The effect of surgical trauma on circulating free DNA levels in cancer patients-implications for studies of circulating tumor DNA

Detection of circulating tumor DNA (ctDNA) post‐treatment is an emerging marker of residual disease. ctDNA constitutes only a minor fraction of the cell‐free DNA (cfDNA) circulating in cancer patients, complicating ctDNA detection. This is exacerbated by trauma‐induced cfDNA. To guide optimal blood sample timing, we investigated the duration and magnitude of surgical trauma‐induced cfDNA in patients with colorectal or bladder cancer. DNA levels were quantified in paired plasma samples collected before and up to 6 weeks after surgery from 436 patients with colorectal cancer and 47 patients with muscle‐invasive bladder cancer. To assess whether trauma‐induced cfDNA fragments are longer than ordinary cfDNA fragments, the concentration of short (< 1 kb) and long (> 1 kb) fragments was determined for 91 patients. Previously reported ctDNA data from 91 patients with colorectal cancer and 47 patients with bladder cancer were used to assess how trauma‐induced DNA affects ctDNA detection. The total cfDNA level increased postoperatively—both in patients with colorectal cancer (mean threefold) and bladder cancer (mean eightfold). The DNA levels were significantly increased up to 4 weeks after surgery in both patient cohorts (P = 0.0005 and P ≤ 0.0001). The concentration of short, but not long, cfDNA fragments increased postoperatively. Of 25 patients with radiological relapse, eight were ctDNA‐positive and 17 were ctDNA‐negative in the period with trauma‐induced DNA. Analysis of longitudinal samples revealed that five of the negative patients became positive shortly after the release of trauma‐induced cfDNA had ceased. In conclusion, surgery was associated with elevated cfDNA levels, persisting up to 4 weeks, which may have masked ctDNA in relapse patients. Trauma‐induced cfDNA was of similar size to ordinary cfDNA. To mitigate the impact of trauma‐induced cfDNA on ctDNA detection, it is recommended that a second blood sample collected after week 4 is analyzed for patients initially ctDNA negative.

The role of total cell-free DNA in predicting outcomes among trauma patients in the intensive care unit: a systematic review

BACKGROUND

Cell-free DNA has been proposed as a means of predicting complications among severely injured patients. The purpose of this systematic review was to assess whether cell-free DNA was useful as a prognostic biomarker for outcomes in trauma patients in the intensive care unit.

METHODS

We searched Pubmed, Embase, Scopus and the Cochrane Central Register for Controlled Trials and reference lists of relevant articles for studies that assessed the prognostic value of cell-free DNA detection in trauma patients in the intensive care unit. Outcomes of interest included survival, posttraumatic complications and severity of trauma. Due to considerable heterogeneity between the included studies, a checklist was formed to assess quality of cell-free DNA measurement.

RESULTS

A total of 14 observational studies, including 904 patients, were eligible for analysis. Ten studies were designed as prospective cohort studies; three studies included selected patients from a cohort while one study was of a retrospective design. We found a significant correlation between higher values of cell-free DNA and higher mortality. This significant correlation was evident as early as on intensive care unit admission. Likewise, cell-free DNA predicted the severity of trauma and posttraumatic complications in a majority of patients.

CONCLUSION

The amount of cell-free DNA can function as a prognostic tool for mortality and to a lesser extent severity of trauma and posttraumatic complications. Standardizing cell-free DNA measurement is paramount to ensure further research in cell-free DNA as a prognostic tool.

Unraveling the potential clinical utility of circulating tumor DNA detection in colorectal cancer-evaluation in a nationwide Danish cohort

BACKGROUND

Increasingly, circulating tumor DNA (ctDNA) is proposed as a tool for minimal residual disease (MRD) assessment. Digital PCR (dPCR) offers low analysis costs and turnaround times of less than a day, making it ripe for clinical implementation. Here, we used tumor-informed dPCR for ctDNA detection in a large colorectal cancer (CRC) cohort to evaluate the potential for post-operative risk assessment and serial monitoring, and how the metastatic site may impact ctDNA detection. Additionally, we assessed how altering the ctDNA-calling algorithm could customize performance for different clinical settings.

PATIENTS AND METHODS

Stage II-III CRC patients (N = 851) treated with a curative intent were recruited. Based on whole-exome sequencing on matched tumor and germline DNA, a mutational target was selected for dPCR analysis. Plasma samples (8 ml) were collected within 60 days after operation and-for a patient subset (n = 246)-every 3-4 months for up to 36 months. Single-target dPCR was used for ctDNA detection.

RESULTS

Both post-operative and serial ctDNA detection were prognostic of recurrence [hazard ratio (HR) = 11.3, 95% confidence interval (CI) 7.8-16.4, P < 0.001; HR = 30.7, 95% CI 20.2-46.7, P < 0.001], with a cumulative ctDNA detection rate of 87% at the end of sample collection in recurrence patients. The ctDNA growth rate was prognostic of survival (HR = 2.6, 95% CI 1.5-4.4, P = 0.001). In recurrence patients, post-operative ctDNA detection was challenging for lung metastases (4/21 detected) and peritoneal metastases (2/10 detected). By modifying the cut-off for calling a sample ctDNA positive, we were able to adjust the sensitivity and specificity of our test for different clinical contexts.

