Weekday of oesophageal cancer surgery in relation to early postoperative outcomes in a nationwide Swedish cohort study

Objectives: Later weekday of surgery for oesophageal cancer seems to increases 5-year mortality, but the mechanisms are unclear. We hypothesised that early postoperative reoperations and mortality might explain this association, since reoperation after oesophagectomy decreases long-term prognosis and later weekday of elective surgery increases 30-day mortality. Design: This was a population-based cohort study during the study period 1987-2014. Setting: All Swedish hospitals conducting elective surgery for oesophageal cancer in Sweden. Participants: Included were 1,748 patients, representing almost all (98%) patients who underwent elective surgery for oesophageal cancer in Sweden during 1987-2010, with follow-up until 2014. Primary and secondary outcome measures: The risk of reoperation or mortality within 30 days of oesophageal cancer surgery was assessed in relation to weekday of surgery by calculating odds ratios (ORs) with 95% confidence intervals (CIs) using multivariable logistic regression. ORs were adjusted for age, co-morbidity, tumour stage, histology, neoadjuvant therapy, and surgeon volume. Results: Surgery Wednesday-Friday did not increase the risk of reoperation or mortality compared to surgery Monday-Tuesday (OR=0.99, 95% CI 0.75-1.31). A decreased point estimate of reoperation (OR=0.88, 95% CI 0.64-1.21) was counteracted by an increased point estimate of mortality (OR=1.28, 95% CI 0.83-1.99). ORs did not increase from Monday to Friday when each weekday was analysed separately. There was no association between weekday of surgery and reoperation specifically for anastomotic leak, laparotomy, or wound infection. Stratification for surgeon volume did not reveal any clear associations between weekday of surgery and risk of 30-day reoperation or mortality. Conclusions: Weekday of oesophageal cancer surgery does not seem to influence the risk of reoperation or mortality within 30 days of surgery, and thus cannot explain the association between weekday of surgery and long-term prognosis.The Swedish Research CouncilThe Swedish Cancer SocietyAccepte

Association between education level and prognosis after esophageal cancer surgery : a Swedish population-based cohort study

Background: An association between education level and survival after esophageal cancer has recently been indicated, but remains uncertain. We conducted a large study with long follow-up to address this issue. Methods: This population-based cohort study included all patients operated for esophageal cancer in Sweden between 1987 and 2010 with follow-up until 2012. Level of education was categorized as compulsory (= 13 years). The main outcome measure was overall 5-year mortality after esophagectomy. Cox regression was used to estimate associations between education level and mortality, expressed as hazard ratios (HRs) with 95% confidence intervals (CIs), with adjustment for sex, age, co-morbidity, tumor stage, tumor histology, and assessing the impact of education level over time. Results: Compared to patients with high education, the adjusted HR for mortality was 1.29 (95% CI 1.07-1.57) in the intermediate educated group and 1.42 (95% CI 1.17-1.71) in the compulsory educated group. The largest differences were found in early tumor stages (T-stage 0-1), with HRs of 1.73 (95% CI 1.00-2.99) and 2.58 (95% CI 1.51-4.42) for intermediate and compulsory educated patients respectively; and for squamous cell carcinoma, with corresponding HRs of 1.38 (95% CI 1.07-1.79) and 1.52 (95% CI 1.19-1.95) respectively. Conclusions: This Swedish population-based study showed an association between higher education level and improved survival after esophageal cancer surgery, independent of established prognostic factors. The associations were stronger in patients of an early tumor stage and squamous cell carcinoma

An autopilot for energy models – Automatic generation of renewable supply curves, hourly capacity factors and hourly synthetic electricity demand for arbitrary world regions

Energy system models are increasingly being used to explore scenarios with large shares of variable renewables. This requires input data of high spatial and temporal resolution and places a considerable preprocessing burden on the modeling team. Here we present a new code set with an open source license for automatic generation of input data for large-scale energy system models for arbitrary regions of the world, including sub-national regions, along with an associated generic capacity expansion model of the electricity system. We use ECMWF ERA5 global reanalysis data along with other public geospatial datasets to generate detailed supply curves and hourly capacity factors for solar photovoltaic power, concentrated solar power, onshore and offshore wind power, and existing and future hydropower. Further, we use a machine learning approach to generate synthetic hourly electricity demand series that describe current demand, which we extend to future years using regional SSP scenarios. Finally, our code set automatically generates costs and losses for HVDC interconnections between neighboring regions. The usefulness of our approach is demonstrated by several different case studies based on input data generated by our code. We show that our model runs of a future European electricity system with high share of renewables are in line with results from more detailed models, despite our use of global datasets and synthetic demand

