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. CONCLUSION: Later weekday of surgery (Thursday or Friday) seems to influence the prognosis adversely for cancers of the gastrointestinal tract.

Surgical resection strategy and the influence of radicality on outcomes in oesophageal cancer.

BACKGROUND: The optimal surgical approach to tumours of the oesophagus and oesophagogastric junction remains controversial. The principal randomized trial comparing transhiatal (THO) and transthoracic (TTO) oesophagectomy showed no survival difference, but suggested that some subgroups of patients may benefit from the more extended lymphadenectomy typically conducted with TTO. METHODS: This was a cohort study based on two prospectively created databases. Short- and long-term outcomes for patients undergoing THO and TTO were compared. The primary outcome measure was overall survival, with secondary outcomes including time to recurrence and patterns of disease relapse. A Cox proportional hazards model provided hazard ratios (HRs) and 95 per cent confidence intervals (c.i.), with adjustments for age, tumour stage, tumour grade, response to chemotherapy and lymphovascular invasion. RESULTS: Of 664 included patients (263 THO, 401 TTO), the distributions of age, sex and histological subtype were similar between the groups. In-hospital mortality (1·1 versus 3·2 per cent for THO and TTO respectively; P = 0·110) and in-hospital stay (14 versus 17 days respectively; P < 0·001) favoured THO. In the adjusted model, there was no difference in overall survival (HR 1·07, 95 per cent c.i. 0·84 to 1·36) or time to tumour recurrence (HR 0·99, 0·76 to 1·29) between the two operations. Local tumour recurrence patterns were similar (22·8 versus 24·4 per cent for THO and TTO respectively). No subgroup could be identified of patients who had benefited from more radical surgery on the basis of tumour location or stage. CONCLUSION: There was no difference in survival or tumour recurrence for TTO and THO.

Gallstones and cholecystectomy in relation to risk of intra- and extrahepatic cholangiocarcinoma.

BACKGROUND: Cholangiocarcinomas are highly lethal tumours of the intrahepatic or extrahepatic biliary tract. The aetiology is largely unknown, and the potential roles of gallstones and gall bladder removal (cholecystectomy) need to be addressed in a large study with a long follow-up. METHODS: A population-based nationwide Swedish cohort study was carried out, in which patients hospitalised for gallstone diagnosis with or without gallbladder removal (cholecystectomy) between 1965 and 2008 were identified in the Swedish Patient Registry. The cohort was followed up for cancer in the Swedish Cancer Registry. The observed numbers of intra- and extrahepatic cholangiocarcinomas that developed after one year of follow-up were compared with the expected numbers, calculated from the corresponding background population, and the relative risks were estimated by standardised incidence ratios (SIRs) and 95% confidence intervals (CIs). RESULTS: Among the 192,960 non-cholecystectomised individuals with gallstones, there was a more than two-fold overall increased risk of both intra- and extra- hepatic cholangiocarcinomas, which remained stable over the follow-up period (SIR 2.77, 95% CI 2.17-3.49, and SIR 2.58, 95% CI 2.21-3.00, respectively). In the cholecystectomy cohort, including 345,251 people and 4,854,969 person-years, 325 incident cholangiocarcinomas were identified, of which 98 (30%) were intrahepatic and 227 (70%) were extrahepatic. Initially (1-4 years after surgery), the risk was increased for both intrahepatic cholangiocarcinoma (SIR 1.80, 95% CI 1.19-2.62) and extrahepatic cholangiocarcinoma (SIR 2.29, 95% CI 1.83-2.82), but no increase remained after 10 years of follow-up or more (SIR 1.10, 95% CI 0.79-1.48, and SIR 0.87, 95% CI 0.70-1.07, respectively). INTERPRETATION: Gallstones seem to increase the risk of both intra- and extrahepatic cholangiocarcinoma. However, this risk seems to decline to the level of the background population with time after cholecystectomy.

Population-based study of the need for cholecystectomy after obesity surgery.

