Search

Purpose: Uterine sarcomas are a rare group of uterine malignancies. Due to the low incidence and changes in uterine sarcoma classification, risk factors are not well characterized. Our objective was to evaluate risk factors for uterine sarcoma and compare risk factors between uterine sarcoma, malignant mixed Mullerian tumors (MMMTs), and type I endometrial carcinomas. Methods: This nested case-control study utilized linked data from population-based medical birth and cancer registries in Denmark, Finland, Norway, and Sweden. Up to 10 controls were matched on country and birth year for each uterine cancer case. Using multivariable adjusted multinomial logistic regression, estimates of the associations between pregnancy-related factors and risk of uterine sarcoma, MMMTs, and type I endometrial carcinomas were determined. Results: Having a very-low-birth-weight infant (< 1500 vs. 2500-3999 g: OR [95% CI] 2.83 [1.61-4.96]) was associated with an increased risk of uterine sarcoma. Whereas, having a more recent pregnancy was associated with reduced risks of MMMT (< 10 vs. >= 30 years: 0.66 [0.20-2.23]) and type 1 endometrial carcinomas (0.35 [0.30-0.41]) but not uterine sarcomas (1.33 [0.90-1.98], p-heterogeneity < 0.01). Conclusion: Our study provides evidence that risk factors for uterine sarcoma and MMMT, previously grouped with uterine sarcomas, vary substantially. Additionally, MMMT and type I endometrial carcinomas are more similar than uterine sarcoma in that pregnancy complications like gestational hypertension and preeclampsia were associated with reduced risks of both but not uterine sarcoma, suggesting different etiologies.

OBJECTIVES: Venous thromboembolic event (VTE) is a severe complication in patients with lung cancer undergoing thoracic surgery. Nevertheless, because of insufficient evidence, there are no clear guidelines, and VTE prophylaxis practices vary widely. This nationwide cohort study was a comparative study investigating VTE risk in surgical departments that routinely administered in-hospital thromboprophylaxis with low-molecular-weight heparin compared to those that did not. METHODS: We identified all patients with non-small-cell lung cancer (NSCLC) who underwent surgery in Denmark during 2010–2021. Thoracic surgery was exclusively performed in the 4 university hospitals. Three hospitals implemented in-hospital thromboprophylaxis as standard care since 2000, while the fourth adopted this practice in September 2016. VTE events were assessed at 6-month follow-up according to hospital and study period, using an inverse probability of treatment weighting approach. RESULTS: We identified 9615 patients. During 6-month follow-up, a total of 190 VTE events were observed, resulting in a weighted rate of 4.5 events per 100 person-years and an absolute risk of 2.2%. There was no clear trend according to hospital site or use of in-hospital thromboprophylaxis with a 2.2% risk in the hospital not using thromboprophylaxis compared to 1.7–3.1% in those that did. CONCLUSIONS: Use of in-hospital thromboprophylaxis did not affect the risk of VTE after surgery for NSCLC, suggesting that relying solely on in-hospital thromboprophylaxis may be insufficient to mitigate VTE risk in these patients. Further research is warranted to investigate the potential benefits of extended thromboprophylaxis in reducing VTE risk in selected NSCLC surgical patients.

Background Venous thromboembolism (VTE) is a potentially preventable serious complication in patients with lung cancer undergoing thoracic operation. We examined the risk and timing of VTE after surgery for primary non-small cell lung cancer (NSCLC). Methods All patients undergoing operation for NSCLC in Denmark between 2003 and 2021 were identified in the Danish Lung Cancer Registry. VTE events in the year after operation were assessed by stage, patient characteristics, and surgical procedure. Results We identified 13,197 patients who underwent operation for NSCLC in 2003 to 2021 (mean age, 67.6 years; 50% female); 10,524 (79.7%) had stage I-II NSCLC, and 2673 (20.3%) had stage III-IV. During 1-year follow-up, there were 335 VTE events, yielding a rate of 2.87 events/100 person-years and an absolute risk of 3.3% (95% CI, 2.3-4.0). VTE risk increased with advancing cancer stage (1.8% for stage I vs 3.9% for stage IV) but varied little by pathologic type, sex, and comorbidity level. Bilobectomy was associated with highest VTE risk (4.8%; 95% CI, 3.2-6.9), followed by pneumonectomy (3.5%; 95% CI, 2.3-5.0). The hazard of VTE was highest during the first 3 months after operation, after which it declined. For stage IV cancer, hazards increased again after 6 months. At 1 year, all-cause death was 12.6% (95% CI, 12.0%-13.1%). Conclusions VTE developed in 3.3% of patients undergoing operation for NSCLC, most commonly within 3 months postoperatively. Prolonged thromboprophylaxis could be considered, particularly in those with advanced cancer stage and undergoing extended resections., Background: Venous thromboembolism (VTE) is a potentially preventable serious complication in patients with lung cancer undergoing thoracic operation. We examined the risk and timing of VTE after surgery for primary non-small cell lung cancer (NSCLC). Methods: All patients undergoing operation for NSCLC in Denmark between 2003 and 2021 were identified in the Danish Lung Cancer Registry. VTE events in the year after operation were assessed by stage, patient characteristics, and surgical procedure. Results: We identified 13,197 patients who underwent operation for NSCLC in 2003 to 2021 (mean age, 67.6 years; 50% female); 10,524 (79.7%) had stage I-II NSCLC, and 2673 (20.3%) had stage III-IV. During 1-year follow-up, there were 335 VTE events, yielding a rate of 2.87 events/100 person-years and an absolute risk of 3.3% (95% CI, 2.3-4.0). VTE risk increased with advancing cancer stage (1.8% for stage I vs 3.9% for stage IV) but varied little by pathologic type, sex, and comorbidity level. Bilobectomy was associated with highest VTE risk (4.8%; 95% CI, 3.2-6.9), followed by pneumonectomy (3.5%; 95% CI, 2.3-5.0). The hazard of VTE was highest during the first 3 months after operation, after which it declined. For stage IV cancer, hazards increased again after 6 months. At 1 year, all-cause death was 12.6% (95% CI, 12.0%-13.1%). Conclusions: VTE developed in 3.3% of patients undergoing operation for NSCLC, most commonly within 3 months postoperatively. Prolonged thromboprophylaxis could be considered, particularly in those with advanced cancer stage and undergoing extended resections.

