Postoperative infections are associated with adverse outcome after resection with curative intent for colorectal cancer

Best practices in wound care for gastrointestinal stoma and colorectal cancer patients from a nursing perspective: A meta-analysis

Colorectal cancer, a type of colon or bowel cancer, poses a major challenge in the treatment of colorectal lesions. Colorectal endoscopic mucosal resection (EMR) is a minimally invasive technique, but the risk of wound infections remains a significant concern. These infections can impede the healing process, affecting daily activities and patient satisfaction. To mitigate the risk of wound infections, various prophylactic measures have been explored, including medication, vaccines, lifestyle adjustments and hygiene practices. This study aims to investigate the prevention of wound infections through prophylactic measures in colorectal EMR. A comprehensive literature review was conducted to identify prophylactic measures that can prevent wound infections. A systematic literature search was conducted using both free words and search terms. The data extraction was performed after a comprehensive literature screening. The meta-analysis was performed using the metabin function of the meta library in R to evaluate the infection incidences in intervention and control groups. A total of 599 infection incidences were considered, with 267 in intervention and 332 in the control group. The results of meta analysis demonstrated significant reduction of wound incidences following the prophylactic measures (risk ratio [RR] = 0.77, 95% confidence interval [CI]: 0.6747; 0.9016, I2 = 78.5%, p < 0.01). The wound infection ratio analysis also exhibited an approximate 6.6% less infection rate in the intervention group, demonstrating significantly less wound infection following the implementation of prophylactic measures. This study highlights the crucial significance of prevention of wound infections by prophylactic measures in colorectal EMR.

Evaluating Postoperative Prognosis: A Single Surgeon's Experience With Total Mesorectal Excision in Middle and Lower Rectal Cancer Cases in Iraq

INTRODUCTION

Surgical intervention for rectal cancer is widely recognized for its potential to significantly impact quality of life, chiefly due to the high probability of permanent colostomy and the associated postoperative complications.

OBJECTIVE

This study aimed to evaluate the short-term outcomes and morbidity associated with total mesorectal excision for middle and lower rectal cancer within an Iraqi cohort, in a prospective setting.

METHODS

This study prospectively collected and analyzed data from 89 patients who underwent a standardized radical rectal resection, with a follow-up period extending to one month post-surgery.

RESULTS

The mean age of patients was 54.4 ± 12.9 years, with a gender distribution of 46 males and 43 females. A total of 33 patients presented with preoperative comorbidities, which heightened the risk of adverse short-term outcomes by a factor of 7.51. The most prevalent comorbidities were hypertension and diabetes mellitus, affecting 22 and 20 patients, respectively. Patients aged 60 years and above were at a 3.97 times greater risk of developing complications. The overall complication rate was 21.35%, with wound infections (9.0%) and cardiovascular events (3.4%) being the most common. Mortality during the follow-up was 1.1%.

CONCLUSION

The findings indicate that increased age and the presence of comorbidities are significant risk factors for morbidity and mortality post-surgery. Neoadjuvant chemoradiotherapy or radiotherapy was shown to reduce morbidity and mortality rates while improving survival. The morbidity and mortality rates observed in this study concur with existing literature.

Pivotal role of myeloid-derived suppressor cells in infection-related tumor growth

BACKGROUND

In this study, we investigated infection-related tumor growth, focusing on myeloid-derived suppressor cells (MDSCs) in clinical and experimental settings.

PATIENTS AND METHODS

In the clinical study, a total 109 patients who underwent gastrectomy or esophagectomy were included. Blood samples were collected from a preoperative time point through 3 months after surgery, and MDSCs were analyzed using flow cytometry. In animal experiments, peritonitis model mice were created by CLP method. We investigated the number of splenic MDSCs in these mice using flow cytometry. Malignant melanoma cells (B16F10) were inoculated on the back of the mice, and tumor growth was monitored. We compared the level of MDSC infiltration around the tumor and the migration ability between CLP and sham-operated mice-derived MDSCs. Finally, we focused on PD-L1+ MDSCs to examine the effectiveness of anti-PD-L1 antibodies on tumor growth in CLP mice.

