| 1. |
- Fuhrman, Barbara J, et al.
(författare)
-
Association of the Age at Menarche with Site-Specific Cancer Risks in Pooled Data from Nine Cohorts
- 2021
-
Ingår i: Cancer Research. - : American Association for Cancer Research (AACR). - 0008-5472 .- 1538-7445. ; 81:8, s. 2246-2255
-
Tidskriftsartikel (refereegranskat)abstract
- The average age at menarche declined in European and U.S. populations during the 19th and 20th centuries. The timing of pubertal events may have broad implications for chronic disease risks in aging women. Here we tested for associations of recalled menarcheal age with risks of 19 cancers in 536,450 women [median age, 60 years (range, 31-39 years)] in nine prospective U.S. and European cohorts that enrolled participants from 1981 to 1998. Cox regression estimated multivariable-adjusted HRs and 95% confidence intervals (CI) for associations of the age at menarche with risk of each cancer in each cohort and random-effects meta-analysis was used to generate summary estimates for each cancer. Over a median 10 years of follow-up, 60,968 women were diagnosed with a first primary incident cancer. Inverse linear associations were observed for seven of 19 cancers studied. Each additional year in the age at menarche was associated with reduced risks of endometrial cancer (HR = 0.91; 95% CI, 0.89-0.94), liver cancer (HR = 0.92; 95% CI, 0.85-0.99), melanoma (HR = 0.95; 95% CI, 0.93-0.98), bladder cancer (HR = 0.96; 95% CI, 0.93-0.99), and cancers of the colon (HR = 0.97; 95% CI, 0.96-0.99), lung (HR = 0.98; 95% CI, 0.96-0.99), and breast (HR = 0.98; 95% CI, 0.93-0.99). All but one of these associations remained statistically significant following adjustment for baseline body mass index. Similarities in the observed associations between menarche and seven cancers suggest shared underlying causes rooted early in life. We propose as a testable hypothesis that early exposure to sex hormones increases mid-life cancer risks by altering functional capacities of stem cells with roles in systemic energy balance and tissue homeostasis. SIGNIFICANCE: Age at menarche is associated with risk for seven cancers in middle-aged women, and understanding the shared underlying causal pathways across these cancers may suggest new avenues for cancer prevention.
|
|
| 2. |
- Guo, Hao, et al.
(författare)
-
Heterogeneity and chemical reactivity of the remote troposphere defined by aircraft measurements
- 2021
-
Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 21:18, s. 13729-13746
-
Tidskriftsartikel (refereegranskat)abstract
- The NASA Atmospheric Tomography (ATom) mission built a photochemical climatology of air parcels based on in situ measurements with the NASA DC-8 aircraft along objectively planned profiling transects through the middle of the Pacific and Atlantic oceans. In this paper we present and analyze a data set of 10 s (21(m) merged and gap-filled observations of the key reactive species driving the chemical budgets of O-3 and CH4 (O-3, CH4, CO, H2O, HCHO, H2O2, CH3OOH, C2H6, higher alkanes, alkenes, aromatics, NOx, HNO3, HNO4, peroxyacetyl nitrate, other organic nitrates), consisting of 146 494 distinct air parcels from ATom deployments 1 through 4. Six models calculated the O-3 and CH4 photochemical tendencies from this modeling data stream for ATom 1. We find that 80 %-90 % of the total reactivity lies in the top 50 % of the parcels and 25 %-35 % in the top 10 %, supporting previous model-only studies that tropospheric chemistry is driven by a fraction of all the air. In other words, accurate simulation of the least reactive 50 % of the troposphere is unimportant for global budgets. Surprisingly, the probability densities of species and reactivities averaged on a model scale (100 km) differ only slightly from the 2 km ATom data, indicating that much of the heterogeneity in tropospheric chemistry can be captured with current global chemistry models. Comparing the ATom reactivities over the tropical oceans with climatological statistics from six global chemistry models, we find excellent agreement with the loss of O-3 and CH4 but sharp disagreement with production of O-3. The models sharply underestimate O-3 production below 4 km in both Pacific and Atlantic basins, and this can be traced to lower NOx levels than observed. Attaching photochemical reactivities to measurements of chemical species allows for a richer, yet more constrained-towhat-matters, set of metrics for model evaluation.
|
|
| 3. |
- Matthews, Charles E., et al.
(författare)
-
Amount and Intensity of Leisure-Time Physical Activity and Lower Cancer Risk
- 2020
-
Ingår i: Journal of Clinical Oncology. - : AMER SOC CLINICAL ONCOLOGY. - 0732-183X .- 1527-7755. ; 38:7, s. 686-697
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To determine whether recommended amounts of leisure-time physical activity (ie, 7.5-15 metabolic equivalent task [MET] hours/week) are associated with lower cancer risk, describe the shape of the dose-response relationship, and explore associations with moderate- and vigorous-intensity physical activity.METHODS: Data from 9 prospective cohorts with self-reported leisure-time physical activity and follow-up for cancer incidence were pooled. Multivariable Cox regression was used to estimate adjusted hazard ratios (HRs) and 95% CIs of the relationships between physical activity with incidence of 15 types of cancer. Dose-response relationships were modeled with restricted cubic spline functions that compared 7.5, 15.0, 22.5, and 30.0 MET hours/week to no leisure-time physical activity, and statistically significant associations were determined using tests for trend (P < .05) and 95% CIs (< 1.0).RESULTS: A total of 755,459 participants (median age, 62 years [range, 32-91 years]; 53% female) were followed for 10.1 years, and 50,620 incident cancers accrued. Engagement in recommended amounts of activity (7.5-15 MET hours/week) was associated with a statistically significant lower risk of 7 of the 15 cancer types studied, including colon (8%-14% lower risk in men), breast (6%-10% lower risk), endometrial (10%-18% lower risk), kidney (11%-17% lower risk), myeloma (14%-19% lower risk), liver (18%-27% lower risk), and non-Hodgkin lymphoma (11%-18% lower risk in women). The dose response was linear in shape for half of the associations and nonlinear for the others. Results for moderate- and vigorous-intensity leisure-time physical activity were mixed. Adjustment for body mass index eliminated the association with endometrial cancer but had limited effect on other cancer types.CONCLUSION: Health care providers, fitness professionals, and public health practitioners should encourage adults to adopt and maintain physical activity at recommended levels to lower risks of multiple cancers.
|
|
