Incidence of late recurrence and second primary cancers 5-10 years after non-metastatic colorectal cancer

The fraction of patients who are cancer-free survivors 5 years after curative-intended surgery for colorectal cancer (CRC) is increasing, suggesting that extending surveillance beyond 5 years may be indicated. Here we estimate the incidence of late recurrence, metachronous CRC, and second primary cancers 5-10 years postoperative. All patients resected for UICC stage I-III CRC in Denmark through 2004-2013 were identified. Through individual-level linkage of nationwide health registry data, recurrence status was determined using a validated algorithm. Cancer-free survivors 5 years after surgery, were included. Cumulative incidence functions (CIF) of late recurrence, metachronous CRC, and second primary cancer 5-10 years postoperative were constructed. Subdistribution hazards ratios (sHR) were computed using Fine-Gray regression. Among 8883 patients, 370 developed late recurrence (5-10-year CIF = 4.1%, 95%CI: 3.7%-4.6%), 270 metachronous CRC (5-10-year CIF = 3.0%, 95%CI: 2.7%-3.4%), and 635 a second primary cancer (5-10-year CIF = 7.2%, 95%CI: 6.7%-7.7%). The risk of late recurrence was reduced for patients operated in 2009-2013 compared to 2004-2008 (2.9% vs. 5.6%, sHR = 0.52, 95% CI: 0.42-0.65). The risk of metachronous CRC was likewise reduced from 4.1% to 2.1% (sHR = 0.50, 95%CI: 0.39-0.65). While the risk of second primary cancer did not change between 2009-2013 and 2004-2008 (7.1% vs. 7.1%, sHR = 0.98, 95% CI: 0.84-1.15). Using nation-wide 10-year follow-up data, we document that the incidences of late recurrence and metachronous CRC are low and decreasing from 2004 to 2013. Thus, despite increasing numbers of long-term cancer survivors, the data do not advocate for extending CRC-specific surveillance beyond 5 years.

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.

Incidence of Recurrence and Time to Recurrence in Stage I to III Colorectal Cancer: A Nationwide Danish Cohort Study

Importance

Management of colorectal cancer (CRC) has been updated continuously over the past 2 decades. While the combination of these initiatives has had implications for improved survival, the implications for rates of recurrence remain unexplored.

Objective

To ascertain the rates of recurrence and describe time to recurrence within 5 years of surgery with curative intent for stages I to III CRC.

Design, Setting, and Participants

This cohort study used the Danish Colorectal Cancer Group Database to identify patients with Union for International Cancer Control (UICC) stages I to III CRC who underwent primary surgery between January 1, 2004, and December 31, 2019. They were followed up until recurrence (event), death (competing event), diagnosis of a second cancer (competing event), emigration (censoring event), 5 years postoperatively (censoring event), or January 1, 2023 (censoring event), whichever came first. Recurrence status was ascertained through individual-level linked data from the Danish Cancer Registry, Danish National Patient Registry, and Danish Pathology Registry using a validated algorithm. Data were analyzed from January 1 to August 8, 2023.

Exposure

Primary surgery performed during 3 calendar periods (2004-2008, 2009-2013, and 2014-2019) stratified by tumor site (colon or rectum) and UICC stage (I, II, and III).

Main Outcomes and Measures

Stage-specific 5-year recurrence reported as the cumulative incidence function (CIF) of recurrence, the association between calendar period of primary surgery and recurrence risk reported as subdistribution hazard ratios (sHRs), and the time from surgery to recurrence.

Results

Of the 34 166 patients with UICC stages I to III CRC (median [IQR] age, 70 [62-77] years); 18 552 males [54.3%]) included in the study, 7027 developed recurrence within 5 years after the primary surgery. For colon cancer, the 5-year CIF of recurrence decreased over the 3 calendar periods from 16.3% to 6.8% for UICC stage I, from 21.9% to 11.6% for UICC stage II, and from 35.3% to 24.6% for UICC stage III colon cancer. For rectal cancer, the 5-year CIF decreased over the 3 periods from 19.9% to 9.5% for stage I, from 25.8% to 18.4% for stage II, and from 38.7% to 28.8% for stage III disease. Patients with stage III disease had a shorter time from surgery to recurrence compared with those with stage I disease (time ratio stage III vs stage I = 0.30; 95% CI, 0.28-0.32). Cancers detected through screening were associated with lower stage-adjusted risks of recurrence (sHR, 0.81; 95% CI, 0.73-0.91) compared with cancers not detected through screening.