CONCLUSIONS

The presented results from 851 stage II-III CRC patients demonstrate that our personalized dPCR approach effectively detects MRD after operation and shows promise for serial ctDNA detection for recurrence surveillance. The ability to adjust sensitivity and specificity shows exciting potential to customize the ctDNA caller for specific clinical settings.

Training prediction models for individual risk assessment of postoperative complications after surgery for colorectal cancer

BACKGROUND

The occurrence of postoperative complications and anastomotic leakage are major drivers of mortality in the immediate phase after colorectal cancer surgery. We trained prediction models for calculating patients' individual risk of complications based only on preoperatively available data in a multidisciplinary team setting. Knowing prior to surgery the probability of developing a complication could aid in improving informed decision-making by surgeon and patient and individualize surgical treatment trajectories.

METHODS

All patients over 18 years of age undergoing any resection for colorectal cancer between January 1, 2014 and December 31, 2019 from the nationwide Danish Colorectal Cancer Group database were included. Data from the database were converted into Observational Medical Outcomes Partnership Common Data Model maintained by the Observation Health Data Science and Informatics initiative. Multiple machine learning models were trained to predict postoperative complications of Clavien-Dindo grade ≥ 3B and anastomotic leakage within 30 days after surgery.

RESULTS

Between 2014 and 2019, 23,907 patients underwent resection for colorectal cancer in Denmark. A Clavien-Dindo complication grade ≥ 3B occurred in 2,958 patients (12.4%). Of 17,190 patients that received an anastomosis, 929 experienced anastomotic leakage (5.4%). Among the compared machine learning models, Lasso Logistic Regression performed best. The predictive model for complications had an area under the receiver operating characteristic curve (AUROC) of 0.704 (95%CI 0.683-0.724) and an AUROC of 0.690 (95%CI 0.655-0.724) for anastomotic leakage.

CONCLUSIONS

The prediction of postoperative complications based only on preoperative variables using a national quality assurance colorectal cancer database shows promise for calculating patient's individual risk. Future work will focus on assessing the value of adding laboratory parameters and drug exposure as candidate predictors. Furthermore, we plan to assess the external validity of our proposed model.

Neoadjuvant intratumoral influenza vaccine treatment in patients with proficient mismatch repair colorectal cancer leads to increased tumor infiltration of CD8+ T cells and upregulation of PD-L1: a phase 1/2 clinical trial

BACKGROUND

In colorectal cancer, the effects of immune checkpoint inhibitors are mostly limited to patients with deficient mismatch repair tumors, characterized by a high grade infiltration of CD8+T cells. Interventions aimed at increasing intratumoral CD8+T-cell infiltration in proficient mismatch repair tumors are lacking.

METHODS

We conducted a proof of concept phase 1/2 clinical trial, where patients with non-metastasizing sigmoid or rectal cancer, scheduled for curative intended surgery, were treated with an endoscopic intratumorally administered neoadjuvant influenza vaccine. Blood and tumor samples were collected before the injection and at the time of surgery. The primary outcome was safety of the intervention. Evaluation of pathological tumor regression grade, immunohistochemistry, flow cytometry of blood, tissue bulk transcriptional analyses, and spatial protein profiling of tumor regions were all secondary outcomes.

RESULTS

A total of 10 patients were included in the trial. Median patient age was 70 years (range 54-78), with 30% women. All patients had proficient mismatch repair Union of International Cancer Control stage I-III tumors. No endoscopic safety events occurred, with all patients undergoing curative surgery as scheduled (median 9 days after intervention). Increased CD8+T-cell tumor infiltration was evident after vaccination (median 73 vs 315 cells/mm², p<0.05), along with significant downregulation of messenger RNA gene expression related to neutrophils and upregulation of transcripts encoding cytotoxic functions. Spatial protein analysis showed significant local upregulation of programmed death-ligand 1 (PD-L1) (adjusted p value<0.05) and downregulation of FOXP3 (adjusted p value<0.05).

CONCLUSIONS

Neoadjuvant intratumoral influenza vaccine treatment in this cohort was demonstrated to be safe and feasible, and to induce CD8+T-cell infiltration and upregulation of PD-L1 proficient mismatch repair sigmoid and rectal tumors. Definitive conclusions regarding safety and efficacy can only be made in larger cohorts.

TRIAL REGISTRATION NUMBER

NCT04591379.

