This cohort study investigates the use of longitudinal data from ultradeep sequencing of cell-free DNA in Danish patients with colorectal cancer.

Statement of translational relevanceSensitive methods for recurrence risk stratification, monitoring therapeutic efficacy, and early recurrence detection may have a major impact on treatment decisions and outcomes for stage III colorectal cancer patients. Circulating tumor DNA assessments performed postoperative, postadjuvant, and serially during surveillance all allowed stratification of patients into high and low risk groups. CtDNA detected recurrence with a significant leadtime compared to CT-imaging and ctDNA growth rates were prognostic of survival.Treatment of ctDNA positive patients with standard adjuvant therapy prevented recurrence in only 20% of patients. Accordingly, further studies exploring the optimal treatment for ctDNA positive patients are needed, as well as interventional studies assessing the clinical utility of ctDNA-based risk-stratification. A promising opportunity is risk-stratified allocation of surveillance resources, which may improve both the cost-effectiveness and the overall clinical outcome of surveillance. Finally, ctDNA growth rates may identify patients who could benefit from immediate therapeutic intervention compared to awaiting recurrence.Research.

Salvage surgery of recurrent or persistent anal cancer following radiotherapy is often followed by perineal wound complications. We examined survival and perineal wound complications in anal cancer salvage surgery during a 10-year period with primary perineal reconstruction predominantly performed using vertical rectus abdominis myocutaneous (VRAM) flap. Between 1997 and 2006, 49 patients underwent anal cancer salvage surgery. Of these, 48 had primary reconstruction with VRAM. Overall survival was computed by the Kaplan-Meier method and mortality rate ratios (MRRs) by Cox regression. One patient (2%) died within 30 days postoperatively. Postoperative complications necessitated reoperation in eight (16%) patients. We found no major perineal wound infections. Major perineal wound breakdown occurred in the only patient in whom VRAM was not used. Five-year survival was 61% [95% confidence interval (CI) 43-75%]. Free resection margins (R0) were obtained in 78% of patients, with 5-year survival of 75% (95% CI 53-87%). Involved margins, microscopically only (R1) or macroscopically (R2), strongly predicted an adverse outcome [age-adjusted 2-year MRRs (95% CI) R1 vs. R0 = 4.1 (0.7-23.6), R2 vs. R0 = 10.9 (2.2-54.2)]. We conclude that anal cancer salvage surgery can yield long-time survival but obtaining free margins is critical. A low rate of perineal complications is achievable by primary perineal reconstruction using VRAM flap.

Compromised immune function may increase the risk of anal squamous cell carcinoma (SCC). We examined the risk of anal SCC in patients with HIV infection and other chronic disorders associated with immunosuppression. A population‐based cohort study was conducted using the Danish National Patient Registry and the Danish Cancer Registry (DCR). We identified all patients with a first‐time hospital contact or procedure for HIV infection, solid organ transplantation or autoimmune disease or a first‐time record of haematologic malignancy in the DCR, 1978–2005, and followed these for a subsequent anal SCC, starting follow‐up 1 year after diagnosis of the index disease. Standardised incidence ratios (SIRs) were computed as the ratio of observed to expected numbers of anal SCCs, based on national age‐, sex‐ and period‐specific rates. Among 4,488 patients with HIV, we observed 21 anal SCCs with 0.3 expected (SIR: 81.1 (95% confidence interval (CI): 51.6–121.9)). Risk of anal SCC was markedly increased among 5,113 solid organ recipients (SIR: 14.4 (CI: 7.0–26.4)) and 30,165 patients with haematologic malignancies (SIR: 2.3 (CI: 1.1–4.2)) but only moderately increased among 242,114 patients with autoimmune diseases (SIR: 1.3 (CI: 1.0–1.6)). SIRs varied according to type of autoimmune disease and were high in patients with Crohn's disease (SIR: 3.1 (CI: 1.2–6.4)), psoriasis (SIR: 3.1 (CI: 1.8–5.1)), polyarteritis nodosa (SIR: 8.8 (CI: 1.5–29.0)) and Wegener's granulomatosis (SIR: 12.4 (CI: 2.1–40.8)). In conclusion, we found HIV infection, solid organ transplantation, haematologic malignancies and a range of specific autoimmune diseases strongly associated with increased risk of anal SCC.

