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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 Limitations FOCUS4-C and FOCUS4-N were closed early owing to COVID-19, so did not accrue their planned recruitment numbers. Conclusions Adaptive stratified medicine studies are feasible in common cancers but present challenges. Capecitabine monotherapy is an effective maintenance therapy. Wee1 inhibition using adavosertib shows significant clinical activity, notably in left-sided colorectal cancer. Trial registration This trial was registered as ISRCTN90061546. Funding This project was jointly funded by the Efficacy and Mechanism Evaluation (EME) programme, a MRC and National Institute for Health and Care Research (NIHR) partnership, and Cancer Research UK. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 9, No. 9. See the NIHR Journals Library website for further project information.

Colorectal cancer (CRC) affects many older adults. We investigated the efficacy and safety of adding anti-epidermal growth factor receptor (EGFR) agents to doublet chemotherapy (DC) in older patients.Patients with RAS wild-type (WT) metastatic CRC (mCRC) receiving first-line DC + anti-EGFR (n = 1191) or DC alone (n = 729) from seven trials in the Aide de Recherche en Cancerologie Digestive database were included. The prognostic and predictive effects of age were investigated. Progression-free and overall survival (OS) were evaluated between age groups (≥70 vs 70) for DC + anti-EGFR. In addition, outcomes were compared between DC+/-anti-EGFR within age groups in three trials with a DC alone arm. Subsequently, the same analysis was conducted for left-sided tumours. Adverse events grade ≥3 (G3+) were compared between age groups.Older (vs younger) patients receiving DC + anti-EGFR had similar progression-free survival (PFS) (8.7 vs 10.3 months; hazard ratio (HR) = 1.20 [0.96-1.49];p = 0.107) but inferior OS (21.3 vs 26.3; HR = 1.36 [1.08-1.72];p = 0.011). DC + anti-EGFR (vs DC alone) improved OS (23.9 vs 20.3; HR = 0.82 [0.70-0.95];p = 0.008) and PFS (11.2 vs 8.9; HR = 0.70 [0.60-0.82];p 0.001) in younger but not older patients: OS (24.7 vs 17.6; HR [95% confidence interval {CI}] = 0.77 [0.58-1.04];p = 0.092) and PFS (9.1 vs 8.7; HR [95% CI] = 0.85[0.63-1.15];p = 0.287). In left-sided 'only' tumours, the following outcomes for older (vs younger) patients were observed. For DC + anti-EGFR, PFS 9 versus 11.2 months; HR1.10 (95% CI 0.83-1.46); p = 0.52, OS 25.6 vs 30.3 HR 1.32 (95% CI 0.97-1.79), p = 0.086. For DC + anti-EGFR (vs DC alone), PFS and OS for younger patients were 11.9 vs 9.2 months HR 0.60 (95% CI 0.47-0.78) p 0.001 and 24.1 versus 23.3 months HR 0.84 (95% CI 0.67-1.04), respectively. For older patients, PFS and OS were 13.1 versus 8.5 months, HR 0.51 (95% CI, 0.28-0.93), P = 0.027 and 26.3 versus 16.5 months HR 0.49 (95% CI, 0.28-0.85), respectively. There was no significant difference in toxicity among different age groups.Older (vs younger) patients with mCRC RAS WT patients had comparable toxicity and efficacy with the addition of anti-EGFR agents to chemotherapy.

PDF - 108K, Materials and Methods. Supplementary Table 1 - Primers used in Sequenom analysis of KRAS, BRAF, NRAS and PIK3CA. Supplementary Table 2 - The sensitivity of Pyrosequencing and Sequenom to detect somatic mutations in KRAS, BRAF, NRAS and PIK3CA. Mutant alleles that could, or could not, be detected indicated by Y and X, respectively. Supplementary Table 3 � Correlations between the site of the metastases and somatic mutation status (by individual mutations and for patients with a single organ metastatic site).Supplementary Table 4 � Correlations between the site of the metastases and somatic mutation status (in any patients with the metastatic site). Supplementary Table 5 � Correlations between the site of the metastases and somatic mutation status (in any patients with, or without, the metastatic site).