RESULTS

In patients with postoperative infectious complication, MDSC number was found to remain elevated 3 months after surgery, when the inflammatory responses were normalized. CLP mice showed increased numbers of MDSCs, and following inoculation with B16F10 cells, this higher number of MDSCs was associated with significant tumor growth. CLP-mice-derived MDSCs had higher levels of accumulation around the tumor and had more enhanced migration ability. Finally, CLP mice had increased numbers of PD-L1+ MDSCs and showed more effective inhibition of tumor growth by anti-PD-L1 antibodies compared to sham-operated mice.

CONCLUSION

Long-lasting enhanced MDSCs associated with infection may contribute to infection-related tumor progression.

Tailored Pre-Operative Antibiotic Prophylaxis to Prevent Post-Operative Surgical Site Infections in General Surgery

The average American today undergoes three inpatient and two outpatient surgical procedures during one's life, each of which carries with it a risk of post-operative infection. It has long been known that post-operative infections cause significant morbidity in the immediate peri-operative period, but recent evidence suggests that they can have long-term consequences as well, increasing a patient's risk of infectious complications in unrelated surgeries performed months or even years later. While there are several theories on the origin of this association, including bacterial colonization of a post-operative infectious wound site, antimicrobial resistance from curative courses of antibiotics, subclinical immunosuppression, or the creation of an inflammatory "pathobiome" following an infectious insult, it is ultimately still unclear why patients who experience a single post-operative infection seem to be at a significantly higher risk of experiencing subsequent ones. Regardless, this association has significant implications for the routine use of pre-operative antibiotic prophylaxis. Indeed, while the prescription of antibiotics pre-operatively has dramatically reduced the rate of post-operative infections, the chosen prophylaxis regimens are typically standardized according to national guidelines, are facing increasing antimicrobial resistance patterns, and have been unable to reduce the risk of post-operative infection to acceptably low levels for certain surgeries. As a result, some clinicians have speculated that tailoring pre-operative antibiotic prophylaxis according to a patient's prior infectious and operative history could improve efficacy and further reduce the rate of post-operative infections. The purpose of this review is to describe the evidence for the link between multiple post-operative infections and explore the efficacy of individualized pre-operative prophylaxis.

Postoperative inflammatory response in colorectal cancer surgery: a meta-analysis

PURPOSE

Surgical removal of the cancerous tissue remains the cornerstone of curative treatment for colorectal cancer and results in an inflammatory response. An exaggerated inflammatory response has been implicated in the promotion of tumor proliferation and has shown associations with postoperative complications. Literature on the preferred surgical technique to minimize inflammatory response is inconclusive. Therefore, the aim of this study was to assess the inflammatory response and postoperative incidence of infectious complications following surgery for colorectal cancer.

METHODS

Embase, PubMed, and Cochrane databases were searched for RCTs that reported inflammatory parameters as a function of surgical modality only. Data related to CRP or IL-6 levels on postoperative days 1 and 3 and data related to postoperative infections were subject to a pairwise meta-analysis to compare open versus laparoscopic techniques.

RESULTS

The literature search and screening process yielded 4151 studies. Ten studies met criteria, including 568 patients. Only studies on laparoscopic and open surgery were found. Pooled analyses found lower Il-6 and CRP levels on postoperative day 1 and lower CRP levels on postoperative day 3 for laparoscopic surgery compared to open surgery. However, there was no difference in incidence of postoperative infectious complications.

CONCLUSION

The findings of this study indicate a superior inflammatory profile for laparoscopic surgery compared to an open approach for colorectal cancer surgery. For future research, it would be worthwhile to conduct a randomized controlled trial to compare the postoperative inflammatory response and related clinical outcomes between minimally invasive surgical approaches, including laparoscopic and robot-assisted surgery.

Preliminary Evaluation of a Novel Artificial Intelligence-based Prediction Model for Surgical Site Infection in Colon Cancer

BACKGROUND/AIM

There are few studies on artificial intelligence-based prediction models for colon cancer built using clinicopathological factors. Here, we aimed to perform a preliminary evaluation of a novel artificial intelligence-based prediction model for surgical site infection (SSI) in patients with stage II-III colon cancer.

