Peritoneal infection after colorectal cancer surgery induces substantial alterations in postoperative protein levels: an exploratory study.

PURPOSE: Peritoneal infection, due to anastomotic leakage, after resection for colorectal cancer have been shown to associate with increased cancer recurrence and mortality, as well as cardiovascsular morbidity. Alterations in circulating protein levels could help shed light on the underlying mechanisms, prompting this exploratory study of 64 patients operated for colorectal cancer with anastomosis. METHODS: Thirty-two cases who suffered a postoperative peritoneal infection were matched with 32 controls who had a complication-free postoperative stay. Proteins in serum samples at their first postoperative visit and at one year after surgery were analysed using proximity extension assays and enzyme-linked immunosorbent assays. Multivariate projection methods, adjusted for multiple testing, were used to compare levels between groups, and enrichment and network analyses were performed. RESULTS: Seventy-seven proteins, out of 270 tested, were differentially expressed at a median sampling time of 41 days postoperatively. These proteins were all normalised one year after surgery. Many of the differentially expressed top hub proteins have known involvement in cancer progression, survival, invasiveness and metastasis. Over-represented pathways were related to cardiomyopathy, cell-adhesion, extracellular matrix, phosphatidylinositol-3-kinase/Akt (PI3K-Akt) and transforming growth factor beta (TGF-ß) signaling. CONCLUSION: These affected proteins and pathways could provide clues as to why patients with peritoneal infection might suffer increased cancer recurrence, mortality and cardiovascular morbidity.

Defunctioning loop ileostomy in anterior resection for rectal cancer and subsequent renal failure: nationwide population-based study.

BACKGROUND: Electrolyte disturbances and dehydration are common after anterior resection for rectal cancer with a defunctioning loop ileostomy. High-quality population-based studies on the impact of a defunctioning loop ileostomy on renal failure are lacking. METHODS: This was a nationwide observational study, based on the Swedish Colorectal Cancer Registry of patients undergoing anterior resection for rectal cancer between 2008 and 2016, with follow-up until 2017. Patients with severe co-morbidity, with age greater than 80 years, and with pre-existing renal failure were excluded. Loop ileostomy at index surgery constituted exposure, while a diagnosis of renal failure was the outcome. Acute and chronic events were analysed separately. Inverse probability weighting with adjustment for confounding derived from a causal diagram was employed. Hazards ratios (HRs) with 95 per cent c.i. are reported. RESULTS: A total of 5355 patients were eligible for analysis. At 5-year follow-up, all renal failure events (acute and chronic) were 7.2 per cent and 3.3 per cent in the defunctioning stoma and no stoma groups respectively. In the weighted analysis, a HR of 11.59 (95 per cent c.i. 5.68 to 23.65) for renal failure in ostomates was detected at 1 year, with the largest effect from acute renal failure (HR 24.04 (95 per cent c.i. 8.38 to 68.93)). Later follow-up demonstrated a similar pattern, but with smaller effect sizes. CONCLUSION: Patients having a loop ileostomy in combination with anterior resection for rectal cancer are more likely to have renal failure, especially early after surgery. Strategies are needed, such as careful fluid management protocols, and further research into alternative stoma types or reduction in stoma formation.

Preoperative biomarkers related to inflammation may identify high-risk anastomoses in colorectal cancer surgery: explorative study.

BACKGROUND: Colorectal anastomotic leakage can be considered a process of failed wound healing, for which related biomarkers might be a promising research area to decrease leak rates. METHODS: Patients who had elective surgery with a primary anastomosis for non-metastatic colorectal cancer, at two university hospitals between 1 January 2010 and 31 December 2015 were included. Patients with an anastomotic leak were identified and matched (1:1) to complication-free controls on the basis of sex, age, tumour stage, tumour location, and operating hospital. Preoperative blood samples were analysed by use of protein panels associated with systemic or enteric inflammation by proteomics, and enzyme-linked immunosorbent assays. Multivariable projection methods were used in the statistical analyses and adjusted for multiple comparisons to reduce false positivity. Rectal cancer tissue samples were evaluated with immunohistochemistry to determine local expression of biomarkers that differed significantly between cases and controls. RESULTS: Out of 726 patients undergoing resection, 41 patients with anastomotic leakage were matched to 41 controls. Patients with rectal cancer with leakage displayed significantly elevated serum levels of 15 proteins related to inflammation. After controlling for a false discovery rate, levels of C-X-C motif chemokine 6 (CXCL6) and C-C motif chemokine 11 (CCL11) remained significant. In patients with colonic cancer with leakage, levels of high-sensitivity C-reactive protein (hs-CRP) were increased before surgery. Local expression of CXCL6 and CCL11, and their receptors, were similar in rectal tissues between cases and controls. CONCLUSION: Patients with anastomotic leakage could have an upregulated inflammatory response before surgery, as expressed by elevated serological levels of CXCL6 and CCL11 for rectal cancer and hs-CRP levels in patients with colonic cancer respectively.

Variations in the management of diffuse low-grade gliomas-A Scandinavian multicenter study.