BACKGROUND: Weight loss following obesity surgery is associated with gallstone formation, but there is limited evidence on whether prophylactic cholecystectomy is indicated during obesity surgery. The aim of this study was to clarify the need for cholecystectomy following obesity surgery. METHODS: A Swedish nationwide, population-based cohort study was conducted during the 22-year interval 1987-2008. Need for later cholecystectomy for gallstone disease was assessed in patients who had undergone obesity surgery in comparison with the general population of corresponding age, sex and calendar year. This need was also compared with the need for cholecystectomy in cohorts of patients who had undergone antireflux surgery and appendicectomy. Standardized incidence ratios (SIRs) with 95 per cent confidence intervals (c.i.) were calculated to estimate the relative risk. RESULTS: In the obesity surgery cohort of 13 443 patients, the observed number of cholecystectomies (1149, 8·5 per cent) exceeded the expected number by over fivefold (SIR 5·5, 95 per cent c.i. 5·1 to 5·8). The observed need for imperative cholecystectomy (for cholecystitis, cholangitis, pancreatitis, or jaundice; 427, 3·2 per cent) was also greater than expected (SIR 5·2, 4·7 to 5·7). The SIR peaked 7-24 months after obesity surgery and decreased with longer follow-up. The SIRs for cholecystectomy after antireflux surgery and appendicectomy were 2·4 (2·2 to 2·6) and 1·7 (1·6 to 1·7) respectively. CONCLUSION: An increased need for cholecystectomy after obesity surgery was confirmed, but was probably partly due to an increased detection of gallbladder disease only because of the surgery; the individual's risk of imperative cholecystectomy was low. Therefore, prophylactic cholecystectomy might not be recommended during obesity surgery.

Increased risk of hepatocellular carcinoma after cholecystectomy.

BACKGROUND: The association between gall bladder removal (cholecystectomy) and hepatocellular carcinoma warrants investigation. An increased intrahepatic bile duct pressure following cholecystectomy might cause chronic inflammation in the surrounding liver tissue, which might induce cancer development. METHODS: A nationwide Swedish population-based cohort study in 1965-2008 included 345,251 patients undergoing cholecystectomy because of gallstone. The number of observed hepatocellular carcinoma cases was divided by the expected number, calculated from the corresponding background Swedish population, thus providing standardised incidence ratios (SIRs) with 95% confidence intervals (CIs). RESULTS: During follow-up of 4,854,969 person-years, 333 new cases of hepatocellular carcinoma were identified, rendering an overall increased risk (SIR 1.24, 95% CI: 1.11-1.38). The risk increased with longer follow-up (P for trend=0.003). Among patients who underwent cholecystectomy 30-43 years earlier, SIR was 2.00 (95% CI: 1.32-2.87). The results were similar after exclusion of 15,634 patients with any recorded risk factor, that is, diabetes, obesity, hepatitis, liver cirrhosis, alcoholism, or blood transfusion. CONCLUSION: Cholecystectomy might be associated with a long-term increased risk of hepatocellular carcinoma.

Cholecystectomy as a risk factor for oesophageal adenocarcinoma.

BACKGROUND: Owing to an increased risk of oesophageal bile exposure after cholecystectomy, an association with oesophageal adenocarcinoma is possible. There are some data in support of this hypothesis, and the aim of this study was to ascertain whether the association could be confirmed. METHODS: A population-based cohort study was undertaken to compare the number of cases of oesophageal adenocarcinoma observed in a cohort of patients who have had a cholecystectomy in Sweden during 1965-2008 with the expected number, calculated from the entire Swedish population of corresponding age, sex and year. The risk of oesophageal adenocarcinoma was assessed by calculating the standardized incidence ratio (SIR) with 95 per cent confidence intervals. RESULTS: The cholecystectomy cohort included 345 251 patients who were followed up for a mean of 15 years and contributed 4 854 969 person-years at risk. The total of 126 new cases of oesophageal adenocarcinoma was greater than expected (SIR 1.29, 1.07 to 1.53). The strength of the association between cholecystectomy and oesophageal adenocarcinoma tended to increase with longer follow-up after cholecystectomy. There was no association between cholecystectomy and oesophageal squamous cell carcinoma (SIR 0.93, 0.81 to 1.08), and in an unoperated cohort of 192 960 patients with gallstones no increased risk of oesophageal adenocarcinoma was identified (SIR 0.99, 0.71 to 1.35). CONCLUSION: Cholecystectomy appears to be linked to an increased risk of oesophageal adenocarcinoma, but the absolute risk is small.