Background Childhood cancer is more common among children with birth defects, suggesting a common aetiology. Whether this association differs by sex is unclear. Methods We performed a population-based nested case-control study using nationwide health registries in four Nordic countries. We included 21 898 cancer cases (0-19 years) and 218 980 matched population controls, born 1967-2014. Associations between childhood cancer and major birth defects were calculated as odds ratios (ORs) with 95% confidence intervals (CIs) using logistic regression models. Effect modification was evaluated using a counterfactual framework to estimate confidence intervals and P-values for the natural indirect effects. Results Birth defects were present for 5.1% (1117/21 898) of childhood cancer cases and 2.2% (4873/218 980) of controls; OR of cancer was higher for chromosomal (OR = 10, 95% CI = 8.6-12) than for non-chromosomal defects (OR = 1.9, 95% CI = 1.8-2.1), strongest between genetic syndromes/microdeletion and renal tumours, Down syndrome and leukaemia, and nervous system defects and central nervous system tumours. The association between birth defects and cancer was stronger among females (OR = 2.8, 95% CI = 2.6-3.1) than males (OR = 2.1, 95% CI = 1.9-2.2, P-interaction <0.001). Male sex was an independent risk factor for childhood cancer, but very little of the overall association between sex and childhood cancer was mediated through birth defects (4.8%, P-NIE <0.001), although more at younger ages (10% below years and 28% below 1 year). Conclusions The birth defect-cancer associations were generally stronger among females than males. Birth defects did not act as a strong mediator for the modest differences in childhood cancer risk by sex, suggesting that other biological pathways are involved., Correction in: International Journal of Epidemiology, Volume 52, Issue 3, June 2023, Page 966DOI: 10.1093/ije/dyad067

Background: Individuals with major birth defects are at increased risk of developing cancer, indicating a common aetiology. However, whether the siblings of individuals with birth defects are also at an increased risk of cancer is unclear. Methods: We used nationwide health registries in four Nordic countries and conducted a nested case-control study. We included 40 538 cancer cases (aged 0-46 years) and 481 945 population controls (matched by birth year and country), born between 1967 and 2014. The relative risk of cancer among individuals whose siblings had birth defects was computed with odds ratios (OR) and 95% confidence intervals (CIs), using logistic regression models. Results: In the total study population (aged 0-46 years), we observed no overall difference in cancer risk between individuals whose siblings had birth defects and those who had unaffected siblings (OR 1.02; 95% CI 0.97-1.08); however, the risk of lymphoid and haematopoietic malignancies was elevated (1.16; 1.05-1.28). The overall risk of childhood cancer (0-19 years) was increased for siblings of individuals who had birth defects (1.09; 1.00-1.19), which was mainly driven by lymphoma (1.35; 1.09-1.66), neuroblastoma (1.51; 1.11-2.05) and renal carcinoma (5.03; 1.73-14.6). The risk of cancer also increased with the number of siblings with birth defects (P-trend = 0.008). Conclusion: Overall risk of cancer among individuals (aged 0-46 years) whose siblings had birth defects was not elevated, but the risk of childhood cancer (ages 0-19 years) was increased. Our novel findings are consistent with the common aetiologies of birth defects and cancer, such as shared genetic predisposition and environmental factors.

