Does the duration of diabetes increase the risk of cancer? A nationwide population-based cohort of patients with new-onset diabetes and a matched reference cohort

Diabetes mellitus and cancer are both common health issues, but the correlation between these two diseases remains unclear. We investigated the association of cumulative exposure of diabetes mellitus as an indication of hyperglycemia in terms of disease duration on multiple cancer types. We hypothesized that the risk of cancer would increase over time after the onset of diabetes. The study population consisted of a population-based cohort of 398,708 people and it was constructed from the Finnish CARING project. The Diabetes group consisted of 185,258 individuals, and the non-diabetic reference group comprised 187,921 individuals. Over 4.1 million person-years were accumulated, and the median follow-up time was 10.55 years. In the diabetes group, 25,899 cancer cases were observed compared with 23,900 cancers in the non-diabetic group. We did not find a clear relationship between the duration of diabetes mellitus and most cancer types examined. However, for cancers of the pancreas, prostate gland, bronchus, and lungs, a temporal relationship was found. Furthermore, even within the cancer types where the relationship was detected, it did not change over time. These findings indicate that diabetes does not independently increase the risk of cancer. Instead, the development of diabetes may be attributed to shared risk factors with cancer, such as obesity and/or insulin resistance accompanied by hyperinsulinemia. Thus, it is likely that the clock for increased cancer risk starts ticking already before onset of diabetes and hyperglycemia.Peer reviewe

Incidence trends of childhood central nervous system tumors in Finland 1990-2017

Introduction Central nervous system (CNS) tumors are a leading cause of cancer-related morbidity and mortality in children. Our aim is to characterize incidence trends of pediatric CNS tumors in Finland over the last three decades. Methods Data on all benign and malignant incident CNS tumors diagnosed in children aged 0-14 years in 1990-2017 were extracted from the Finnish Cancer Registry and classified according to the 2016 WHO classification of CNS tumors. We analyzed age-standardized incidence rates (ASR) for pediatric CNS tumors overall and by sex, age, tumor histology, grade, and location using Poisson regression. We used joinpoint regression to evaluate changes in trends. Results Overall, 1117 pediatric CNS tumor cases were registered in Finland with a 1.2:1 male to female ratio. The average annual ASR was 4.3 per 100,000 person-years (95% CI 4.26, 4.34). The most common tumor type was pilocytic astrocytoma (30% of tumors), followed by medulloblastoma (10%) with incidence rates of 1.30 and 0.45 per 100,000 person-years, respectively. The overall incidence of pediatric CNS tumors increased by an annual percentage change (APC) of 0.8% (95% CI 0.2, 1.4). We observed no major changes in incidence trends of tumor histology groups or tumor location groups. The ASR of benign tumors increased by an APC of 1.0 (95% CI 0.1, 2.0). Conclusions Utilizing the high-quality and completeness of data in the Finnish Cancer registry, we found that the incidence of pediatric CNS tumors in Finland has increased slightly from 1990 until 2017. Although variations in diagnostic and registration practices over time might have affected the rates, the trend may also reflect a true increase in incidence.Peer reviewe

Parental occupational exposure to low-frequency magnetic fields and risk of leukaemia in the offspring : findings from the Childhood Leukaemia International Consortium (CLIC)

OBJECTIVES: Previously published studies on parental occupational exposure to extremely low-frequency magnetic fields (ELF-MF) and risk of acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) in their offspring were inconsistent. We therefore evaluated this question within the Childhood Leukemia International Consortium. METHODS: We pooled 11 case-control studies including 9723 childhood leukaemia cases and 17 099 controls. Parental occupational ELF-MF exposure was estimated by linking jobs to an ELF-MF job-exposure matrix (JEM). Logistic regression models were used to estimate ORs and 95% CIs in pooled analyses and meta-analyses. RESULTS: ORs from pooled analyses for paternal ELF-MF exposure >0.2 microtesla (µT) at conception were 1.04 (95% CI 0.95 to 1.13) for ALL and 1.06 (95% CI 0.87 to 1.29) for AML, compared with ≤0.2 µT. Corresponding ORs for maternal ELF-MF exposure during pregnancy were 1.00 (95% CI 0.89 to 1.12) for ALL and 0.85 (95% CI 0.61 to 1.16) for AML. No trends of increasing ORs with increasing exposure level were evident. Furthermore, no associations were observed in the meta-analyses. CONCLUSIONS: In this large international dataset applying a comprehensive quantitative JEM, we did not find any associations between parental occupational ELF-MF exposure and childhood leukaemia