Association of influenza vaccine and risk of recurrence in patients undergoing curative surgery for colorectal cancer

BACKGROUND

There is increasing evidence that the inactivated influenza vaccine contains immunostimulatory properties that favor cytotoxicity and benefit survival in large population-based studies. This study aimed to determine whether an influenza vaccine was associated with risk of recurrence, overall mortality, and disease-free survival in patients undergoing curative surgery for colorectal cancer.

MATERIAL AND METHODS

We performed a register-based study based in Denmark in the period 2009-2015. The primary outcome was a risk of recurrence, while the secondary outcomes were overall mortality and disease-free survival.

RESULTS

A total of 9869 patients were included, with 5146 patients receiving an influenza vaccine between one year before and six months after surgery. In a multivariate Cox regression model, there was no association with risk of recurrence (HR 0.94, 95% CI 0.85-1.05), overall mortality (HR 0.95, 95% CI 0.87-1.03), and disease-free survival (HR 1.01, 95% CI 0.94-1.09). In patients receiving the vaccine between six and twelve months before surgery, we found an association to decreased risk of recurrence (HR 0.78, 95% CI 0.67-0.91) but no association with overall mortality (HR 1.04, 95% CI 0.93-1.17) or disease-free survival (HR 0.97, 95% CI 0.88-1.07). Subgroup analysis of patients revealed contradictory results.

CONCLUSION

We believe that this study's findings support the need for further clinical studies to investigate the causal effects of the influenza vaccine on oncological outcomes.

ctDNA for Risk of Recurrence Assessment in Patients Treated with Neoadjuvant Treatment: A Systematic Review and Meta-analysis

BACKGROUND

We wanted to investigate the association between circulating tumor DNA (ctDNA) detection at baseline, during and after neoadjuvant treatment, after surgery, and recurrence, in patients with nonmetastatic cancer.

PATIENTS AND METHODS

In this systematic review and meta-analysis, we included studies that investigated patients undergoing neoadjuvant treatment for nonmetastatic cancer and provided recurrence indices stratified for ctDNA status at the following timepoints: baseline, during treatment, posttreatment, and postsurgery. Study quality was reported with the Newcastle-Ottawa scale, REMARK checklist, and GRADE approach. PubMed, Embase, Cochrane Library, and Web of Science were our data sources (inception to 3 June 2021). The main outcome was risk of recurrence.

RESULTS

We identified ten studies including 727 patients with rectal, breast, gastric, and bladder cancer. All studies reported posttreatment ctDNA analysis, while seven, four, and six reported baseline, during treatment, and postsurgery ctDNA analysis, respectively. ctDNA detection was associated to recurrence across all timepoints [baseline: risk ratio (RR) 2.86, 95% confidence interval (CI) 1.33-6.14, during treatment: RR 3.81, 95% CI 2.09-6.92, posttreatment: RR 4.29, 95% CI 2.79-6.60, postsurgery: RR 8.03, 95% CI 3.16-20.43]. Heterogeneity was low to moderate.

CONCLUSIONS

This meta-analysis of observational studies found that ctDNA detection in patients undergoing neoadjuvant treatment for nonmetastatic cancer was associated with recurrence. A stronger association was evident in posttreatment and postsurgery timepoints. However, some studies reported low negative predictive value (NPV) of pathological complete response, showing that ctDNA-detection-guided escalation and de-escalation studies following neoadjuvant treatment regimens are needed before its role as a treatment guidance can be affirmed.

Perioperative changes in cell-free DNA for patients undergoing surgery for colon cancer

BACKGROUND

Various conditions with cellular decay are associated with elevated cell-free DNA (cfDNA). This study aimed to investigate if perioperatively measured cfDNA levels were associated with the surgical approach, complications, or recurrence.

METHODS

Plasma was obtained from patients who underwent surgery for colon cancer at admission and at the time of discharge. Quantitative measurement of cfDNA was performed by amplifying two amplicons of 102 base pairs (bp) and 132 bp of Beta-2-Microglobulin (B2M) and Peptidyl-Prolyl cis-trans Isomerase A (PPIA), respectively.

RESULTS

cfDNA was measured in 48 patients who underwent surgery for colonic cancer. Sixteen patients had recurrence during the follow-up period, fifteen developed a postoperative complication, and seventeen patients developed neither, acting as the control group. Postoperative cfDNA levels were significantly elevated from baseline samples, across all groups, with a median preoperatively B2M level of 48.3 alleles per mL and postoperatively of 220 alleles per mL and a median preoperatively level PPIA of 26.9 alleles per mL and postoperatively of 111.6 alleles per mL (p < 0.001 for B2M and p < 0.001 for PPIA). Postoperative levels of PPIA, but not B2M, were significantly higher in patients experiencing complications than in the control group (p = 0.036). However, a tendency towards an association between the surgical approach and the changes in cfDNA levels was found for PPIA (p = 0.058), and B2M (p = 0.087).

CONCLUSIONS

Plasma cfDNA was increased after surgery in all patients with colon cancer. Postoperative PPIA levels were significantly higher in patients experiencing surgical complications but not in B2M levels.

