Risk of connective tissue disease and related disorders among women with breast implants: a nation-wide retrospective cohort study in Sweden.

Objective: To examine the relation between connective tissue disease and related conditions and breast implants.

Design: Retrospective cohort study of all women in the Swedish national inpatient registry who underwent breast augmentation surgery with artificial implants during 1964-93, compared with women who underwent breast reduction surgery during the same period.

Setting: Sweden.

Smoking and the risk of leukemia, lymphoma, and multiple myeloma (Sweden).

While several epidemiologic studies have indicated a link between smoking and the risk of developing hematolymphoproliferative cancers (chiefly leukemias, lymphomas, and multiple myelomas), in particular myeloid leukemia, the role of tobacco in the etiology of these neoplasms remains unclear. To evaluate the potential impact of tobacco use on development of leukemia, lymphoma, and multiple myeloma, we conducted a cohort study of 334,957 Swedish construction workers using prospectively collected exposure-information with complete long-term follow-up. A total of 1,322 incident neoplasms occurred during the study period, 1971-91.

Response rate to mailed epidemiologic questionnaires: a population-based randomized trial of variations in design and mailing routines.

Although self-administered questionnaires are major sources of information in epidemiology, comparatively little has been done to study practical aspects of design and mailing. The objective of this study was to evaluate various measures taken to increase the response rate. A questionnaire was mailed in July 1995 to a random sample (n = 2,000) of the Swedish population aged 20-79 years.

Risk of urinary tract cancers following kidney or ureter stones.

Background: A relationship has been suggested between kidney or ureter stones and the development of urinary tract cancers. In this study, a population-based cohort of patients hospitalized for kidney or ureter stones in Sweden was followed for up to 25 years to examine subsequent risks for developing renal cell, renal pelvis/ureter, or bladder cancer.

Methods: Data from the national Swedish In-patient Register and the national Swedish Cancer Registry were linked to follow 61,144 patients who were hospitalized for kidney or ureter stones from 1965 through 1983.

Risk of Hodgkin's disease subsequent to tonsillectomy: a population-based cohort study in Sweden.

Although some studies have linked excess of Hodgkin's disease (HD) to tonsillectomy, the findings have not been consistent. In particular, risk of HD by age at tonsillectomy has not been fully evaluated, despite the notable change in immunologic function of the tonsils between childhood and adulthood. To evaluate the risk of HD and other lymphomas, associated with tonsillectomy according to age at surgery, a population-based cohort study was conducted.

Blood transfusion and non-Hodgkin lymphoma: lack of association.

Background: Non-Hodgkin lymphoma is the seventh most commonly diagnosed malignant condition worldwide, and its incidence has increased markedly in recent decades. Blood transfusions have been implicated as a possible risk factor for non-Hodgkin lymphoma.

Objective: To determine whether blood transfusions are associated with an elevated risk for non-Hodgkin lymphoma.

The risk of pancreatic cancer following pancreatitis: an association due to confounding?

Background & Aims: Chronic pancreatitis has been suggested as a causal risk factor for pancreatic cancer in a recent study. The aim of this study was to clarify the relationship between chronic pancreatitis and pancreatic cancer.

Methods: All patients in the Swedish inpatient Register with a discharge diagnosis of pancreatitis from 1965 to 1983 were identified.

Risk of endometrial and breast cancer in patients with diabetes mellitus.

Diabetes mellitus patients have metabolic and endocrine alterations that could contribute to an increased incidence of hormone-related cancers. We assessed the incidence of endometrial and breast cancer among 80,005 women and the incidence of breast cancer among 73,847 men (total of 153,852 patients) identified in the Swedish In-patient Register as having been hospitalized for diabetes mellitus in the period 1965-1983. These patients underwent follow-up through 1989 via the Swedish Cancer Register and other nation-wide Swedish registers.

Body size and prostate cancer: a 20-year follow-up study among 135006 Swedish construction workers.

Background: Obesity is associated with endocrine changes (e.g., increased estrogen and decreased testosterone in the blood) that have been implicated in the cause of prostate cancer and, therefore, an association between body weight and the risk of developing prostate cancer would be expected.

Survival after colon cancer 1973-1990 in Sweden. Convergence between catchment areas.

Objective: The objective of the study is to analyze the temporal trends in relative survival among patients with colon cancer in catchment areas of hospitals of different categories and regions in Sweden.

Background: In Sweden, cancer of the colon is the second most common type of cancer in women and the third most common in men, afflicting approximately 3000 individuals annually. During the past decades, survival has improved, but it is not clear what factors have contributed to this development.

Reliability of retrospective information on diet 20 years ago and consistency of independent measurements of remote adolescent diet.

Although dietary exposures in the distant past are considered important in the etiology of several diseases, few studies have addressed methodological aspects of long-term (> or = 20 yrs) recall. We evaluated the reliability of retrospective self-reports about diet 20 years before the interview and consistency (between siblings) of self-reports about diet during adolescence in a population-based case-control study of stomach cancer in Sweden. Short-term reliability (a questionnaire self-administered 9-12 mos after the personal interview) of reports on diet 20 years ago by 374 control subjects showed mean correlation coefficients for 42 foods/beverages of 0.