PATIENTS AND METHODS

The medical records of 730 patients who underwent radical surgery for stage II-III colon cancer between 2000 and 2018 at our institute were retrospectively analyzed. Kaplan-Meier curves were used to examine the association between SSI and oncological outcomes (recurrence-free survival time). Next, we used the machine learning software Prediction One to predict SSI. Receiver-operating characteristic curve analysis was used to evaluate the accuracy of the artificial intelligence model.

RESULTS

The prognosis in terms of recurrence-free survival time was poor in patients with SSI (p=0.005, 95% confidence interval=4892.061-5525.251). The area under the curve of the artificial intelligence model in predicting SSI was 0.731.

CONCLUSION

As SSI is an important prognostic factor associated with oncological outcomes, the prediction of SSI occurrence is important. Based on our preliminary evaluation, the artificial intelligence model for predicting SSI in patients with stage II-III colon cancer was as accurate as the previously reported model derived through conventional statistical analysis.

Surgical site infection after laparoscopic resection of colorectal cancer is associated with compromised long-term oncological outcome

Background

We evaluated the influence of infectious complications, particularly surgical site infection (SSI), on long-term oncological results after elective laparoscopic resection of colorectal cancer.

Methods

A total of 199 patients who underwent laparoscopic elective resection with negative resection margins for stage I–III colorectal cancer were retrospectively examined. The postoperative course was recorded based on hospital records, and cancer relapse was diagnosed based on radiological or pathological findings under a standardized follow-up program. The severity of complications was graded using Clavien-Dindo (CD) classification.

Results

SSI was found in 25 patients (12.6%), with 12 (6.0%) showing anastomotic leak. The postoperative relapse-free survival (RFS) rate was significantly lower in patients with SSI (49.2%) than in patients without SSI (87.2%, P<0.001). Differences in RFS were found after both colectomy and rectal resection (P<0.001 and P<0.001, respectively). RFS did not differ between patients who had major SSI CD (grade III) and those who had minor SSI CD (grades I or II). Multivariate Cox regression analysis identified the occurrence of SSI and pathological stage as independent co-factors for RFS (P<0.001 and P=0.003).

Conclusion

These results suggest that postoperative SSI compromises long-term oncological results after laparoscopic colorectal resection. Further improvements in surgical technique and refinements in perioperative care may improve long-term oncological results.

Role of Microbial Infection-Induced Inflammation in the Development of Gastrointestinal Cancers

There has been increasing evidence that a local inflammatory response stimulates tumor cells to acquire metastatic potential, and the concept of inflammatory oncotaxis has been spreading in recent years. However, the interaction between microbial inflammation and the development of gastrointestinal cancer is still unclear. This review summarizes the present knowledge on the role of microbial inflammation in the development of gastrointestinal cancers from the perspective of molecular biological findings. Chronic inflammation caused by bacterial infection is known to induce cancers as exemplified by Helicobacter pylori, which is associated with the development of gastric cancer via the activation of the TLR4 pathway by bacterial lipopolysaccharide followed by cancer growth through CagA-MET signaling. In addition, the development of inflammatory bowel diseases has been known to become a risk factor for colorectal cancers, where inflammation caused by certain bacterial infections plays a key role. It is also known that the cancer microenvironment is associated with cancer growth. Moreover, infectious complication after surgery for gastrointestinal cancers may promote tumor progression via the stimulation of pathogen-associated molecular patterns and various inflammatory mediators secreted by immunocytes. Further research on the link between microbial inflammation and cancer progression is needed to drive a paradigm shift in cancer treatment.

Candida albicans mycotic aneurysm of aortic arch following laparoscopic right hemicolectomy for colon cancer

An 81-year-old man was referred to the colorectal surgeons for an elective laparoscopic right hemicolectomy for a caecal adenocarcinoma (T2N0M0). The operation was uneventful; however, 12 days postoperatively the patient developed symptoms of sepsis of unknown origin. After extensive investigations and work up, Candida albicans was grown as the causative organism with the site of infection being a new saccular mycotic aneurysm arising from the distal, posterior aspect of the aortic arch. The mycotic aneurysm was not initially considered as a differential diagnosis, and this case highlights the importance of consideration of mycotic aneurysm as a differential diagnosis in postsurgical septic patients.