Purpose:The DNA damage immune response (DDIR) assay was developed in breast cancer based on biology associated with deficiencies in homologous recombination and Fanconi anemia pathways. A positive DDIR call identifies patients likely to respond to platinum-based chemotherapies in breast and esophageal cancers. In colorectal cancer, there is currently no biomarker to predict response to oxaliplatin. We tested the ability of the DDIR assay to predict response to oxaliplatin-based chemotherapy in colorectal cancer and characterized the biology in DDIR-positive colorectal cancer.Experimental Design:Samples and clinical data were assessed according to DDIR status from patients who received either 5-fluorouracil (5-FU) or 5FUFA (bolus and infusion 5-FU with folinic acid) plus oxaliplatin (FOLFOX) within the FOCUS trial (n = 361, stage IV), or neoadjuvant FOLFOX in the FOxTROT trial (n = 97, stage II/III). Whole transcriptome, mutation, and IHC data of these samples were used to interrogate the biology of DDIR in colorectal cancer.Results:Contrary to our hypothesis, DDIR-negative patients displayed a trend toward improved outcome for oxaliplatin-based chemotherapy compared with DDIR-positive patients. DDIR positivity was associated with microsatellite instability (MSI) and colorectal molecular subtype 1. Refinement of the DDIR signature, based on overlapping IFN-related chemokine signaling associated with DDIR positivity across colorectal cancer and breast cancer cohorts, further confirmed that the DDIR assay did not have predictive value for oxaliplatin-based chemotherapy in colorectal cancer.Conclusions:DDIR positivity does not predict improved response following oxaliplatin treatment in colorectal cancer. However, data presented here suggest the potential of the DDIR assay in identifying immune-rich tumors that may benefit from immune checkpoint blockade, beyond current use of MSI status.

Insights into oncogenesis derived from cancer susceptibility loci (SNP) hold the potential to facilitate better cancer management and treatment through precision oncology. However, therapeutic insights have thus far been limited by our current lack of understanding regarding both interactions of these loci with somatic cancer driver mutations and their influence on tumorigenesis. For example, although both germline and somatic genetic variation to the p53 tumor suppressor pathway are known to promote tumorigenesis, little is known about the extent to which such variants cooperate to alter pathway activity. Here we hypothesize that cancer risk-associated germline variants interact with somatic TP53 mutational status to modify cancer risk, progression, and response to therapy. Focusing on a cancer risk SNP (rs78378222) with a well-documented ability to directly influence p53 activity as well as integration of germline datasets relating to cancer susceptibility with tumor data capturing somatically-acquired genetic variation provided supportive evidence for this hypothesis. Integration of germline and somatic genetic data enabled identification of a novel entry point for therapeutic manipulation of p53 activities. A cluster of cancer risk SNPs resulted in increased expression of prosurvival p53 target gene KITLG and attenuation of p53-mediated responses to genotoxic therapies, which were reversed by pharmacologic inhibition of the prosurvival c-KIT signal. Together, our results offer evidence of how cancer susceptibility SNPs can interact with cancer driver genes to affect cancer progression and identify novel combinatorial therapies.Significance:These results offer evidence of how cancer susceptibility SNPs can interact with cancer driver genes to affect cancer progression and present novel therapeutic targets.

Supplementary Methods; Supplementary Figures S1-S5

Supplementary Results

Supplementary data to accompany manuscript

PDF - 26K, Kaplan-Meier plots of OS and PFS for patients with PIK3CA wild type or mutant tumours.

PDF - 63K

Purpose: Somatic mutation status at KRAS, BRAF, and NRAS is associated with prognosis in patients with advanced colorectal cancer (aCRC); however, it remains unclear whether there are intralocus, variant-specific differences in survival and other clinicopathologic parameters.Experimental Design: We profiled 2,157 aCRCs for somatic mutations in KRAS, BRAF, and NRAS and determined microsatellite instability status. We sought inter- and intralocus correlations between mutations and variant-specific associations with survival and clinicopathology.Results: KRAS mutations were rarely found together and those in codons 12 and 13 conferred poor prognosis [hazard ratio (HR), 1.44; 95% confidence interval (CI), 1.28–1.61; P = 6.4 × 10−10 and HR, 1.53; 95% CI, 1.26–1.86; P = 1.5 × 10−05, respectively]. For BRAF, more c.1781A>G (p.D594G) CRCs carried RAS mutations [14% (3/21)] compared with c.1799T>A (p.V600E) CRCs [1% (2/178), P = 9.0 × 10−03]. c.1799T>A (p.V600E) was associated with poor prognosis (HR, 2.60; 95% CI, 2.06–3.28; P = 1.0 × 10−15), whereas c.1781A>G (p.D594G) was not (HR, 1.30; 95% CI, 0.73–2.31; P = 0.37); this intralocus difference was significant (P = 0.04). More c.1799T>A (p.V600E) colorectal cancers were found in the right colon [47% (47/100)], compared with c.1781A>G (p.D594G) colorectal cancers [7% (1/15), P = 3.7 × 10−03]. For NRAS, 5% (3/60) of codon 61 mutant colorectal cancers had KRAS mutations compared with 44% (10/23) of codons 12 and 13 mutant colorectal cancers (P = 7.9 × 10−05). Codon 61 mutations conferred poor prognosis (HR, 1.47; 95% CI, 1.09–1.99; P = 0.01), whereas codons 12 and 13 mutations did not (HR, 1.29; 95% CI, 0.64–2.58; P = 0.48).Conclusions: Our data show considerable intralocus variation in the outcomes of mutations in BRAF and NRAS. These data need to be considered in patient management and personalized cancer therapy. Clin Cancer Res; 23(11); 2742–9. ©2016 AACR.

