Detection of circulating tumor DNA by tumor-informed whole-genome sequencing enables prediction of recurrence in stage III colorectal cancer patients.

INTRODUCTION: Circulating tumor (ctDNA) can be used to detect residual disease after cancer treatment. Detecting low-level ctDNA is challenging, due to the limited number of recoverable ctDNA fragments at any target loci. In response, we applied tumor-informed whole-genome sequencing (WGS), leveraging thousands of mutations for ctDNA detection. METHODS: Performance was evaluated in serial plasma samples (n = 1283) from 144 stage III colorectal cancer patients. Tumor/normal WGS was used to establish a patient-specific mutational fingerprint, which was searched for in 20x WGS plasma profiles. For reproducibility, paired aliquots of 172 plasma samples were analyzed in two independent laboratories. De novo variant calling was performed for serial plasma samples with a ctDNA level > 10 % (n = 17) to explore genomic evolution. RESULTS: WGS-based ctDNA detection was prognostic of recurrence: post-operation (Hazard ratio [HR] 6.75, 95 %CI 3.18-14.3, p < 0.001), post-adjuvant chemotherapy (HR 28.9, 95 %CI 10.1-82.8; p < 0.001), and during surveillance (HR 22.8, 95 %CI 13.7-37.9, p < 0.0001). The 3-year cumulative incidence of ctDNA detection in recurrence patients was 95 %. ctDNA was detected a median of 8.7 months before radiological recurrence. The independently analyzed plasma aliquots showed excellent agreement (Cohens Kappa=0.9, r = 0.99). Genomic characterization of serial plasma revealed significant evolution in mutations and copy number alterations, and the timing of mutational processes, such as 5-fluorouracil-induced mutations. CONCLUSION: Our study supports the use of WGS for sensitive ctDNA detection and demonstrates that post-treatment ctDNA detection is highly prognostic of recurrence. Furthermore, plasma WGS can identify genomic differences distinguishing the primary tumor and relapsing metastasis, and monitor treatment-induced genomic changes.

Anastomotic perfusion assessment with indocyanine green in robot-assisted low-anterior resection, a multicenter study of interobserver variation.

BACKGROUND: Securing sufficient blood perfusion to the anastomotic area after low-anterior resection is a crucial factor in preventing anastomotic leakage (AL). Intra-operative indocyanine green fluorescent imaging (ICG-FI) has been suggested as a tool to assess perfusion. However, knowledge of inter-observer variation among surgeons in the interpretation of ICG-FI is sparse. Our primary objective was to evaluate inter-observer variation among surgeons in the interpretation of bowel blood-perfusion assessed visually by ICG-FI. Our secondary objective was to compare the results both from the visual assessment of ICG and from computer-based quantitative analyses of ICG-FI between patients with and without the development of AL. METHOD: A multicenter study, including patients undergoing robot-assisted low anterior resection with stapled anastomosis. ICG-FI was evaluated visually by the surgeon intra-operatively. Postoperatively, recorded videos were anonymized and exchanged between centers for inter-observer evaluation. Time to visibility (TTV), time to maximum visibility (TMV), and time to wash-out (TWO) were visually assessed. In addition, the ICG-FI video-recordings were analyzed using validated pixel analysis software to quantify blood perfusion. RESULTS: Fifty-five patients were included, and five developed clinical AL. Bland-Altman plots (BA plots) demonstrated wide inter-observer variation for visually assessed fluorescence on all parameters (TTV, TMV, and TWO). Comparing leak-group with no-leak group, we found no significant differences for TTV: Hazard Ratio; HR = 0.82 (CI 0.32; 2.08), TMV: HR = 0.62 (CI 0.24; 1.59), or TWO: HR = 1.11 (CI 0.40; 3.11). In the quantitative pixel analysis, a lower slope of the fluorescence time-curve was found in patients with a subsequent leak: median 0.08 (0.07;0.10) compared with non-leak patients: median 0.13 (0.10;0.17) (p = 0.04). CONCLUSION: The surgeon's visual assessment of the ICG-FI demonstrated wide inter-observer variation, there were no differences between patients with and without AL. However, quantitative pixel analysis showed a significant difference between groups. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04766060.

Scandinavian Surgical Society: The Oldest International Surgical Society in the World.

Scandinavian Surgical Society (SSS), Nordisk Kirurgisk Förening, founded in 1893, is the oldest international surgical society in the world. The purpose of the society is to promote scientific and clinical work as well as education in the field of surgery in the Nordic countries; Denmark, Finland, Sweden, Norway and Iceland. Nordic co-operation has long traditions in the medical field. The surgical development through the surgical communities and the long-term co-operation between the Nordic surgeons have affected the patient care and development of surgery throughout the Nordic region. An overview and a historical glance of the surgical communities in the Nordic countries from the 18th century are described as well as activities in the SSS from the beginning of 1893 to these days.

Fourteen years' experience with the CarboMedics valve in young adults with aortic valve disease.

BACKGROUND AND AIM OF THE STUDY: Homografts and the Ross procedure are recommended by many surgeons for aortic valve replacement (AVR) in young adults. The study aim was to monitor patient outcome over a 14-year period after implanting mechanical CarboMedics prosthetic heart valves in young adults with aortic valve disease. METHODS: Between November 1987 and December 2000, 55 patients (42 males, 13 females; median age 33 years; range 15-40 years) each received a CarboMedics valve in the aortic position. All patients were included on a consecutive and non-selected basis. Concomitant surgery was performed in five patients. Anticoagulation was commenced on postoperative day 1. After discharge, patients were followed up by their cardiologist or general practitioner using questionnaires and telephone calls. Actuarial estimates of survival and freedom from morbid events were calculated using the Kaplan-Meier method. RESULTS: No patient died during surgery. Complete follow up data were available for all patients; total follow up was 404 patient-years (pt-yr). The 30-day mortality rate was zero. Actuarial survival at 14 years was 90 +/- 4.9%, and actuarial freedom from all valve-related events 92 +/- 3.7%. No valve thrombosis or major bleeding events were identified. Linearized rates per 100 pt-yr were: embolism 0.25; paravalvular leakage 0.25; prosthetic endocarditis 0.25; and reoperation 0.50. There was no hemolysis, prosthetic valve dysfunction, or structural deterioration. CONCLUSION: Over a 14-year period, implantation of the CarboMedics prosthetic heart valve has proven to be an excellent solution for AVR in young adults with aortic valve disease.