Conclusions and Relevance

In this cohort of patients with CRC, the risk of recurrence decreased in patients with stages I to III disease during the study period. Cancer detection by screening was associated with an even lower risk of recurrence. Time to recurrence differed according to UICC stage. Because the risk of recurrence was so low in selected patient groups, future research is warranted to explore risk-stratified surveillance protocols in patients with CRC.

DREAMS: deep read-level error model for sequencing data applied to low-frequency variant calling and circulating tumor DNA detection

Circulating tumor DNA detection using next-generation sequencing (NGS) data of plasma DNA is promising for cancer identification and characterization. However, the tumor signal in the blood is often low and difficult to distinguish from errors. We present DREAMS (Deep Read-level Modelling of Sequencing-errors) for estimating error rates of individual read positions. Using DREAMS, we develop statistical methods for variant calling (DREAMS-vc) and cancer detection (DREAMS-cc). For evaluation, we generate deep targeted NGS data of matching tumor and plasma DNA from 85 colorectal cancer patients. The DREAMS approach performs better than state-of-the-art methods for variant calling and cancer detection.

Identifying Recurrences Among Non-Metastatic Colorectal Cancer Patients Using National Health Data Registries: Validation and Optimization of a Registry-Based Algorithm in a Modern Danish Cohort

Purpose

Colorectal cancer (CRC) recurrence is not routinely recorded in Danish health data registries. Here, we aimed to revalidate a registry-based algorithm to identify recurrences in a contemporary cohort and to investigate the accuracy of estimating the time to recurrence (TTR).

Patients and Methods

We ascertained data on 1129 patients operated for UICC TNM stage I-III CRC during 2012-2017 registered in the CRC biobank at the Department of Molecular Medicine, Aarhus University Hospital, Denmark. Individual-level data were linked with data from the Danish Colorectal Cancer Group database, Danish Cancer Registry, Danish National Registry of Patients, and Danish Pathology Registry. The algorithm identified recurrence based on diagnosis codes of local recurrence or metastases, the receipt of chemotherapy, or a pathological tissue assessment code of recurrence more than 180 days after CRC surgery. A subgroup was selected for validation of the algorithm using medical record reviews as a reference standard.

Results

We found a 3-year cumulative recurrence rate of 20% (95% CI: 17-22%). Manual medical record review identified 80 recurrences in the validation cohort of 522 patients. The algorithm detected recurrence with 94% sensitivity (75/80; 95% CI: 86-98%) and 98% specificity (431/442; 95% CI: 96-99%). The positive and negative predictive values of the algorithm were 87% (95% CI: 78-93%) and 99% (95% CI: 97-100%), respectively. The median difference in TTR (TTR_{Medical_chart}-TTR_algorithm) was -8 days (IQR: -21 to +3 days). Restricting the algorithm to chemotherapy codes from oncology departments increased the positive predictive value from 87% to 94% without changing the negative predictive value (99%).

Conclusion

The algorithm detected recurrence and TTR with high precision in this contemporary cohort. Restriction to chemotherapy codes from oncology departments using department classifications improves the algorithm. The algorithm is suitable for use in future observational studies.

Abstract 1959: Sensitive detection of circulating tumor DNA by whole genome sequencing: Validation of MRDetect using serial blood samples from stage III colorectal cancer patients

Background: While detection of circulating tumor DNA (ctDNA) is associated with poor cancer prognosis, the clinical utility for guiding treatment decisions is unresolved. Patients with minimal residual disease (MRD) often have less than one genome equivalent of ctDNA per 10 mL blood. Consequently, it is stochastic whether a 10 mL sample contains ctDNA from a particular genomic locus. Consequently, the sensitivity of ctDNA detection methods targeting a limited number of tumor loci is heavily affected by sampling bias. To overcome this challenge, we developed MRDetect; a whole genome sequencing (WGS) approach, which detects ctDNA using the patient-specific cumulative signal from tens of thousands of mutations throughout the genome. Recently, we showed how MRDetect found ctDNA fractions down to 10-4. Here, we performed a validation study to confirm the prognostic impact of MRDetect.