Association of postoperative influenza vaccine on overall mortality in patients undergoing curative surgery for solid tumors

Recent findings have found that the influenza vaccine induces changes in the immune system in favor of antitumor cytotoxicity. The aim of our study was to investigate if an influenza vaccine given in the postoperative period decreased overall and cancer-specific mortality in patients undergoing curative surgery for solid cancers. We conducted a registry-based national observational study in Denmark in the period January 1, 2010 to December 31, 2015 with a follow-up period of 3 years starting from 180 days after surgery. Patients with solid cancers undergoing curative surgery were included. The primary outcome was overall mortality. The secondary outcome was cancer-specific mortality. A total of 21 462 patients were included in the study with 2557 patients receiving an influenza vaccine within 6 months after surgery. In a Cox regression model, a decrease in overall mortality (hazard ratio [HR] = 0.89, 95% confidence interval [CI] = 0.81-0.99, P = .03) and cancer-related mortality (HR = 0.82, 95% CI = 0.71-0.93, P = .003) was found among patients given a vaccine vs patients never receiving a vaccine. In a predefined subgroup of patients receiving a vaccine within 30 days after surgery, a decrease in overall mortality (HR = 0.82, 95% CI = 0.72-0.94, P = .007) and cancer-specific mortality (HR = 0.70, 95% CI = 0.53-0.91, P = .009) was found. No association was evident in patients receiving the vaccine after 30 days to 6 months after surgery (overall mortality: HR = 0.96, 95% CI = 0.86-1.07, P = .46); cancer-specific mortality: HR = 0.88, 95% CI = 0.76-1.03, P = .12). These findings must be investigated in larger clinical trials where both immunological biomarkers and survival outcomes are included.

Assessment of perioperative stress in colorectal cancer by use of in vitro cell models: a systematic review

Background

The perioperative period is important for patient outcome. Colorectal cancer surgery can lead to metastatic disease due to release of disseminated tumor cells and the induction of surgical stress response. To explore the overall effects on surgically-induced changes in serum composition, in vitro model systems are useful.

Methods

A systematic search in PubMed and EMBASE was performed to identify studies describing in vitro models used to investigate cancer cell growth/proliferation, cell migration, cell invasion and cell death of serum taken pre- and postoperatively from patients undergoing colorectal tumor resection.

Results

Two authors (MG and TK) independently reviewed 984 studies and identified five studies, which fulfilled the inclusion criteria. Disagreements were solved by discussion. All studies investigated cell proliferation and cell invasion, whereas three studies investigated cell migration, and only one study investigated cell death/apoptosis. One study investigated postoperative peritoneal infection due to anastomotic leak, one study investigated mode of anesthesia (general anesthesia with volatile or intravenous anesthetics), and one study investigated preoperative intervention with granulocyte macrophage colony stimulating factor (GMCSF). In all studies an increased proliferation, cell migration and invasion was demonstrated after surgery. Anesthetics with propofol and intervention with GMCSF significantly reduced postoperative cell proliferation, whereas peritoneal infection enhanced the invasive capability of tumor cells.

Conclusion

This study suggests that in vitro cell models are useful and reliable tools to explore the effect of surgery on colorectal cancer cell proliferation and metastatic ability. The models should therefore be considered as additional tests to investigate the effects of perioperative interventions.

Developing prediction models for short-term mortality after surgery for colorectal cancer using a Danish national quality assurance database

PURPOSE

The majority of colorectal cancer surgeries are performed electively, and treatment is often decided at the multidisciplinary team conference. Although the average 30-day mortality rate is low, there is substantial population heterogeneity from young, healthy patients to frail, elderly patients. The individual risk of surgery can vary widely, and tailoring treatment for colorectal cancer may lead to better outcomes. This requires prediction of risk that is accurate and available prior to surgery.

METHODS

Data from the Danish Colorectal Cancer Group database was transformed into the Observational Medical Outcomes Partnership Common Data Model. Models were developed to predict the risk of mortality within 30, 90, and 180 days after colorectal cancer surgery using only covariates decided at the multidisciplinary team conference. Several machine-learning models were trained, but due to superior performance, a Least Absolute Shrinkage and Selection Operator logistic regression was used for the final model. Performance was assessed with discrimination (area under the receiver operating characteristic and precision recall curve) and calibration measures (calibration in large, intercept, slope, and Brier score).

RESULTS

The cohort contained 65,612 patients operated for colorectal cancer in the period from 2001 to 2019 in Denmark. The Least Absolute Shrinkage and Selection Operator model showed an area under the receiver operating characteristic for 30-, 90-, and 180-day mortality after colorectal cancer surgery of 0.871 (95% CI: 0.86-0.882), 0.874 (95% CI: 0.864-0.882), and 0.876 (95% CI: 0.867-0.883) and calibration in large of 1.01, 0.98, and 1.01, respectively.

CONCLUSION

The postoperative short-term mortality prediction model showed excellent discrimination and calibration using only preoperatively known predictors.