PDF - 130K, Kaplan-Meier plots of OS and PFS for patients with PIK3CA wild type or mutant tumours, that were also KRAS wild type.

Purpose: To study the somatic molecular profile of the EGF receptor (EGFR) pathway in advanced colorectal cancer, its relationship to prognosis, the site of the primary and metastases, and response to cetuximab.Experimental Design: We used Sequenom and Pyrosequencing for high-throughput somatic profiling of the EGFR pathway in 1,976 tumors from patients with advanced colorectal cancer from the COIN trial (oxaliplatin and fluoropyrimidine chemotherapy ± cetuximab). Correlations between mutations, clinicopathologic, response, and survival data were carried out.Results: Sequenom and Pyrosequencing had 99.0% (9,961/10,063) genotype concordance. We identified 13 different KRAS mutations in 42.3% of advanced colorectal cancers, 2 BRAF mutations in 9.0%, 4 NRAS mutations in 3.6%, and 5 PIK3CA mutations in 12.7%. 4.2% of advanced colorectal cancers had microsatellite instability (MSI). KRAS and PIK3CA exon 9, but not exon 20, mutations cooccurred (P = 8.9 × 10−4) as did MSI and BRAF mutations (P = 5.3 × 10−10). KRAS mutations were associated with right colon cancers (P = 5.2 × 10−5) and BRAF mutations with right (P = 7.2 × 10−5) and transverse colon (P = 9.8 × 10−6) cancers. KRAS mutations were associated with lung-only metastases (P = 2.3 × 10−4), BRAF mutations with peritoneal (P = 9.2 × 10−4) and nodal-only (P = 3.7 × 10−5) metastases, and MSI (BRAFWT) with nodal-only metastases (P = 2.9 × 10−4). MSI (BRAFWT) was associated with worse survival (HR = 1.89, 95% CI 1.30–2.76, P = 8.5 × 10−4). No mutations, subsets of mutations, or MSI status were associated with response to cetuximab.Conclusions: Our data support a functional cooperation between KRAS and PIK3CA in colorectal tumorigenesis and link somatic profiles to the sites of metastases. MSI was associated with poor prognosis in advanced disease, and no individual somatic profile was associated with response to cetuximab in COIN. Clin Cancer Res; 19(15); 4104–13. ©2013 AACR.

Figures S1-S9, Tables S1, S2

PDF - 89K, Inter-relationships between somatic mutations in the EGFR pathway and MSI-status in aCRC.

Purpose:The cytokine IL22 promotes tumor progression in murine models of colorectal cancer. However, the clinical significance of IL22 in human colorectal cancer remains unclear. We sought to determine whether the IL22 pathway is associated with prognosis in human colorectal cancer, and to identify mechanisms by which IL22 can influence disease progression.Experimental Design:Transcriptomic data from stage II/III colon cancers in independent discovery (GSE39582 population-based cohort, N = 566) and verification (PETACC3 clinical trial, N = 752) datasets were used to investigate the association between IL22 receptor expression (encoded by the genes IL22RA1 and IL10RB), tumor mutation status, and clinical outcome using Cox proportional hazard models. Functional interactions between IL22 and mutant KRAS were elucidated using human colorectal cancer cell lines and primary tumor organoids.Results:Transcriptomic analysis revealed a poor-prognosis subset of tumors characterized by high expression of IL22RA1, the alpha subunit of the heterodimeric IL22 receptor, and KRAS mutation [relapse-free survival (RFS): HR = 2.93, P = 0.0006; overall survival (OS): HR = 2.45, P = 0.0023]. KRAS mutations showed a similar interaction with IL10RB and conferred the worst prognosis in tumors with high expression of both IL22RA1 and IL10RB (RFS: HR = 3.81, P = 0.0036; OS: HR = 3.90, P = 0.0050). Analysis of human colorectal cancer cell lines and primary tumor organoids, including an isogenic cell line pair that differed only in KRAS mutation status, showed that IL22 and mutant KRAS cooperatively enhance cancer cell proliferation, in part through augmentation of the Myc pathway.Conclusions:Interactions between KRAS and IL22 signaling may underlie a previously unrecognized subset of clinically aggressive colorectal cancer that could benefit from therapeutic modulation of the IL22 pathway.