Impact of postoperative infectious complications on adjuvant chemotherapy administration after gastrectomy for advanced gastric cancer

BACKGROUND

The aim of this study was to investigate the impact of postoperative infectious complications on adjuvant chemotherapy administration in patients with gastric cancer.

METHODS

A retrospective review of 308 patients who underwent curative resection for gastric cancer was performed. Patients were divided into two groups based on the presence (90 patients, 29.2%) or absence (218 patients, 70.8%) of postoperative infectious complications to analyze clinicopathological characteristics, treatment factors and survival.

RESULTS

Fewer patients with postoperative infectious complication received adjuvant chemotherapy compared to those without postoperative infectious complication. The proportion of patients who started treatment within 6 weeks after surgery was significantly lower in patients with postoperative infectious complication. The treatment completion rate was significantly lower in patients with postoperative infectious complication. The number of treatment cycles and relative dose intensity was significantly lower in patients with postoperative infectious complication. In univariate analysis, only postoperative infectious complication was significantly associated with continuation of adjuvant chemotherapy. Multivariate analysis demonstrated tumor depth, nodal involvement, postoperative infectious complication and adjuvant chemotherapy were significantly associated with overall survival.

CONCLUSION

Postoperative infectious complications are significantly associated with the delay of adjuvant chemotherapy and predict adverse clinical outcome in patients with gastric cancer.

Potential mechanisms of tumor progression associated with postoperative infectious complications

There is increasing evidence that postoperative infectious complications (PICs) are associated with poor prognosis after potentially curative surgery. However, the role that PICs play in tumor development remains unclear. In this article, we reviewed the literature for novel insights on the mechanisms of cancer progression associated with PICs. The Medline and EMBASE databases were searched for publications regarding the role of suppression of antitumor immunity by PIC in tumor progression and selected 916 manuscripts were selected for this review. In addition, a summary of the authors' own experimental data from this field was set in the context of current knowledge regarding cancer progression under septic conditions. Initially, sepsis/microbial infection dramatically activates the systemic immune system with increases in pro-inflammatory mediators, which results in the development of systemic inflammatory response syndrome; however, when sepsis persists in septic patients, a shift toward an anti-inflammatory immunosuppressive state, characterized by macrophage deactivation, reduced antigen presentation, T cell anergy, and a shift in the T helper cell pattern to a predominantly TH2-type response, occurs. Thus, various cytokine reactions and the immune status dynamically change during microbial infection, including PIC. We proposed three possible mechanisms for the tumor progression associated with PIC: first, a mechanism in which microbes and/or microbial PAMPs may be directly involved in cancer growth; second, a mechanism in which factors released from immunocompetent cells during infections may affect tumor progression; and third, a mechanism in which factors suppress host tumor immunity during infections, which may result in tumor progression. A more detailed understanding by surgeons of the immunological features in cancer patients with PIC can subsequently open new avenues for improving unfavorable long-term oncological outcomes associated with PICs.

[The role of neutrophil CD64 index in the diagnosis of infectious complications after colorectal resection]

OBJECTIVE

To determine diagnostic value of neutrophil CD64 index (iCD64n) in the diagnosis of postoperative infectious complications after colorectal resections.

MATERIAL AND METHODS

Seventy-three patients underwent colorectal surgery for the period from January to December 2018. These patients were included into a single-center study. Peripheral blood samples were taken on 3 and 6 postoperative days (POD) to check iCD64n level. We analyzed incidence of postoperative infectious complications, sensitivity (Se) and specificity (Sp) of postoperative iCD64n level on the 3^rd and 6^th POD.