Background: High birthweight may predispose children to acute lymphoid leukemia, whereas low birthweight is associated with childhood morbidity and mortality. Low and high birthweight have been inconsistently associated with mortality in children with leukemia. Material and methods: In a cohort of childhood and adolescent leukemia (0-19 years) patients from registries in Denmark, Norway, Sweden, and Washington State in the United States (1967-2015), five-year all-cause mortality was assessed by birthweight and other measures of fetal growth using the cumulative incidence function and Cox regression with adjustment for sex, diagnosis year, country, the presence of Down's syndrome or other malformations, and type of leukemia. Results: Among 7148 children and adolescents with leukemia (55% male), 4.6% were low (<2500 g) and 19% were high (>= 4000 g) birthweight. Compared with average weight, hazard ratios (HRs) of death associated with low birthweight varied by age at leukemia diagnosis: 1.5 (95% confidence interval (CI): 0.7, 3.2) for patients 0-1 year old, 1.6 (95% CI: 1.0, 2.6) for >1-2 years old; 1.0 (95% CI: 0.6, 1.5) for 3-8 years old; 1.0 (95% CI: 0.6, 1.8) for 9-13 years old; and 1.2 (95% CI: 0.7, 2.1) for 14-19 years old, and were similar for size for gestational age and Ponderal index. In analyses restricted to children born full term (37-41 weeks of gestation), results were only slightly attenuated but risk was markedly increased for infants aged <= 1 year (HR for low birthweight = 3.2, 95% CI: 1.2, 8.8). Conclusion: This cohort study does not suggest that low birthweight or SGA is associated with increased five-year all-cause mortality risk among children with any type of childhood leukemia or acute lymphoblastic leukemia, specifically, beyond infancy.

Epithelial ovarian cancer is a fatal disease of largely unknown etiology. Higher parity is associated with reduced risk of ovarian cancer. However, among parous women, the impact of pregnancy-related factors on risk is not well understood. This population-based case-control study included all parous women with epithelial ovarian cancer in Denmark, Finland, Norway and Sweden during 1967-2013 (n = 10,957) and up to 10 matched controls (n = 107,864). We used conditional logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for pregnancy-related factors and ovarian cancer risk by histological subtype. Preterm delivery was associated with an increased risk [pregnancy length (last pregnancy) 30 vs. 39-41 weeks, OR 1.33 (95% CI 1.06-1.67), adjusted for number of births]; the OR increased as pregnancy length decreased (p for trend < 0.001). Older age at first and last birth was associated with a decreased risk [first birth: 30-39 vs. <25 years: adjusted OR 0.76 (95% CI 0.70-0.83); last birth 30-39 vs. <25 years: adjusted OR 0.76 (95% CI 0.71-0.82)]. Increasing number of births was protective [>= 4 births vs. 1; OR 0.63 (95% CI 0.59-0.68)] for all subtypes, most pronounced for clear-cell tumors [OR 0.30, (95% CI 0.21-0.44), p(heterogeneity)<0.001]. No associations were observed for multiple pregnancies, preeclampsia or offspring size. In conclusion, in addition to high parity, full-term pregnancies and pregnancies at older ages were associated with decreased risk of ovarian cancer. Our findings favor the cell clearance hypothesis, i.e. a recent pregnancy provides protection by clearing of precancerous cells from the epithelium of the ovary/fallopian tubes, mediated by placental or ovarian hormones.

Certain features of pregnancy are important risk factors for breast cancer, such as protection afforded by young age at first birth. Preeclampsia, a pregnancy complication, is associated with reduced maternal breast cancer risk. However, questions remain regarding causality, biological mechanisms and the relation of other hypertensive conditions to risk. We conducted a population-based case-control study of breast cancer cases (n = 116,196) in parous women identified through linkage of birth and cancer registries in Denmark, Finland, Norway and Sweden (1967-2013), including up to 10 matched controls per case (n = 1,147,192) sampled from the birth registries (complete data were not available on all variables). Odds ratios (ORs) with 95% confidence intervals (CIs) were derived from unconditional logistic regression models including matching factors (country, maternal birth year) and parity. Hypertension diagnosed before pregnancy (OR 0.87; 95% CI 0.78-0.97), gestational hypertension (OR 0.90; 95% CI 0.86-0.93) and preeclampsia (OR 0.91; 95% CI 0.88-0.95) were associated with reduced breast cancer risk. Results remained similar after adjustment for smoking and maternal body mass index before first pregnancy, and were generally similar stratified by parity, age at breast cancer diagnosis, time since first and last birth, sex of the offspring and calendar time. Except for retained placenta (OR 1.14; 95% CI 0.98-1.32), no other pregnancy complication appeared associated with breast cancer risk. The mechanisms mediating the modest risk reductions for history of preeclampsia or hypertension preceding or arising during pregnancy, and possible increased risk with history of retained placenta are unknown and warrant further laboratory, clinical and epidemiological investigation.