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Abstract The location of a patient’s colorectal cancer (CRC) influences their outcome but inherited factors may also be involved. We studied 1899 patients with advanced CRC (514 had proximal colonic, 493 distal colonic and 892 rectal tumours) and carried out genome-wide association studies for survival. Single nucleotide polymorphisms (SNPs) suggestive of association (P

Summary: Background: It is uncertain which biological features underpin the response of rectal cancer (RC) to radiotherapy. No biomarker is currently in clinical use to select patients for treatment modifications. Methods: We identified two cohorts of patients (total N = 249) with RC treated with neoadjuvant radiotherapy (45Gy/25) plus fluoropyrimidine. This discovery set included 57 cases with pathological complete response (pCR) to chemoradiotherapy (23%). Pre-treatment cancer biopsies were assessed using transcriptome-wide mRNA expression and targeted DNA sequencing for copy number and driver mutations. Biological candidate and machine learning (ML) approaches were used to identify predictors of pCR to radiotherapy independent of tumour stage. Findings were assessed in 107 cases from an independent validation set (GSE87211). Findings: Three gene expression sets showed significant independent associations with pCR: Fibroblast-TGFβ Response Signature (F-TBRS) with radioresistance; and cytotoxic lymphocyte (CL) expression signature and consensus molecular subtype CMS1 with radiosensitivity. These associations were replicated in the validation cohort. In parallel, a gradient boosting machine model comprising the expression of 33 genes generated in the discovery cohort showed high performance in GSE87211 with 90% sensitivity, 86% specificity. Biological and ML signatures indicated similar mechanisms underlying radiation response, and showed better AUC and p-values than published transcriptomic signatures of radiation response in RC. Interpretation: RCs responding completely to chemoradiotherapy (CRT) have biological characteristics of immune response and absence of immune inhibitory TGFβ signalling. These tumours may be identified with a potential biomarker based on a 33 gene expression signature. This could help select patients likely to respond to treatment with a primary radiotherapy approach as for anal cancer. Conversely, those with predicted radioresistance may be candidates for clinical trials evaluating addition of immune-oncology agents and stromal TGFβ signalling inhibition. Funding: The Stratification in Colorectal Cancer Consortium (S:CORT) was funded by the Medical Research Council and Cancer Research UK (MR/M016587/1).

It remains critical to identify colorectal cancers (CRC) that will disseminate as early as possible. Here, the authors identify CRC tumours that are aggressive and prone to early dissemination, characterised by epithelial TGFβ and growth-factor signalling - which could be targeted with MEK/EGFR inhibitors.

Abstract Personalized treatment approaches for patients with limited liver metastases from colorectal cancer are critically needed. By leveraging three large, independent cohorts of patients with colorectal liver metastases (n = 336), we found that a proliferative subtype associated with elevated CIN70 scores is linked to immune exclusion, increased metastatic proclivity, and inferior overall survival in colorectal liver metastases; however, high CIN70 scores generate a therapeutic vulnerability to DNA-damaging therapies leading to improved treatment responses. We propose CIN70 as a candidate biomarker to personalize systemic treatment options for patients with metastatic colorectal cancer. These findings are potentially broadly applicable to other human cancers.

Abstract Background Inflammation is a hallmark of cancer, and systemic markers of inflammation are increasingly recognised as negative prognostic factors for clinical outcome. Neutrophil‐to‐lymphocyte ratio (NLR) is readily available from routine blood testing of patients diagnosed with cancer. Methods Peer‐reviewed publications from PubMed/MEDLINE, Web of Science and EMBASE were identified according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis (PRISMA) guidelines. Hazard ratios (HR) for overall survival (OS) and surrogate endpoints (SE; comprising disease‐, recurrence‐ and progression‐free survival) were pooled using a random effects model. Additional analysis was carried out to further investigate NLR as an independent prognostic factor and account for heterogeneity. Results Seventy‐one eligible papers comprising 32,788 patients were identified. High NLR was associated with poor clinical outcomes. Significant publication bias was observed, and larger studies also adjusted for more covariates. Correcting for publication bias in multivariate studies brought our best estimate for true effect size to HR = 1.57 (95% CI 1.39–1.78; p