RESULTS

Postoperative infectious complications developed in 10 (13.7%) patients. Median iCD64n was significantly higher (p=0.0017 for POD 3; p=0.018 for POD 6) in patients with infectious complications (1.6 on POD 3; 1.3 on POD 6) compared to those without complications (1.1 on POD 3; 0.9 on POD 6). Area under curve (AUC) on the 3^rd POD was 0.8 with the cut-off value of 1.4, Se - 70%, Sp - 93.7% (p=0.002). On the 6^th POD, AUC was 0.91 with cut-off value of 1.23, Se - 80%, Sp - 93.7% (p<0.001).

CONCLUSION

Neutrophil CD64 index is a valuable predictor for the diagnosis of postoperative infectious complications after colorectal resections. It is a useful tool to ensure a safe early discharge.

The study is registered on the website «clinictrials.gov» (registration number NCT03559335).

Postoperative pneumonia causes the loss of skeletal muscle volume and poor prognosis in patients undergoing esophagectomy for esophageal cancer

PURPOSES

This retrospective study investigated the effect of postoperative pneumonia on the loss of skeletal muscle volume after esophagectomy for esophageal cancer.

METHODS

A total of 123 patients who had undergone esophagectomy for esophageal cancer and had (30 patients) or did not have (93 patients) postoperative pneumonia were included in the analysis. The association of clinicopathological characteristics with loss of skeletal muscle volume and long-term survival were evaluated in patients with or without postoperative pneumonia.

RESULTS

There were no differences in the psoas muscle volume index (PI), lymphocyte count, serum albumin level, or prognostic nutritional index between the two groups both preoperatively and at 6 months after surgery. The decrease in PI at 6 months after surgery was significant in patients with postoperative pneumonia (- 9.9 ± 2.5%) but not in those without pneumonia (- 2.6 ± 1.6%). Patients with postoperative pneumonia had a significantly increased frequency of asymptomatic pneumonia at 6 months after surgery compared with those who did not have postoperative pneumonia (36.7% vs. 19.4%). Overall survival was significantly poorer in patients with postoperative pneumonia than in those without pneumonia (p < 0.05).

CONCLUSIONS

Postoperative pneumonia was associated with the loss of skeletal muscle volume and asymptomatic pneumonia within 6 months of surgery as well as poorer overall survival.

A Potential Mechanism of Tumor Progression during Systemic Infections Via the Hepatocyte Growth Factor (HGF)/c-Met Signaling Pathway

Background: Increasing evidence has demonstrated that postoperative infectious complications (PICs) after digestive surgery are significantly associated with negative long-term outcomes; however, precise mechanisms of how PICs affect the poor long-term survival remain unclear. Here, we focused on the hepatocyte growth factor (HGF)/c-Met signaling pathway as one of those mechanisms. Methods: In the clinical setting, serum HGF levels were measured in the patients with sepsis and those with PICs after undergoing esophagectomy. Using a liver metastasis mouse model with cecal ligation and puncture (CLP), expressions of HGF and the roles of the HGF/c-Met pathway in the progression of tumor cells were examined. Results: Serum HGF levels were very high in the patients with intra-abdominal infection on postoperative days (PODs) 1, 3, and 5; similarly, compared to the patients without PICs, those with PICs had significantly higher serum HGF levels on 1, 3, and 5 days after esophagectomy. The patients with PICs showed poorer overall survival than those without PICs, and the patients with high serum HGF levels on POD 3 showed poorer prognosis than those with low HGF levels. Similarly, at 24 and 72 h after operation, serum levels of HGF in CLP mice were significantly higher than those in sham-operated mice. Intraperitoneal injection of mouse recombinant HGF significantly promoted liver metastases in sham-operated mice on 14 days after surgery. Knocking down c-Met expression on NL17 tumor cells by RNAi technology significantly inhibited the promotion of CLP-induced liver metastases. Conclusions: Infections after surgery increased serum HGF levels in the clinical as well as experimental settings. Induction of high serum HGF levels by CLP promoted liver metastases in a murine liver metastasis model, suggesting the involvement of the HGF/c-Met signaling pathway in tumor promotion mechanisms. Thus, targeting the HGF/c-Met signaling pathway may be a promising approach for malignant tumors, particularly in the patients with PICs.