An Autopilot for Energy Models – Automatic Generation of Renewable Supply Curves, Hourly Capacity Factors and Hourly Synthetic Electricity Demand for Arbitrary World Regions

Energy system models are increasingly being used to explore scenarios with large shares of variable renewables. This requires input data of high spatial and temporal resolution and places a considerable preprocessing burden on the modeling team. Here we present a new code set with an open source license for automatic generation of input data for large-scale energy system models for arbitrary regions of the world, including sub-national regions, along with an associated generic capacity expansion model of the electricity system. We use ECMWF ERA5 global reanalysis data along with other public geospatial datasets to generate detailed supply curves and hourly capacity factors for solar photovoltaic power, concentrated solar power, onshore and offshore wind power, and existing and future hydropower. Further, we use a machine learning approach to generate synthetic hourly electricity demand series that describe current demand, which we extend to future years using regional SSP scenarios. Finally, our code set automatically generates costs and losses for HVDC interconnections between neighboring regions. The usefulness of our approach is demonstrated by several different case studies based on input data generated by our code. We show that our model runs of a future European electricity system with high share of renewables are in line with results from more detailed models, despite our use of global datasets and synthetic demand

Historical wind deployment and implications for energy system models

A critical parameter in modeling studies of future decarbonized energy systems is the potential future capacity for onshore wind power. Wind power potential in energy system models is subject to assumptions regarding: (i) constraints on land availability for wind deployment; (ii) how densely wind turbines may be placed over larger areas, and (iii) allocation of capacity with respect to wind speed. By analyzing comprehensive databases of wind turbine locations and other GIS data in eleven countries and seventeen states in Australia, Canada, and the US; all with high penetration levels of wind power, we find that: i) large wind turbines are installed on most land types, even protected areas and land areas with high population density; ii) it is not uncommon with a deployment density up to 0.5 MW/km2 on municipality or county level, with rare outlier municipalities reaching up to 1.5 MW/km2 installed capacity; and iii) wind power has historically been allocated to relatively windy sites with average wind speed above 6 m/s. In many cases, allocation methods used in energy system models do not consistently reflect actual installations. For instance, we find no evidence of concentration of installations at the windiest sites, as is frequently assumed in energy system models. We conclude that assumptions made in models regarding wind power potentials are poorly reflective of historical installation patterns, and we provide new data to enable assumptions that have a more robust empirical foundation

Tumour staging of oesophageal cancer in the Swedish Cancer Registry: a nationwide validation study

Background: Tumour stage was introduced to the Swedish Cancer Registry in 2004, but this key variable for prognostic research has not yet been validated. We validated the tumour stage data in surgically treated oesophageal cancer patients. Material and Methods: Completeness and accuracy of tumour stage according to the TNM system (“Tumour Node Metastasis”) in the Cancer Registry were compared with a cohort study including comprehensive tumour stage data based on the pathological TNM of almost all patients operated for oesophageal cancer in 2006-2010 in Sweden. Results: Of the 397 patients with pathological TNM data in the comparison cohort, the Cancer Registry reported an overall TNM stage in 390 patients (98.2%), which was based on the pathological TNM of 104 patients (26.2%), the clinical TNM of 183 patients (46.1%), and the pathological or clinical TNM (undefined) of 110 patients (27.7%). The completeness for the separate T, N, and M components was 89.4%, 90.9%, and 85.1%, respectively. The concordance with tumour stage was 98.2%, while it was 51.1%, 70.5%, and 80.4% for the separate T, N, and M components, respectively. While the concordance with tumour stage was high for all TNM assessment groups (98.1-98.4%), the concordance of the T and N components was highest when using pathological TNM (82.7% and 95.2%, respectively), and the concordance of the M component was highest when using clinical TNM (88.5%). Conclusion: Although the overall completeness of tumour stage is high, the recording of pathological TNM stage and individual components could be improved within the Swedish Cancer Registry.Swedish Research Council (SIMSAM)Swedish Cancer SocietyAccepte

