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

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

Weekday of cancer surgery in relation to prognosis

BACKGROUND: Later weekday of surgery seems to affect the prognosis adversely in oesophageal cancer, whereas any such influence on other cancer sites is unknown. This study aimed to test whether weekday of surgery influenced prognosis following commonly performed cancer operations. METHODS: This nationwide Swedish population-based cohort study from 1997 to 2014 analysed weekday of elective surgery for ten major cancers in relation to disease-specific and all-cause mortality. Cox regression provided hazard ratios with 95 per cent confidence intervals, adjusted for the co-variables age, sex, co-morbidity, hospital volume, calendar year and tumour stage. RESULTS: A total of 228 927 patients were included. Later weekday of surgery (Thursdays and, even more so, Fridays) was associated with increased mortality rates for gastrointestinal cancers. Adjusted hazard ratios for disease-specific mortality, comparing surgery on Friday with that on Monday, were 1·57 (95 per cent c.i. 1·31 to 1·88) for oesophagogastric cancer, 1·49 (1·17 to 1·88) for liver/pancreatic/biliary cancer and 1·53 (1·44 to 1·63) for colorectal cancer. Excluding mortality during the initial 90 days of surgery made little difference to these findings, and all-cause mortality was similar to disease-specific mortality. The associations were similar in analyses stratified for co-variables. No consistent associations were found between weekday of surgery and prognosis for cancer of the head and neck, lung, thyroid, breast, kidney/bladder, prostate or ovary/uterus.the Swedish Research Councilthe Swedish Cancer SocietyKarolinska Institutet Distinguished Professor Award to Professor Jesper LagergrenAccepte

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

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

Education level influences long-term survival after esophageal cancer surgery in a nationwide Swedish cohort study

Objectives: This study aimed to investigate whether a higher education level is associated with an improved long-term survival after oesophagectomy for cancer. Design: A prospective, population-based cohort study. Setting: Sweden—nationwide. Participants: 90% of all patients with oesophageal and cardia cancer who underwent a resection in Sweden in 2001–2005 were enrolled in this study (N=600; 80.3% male) and followed up until death or the end of the study period (2012). The study exposure was level of education, defined as compulsory (≤9 years), moderate (10–12 years) or high (≥13 years). Outcome measures: The main outcome measure was overall 5-year survival after oesophagectomy. Cox regression was used to estimate the associations between education level and mortality, expressed as HRs with 95% CIs, with adjustment for sex, age, tumour stage, histological type, complications, comorbidities and annual surgeon volume. The patient group with highest education was used as the reference category. Results: Among the 600 included patients, 281 (46.8%) had compulsory education, 238 (39.7%) had moderate education and 81 (13.5%) had high education. The overall 5-year survival rate was 23.1%, 24.4% and 32.1% among patients with compulsory, moderate and high education, respectively. After adjustment for confounders, a slightly higher, yet not statistically significantly increased point HR was found among the compulsory educated patients (HR 1.08, 95% CI 0.80 to 1.47). In patients with tumour stage IV, increased adjusted HRs were found for compulsory (HR 2.88, 95% CI 1.07 to 7.73) and moderately (HR 2.83, 95% CI 1.15 to 6.95) educated patients. No statistically significant associations were found for the other tumour stages. Conclusions: This study provides limited evidence of an association between lower education and worse longterm survival after oesophagectomy for cancer.Swedish Research Council (SIMSAM)Swedish Cancer SocietyPublishe

Modelling managed forest ecosystems in Sweden : Poster presentation:

In this work, the forestry-enabled dynamic vegetation model LPJ-GUESS was used to simulate forest standing volume for the three main regions of Sweden. At the regional scale, the model results were evaluated against observational data from the Swedish National Forest Inventory. Carbon fluxes of net ecosystem exchange (NEE), gross primary productivity (GPP), and ecosystem respiration (Reco) were simulated at the local scale on a daily time step for two sites in Sweden and results were evaluated against data from the Integrated Carbon Observation System (ICOS). The model produced adequate results of standing volume in monocultures of Norway spruce and Scots pine for southern and central Sweden, after an updated parameterization of the species. Stand-scale simulations of carbon fluxes produced mixed results after an evaluation against EC data from ICOS

Risk factors for marginal ulcer after gastric bypass surgery for obesity:A population-based cohort study

ObjectiveThis study aimed to assess risk factors for developing marginal ulcer (MU) after gastric bypass (GBP) surgery for obesity.BackgroundMU is a common and potentially serious complication of GBP surgery, little is known about its etiology.MethodsThis population-based cohort study of GBP in 2006-2011 evaluated MU in relation to diabetes, hyperlipidemia, hypertension, chronic obstructive pulmonary disease (COPD), ulcer history, use of proton pump inhibitors (PPIs), aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and selective serotonin reuptake inhibitors (SSRIs). Multivariable Cox proportional hazard regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for confounding.ResultsAmong 20,294 GBP patients, diabetes and peptic ulcer history entailed statistically significantly increased risk of MU (HR = 1.26, 95% CI 1.03-1.55 and HR  =  2.70, 95% CI 1.81-4.03), although hyperlipidemia, hypertension, and COPD did not. PPI users had an increased HR of MU (HR  =  1.37, 95% CI 1.17-1.60). Aspirin and NSAID consumption less than or equal to median entailed decreased HRs of MU (HR  =  0.56, 95% CI 0.37-0.86 and HR  =  0.30, 95% CI 0.24-0.38), although aspirin and NSAID users more than median had an increased risk and no association with MU, respectively (HR  =  1.90, 95% CI 1.41-2.58 and HR  =  0.90, 95% CI 0.76-1.87). The use of SSRI less than or equal to median had a decreased risk of MU (HR  =  0.50, 95% CI 0.37-0.67), although use more than median entailed increased HR (HR  =  1.26, 95% CI 1.01-1.56).ConclusionsDiabetes and peptic ulcer history seem to be risk factors for MU, but not hyperlipidemia, hypertension, or COPD. Limited doses of aspirin, NSAIDs, and SSRIs might not increase the risk, although higher doses of aspirin do. The association with PPI could be due to confounding by indication