Aim: Validation of MRDetect for sensitive ctDNA detection to monitor residual disease in stage III colorectal cancer (CRC) patients treated with curative intent.

Methods: From a large, uniform cohort of stage III CRC patients n = 146), we had plasma samples collected every third month (n = 938, median = 9 per patient) and a median follow-up of 34 months. For each patient, a genome-wide mutational signature was established by WGS of tumor and matched normal DNA. Enhanced by an AI-based error suppression model, this signature was used to detect ctDNA in 1-2 mL plasma samples using WGS (20x coverage). We used de-novo point mutation and copy number variation analysis to investigate cancer evolution after treatment. To evaluate the reproducibility of MRDetect, aliquot samples (n = 2x190 samples) from 5 recurrence and 10 non-recurrence patients were processed and sequenced at two independent laboratories. Outcome measures: ctDNA status, tumor fraction, false positive rate, Time To ctDNA Recurrence (TTcR), and Time To radiological Recurrence (TTrR).

Results: Analysis of paired samples showed great reproducibility with high agreement between both ctDNA status calls (Cohens Kappa = 0.81) and the estimated tumor fractions (r2 = 0.99). MRDetect revealed post-operative ctDNA in all recurrence patients (5/5) with detected tumor fractions down to 2 x 10-4. Median TTcR was 0.9 month (range 0.5 - 7.3 months) while median TTrR was 12.8 months (range 11.3 - 31.1 months). The false positive rate was 1% (1/100), assessed in longitudinal samples from the 10 non-relapsing patients. Tumor evolution dynamics in plasma samples revealed novel amplification and deletions, which were absent in the primary tissue but confirmed in metachronous metastases. We will present results from the full cohort at AACR 2022.

Conclusion: MRDetect detects ctDNA with high sensitivity and specificity and enables effective postoperative assessment of MRD, cancer evolution dynamics and early relapse detection.

Citation Format: Amanda Frydendahl, Thomas Reinert, Jesper Nors, Sunil Deochand, Dillon Maloney, Noah Friedman, Tomer Lauterman, Danielle Afterman, Imane Bourzgui, Nidhi Ramaraj, Zohar Donenhirsh, Ronel Veksler, Ravi Kandasamy, Iman Tavassoly, Jonathan Rosenfeld, Anders Husted Andersen, Uffe S. Løve, Per V. Andersen, Ole Thorlacius-Ussing, Lene Hjerrild Iversen, Kåre Andersson Gotschalck, Boris Oklander, Asaf Zviran, Claus Lindbjerg Andersen. Sensitive detection of circulating tumor DNA by whole genome sequencing: Validation of MRDetect using serial blood samples from stage III colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1959.

Postoperative paralytic ileus after cytoreductive surgery combined with heated intraperitoneal chemotherapy

Background

Patients with peritoneal malignancy treated by cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) are prone to develop postoperative paralytic ileus (POI). POI is associated with significant increase in both morbidity and mortality. CRS and HIPEC commonly result in prolonged POI (PPOI). The objective was to clarify the extent of PPOI in patients treated by CRS and HIPEC for peritoneal malignancy.

Methods

This was a prospective multicenter study including patients operated with CRS and HIPEC at the Department of Surgery, Aarhus University Hospital, Denmark and the Peritoneal Malignancy Institute, Basingstoke, United Kingdom. A total of 85 patients were included over 5 months. Patients prospectively reported parameters of postoperative gastrointestinal function in a diary from post-operative day 1 (POD1) until discharge. PPOI was defined as first defecation on POD6 or later.

Results

Median time to first flatus passage was 4 days (range 1–12). Median time to first defecation was 6 days (1–14). Median time to removal of nasojejunal tube was 4 days (3–13) and 7 days (1–43) for nasogastric tube. Forty-six patients (54%) developed PPOI. Patients with PPOI had longer time to first flatus (p<0.0001) and longer time to removal of nasojejunal tube (p=0.001). Duration of surgery correlated to time to first flatus (p=0.015) and time to removal of nasogastric or nasojejunal tube (p<0.0001) but not to time to first defecation (p=0.321).

Conclusions

Postoperative gastrointestinal paralysis remains a common and serious problem in patients treated with CRS and HIPEC.