BACKGROUND: Early extensive surgery is a cornerstone in treatment of diffuse low-grade gliomas (DLGGs), and an additional survival benefit has been demonstrated from early radiochemotherapy in selected "high-risk" patients. Still, there are a number of controversies related to DLGG management. The objective of this multicenter population-based cohort study was to explore potential variations in diagnostic work-up and treatment between treating centers in 2 Scandinavian countries with similar public health care systems. METHODS: Patients screened for inclusion underwent primary surgery of a histopathologically verified diffuse WHO grade II glioma in the time period 2012 through 2017. Clinical and radiological data were collected from medical records and locally conducted research projects, whereupon differences between countries and inter-hospital variations were explored. RESULTS: A total of 642 patients were included (male:female ratio 1:4), and annual age-standardized incidence rates were 0.9 and 0.8 per 100 000 in Norway and Sweden, respectively. Considerable inter-hospital variations were observed in preoperative work-up, tumor diagnostics, surgical strategies, techniques for intraoperative guidance, as well as choice and timing of adjuvant therapy. CONCLUSIONS: Despite geographical population-based case selection, similar health care organizations, and existing guidelines, there were considerable variations in DLGG management. While some can be attributed to differences in clinical implementation of current scientific knowledge, some of the observed inter-hospital variations reflect controversies related to diagnostics and treatment. Quantification of these disparities renders possible identification of treatment patterns associated with better or worse outcomes and may thus represent a step toward more uniform evidence-based care.

Defunctioning stomas may reduce chances of a stoma-free outcome after anterior resection for rectal cancer.

AIM: To investigate the conflicting consequences of faecal diversion on stoma outcomes and anastomotic leakage in anterior resection for rectal cancer, including interaction effects determined by the extent of mesorectal excision. METHOD: Anterior resections between 2007 and 2016 were identified using the Swedish Colorectal Cancer Registry. National Patient Registry data were added to determine stoma outcome 2 years after surgery. Tumour distance from the anal verge constituted a proxy for extent of mesorectal excision [total mesorectal excision (TME): ≤10 cm; partial mesorectal excision (PME): 13-15 cm]. With confounder-adjusted probit regression, the total effect of defunctioning stoma on permanent stoma, and the interaction effect of extent of mesorectal excision, were estimated together with the indirect effect through anastomotic leakage. Baseline risks, risk differences (RDs) and relative risks (RRs) were reported. RESULTS: The main study cohort included 4529 patients. Defunctioning stomas influenced the absolute permanent stoma risk (TME: RD 0.11 [95% CI 0.09-0.13]; PME: RD 0.15 [95% CI 0.13-0.16]). The baseline risk was higher in TME, with a resulting greater RR in PME (2.23 [95% CI 1.43-3.02] vs 4.36 [95% CI 3.05-5.68]). The indirect reduction in permanent stoma rates, due to the alleviating effect of faecal diversion on anastomotic leakage, was small (TME: 0.89 [95% CI 0.81-0.96]; PME: 0.96 [95% CI 0.91-1.00]). CONCLUSION: In anterior resection for rectal cancer, defunctioning stomas may reduce chances of a stoma-free outcome. Considering leakage reduction benefits, consequences of routine diversion in TME might be fairly balanced, while this seems questionable in PME.

Anterior resection for rectal cancer in Sweden: validation of a registry-based method to determine long-term stoma outcome.

BACKGROUND: A permanent stoma after anterior resection for rectal cancer is common. Nationwide registries provide sufficient power to evaluate factors influencing this phenomenon, but validation is required to ensure the quality of registry-based stoma outcomes. METHODS: Patients who underwent anterior resection for rectal cancer in the Northern healthcare region of Sweden between 1 January 2007 and 31 December 2013 were reviewed by medical records and followed until 31 December 2014 with regard to stoma outcome. A registry-based method to determine nationwide long-term stoma outcomes, using data from the National Patient Registry and the Swedish Colorectal Cancer Registry, was developed and internally validated using the chart reviewed reference cohort. Accuracy was evaluated with positive and negative predictive values and Kappa values. Following validation, the stoma outcome in all patients treated with an anterior resection for rectal cancer in Sweden during the study period was estimated. Possible regional differences in determined stoma outcomes between the six Swedish healthcare regions were subsequently evaluated with the χ2 test. RESULTS: With 312 chart reviewed patients as reference, stoma outcome was accurately predicted through the registry-based method in 299 cases (95.8%), with a positive predictive value of 85.1% (95% CI 75.8%-91.8%), and a negative predictive value of 100.0% (95% CI 98.4%-100.0%), while the Kappa value was 0.89 (95% CI 0.82-0.95). In Sweden, 4768 patients underwent anterior resection during the study period, of which 942 (19.8%) were determined to have a permanent stoma. The stoma rate varied regionally between 17.8-29.2%, to a statistically significant degree (p = .001). CONCLUSION: Using data from two national registries to determine long-term stoma outcome after anterior resection for rectal cancer proved to be reliable in comparison to chart review. Permanent stoma prevalence after such surgery remains at a significant level, while stoma outcomes vary substantially between different healthcare regions in Sweden.