The impact of time to surgery on oncological outcomes in stage I-III dMMR colon cancer - A nationwide cohort study

INTRODUCTION

One of the considerations when investigating neoadjuvant interventions is the prolonging of time from diagnosis to curative surgery (i.e. the treatment interval [TI]). The aim of this study was to investigate the association between the length of TI and overall survival and disease-free survival in patients with deficient mismatch repair (dMMR) colon cancer.

MATERIALS AND METHODS

This retrospective propensity score-adjusted study included all patients of ≥18 years of age undergoing elective curative surgery for stage I-III, dMMR colon cancer. Data were extracted from four Danish patient databases. Outcomes were investigated in groups with TIs of ≤14 days versus >14 days. Propensity scores were computed using all demographics, diagnoses and measurements. Matching was done in a 1:1 ratio.

RESULTS

A total of 4130 patients were included in the study with a mean age of 73.8 years and a median follow-up time of 43.9 months. After matching, 2794 patients were included in the analysis of overall survival. No significant difference in overall survival was seen between patients with TIs of ≤14 days versus >14 days (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.81-1.17; p = 0.78). In the analysis of disease-free survival, 1798 patients were included after matching. This showed no significant difference between patients with TIs of ≤14 days versus >14 days (HR, 0.85; 95% CI, 0.69-1.06; p = 0.14).

CONCLUSION

No associations were found between TI and overall survival and disease-free survival in patients with stage I-III, dMMR colon cancer undergoing elective curative surgery.

Circulating tumour DNA and risk of recurrence in patients with asymptomatic versus symptomatic colorectal cancer

BACKGROUND

Multiple initiatives aim to develop circulating tumour DNA (ctDNA) tests for early cancer detection in asymptomatic individuals. The few studies describing ctDNA-testing in both asymptomatic and symptomatic patients report lower ctDNA detection in the asymptomatic patients. Here, we explore if asymptomatic patients differ from symptomatic patients e.g. by including a 'low-ctDNA-shedding' and 'less-aggressive' subgroup.

METHODS

ctDNA assessment was performed in two independent cohorts of consecutively recruited patients with asymptomatic colorectal cancer (CRC) (Cohort#1: n = 215, Cohort#2: n = 368) and symptomatic CRC (Cohort#1: n = 117, Cohort#2: n = 722).

RESULTS

After adjusting for tumour stage and size, the odds of ctDNA detection was significantly lower in asymptomatic patients compared to symptomatic patients (Cohort#1: OR: 0.4, 95%CI: 0.2-0.8, Cohort#2: OR: 0.7, 95%CI: 0.5-0.9). Further, the recurrence risk was lower in asymptomatic patients (Cohort#1: sHR: 0.6, 95%CI: 0.3-1.2, Cohort#2: sHR: 0.6, 95%CI: 0.4-1.0). Notably, ctDNA-negative asymptomatic patients had the lowest recurrence risk compared to the symptomatic patients (Cohort#1: sHR: 0.2, 95%CI: 0.1-0.6, Cohort#2: sHR: 0.3, 95%CI: 0.2-0.6).

CONCLUSIONS

Our study suggests that asymptomatic patients are enriched for a 'low-ctDNA-shedding-low-recurrence-risk' subgroup. Such insights are needed to guide ctDNA-based early-detection initiatives and should prompt discussions about de-escalation of therapy and follow-up for ctDNA-negative asymptomatic CRC patients.

Mismatch Repair Status and Surgical Outcomes in Localized Colorectal Cancer: A Nationwide Cohort Study

Objective

This study examined the association between deficient mismatch repair (dMMR) versus proficient MMR (pMMR) status and overall survival and disease-free survival in patients with localized colorectal cancer.

Background

Several distinctions exist between patients with dMMR and pMMR colorectal cancer. However, the impact on prognosis is yet to be investigated in large-scale cohort studies.

Methods

In this cohort study, we included patients who underwent curative-intent surgery for localized colorectal cancer between 2009 and 2020. Patients were identified in the Danish Colorectal Cancer Group database and patient-level data were extracted from 6 registry databases. After inclusion, patients with dMMR status were matched 1:1 to patients with pMMR status using an estimated propensity score.

Results

After matching, 5994 patients were included. The patients had a median age of 74 years and a median follow-up of 4.1 years. There was no significant association between mismatch repair (MMR) status and overall survival (hazard ratio, 0.91; 95% confidence interval [CI], 0.81-1.03) or disease-free survival (hazard ratio, 0.89; 95% CI, 0.78-1.01). However, the restricted 5-year mean disease-free survival time, calculated due to violation of the proportional hazards assumption, showed a significant absolute difference of 0.13 years (95% CI, 0.03-0.23; P = 0.01) in favor of the dMMR group.

Conclusions

No significant association with overall survival was found according to MMR status. dMMR status was, however, found to be associated with marginally improved disease-free survival compared to pMMR status in patients with localized colorectal cancer undergoing curative-intent surgery.