Multiplex immunofluorescence is a powerful tool for the simultaneous detection of tissue‐based biomarkers, revolutionising traditional immunohistochemistry. The Opal methodology allows up to eight biomarkers to be measured concomitantly without cross‐reactivity, permitting identification of different cell populations within the tumour microenvironment. In this study, we aimed to validate a multiplex immunofluorescence workflow in two complementary multiplex panels and evaluate the tumour immune microenvironment in colorectal cancer (CRC) formalin‐fixed paraffin‐embedded tissue. We stained CRC and tonsil samples using Opal multiplex immunofluorescence on a Leica BOND RX immunostainer. We then acquired images on an Akoya Vectra Polaris and performed multispectral unmixing using inform. Antibody panels were validated on tissue microarray sections containing cores from six normal tissue types, using qupath for image analysis. Comparisons between chromogenic immunohistochemistry and multiplex immunofluorescence on consecutive sections from the same tissue microarray showed significant correlation (rs > 0.9, P‐value

Eukaryotic topoisomerase 1 (TOP1) regulates DNA topology to ensure efficient DNA replication and transcription. Here, the authors reveal insights into the molecular resolution of topoisomerase 1-DNA adducts by TEX264, p97 and SPRTN.

Abstract Background Trials have become bigger and more complicated due to the complexity introduced by biomarker stratification, and the advent of multi-arm multi-stage trials, and umbrella and basket platform designs. The trials unit at University College London has been at the forefront of this work, with ground-breaking trials such as STAMPEDE and FOCUS4. The trial management and data management teams on these trials have summarised the operational challenges, to enable the broader clinical trials community to learn from their experiences. In a small-scale qualitative study, we examined the personal experience of individual researchers working on these trials. Commentary We found reports of high workloads, with potentially significant stress for individuals and with an impact on their career choices. We conclude that there was an initial underestimation of the work required and of the inherent, largely unanticipated, challenges. We discuss the importance of fully understanding these trials’ resource requirements, both for those writing grant applications and critically, for those with responsibility for deciding on funding. The working environment was characterised by three features: complexity, scale and heightened expectations. These features are highly attractive for professional development and engender high levels of loyalty and commitment. We observed a trade-off between these intrinsic rewards and the continuous demands of overlapping tasks, balancing a mix of routine and high-profile work, and the changing nature of pivotal roles. Such demands present challenges for colleague relationships, by enhancing the potential for competition and by disrupting the natural opportunities to pause, review and celebrate team achievements. In addition, molecular stratification in effect brings the patient into the trial office, as a specific individual, despite anonymisation, who is owed test results and a treatment decision. We discuss these observations with a view to interconnecting the need for compassion for patients with caring for the researchers engaged in the research ecosystem who are aiming to produce much hoped-for advances in medical science. Conclusions There is a need for increased awareness of the challenge these studies place on those throughout the team delivering the study. Such considerations must influence leaders and funders, both in their initial budget considerations and throughout delivery.

Oncolytic viruses and radiotherapy represent two diverse areas of cancer therapy, utilizing quite different treatment modalities and with non-overlapping cytotoxicity profiles. It is, therefore, an intriguing possibility to consider that oncolytic (“cancer-killing”) viruses may act as cancer-selective radiosensitizers, enhancing the therapeutic consequences of radiation treatment on tumors while exerting minimal effects on normal tissue. There is a solid mechanistic basis for this potential synergy, with many viruses having developed strategies to inhibit cellular DNA repair pathways in order to protect themselves, during genome replication, from unwanted interference by cell processes that are normally triggered by DNA damage. Exploiting these abilities to inhibit cellular DNA repair following damage by therapeutic irradiation may well augment the anticancer potency of the approach. In this review, we focus on oncolytic adenovirus, the most widely developed and best understood oncolytic virus, and explore its various mechanisms for modulating cellular DNA repair pathways. The most obvious effects of the various adenovirus serotypes are to interfere with activity of the MRE11-Rad50-Nbs1 complex, temporally one of the first sensors of double-stranded DNA damage, and inhibition of DNA ligase IV, a central repair enzyme for healing double-stranded breaks by non-homologous end joining (NHEJ). There have been several preclinical and clinical studies of this approach and we assess the current state of progress. In addition, oncolytic viruses provide the option to promote a localized proinflammatory response, both by mediating immunogenic death of cancer cells by oncosis and also by encoding and expressing proinflammatory biologics within the tumor microenvironment. Both of these approaches provide exciting potential to augment the known immunological consequences of radiotherapy, aiming to develop systems capable of creating a systemic anticancer immune response following localized tumor treatment.