Meta-analysis of the impact of postoperative infective complications on oncological outcomes in colorectal cancer surgery

BACKGROUND

Cancer outcomes are complex, involving prevention, early detection and optimal multidisciplinary care. Postoperative infection and surgical site-infection (SSI) are not only uncomfortable for patients and costly, but may also be associated with poor oncological outcomes. A meta-analysis was undertaken to assess the oncological effects of SSI in patients with colorectal cancer.

METHODS

An ethically approved PROSPERO-registered meta-analysis was conducted following PRISMA guidelines. PubMed and Scopus databases were searched for studies published between 2007 and 2017 reporting the effects of postoperative infective complications on oncological survival in colorectal cancer. Results were separated into those for SSI and those concerning anastomotic leakage. Articles with a Methodological Index for Non-Randomized Studies score of at least 18 were included. Hazard ratios (HRs) with 95 per cent confidence intervals were computed for risk factors using an observed to expected and variance fixed-effect model.

RESULTS

Of 5027 articles were reviewed, 43 met the inclusion criteria, with a total of 154 981 patients. Infective complications had significant negative effects on overall survival (HR 1·37, 95 per cent c.i. 1·28 to 1·46) and cancer-specific survival (HR 2·58, 2·15 to 3·10). Anastomotic leakage occurred in 7·4 per cent and had a significant negative impact on disease-free survival (HR 1·14, 1·09 to 1·20), overall survival (HR 1·34, 1·28 to 1·39), cancer-specific survival (HR 1·43, 1·31 to 1·55), local recurrence (HR 1·18, 1·06 to 1·32) and overall recurrence (HR 1·46, 1·27 to 1·68).

CONCLUSION

This meta-analysis identified a significant negative impact of postoperative infective complications on overall and cancer-specific survival in patients undergoing colorectal surgery.

Toll-like receptors: exploring their potential connection with post-operative infectious complications and cancer recurrence

Cancer is the leading cause of death in North America. Despite modern advances in cancer therapy, many patients will ultimately develop cancer metastasis resulting in mortality. Surgery to resect early stage solid malignancies remains the cornerstone of cancer treatment. However, surgery places patients at risk of developing post-operative infectious complications that are linked to earlier cancer metastatic recurrence and cancer mortality. Toll-like receptors (TLRs) are evolutionarily-conserved sentinel receptors of the innate immune system that are activated by microbial products present during infection, leading to activation of innate immunity. Numerous types of solid cancer cells also express TLRs, with their activation augmenting their ability to metastasize. Similarly, healthy host-tissue TLRs activated during infection induce a prometastatic environment in the host. Cancer cells additionally secrete TLR activating ligands that activate both cancer TLRs and host TLRs to promote metastasis. Consequently, TLRs are an attractive therapeutic candidate to target infection-induced cancer metastasis and progression.

Sepsis increases perioperative metastases in a murine model

Background

Cancer surgery can promote tumour metastases and worsen prognosis, however, the effect of perioperative complications on metastatic disease remains unclear. In this study we sought to evaluate the effect of common perioperative complications including perioperative blood loss, hypothermia, and sepsis on tumour metastases in a murine model.

Methods

Prior to surgery, pulmonary metastases were established by intravenous challenge of CT26LacZ colon cancer cells in BALB/c mice. Surgical stress was generated through partial hepatectomy (PH) or left nephrectomy (LN). Sepsis was induced by puncturing the cecum to express stool into the abdomen. Hemorrhagic shock was induced by removal of 30% of total blood volume (i.e. stage 3 hemorrhage) via the saphenous vein. Hypothermia was induced by removing the heating apparatus during surgery and lowering core body temperatures to 30 °C. Lung tumour burden was quantified 3 days following surgery.