Time From Colorectal Cancer Surgery to Adjuvant Chemotherapy: Post Hoc Analysis of the SCOT Randomized Clinical Trial

Importance

The timing of adjuvant chemotherapy after surgery for colorectal cancer and its association with long-term outcomes have been investigated in national cohort studies, with no consensus on the optimal time from surgery to adjuvant chemotherapy.

Objective

To analyze the association between the timing of adjuvant chemotherapy after surgery for colorectal cancer and disease-free survival.

Design, Setting, and Participants

This is a post hoc analysis of the phase 3 SCOT randomized clinical trial, from 244 centers in 6 countries, investigating the noninferiority of 3 vs 6 months of adjuvant chemotherapy. Patients with high-risk stage II or stage III nonmetastatic colorectal cancer who underwent curative-intended surgery were randomized to either 3 or 6 months of adjuvant chemotherapy consisting of fluoropyrimidine and oxaliplatin regimens. Those with complete information on the date of surgery, treatment type, and long-term follow-up were investigated for the primary and secondary end points. Data were analyzed from May 2022 to February 2024.

Intervention

In the post hoc analysis, patients were grouped according to the start of adjuvant chemotherapy being less than 6 weeks vs greater than 6 weeks after surgery.

Main Outcomes and Measures

The primary end point was disease-free survival. The secondary end points were adverse events in the total treatment period or the first cycle of adjuvant chemotherapy.

Results

A total of 5719 patients (2251 [39.4%] female; mean [SD] age, 63.4 [9.3] years) were included in the primary analysis after data curation; among them, 914 were in the early-start group and 4805 were in the late-start group. Median (IQR) follow-up was 72.0 (47.3-88.1) months, with a median (IQR) of 56 (41-66) days from surgery to chemotherapy. Five-year disease-free survival was 78.0% (95% CI, 75.3%-80.8%) in the early-start group and 73.2% (95% CI, 72.0%-74.5%) in the late-start group. In an adjusted Cox regression analysis, the start of adjuvant chemotherapy greater than 6 weeks after surgery was associated with worse disease-free survival (hazard ratio, 1.24; 95% CI, 1.06-1.46; P = .01). In adjusted logistic regression models, there was no association with adverse events in the total treatment period (odds ratio, 0.82; 95% CI, 0.65-1.04; P = .09) or adverse events in the first cycle of treatment (odds ratio, 0.77; 95% CI, 0.56-1.09; P = .13).

Conclusions and Relevance

In this international population of patients with high-risk stage II and stage III colorectal cancer, starting adjuvant chemotherapy more than 6 weeks after surgery was associated with worse disease-free survival, with no difference in adverse events between the groups.

Trial Registration

isrctn.org Identifier: ISRCTN59757862.

Major Adverse Cardiovascular Events After Colorectal Cancer Surgery, Oncological Outcomes, and Long-term Mortality: A Nationwide Retrospective Propensity Score-Matched Cohort Study

Objective

To investigate the occurrence of major adverse cardiovascular events (MACE) following colorectal cancer (CRC) surgery and its association with long-term mortality and oncological outcomes.

Background

Cardiovascular complications after noncardiac surgery are a leading cause of perioperative mortality. However, limited knowledge exists on how these complications impact on long-term mortality.

Methods

This retrospective cohort study used data from 4 nationwide Danish health registries and included all patients undergoing elective surgery with curative intent for CRC between 2001 and 2019. Patients experiencing MACE, defined as acute myocardial infarction, stroke, new-onset heart failure, or nonfatal cardiac arrest, within 30 days of surgery were matched with those who did not using 1:1 propensity score matching (PSM). The outcomes were all-cause mortality within 1, 3, or 5 years of surgery, as well as 5-year cancer recurrence and disease-free survival.

Results

Out of 39,747 patients, 900 (2.3%) had MACE. PSM resulted in 809 pairs of matched patients. Within 1 year of surgery, 110 (13.6%) patients with MACE and 2063 (5.4%) without MACE died (PSM-adjusted hazard ratio [HR] = 1.36; 95% confidence interval [CI] = 1.02-1.83). Within 3 years, 248 (30.6%) patients with MACE and 6268 (16.5%) without MACE died (PSM-adjusted HR = 1.32; 95% CI = 1.07-1.62). Within 5 years, 333 (41.1%) patients with MACE and 9232 (24.3%) without MACE died (PSM-adjusted HR = 1.25; 95% CI = 1.04-1.50). For recurrence and disease-free survival, no statistically significant differences were observed.

Conclusions

MACE within 30 days of CRC surgery is associated with higher overall long-term mortality. Investigating causality and preventive measures is urgent in this group.