Background: Complex trials with innovative designs are becoming increasingly common and offer the potential to improve patient outcomes in a shorter time frame. There is evidence that patients with colorectal cancer fall into different subgroups with varying responsiveness to therapy, and that this variation is linked to genetic biomarkers. To the best of our knowledge, FOCUS4 was the first molecularly stratified trial in metastatic colorectal cancer and remains one of the first umbrella trial designs to be launched globally. Objectives: To identify novel therapies that improve disease control within the molecular subgroup of metastatic colorectal cancer in which the novel therapies were expected to be most effective. Design: This was a Phase II/III molecularly stratified umbrella trial that used adaptive statistical methodology to decide which subtrial should close early; new subtrials were added as protocol amendments. Setting: The maintenance setting following 16 weeks of first-line combination chemotherapy. Participants: Patients with newly diagnosed metastatic colorectal cancer were registered, and central laboratory testing was used to stratify their tumour into molecular subtypes. Following 16 weeks of first-line therapy, patients with stable or responding disease were eligible for randomisation into either a molecularly stratified subtrial or the non-stratified FOCUS4-N trial. Interventions: Of the 20 drug combinations that were explored for inclusion in the platform trial, three molecularly targeted subtrials were activated: FOCUS4-B (PIK3CA mutation or PTEN overexpression) – aspirin versus placebo; FOCUS4-C (TP53 and RAS mutation) – adavosertib (AstraZeneca Ltd, Cambridge, UK) versus active monitoring; and FOCUS4-D (BRAF-PIK3CA-RAS wild type) – AZD8931 versus placebo. A non-stratified subtrial was also carried out: FOCUS4-N – capecitabine versus active monitoring. Main outcome measures: The main outcome measure was progression-free survival from the time of randomisation to progression, comparing the intervention with active monitoring/placebo. Toxicity and overall survival data were collected in all randomised patients, and quality of life (using EuroQol-5 Dimensions) data were collected in FOCUS4-N only. Results: Between January 2014 and October 2020, 1434 patients were registered from 88 hospitals in the UK. Successful biomarker testing was completed in 1291 out of 1382 samples (93%), and 908 out of 1315 patients (69%) completing 16 weeks of first-line therapy were eligible for randomisation, with 361 randomly allocated to a subtrial. FOCUS4-B evaluated aspirin versus placebo in the PIK3CA-mutant/PTEN-loss subgroup, but recruited only six patients, so was closed for futility. FOCUS4-C evaluated adavosertib versus active monitoring in 67 patients in the RAS + TP53 double-mutant subgroup and met its primary end point, showing an improvement in progression-free survival (median 3.61 vs. 1.87 months; hazard ratio 0.35, 95% confidence interval 0.18 to 0.68; p = 0022). FOCUS4-D evaluated AZD8931 in 32 patients in the BRAF-PIK3CA-RAS wild-type subgroup and showed no benefit, so was discontinued after the first interim analysis. FOCUS4-N evaluated capecitabine monotherapy versus active monitoring in 254 patients and met its primary end point, showing improvement in progression-free survival (hazard ratio 0.40, 95% confidence interval 0.21 to 0.75; p

Purpose: Oxaliplatin forms part of routine treatment of advanced colorectal cancer; however, it often causes severe peripheral neuropathy, resulting in treatment discontinuation. We sought to determine the molecular and cellular mechanism underlying this toxicity., Patients and Methods: We exome resequenced blood DNA samples from nine patients with advanced colorectal cancer who had severe peripheral neuropathy associated with oxaliplatin (PNAO) within 12 weeks of treatment. We Sanger sequenced the ERCC4 and ERCC6 open reading frames in 63 patients with PNAO and carried out targeted genotyping in 1,763 patients without PNAO. We tested the functionality of ERCC4 variants using viability and DNA repair assays in Schizosaccharomyces pombe and human cell lines after exposure to oxaliplatin and ultraviolet light., Results: Exome resequencing identified one patient carrying a novel germline truncating mutation in the nucleotide excision repair (NER) gene ERCC4 . This mutation was functionally associated with sensitivity to oxaliplatin ( P = 3.5 × 10 -2 ). We subsequently found that multiple rare ERCC4 nonsynonymous variants were over-represented in affected individuals ( P = 7.7 × 10 -3 ) and three of these were defective in the repair of ultraviolet light-induced DNA damage ( P < 1 × 10 -3 ). We validated a role for NER genes in PNAO by finding that multiple rare ERCC6 nonsynonymous variants were similarly over-represented in affected individuals ( P = 2.4 × 10 -8 ). Excluding private variants, 22.2% of patients (14 of 63 patients) with PNAO carried Pro379Ser or Glu875Gly in ERCC4 or Asp425Ala, Gly446Asp, or Ser797Cys in ERCC6 , compared with 8.7% of unaffected patients (152 of 1,750 patients; odds ratio, 3.0; 95% CI, 1.6 to 5.6; P = 2.5 × 10 -4 )., Conclusion: Our study provides evidence for a role of NER genes in PNAO, together with mechanistic insights., Competing Interests: None of the sponsors played a role in the study design or in the collection, analysis, and interpretation of the data.