Results

Surgically stressed mice subjected to stage 3 hemorrhage or hypothermia did not show an additional increase in lung tumour burden. In contrast, surgically stressed mice subjected to intraoperative sepsis demonstrated an additional 2-fold increase in the number of tumour metastases. Furthermore, natural killer (NK) cell function, as assessed by YAC-1 tumour cell lysis, was significantly attenuated in surgically stressed mice subjected to intraoperative sepsis. Both NK cell-mediated cytotoxic function and lung tumour burden were improved with perioperative administration of polyI:C, which is a toll-like receptor (TLR)-3 ligand.

Conclusions

Perioperative sepsis alone, but not hemorrhage or hypothermia, enhances the prometastatic effect of surgery in murine models of cancer. Understanding the cellular mechanisms underlying perioperative immune suppression will facilitate the development of immunomodulation strategies that can attenuate metastatic disease.

Perioperative Increase in Neutrophil CD64 Expression is an Indicator for Intra-abdominal Infection after Colorectal Cancer Surgery

BACKGROUND

Colorectal surgery is associated with a high incidence of postoperative infections. Early clinical signs are difficult to distinguish from the systemic inflammatory response related to surgical trauma. Timely diagnosis may significantly improve the outcome. The objective of this study was to compare a new biomarker index CD64 for neutrophils (iCD64n) with standard biomarkers, white blood cell (WBC) count, neutrophil/lymphocyte ratio (NLR), C-reactive protein (CRP) and procalcitonin (PCT) for the early detection of postoperative infection.

METHODS

The prospective study included 200 consecutive patients with elective colorectal cancer surgery. Postoperative values of biomarkers from the postoperative day (POD) 1 to POD5 were analysed by the receiver operating characteristic (ROC) analysis to predict infection. The Cox regression model and the Kaplan-Meier method were used to assess prognostic factors and survival.

RESULTS

The increase of index CD64n (iCD64n) after surgery, expressed as the ratio iCD64n after/before surgery was a better predictor of infection than its absolute value. The best 30-day predictors of all infections were CRP on POD4 (AUC 0.72, 99% CI 0.61-0.83) and NLR on POD5 (AUC 0.69, 99% CI 0.57-0.80). The best 15-day predictors of organ/space surgical site infection (SSI) were the ratio iCD64n on POD1 (AUC 0.72, 99% CI 0.58-0.86), POD3 (AUC 0.73, 99% CI 0.59-0.87) and CRP on POD3 (AUC 0.72, 99% CI 0.57-0.86), POD4 (AUC 0.79, 99% CI 0.64-0.93). In a multivariate analysis independent risk factors for infections were duration of surgery and perioperative transfusion while the infection itself was identified as a risk factor for a worse long-term survival.

CONCLUSIONS

The ratio iCD64n on POD1 is the best early predictor of intra-abdominal infection after colorectal cancer surgery. CRP predicts the infection with the same predictive value on POD3.

Post-Operative Infection Is an Independent Risk Factor for Worse Long-Term Survival after Colorectal Cancer Surgery

BACKGROUND

Colorectal cancer surgery is associated with a high incidence of post-operative infections, the outcome of which may be improved if diagnosed and treated early enough. We compared white blood cell (WBC) count, C-reactive protein (CRP), and procalcitonin (PCT) as predictors of post-operative infections and analyzed their impact on long-term survival.

METHODS

This retrospective study included 186 patients undergoing colorectal surgery. Post-operative values of WBC, CRP, and PCT were analyzed by the receiver operating characteristic (ROC) analysis. We followed infections 30 d after the surgery. A five-year survival was analyzed by Kaplan-Meier method and prognostic factors by Cox regression model.

RESULTS

Fifty-five patients (29.5%) developed post-operative infection, the most frequent of which was surgical site infection (SSI). C-reactive protein on post-operative day three and PCT on post-operative day two demonstrated the highest diagnostic accuracy for infection (area under the curve [AUC] 0.739 and 0.735). C-reactive protein on post-operative day three was an independent predictor of infection. Five-year survival was higher in the non-infected group (70.8%), compared with the infected group (52.1%). The worst survival (40.9%) was identified in patients with organ/space SSI. Post-operative infection and tumor stage III-IV were independent predictors of a worse five-year survival.