Surgeon age in relation to patients’ long-term survival after gastrectomy for gastric adenocarcinoma: nationwide population-based cohort study

Background: Increasing surgeon age may influence patient outcomes after complex procedures due to gained experience but also decreased technical and cognitive abilities. This study aimed to clarify whether surgeon age influences patients’ long-term survival after gastrectomy for gastric adenocarcinoma. Methods: Population-based cohort study including all patients who underwent open and curatively intended gastrectomy for gastric adenocarcinoma between 2006 and 2015 in Sweden, with follow-up throughout 2020. Surgeon age, categorized into three equal-sized groups (tertiles), was assessed in relation to 5-year all-cause mortality rate (main outcome) and 5-year disease-specific death (secondary outcome) using multivariable Cox regression adjusted for patient age, sex, education, co-morbidity, pathological tumour stage, tumour sublocation and neoadjuvant therapy. Lymph node yield, resection margin status, in-hospital complications and annual surgeon volume of gastrectomy were considered potential mediators. Results: Among 1647 patients, the 5-year all-cause mortality rate was increased for surgeon age ≥55 years (adjusted HR 1.21, 95% c.i. 1.04 to 1.41) and borderline elevated for age 47–54 years (HR 1.16, 95% c.i. 0.99 to 1.36), compared with age ≤46 years. Five-year disease-specific death was increased for surgeon age ≥55 years (HR 1.25, 95% c.i. 1.06 to 1.48) and 47–54 years (HR 1.22, 95% c.i. 1.02 to 1.44), compared with age ≤46 years. The associations attenuated and became statistically non-significant after adjustment for lymph node yield, resection margin status and complications. Conclusion: Surgeon age ≥47 years might be associated with worse long-term survival in patients who undergo gastrectomy for gastric adenocarcinoma, possibly mediated in part by differences in lymph node yield, resection margin status and complications

Weekday of esophageal cancer surgery and its relation to prognosis

Objective: To assess whether weekday of surgery influences long-term survival in esophageal cancer. Summary Background Data: Increased 30-day mortality rates have been reported in patients undergoing elective surgery later compared to earlier in the week Methods: This population-based cohort study included 98% of all esophageal cancer patients who underwent elective surgery in Sweden in 1987-2010, with follow-up until 2014. The association between weekday of surgery and 5-year all-cause and disease-specific mortality was analyzed using a multivariable Cox proportional hazards model, providing hazard ratios (HRs) with 95% confidence intervals (CIs), adjusted for age, co-morbidity, tumor stage, histology, neoadjuvant therapy, and surgeon volume. Results: Among 1,748 included patients, surgery conducted Wednesday-Friday entailed 13% increased all-cause 5-year mortality compared to surgery Monday-Tuesday (HR=1.13, 95% CI 1.01-1.26). The corresponding association was strong for early tumor stages (0-I) (HR=1.59, 95% CI 1.17-2.16), moderate for intermediate tumor stage (II) (HR=1.28, 95% CI 1.07-1.53), and absent in advanced tumor stages (III-IV) (HR=0.93, 95%CI 0.79-1.09). The increase in 5-year mortality for each later weekday (discrete variable) was 7% for all tumor stages (HR=1.07, 95% CI 1.02-1.12), 24% for early tumor stages (HR=1.24, 95% CI 1.09-1.41), 13% for intermediate stage (HR=1.13, 95% CI 1.05-1.22), while no increase was found for advanced stages (HR=0.98, 95% CI 0.92-1.05). The disease-specific 5-year mortality was similar to the all-cause mortality. Conclusions: The increased 5-year mortality of potentially curable esophageal cancer following surgery later in the week suggests that this surgery is better performed earlier in the week.Swedish Research CouncilSwedish Cancer SocietyAccepte

Prognosis following cancer surgery during holiday periods

Swedish Research Council for Health, Working Life and Welfare (Forte)Accepte