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.

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.

Impact of Whole Genome Doubling on Detection of Circulating Tumor DNA in Colorectal Cancer.

Objective: Circulating tumor DNA (ctDNA) is a candidate biomarker of cancer with practice-changing potential in the detection of both early and residual disease. Disease stage and tumor size affect the probability of ctDNA detection, whereas little is known about the influence of other tumor characteristics on ctDNA detection. This study investigates the impact of tumor cell whole-genome doubling (WGD) on the detection of ctDNA in plasma collected preoperatively from newly diagnosed colorectal cancer (CRC) patients.

Training of radiology specialists in local staging of primary rectal cancer on MRI: a prospective intervention study exploring the impact of various educational elements on the interpretive performance.

Background: MRI interpretation and accurate radiological staging are crucial to the important treatment decisions and a consequent successful patient outcome in rectal cancer.

Aims: To investigate the effect of intensive training on rectal cancer MRI staging performance of radiologists and the impact of different course elements on learning outcomes.

Methods: In this prospective intervention study, 17 radiology specialists and 1 radiology registrar participated in a training programme including a 6-hour imaging workshop, a 3-hour session of individual feedback and independent MRI readings of primary rectal cancer cases.

Diagnostic performance of MRI and endoscopy for assessing complete response in rectal cancer after neoadjuvant chemoradiotherapy: a systematic review of the literature.

Background: The diagnostic performance of magnetic resonance imaging (MRI) modalities and/or endoscopy for assessing complete response in rectal cancer after neoadjuvant chemoradiotherapy (nCRT) is unclear.

Purpose: To summarize existing evidence on the diagnostic performance of diffusion-weighted MRI, perfusion-weighted MRI, T2-weighted MR tumor regression grade, and/or endoscopy for assessing complete tumor response after nCRT.

Material And Methods: MEDLINE and Embase databases were searched.

Postoperative MRI Findings Following Conventional and Extralevator Abdominoperineal Excision in Low Rectal Cancer.

The disparity in outcomes for low rectal cancer may reflect differences in operative approach and quality. The extralevator abdominoperineal excision (ELAPE) was developed to reduce margin involvement in low rectal cancers by widening the excision of the conventional abdominoperineal excision (c-APE) to include the posterior pelvic diaphragm. This study aimed to determine the prevalence and localization of inadvertent residual pelvic diaphragm on postoperative MRI after intended ELAPE and c-APE.

Impact of a multidisciplinary training programme on outcome of upper rectal cancer by critical appraisal of the extent of mesorectal excision with postoperative MRI.

Background: Optimal management of patients with upper rectal cancer remains unclear. Partial mesorectal excision (PME) without neoadjuvant therapy is currently advocated for the majority of patients. Recent studies, however, reported a high risk of local recurrence and suboptimal surgery.

Pelvic insufficiency fractures frequently occur following preoperative chemo-radiotherapy for rectal cancer - a nationwide MRI study.

Aim: The aim of this prospective case-control study was to evaluate the rate of pelvic insufficiency fractures (PIFs) in Denmark using MRI at the 3-year follow-up. All patients had rectal cancer and had undergone surgery with or without preoperative chemo-radiotherapy (CRT).

Method: Patients registered with primary rectal cancer in the Danish Colorectal Cancer Group database, who underwent rectal cancer resection from April 2011 through August 2012, were invited to participate in a national MRI study aiming to detect local recurrence and evaluate quality of the surgical treatment.

Cancer of the upper rectum.

Rectal cancer constitutes one-third of all colorectal cancers, and the incidence in Denmark increasing. In 2012, 1.400 cases were registered, and of these 38% were located in the upper rectum.

Objective measurement of the distal resection margin by MRI of the fresh and fixed specimen after partial mesorectal excision for rectal cancer: 5 cm is not just 5 cm and depends on when measured.

Background: Most studies have directly established the optimal perioperative in situ clearance margin in surgery for rectal cancer from the histologically observed extent of distal spread, neglecting the tissue variability that occurs after resection and fixation of the rectal specimen.

Purpose: To measure the length of the distal resection margin in the fresh and fixed specimen following partial mesorectal excision for rectal cancer using magnetic resonance imaging (MRI) to document tissue shrinkage after surgical removal and fixation.

Material And Methods: The length of the distal resection margin was measured by MRI of the fresh and fixed specimen and at histopathological examination of the fixed specimen in 10 patients who underwent surgery for upper rectal cancer.

Neoadjuvant therapy abolishes the functional benefits of a larger rectal remnant, as measured by magnetic resonance imaging after restorative rectal cancer surgery.

Background: The combination of advances in surgical technique and neoadjuvant therapy for rectal cancer has resulted in more patients undergoing sphincter-preserving surgery. Unfortunately, numerous patients subsequently experience bowel dysfunction, and may suffer from lifelong severe disability with major impact on their quality of life. The aim of the present study was to investigate whether the risk of severe LARS in patients was associated with the length of remnant rectum.

Suboptimal surgery and omission of neoadjuvant therapy for upper rectal cancer is associated with a high risk of local recurrence.

Aim: The aim of the present study was to estimate the risk of local recurrence in an audited cohort of patients, with a particular focus on patients with upper rectal cancer treated by partial mesorectal excision without neoadjuvant therapy.

Method: Perioperative clinical data on all patients who underwent mesorectal excision for primary adenocarcinoma of the rectum in the period from 2007 to 2010 were prospectively collected and follow-up data on oncological outcome were retrieved from patient records. Three-year actuarial local recurrence rates were estimated using Kaplan-Meier methods.

Extent and completeness of mesorectal excision evaluated by postoperative magnetic resonance imaging.

Background: The major advance in rectal cancer management over the past 20 years has been the standardization of mesorectal excision. The aim of this study was to determine the prevalence and localization of inadvertent residual mesorectum detected on magnetic resonance imaging (MRI) after rectal cancer surgery.

Methods: Postoperative T2-weighted MRI of the pelvis was performed on patients following mesorectal excision.