BackgroundEarly detection plays an essential role to reduce colorectal cancer (CRC) mortality. While current screening methods suffer from poor compliance, liquid biopsy-based strategies for cancer detection is rapidly gaining promise. Here, we describe the development of TriMeth, a minimal-invasive blood-based test for detection of early-stage colorectal cancer. The test is based on assessment of three tumour-specific DNA methylation markers in circulating cell-free DNA.ResultsA thorough multi-step biomarker discovery study based on DNA methylation profiles of more than 5000 tumours and blood cell populations identified CRC-specific DNA methylation markers. The DNA methylation patterns of biomarker candidates were validated by bisulfite sequencing and methylation-specific droplet digital PCR in CRC tumour tissue and peripheral blood leucocytes. The three best performing markers were first applied to plasma from 113 primarily early-stage CRC patients and 87 age- and gender-matched colonoscopy-verified controls. Based on this, the test scoring algorithm was locked, and then TriMeth was validated in an independent cohort comprising 143 CRC patients and 91 controls. Three DNA methylation markers, C9orf50, KCNQ5, and CLIP4, were identified, each capable of discriminating plasma from colorectal cancer patients and healthy individuals (areas under the curve 0.86, 0.91, and 0.88). When combined in the TriMeth test, an average sensitivity of 85% (218/256) was observed (stage I: 80% (33/41), stage II: 85% (121/143), stage III: 89% (49/55), and stage IV: 88% (15/17)) at 99% (176/178) specificity in two independent plasma cohorts.ConclusionTriMeth enables detection of early-stage colorectal cancer with high sensitivity and specificity. The reported results underline the potential utility of DNA methylation-based detection of circulating tumour DNA in the clinical management of colorectal cancer.

BackgroundColorectal cancer (CRC) is one of the most common cancers in the western world. Screening is an efficient method of reducing cancer-related mortality. Molecular biomarkers for cancer in general and CRC in particular have been proposed, and hypermethylated DNA from stool or blood samples are already implemented as biomarkers for CRC screening.We aimed to evaluate the performance of proven hypermethylated DNA promoter regions as plasma based biomarkers for CRC detection.MethodsWe conducted a cross-sectional case-control study of 193 CRC patients and 102 colonoscopy-verified healthy controls. Using methylation specific polymerase chain reaction, we evaluated 30 DNA promoter regions previously found to be CRC specific. We used multivariable logistic regression with stepwise backwards selection, and subsequent leave-pair-out cross validation, to calculate the optimism corrected area under the receiver operating characteristics curve (AUC) for all stage as well as early stage CRC.ResultsNone of the individual DNA promoter regions provided an overall sensitivity above 30% at a reasonable specificity. However, seven hypermethylated promoter regions (ALX4, BMP3, NPTX2, RARB, SDC2, SEPT9, and VIM) along with the covariates sex and age yielded an optimism corrected AUC of 0.86 for all stage CRC and 0.85 for early stage CRC. Overall sensitivity for CRC detection was 90.7% at 72.5% specificity using a cut point value of 0.5.ConclusionsIndividual hypermethylated DNA promoter regions have limited value as CRC screening markers. However, a panel of seven hypermethylated promoter regions show great promise as a model for CRC detection.

Hypermethylation of the promoters of specific genes measured in blood or stool samples could be used as a CRC biomarker and provide prognostic information. The majority of studies, however, include only a few patients with poorly defined control groups. Further studies are therefore needed before hypermethylated DNA can be widely applied as a clinical biomarker for CRC detection and prognosis.

Distressing long-term anorectal and sexual dysfunction was common after radiotherapy for anal cancer, and morbidity due to urinary dysfunction was moderate.