Excess risk of primary liver cancer in patients with diabetes mellitus.

Background: Chronic infection with hepatitis B virus, alcohol consumption, and cirrhosis of the liver are recognized risk factors for primary liver cancer. A few, but not all, studies have suggested that diabetes mellitus also increases risk for this cancer.

Purpose: We conducted a population-based cohort study to analyze the risk of developing primary liver cancer and biliary tract (gallbladder, extrahepatic bile ducts, and ampulla of Vater) cancers among patients with diabetes.

Causes of death among patients surviving at least one year following splenectomy.

Background: To assess the mortality (mostly long-term sequelae) of patients undergoing splenectomy, we carried out a population-based study in Sweden.

Methods: Using the unique personal identification number assigned to each Swedish resident, we linked centralized hospitalization records with nationwide mortality data. After initially assessing risks within the first 12 months after splenectomy, we excluded deaths during the first year and computed standardized mortality ratios (SMRs) for 1,297 patients splenectomized for external trauma and 991 surgically treated for nonmalignant conditions of adjacent organs who were alive at 12 months following surgery.

Smoking and colorectal cancer: a 20-year follow-up study of Swedish construction workers.

Background: Although cigarette smoking has consistently been shown to be positively related to the risk of adenomatous polyp development (benign neoplastic growth of epithelial tissue in the colon), most studies of cigarette smoking and the risk of colorectal cancer have been negative. However, in two large prospective studies in women and men, a statistically significant association between cigarette smoking and an increased risk of colorectal cancer was found, but only after more than 35 years of smoking.

Purpose: To shed further light on the alleged relationship between long-term smoking and colorectal cancer risk, we performed a retrospective cohort study among Swedish construction workers, with many long-term smokers, complete long-term follow-up, and a large number of observed cases.

A prospective study of smoking and risk of prostate cancer.

We evaluated the hypothesis that smoking increases the incidence of and mortality from prostate cancer. High-quality smoking information was collected in 1971-1975 in a nation-wide cohort of 135,006 male construction workers in Sweden. We achieved virtually complete follow-up through record linkages and ascertained as of December 1991 2,368 incident cases of prostate cancer and 709 deaths due to this disease.

The risk of stomach cancer in patients with gastric or duodenal ulcer disease.

Background: Helicobacter pylori infection, now considered to be a cause of gastric cancer, is also strongly associated with gastric and duodenal ulcer disease. The discovery of these relations has brought the long-controversial connection between peptic ulcers and gastric cancer into focus.

Methods: We estimated the risk of stomach cancer in a large cohort of hospitalized patients with gastric or duodenal ulcers, as recorded in the Swedish Inpatient Register between 1965 and 1983.

Can endoscopic biopsy specimens be used for reliable Laurén classification of gastric cancer?

Background: The aim of this study was to ascertain whether routine endoscopic biopsy specimens are of sufficient quality and representative enough to enable reliable classification of histologic type, grade of differentiation, and frequency of signet ring cells.

Methods: As part of a population-based etiologic study of gastric cancer in Sweden, the histologic slides of 687 incident cases were independently reviewed by one pathologist. In 305 cases both biopsy and surgical specimens were available for assessment of sensitivity and specificity of diagnoses on the basis of biopsy specimens, with the classification based on surgical specimens as the gold standard.

Risk of cancer following splenectomy.

Only 2 small population-based studies have previously evaluated cancer risk in splenectomized patients. Our objective was thus to investigate cancer incidence following splenectomy for external trauma or for surgical treatment of non-malignant conditions of adjacent organs. Using the unique personal identification number assigned to each Swedish resident, we linked centralized hospitalization records with nationwide total population and cancer incidence data.

Drug treatment of functional dyspepsia: a systematic analysis of trial methodology with recommendations for design of future trials.

Objectives: To evaluate drug treatment of functional dyspepsia (including Helicobacter pylori) and provide guidelines for future trials based on a critical systematic overview of published studies.

Methods: Data sources were a Medline search for articles published in English going back to 1966 and a manual search of four GI journals going back to 1980. Original randomized, double-blind, placebo-controlled trials were selected that enrolled at least 20 patients.

The risk of esophageal cancer in patients with achalasia. A population-based study.

Objective: To determine more precise and accurate cancer risk estimates for achalasia that could be used to plan surveillance.

Design: Cohort.

Setting: Swedish population.

Incidence of cancer among patients with systemic sclerosis.

Background: To determine cancer risk among patients with systemic sclerosis and localized scleroderma, a population-based retrospective cohort study was performed. Patients in Sweden with a discharge diagnosis of systemic sclerosis or localized scleroderma were obtained from the computerized database of hospital discharge diagnoses for the years 1965-1983. Nine hundred seventeen patients with systemic sclerosis and 102 with localized scleroderma were identified.