CONCLUSIONS

C-reactive protein on post-operative day three and PCT on post-operative day two may be early predictors of infection after colorectal cancer surgery. Post-operative infections in particular organ/space SSI have a negative impact on long-term survival.

The impact of the type and severity of postoperative complications on long-term outcomes following surgery for colorectal cancer: A systematic review and meta-analysis

BACKGROUND

This systematic review investigated the impact of complications by type (infective vs. non-infective) and severity (using the Clavien Dindo scale) on long-term outcome following surgery for colorectal cancer.

METHODS

A systematic review was performed using appropriate keywords. Meta-analysis using a random effects model was performed.

RESULTS

14 studies were included with a total 18,611 patients. Infective complications had a significant impact on disease free (HR 1.41, 95%CI 1.08-1.83, p=0.01) and overall survival (1.37 95%CI 1.22-1.55, p<0.001). Non-infective complications had no significant impact on either disease free (HR 1.21, 95%CI 0.97-1.52, p=0.09) or overall survival (HR 1.35, 95%CI 0.92-1.97, p=0.12). Complication severity had a significant impact on both disease free (HR 1.41, 95%CI 1.18-1.68, p<0.001) and overall survival (HR 1.45, 95%CI 1.25-1.69, p<0.001).

DISCUSSION

Both type and severity of postoperative complications have an impact on long-term survival following surgery for colorectal cancer.

Determinants of recurrence after intended curative resection for colorectal cancer

Despite intended curative resection, colorectal cancer will recur in ∼45% of the patients. Results of meta-analyses conclude that frequent follow-up does not lead to early detection of recurrence, but improves overall survival. The present literature shows that several factors play important roles in development of recurrence. It is well established that emergency surgery is a major determinant of recurrence. Moreover, anastomotic leakages, postoperative bacterial infections, and blood transfusions increase the recurrence rates although the exact mechanisms still remain obscure. From pathology studies it has been shown that tumors behave differently depending on their location and recur more often when micrometastases are present in lymph nodes and around vessels and nerves. K-ras mutations, microsatellite instability, and mismatch repair genes have also been shown to be important in relation with recurrences, and tumors appear to have different mutations depending on their location. Patients with stage II or III disease are often treated with adjuvant chemotherapy despite the fact that the treatments are far from efficient among all patients, who are at risk of recurrence. Studies are now being presented identifying subgroups, in which the therapy is inefficient. Unfortunately, only few of these facts are implemented in the present follow-up programs. Therefore, further research is urgently needed to verify which of the well-known parameters as well as new parameters that must be added to the current follow-up programs to identify patients at risk of recurrence.

Meta-analysis of the effect of postoperative in-hospital morbidity on long-term patient survival

BACKGROUND

Major surgery is associated with high rates of postoperative complications, many of which are deemed preventable. It has been suggested that these complications not only present a risk to patients in the short term, but may also reduce long-term survival. The aim of this review was to examine the effects of postoperative complications on long-term survival.

METHODS

MEDLINE, Web of Science and reference lists of relevant articles were searched up to July 2013. Studies assessing only procedure-specific, or technical failure-related, complications were excluded, as were studies of poor methodological quality. Meta-analysis was performed using a random-effects model. Risk of bias was assessed using funnel plots.

RESULTS

Eighteen eligible studies were included, comprising results for 134 785 patients with an overall complication rate of 22·6 (range 10·6-69) per cent. The studies included operations for both benign and malignant disease. Median follow-up was 43 (range 28-96) months. Meta-analysis demonstrated reduced overall survival after any postoperative complication for ten studies with eligible data (20 755 patients), with a hazard ratio (HR) of 1·28 (95 per cent confidence interval 1·21 to 1·34). Similar results were found for overall survival following infectious complications: HR 1·92 (1·50 to 2·35). In analyses of disease-free survival the HR was 1·26 (1·10 to 1·42) for all postoperative complications and 1·55 (1·12 to 1·99) for infectious complications. Inclusion of poor-quality studies in a sensitivity analysis had no effect on the results.

CONCLUSION

Postoperative complications have a negative effect on long-term survival. This relationship appears to be stronger for infectious complications.