Leakage Rate After Laparoscopic Ileocolic Intracorporeal Anastomosis

BACKGROUND AND AIMS

The prevailing technique in laparoscopic resection of the right colon has been laparoscopic-assisted procedure with externalization of the bowel for extracorporeal creation of the ileocolic anastomosis. The total laparoscopic technique performing all steps intracorporeally, however, has gained increasing interest. The purpose of this study was to describe our experience with creation of an ileocolic intracorporeal anastomosis (IIA) and to determine anastomotic leakage (AL) rate and short-term outcome of performing IIA.

MATERIALS AND METHODS

In the period 2011-2017, 2 surgeons in two centers performed 96 laparoscopic resections of malignant and premalignant diseases in the right colon. A linear stapler was used to construct an isoperistaltic side-to-side anastomosis, closing the residual defect with a running suture. Data regarding the surgical procedure and the postoperative course were recorded prospectively. Complications were defined as postoperative until the 30th postoperative day. Readmission was defined as any readmission related to the surgical procedure within 90 days postoperative.

RESULTS

AL rate was observed in 4 patients (4.2%, 95% CI = 1.15-10.33). Postoperative complications occurred in a total of 20 patients (20.83%, 95% CI = 13.22-30.33), none of them fatal. Patients with AL had increased risk of other postoperative complications with OR = 14.25 (95% CI = 1.03-757.36, P = .0236) and complications of Clavien-Dindo Grade ≥IIIb (OR = 10.8, P = .012). Smoking was the only factor predisposing to AL. Patients without AL stayed in hospital a median of 3 days, compared with 32 days for patients with AL.

CONCLUSION

IIA was found to be a feasible and safe technique in laparoscopic resections of the right colon with an AL rate of 4.2%.

Perioperative lipid-enriched enteral nutrition versus standard care in patients undergoing elective colorectal surgery (SANICS II): a multicentre, double-blind, randomised controlled trial

BACKGROUND

Postoperative ileus and anastomotic leakage severely impair recovery after colorectal resection. We investigated the effect of perioperative lipid-enriched enteral nutrition versus standard care on the risk of postoperative ileus, anastomotic leakage, and other clinical outcomes.

METHODS

We did an international, multicentre, double-blind, randomised, controlled trial of patients (≥18 years) undergoing elective colorectal surgery with primary anastomosis at six clinical centres in the Netherlands and Denmark. Patients were randomly assigned (1:1), stratified by location (colonic and rectal) and type of surgery (laparoscopic and open), via online randomisation software, with block sizes of six, to receive either continuous lipid-enriched enteral tube feeding from 3 h before until 6 h after surgery (intervention) or no perioperative nutrition (control). Surgeons, patients, and researchers were masked to treatment allocation for the entire study period. The primary outcome was postoperative ileus. Secondary outcomes included anastomotic leakage, pneumonia, preoperative gastric volumes, time to functional recovery, length of hospital stay, the need for additional interventions, intensive care unit admission, postoperative inflammatory response, and surgical complications. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT02175979, and trialregister.nl, number NTR4670.

FINDINGS

Between July 28, 2014, and February 20, 2017, 280 patients were randomly assigned, 15 of whom were excluded after random allocation because they fulfilled one or more exclusion criteria. 265 patients received perioperative nutrition (n=132) or standard care (n=133) and were included in the analyses. A postoperative ileus occurred in 37 (28%) patients in the intervention group versus 29 (22%) in the control group (risk ratio [RR] 1·09, 95% CI 0·95-1·25; p=0·24). Anastomotic leakage occurred in 12 (9%) patients in the intervention group versus 11 (8%) in the control group (RR 1·01, 95% CI 0·94-1·09; p=0·81). Pneumonia occurred in ten (8%) patients in the intervention group versus three (2%) in the control group (RR 1·06, 95% CI 1·00-1·12; p=0·051). All other secondary outcomes were similar between groups (all p>0·05).

INTERPRETATION

Perioperative lipid-enriched enteral nutrition in patients undergoing elective colorectal surgery has no advantage over standard care in terms of postoperative complications.

FUNDING

Netherlands Organisation for Health Research and Development (ZonMW), Fonds NutsOhra, and Danone Research.