Role of Adjuvant Treatment if Surgery Is Optimal: A Clinical Epidemiologist’s View