Neoadjuvant calcium electroporation for potentially curable colorectal cancer

BACKGROUND

The development of new perioperative treatment modalities to activate the immune system in colorectal cancer might have a beneficial effect on reducing the risk of recurrence after surgery. Calcium electroporation is a promising treatment modality that potentially modulates the tumor microenvironment. The aim of this study was to evaluate the safety of the procedure in the neoadjuvant setting in localized left-sided colorectal cancer (CRC).

METHODS

The study included patients with potentially curable sigmoid or rectal cancer with no indication for other neoadjuvant treatment. Patients were offered calcium electroporation as a neoadjuvant treatment before elective surgery. Follow-up visits were conducted on the preoperative day before elective surgery, POD2, POD14, and POD30, with an evaluation of adverse events, impact on elective surgery, clinical examination, and quality of recovery.

RESULTS

Endoscopic calcium electroporation was performed as an outpatient procedure in all 21 cases, with no procedure-related complications reported. At follow-up, five adverse events were registered, two of which were classified as serious adverse events. Surgery was performed as planned in 19 patients (median time to surgery, 8 days), and the final two patients underwent surgery with a delay due to adverse events (14 and 33 days). No significant impact on the quality of recovery scores nor inflammatory markers were seen before and after calcium electroporation, nor baseline and POD30.

CONCLUSIONS

Endoscopic calcium electroporation is a safe and feasible procedure in patients with potentially curable CRC. The study showed limited side effects and limited impact on the following elective surgical resection.

Association between Deficient MSH2/MSH6 vs MLH1/PMS2 Status and Survival Rates in Localized Colorectal Cancer: A Nationwide Cohort Study

OBJECTIVE

This study investigated the association between loss of MSH2/MSH6 versus loss of MLH1/PMS2 expression and overall survival and disease-free survival in patients with localized colorectal cancer.

BACKGROUND

The risk of developing colorectal cancer varies depending on the expression of mismatch repair proteins. However, it is unknown if the prognosis differs accordingly.

METHODS

In this retrospective study, we included a Danish cohort of patients who underwent surgery for colorectal cancer between 2009 and 2020. The Danish Colorectal Cancer Group database was used to identify patients, and patient-level data were extracted from six registries. Subsequently, patients with proficient mismatch repair status, with metastatic disease, who underwent emergency surgery, or who received neoadjuvant therapy were excluded. Patients were then propensity score matched in a 1:1 ratio.

RESULTS

A total of 3,625 patients with localized deficient mismatch repair colorectal cancer were included in the study. Patients had a median age of 75 years and a median follow-up of 4.3 years. Before matching, the MSH2/MSH6 versus MLH1/PMS2 groups differed in age, gender, and comorbidities. After matching, 556 patients were included and loss of MSH2/MSH6 was significantly associated with better overall survival (hazard ratio 0.60; 95% CI, 0.37-0.94); however, not disease-free survival (hazard ratio 0.84; 95% CI, 0.54-1.30).

CONCLUSIONS

In patients with localized deficient mismatch repair colorectal cancer who underwent surgery, a significant association was found between loss of MSH2/MSH6 versus loss of MLH1/PMS2 expression and overall survival. Thus, these patients may be a target for a differentiated follow-up strategy.

Correlations between preoperative statin treatment with short- and long-term survival following colorectal cancer surgery: a propensity score-matched national cohort study

INTRODUCTION

The pleiotropic effects of statins have attracted considerable attention in oncological treatment. Several preclinical and epidemiological studies have highlighted their potential anti-tumor properties in patients with colorectal cancer, although results have been conflicting. This study aimed to examine the association between statin exposure before colorectal cancer surgery with long and short-term survival outcomes.

METHODS

This retrospective propensity score-adjusted study was conducted on a Danish cohort of patients who underwent elective curative-intended surgery for stage I-III colorectal cancer in 2008-2020, using four national patient databases. The primary and secondary outcomes were overall, 90-day, and disease-free survival. Propensity scores were calculated using all available data to match patients with and without statin exposure in a 1:1 ratio.

RESULTS

Following propensity score matching, 7120 patients were included in the primary analysis. The median follow-up time was 5 years. A Cox proportional hazards model showed no statistically significant difference in overall survival between patients with or without statin exposure 365 days before surgery (HR 0.93, 95% CI 0.85-1.02) and no association with 90-day survival (OR 0.91, 95% CI 0.76-1.10). However, a subgroup analysis examining a 90-day exposure before surgery found a statistically significant association with increased overall survival (HR 0.85, 95% CI 0.77-0.93).

CONCLUSION

Although a subgroup of patients with a preoperative exposure time of 90 days showed statistically significant better overall survival, we found no statistically significant association between statin exposure 1 year before colorectal cancer surgery and overall survival.

[Improved immunologic response after laparoscopic versus open colorectal cancer surgery]

Laparoscopic colorectal cancer surgery results in a reduced impact on the immune system compared with open surgery. This is important when taken into consideration that the immune system may have an instrumental role in the advancement of cancer in the perioperative period. Several studies have shown that the perioperative period is characterized by an immune incompetent period, which is believed to favour tumour metastasis. In this paper factors associated with the cellular and innate immune response in relation to laparoscopic and open colorectal cancer surgery are reviewed.

