Showing papers by "Olof Nyrén published in 1995"

Cancer Risk After Hip Replacement With Metal Implants: a Population-Based Cohort Study in Sweden

Abstract: Background : Joint replacement with metal implants has been the standard procedure for surgical treatment of irreversible degeneration of hip and knee joints for more than two decades However, reports of local malignancy after joint replacement and experimental studies that suggest a carcinogenic action of metal ions and polymethylmethacrylate (an acrylic compound used to stabilize the implant in the host) have raised concern about the possible long-term risks associated with metal implants Purpose : Our aim was to study cancer risk in a Swedish cohort of patients who had hip replacement surgery during the period 1965 through 1983 Methods : We studied the risk of cancer in a cohort of 39 154 patients (14 869 men and 24 285 women), identified in the nationwide Swedish Inpatient Register with at least one hip replacement during the period 1965 through 1983 The patients were followed through 1989 by means of record linkage to the Swedish Cancer Register The cohort contributed a total of 327922 person-years at risk Standardized incidence ratios (SIRs) were computed using age-, sex-, and period-specific incidence rates derived from the entire Swedish population Results : The overall relative risk of cancer was increased by only 3% Bone cancer-the focus of previous concerns-occurred in six cases versus 43 expected, and connective tissue cancer occurred in 28 cases versus 259 expected Increased risks were observed for kidney cancer (SIR = 131 ; 95% confidence interval [CI] = 113-151), prostate cancer (SIR = 113 ; 95% CI = 104-122), and melanoma (SIR = 123 ; 95% CI = 100-150) The relative risk of gastric cancer steadily declined with increasing follow-up time, in both men and women (SIR = 058 ; 95% CI = 039-084 more than 10 years after hip replacement) Conclusion: In this study, the largest study to date to evaluate hip replacement and subsequent cancer risk, the overall cancer risk appears to be negligible from a public health perspective, and our results have not produced any strong evidence against the continued use of these devices Nevertheless, the small but statistically significant increases in kidney and prostate cancers and the decrease in gastric cancer deserve further studv [J Natl Cancer Inst 87 :28-33,

Incidence of cancer among patients with systemic sclerosis.

Abstract: 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. Methods. Using record linkage analysis with data from the Swedish National Cancer Registry, standardized incidence ratios (SIR)s (the ratio of observed to expected incidence) were calculated for specific cancer sites. Results. The SIR for developing cancer in the cohort with systemic sclerosis was 1.5 (95% CI, 1.2–1.9). For specific cancer sites, risks were elevated for lung cancer (SIR, 4.9; 95% CI, 2.8–8.1), nonmelanoma skin cancers (SIR, 4.2; 95% CI, 1.4–9.8), and primary liver cancer (SIR, 3.3; 95% CI, 1.1–7.6). There was a suggestive increase in hematopoietic cancers (SIR, 2.3; 95% CI, 0.9–4.8). In contrast, cancer risks in the similarly ascertained cohort with localized scleroderma were no different from those of the general population. Conclusions. This study confirms earlier reports of an association between systemic sclerosis and an increased risk of cancer. Specific tumor sites correspond to the sites commonly affected by fibrosis such as the lung and skin.

Prevalence of Helicobacter pylori infection in subtypes of gastric cancer

Abstract: Background & Aims: Although Helicobacter pylori has already been declared a human carcinogen, the exact nature of the association with gastric cancer remains to be explored. The aim of this study was to determine if the association is confined to specific types of gastric cancer. Methods: The prevalence of H. pylori immunoglobulin G antibodies (HM-CAP immunoassay; Enteric Products Inc., Westbury, NY) was determined in prospectively collected sera from 279 patients with gastric cancer. Results: The overall prevalence of H. pylori seropositivity was 77%. The prevalence of H. pylori infection was significantly lower among patients with tumors of the gastric cardia compared with those with other gastric locations. Age-adjusted H. pylori seroprevalence among patients with the intestinal type of gastric cancer tended to be higher than among those with the diffuse type according to Lauren ( P > 0.05). In both histological types, the seroprevalence decreased with increasing age. Multivariate logistic regression analysis showed that high age and proximal tumor location were independent predictors of absence of H. pylori . Conclusions: The association with H. pylori infection is similar regardless of the histological features of the tumor, whereas it is stronger for noncardiac gastric cancer than for cardiac cancer. The apparent loss of H. pylori seropositivity among patients with gastric cancer is determined by age rather than tumor stage.

Silicone breast implants and risk of cancer

Abstract: To the Editor. —We examined cancer risk following breast implant surgery in Sweden by use of a nationwide linked registry. The registry combines individual hospital discharge information with subsequent cancer incidence. The methods of this linked-registry approach have been reported in a study that evaluated cancer risk associated with discharge diagnoses.1 We identified 1756 Swedish women who received breast implants for nonmedical (cosmetic) reasons during the period 1965 through 1983. The patients were followed up for cancer occurrence through 1989. They contributed 20610 person-years of experience, with an average duration of 11.7 years since implant. We analyzed all major cancer sites, using national Swedish incidence rates to calculate expected numbers. In all, 34 cases of cancer were identified during the study period compared with 33.7 expected cases (standardized incidence ratio [SIR], 1.01; 95% confidence interval [CI], 0.7 to 1.4). No cancers were observed in the first year of follow-up.