Associations between pre-operative cholesterol levels with long-term survival after colorectal cancer surgery: a nationwide propensity score-matched cohort study

PURPOSE

Altered lipid metabolism frequently occurs in patients with solid cancers and dyslipidemia has been associated with poorer outcomes in patients with colorectal cancer. This study sought to investigate whether cholesterol levels are associated with clinical outcomes and can serve as survival predictors.

METHODS

We conducted a retrospective cohort study with Danish patients diagnosed with colorectal cancer who had surgery with curative intent for UICC stages I to III between 2015 and 2020. Using propensity score adjustment, we matched patients in a 1:1 ratio to examine the impact of total cholesterol (TC) > 4 mmol/L vs. ≤ 4 mmol/L within 365 days prior to surgery on overall survival (OS) and disease-free survival (DFS).

RESULTS

A total of 3443 patients were included in the study. Median follow-up time was 3.8 years. Following propensity score matching, 1572 patients were included in the main analysis. There was no statistically significant difference in OS or DFS between patients with TC > 4 mmol/L compared with TC ≤ 4 mmol/L (HR: 0.82, 95% CI, 0.65-1.03, HR: 0.87, 95% CI, 0.68-1.12, respectively.). A subgroup analysis investigating TC > 4 mmol/L as well as low-density lipoprotein (LDL) > 3 mmol/L found a significant correlation with OS (HR: 0.74, 95% CI, 0.54-0.99).

CONCLUSION

TC levels alone were not associated with OS or DFS in patients with colorectal cancer. Interestingly, higher TC and LDL levels were linked to better overall survival, suggesting the need for further exploration of cholesterol's role in colorectal cancer.

TRIAL REGISTRATION

Not applicable.

Development of a Fully Automated Method to Obtain Reproducible Lymphocyte Counts in Patients With Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. Although clinical outcome varies among patients diagnosed within the same TNM stage it is the cornerstone in treatment decisions as well as follow-up programmes. Tumor-infiltrating lymphocytes have added value when evaluating survival outcomes. The aim of this study was to develop a fully automated method for quantification of subsets of T lymphocytes in the invasive margin and central tumor in patients with CRC based on Deep Learning powered artificial intelligence. The study cohort consisted of 163 consecutive patients with a primary diagnosis of CRC followed by a surgical resection. Double-labeling immunohistochemical staining with cytokeratin in combination with CD3 or CD8, respectively, was performed on 1 representative slide from each patient. Visiopharm Quantitative Digital Pathology software was used to develop Application Protocol Packages for visualization of architectural details (background, normal epithelium, cancer epithelium, surrounding tissue), identification of central tumor and invasive margin as well as subsequent quantitative analysis of immune cells. Fully automated counts for CD3 and CD8 positive T cells were obtained in 93% and 92% of the cases, respectively. In the remaining cases, manual editing was required. In conclusion, the development of a fully automated method for counting CD3 + and CD8 + lymphocytes in a cohort of patients with CRC provided excellent results eliminating not only observer variability in lymphocyte counts but also in identifying the regions of interest for the quantitative analysis. Validation of the performance of the Application Protocol Packages including clinical correlation is needed.

Routine CT evaluation of central vascular ligation in patients undergoing complete mesocolic excision for sigmoid colon cancer

AIM

Objective and reproducible quality measures of complete mesocolic excision (CME) for colon cancer are not currently available. This study aimed to measure the inferior mesenteric stump length following CME for sigmoid colon cancer and explore surgical, pathological and oncological outcomes in patients with a stump length of <10 mm vs. ≥10 mm.

METHOD

This was a single-centre, retrospective cohort study including patients undergoing minimally invasive surgery for sigmoid colon cancer between May 2013 and May 2015. Follow-up CT scans were reviewed, and a vascular stump cut-off of <10 mm for adequate central ligation of the inferior mesenteric artery was applied. Differences in perioperative, histopathological and oncological outcome parameters (overall, disease-free and recurrence-free survival) were explored between <10 mm vs. ≥10 mm groups.

RESULTS

A total of 127 patients (43% female) with a median age of 68 years were included. The median follow-up time was 68 months. CT measurements showed good interrater agreement (90% absolute agreement) and reliability among raters (kappa = 0.77, 95% CI 0.53-1.00, p < 0.001). A stump length ≥10 mm was associated with longer operating time (150 vs. 180 min, p = 0.021), intramesocolic resection (p = 0.008), and a shorter distance from the bowel wall to vascular tie (120 vs. 102 mm, p = 0.005).

CONCLUSION

An arterial stump length ≥10 mm in sigmoid resection for colon cancer was associated with key clinical quality measures. Measurement of arterial stump length using routine follow-up CT may serve as a quality indicator of vascular ligation in CME surgery.