Supplementary Tables S1-5 and Figure S1. Supplementary Table S1 - Multivariate model of overall survival including known prognostic factors; Supplementary Table S2 - Univariate analyses of survival in our validation phase; Supplementary Table S3: Gene-dose effect for rs9929218; Supplementary Table S4 - Distribution of rs9929218 genotype by disease stage; Supplementary Table S5 - Univariate analysis of rs9929218 on overall survival according to COIN trial arm; Supplementary Figure S1 - The effect of rs9929218 on survival from the time of diagnosis to death.

Figure - Correlation plot showing inter- and intra-genic relationships between somatic KRAS, BRAF and NRAS mutations and MSI status in aCRC. Tables - Heterogeneity Tests comparing OS to diagnosis to death (Table S1) and the effect of cetuximab on OS (Table S2).

Purpose: Genome-wide association studies have identified numerous loci associated with colorectal cancer risk. Several of these have also been associated with patient survival, although none have been validated. Here, we used large independent training and validation cohorts to identify robust prognostic biomarkers for colorectal cancer.Experimental Design: In our training phase, we analyzed 20 colorectal cancer-risk SNPs from 14 genome-wide associated loci, for their effects on survival in 2,083 patients with advanced colorectal cancer. A Cox survival model was used, stratified for treatment, adjusted for known prognostic factors, and corrected for multiple testing. Three SNPs were subsequently analyzed in an independent validation cohort of 5,552 colorectal cancer patients. A validated SNP was analyzed by disease stage and response to treatment.Results: Three variants associated with survival in the training phase; however, only rs9929218 at 16q22 (intron 2 of CDH1, encoding E-cadherin) was significant in the validation phase. Patients homozygous for the minor allele (AA genotype) had worse survival (training phase HR, 1.43; 95% confidence intervals; CI, 1.20–1.71, P = 5.8 × 10−5; validation phase HR, 1.18; 95% CI, 1.01–1.37, P = 3.2 × 10−2; combined HR, 1.28; 95% CI, 1.14–1.43, P = 2.2 × 10−5). This effect was independent of known prognostic factors, and was significant amongst patients with stage IV disease (P = 2.7 × 10−5). rs9929218 was also associated with poor response to chemotherapy (P = 3.9 × 10−4).Conclusions: We demonstrate the potential of common inherited genetic variants to inform patient outcome and show that rs9929218 identifies approximately 8% of colorectal cancer patients with poor prognosis. rs9929218 may affect CDH1 expression and E-cadherin plays a role in epithelial-to-mesenchymal transition providing a mechanism underlying its prognostic potential. Clin Cancer Res; 21(15); 3453–61. ©2015 AACR.

supplementary methods

Cancer patients treated with capecitabine and oxaliplatin (XELOX) often develop hand-foot syndrome (HFS) or palmar-plantar erythrodysesthesia. Genetic variation in ST6GAL1 is a risk factor for type-2 diabetes (T2D), a disease also associated with HFS. We analysed genome-wide association data for ten toxicities in advanced colorectal cancer (CRC) patients from the COIN and COIN-B trials. 1,055 patients were treated with XELOX ±cetuximab and 745 with folinic acid, fluorouracil and oxaliplatin ±cetuximab. We also analysed rs6783836 in ST6GAL1 with HFS in CRC patients from QUASAR2. Using UK Biobank data, we sought to confirm an association between ST6GAL1 and T2D (17,384 cases, 317,887 controls) and analysed rs6783836 against markers of diabetes, inflammation and psoriasis. We found that 68% of patients from COIN and COIN-B with grade 2-3 HFS responded to treatment as compared to 58% with grade 0-1 HFS (Odds Ratio [OR]=1.1, 95% Confidence Interval [CI]=1.02-1.2, P=2.0x10-4). HFS was also associated with improved overall survival (Hazard Ratio=0.92, 95%CI=0.84-0.99, P=4.6x10-2). rs6783836 at ST6GAL1 was associated with HFS in patients treated with XELOX (OR=3.1, 95%CI=2.1-4.6, P=4.3x10-8) and was borderline significant in patients receiving capecitabine from QUASAR2, but with an opposite allele effect (OR=0.66, 95% CI=0.42-1.03, P=0.05). ST6GAL1 was associated with T2D (lead SNP rs3887925, OR=0.94, 95%CI=0.92-0.96, P=1.2x10-8) and the rs6783836-T allele was associated with lowered HbA1c levels (P=5.9x10-3) and lymphocyte count (P=2.7x10-3), and psoriasis (P=7.5x10-3) beyond thresholds for multiple testing. In conclusion, HFS is a biomarker of treatment outcome and rs6783836 in ST6GAL1 is a potential biomarker for HFS with links to T2D and inflammation.

Outcomes inPatients with newly diagnosed mCRC were registered into FOCUS4 and tested forFOCUS4-C was conducted between April 2017 and Mar 2020 during which time 718 patients were registered; 247 (34%) wereIn this phase II randomized trial, adavosertib improved PFS compared with AM and demonstrates potential as a well-tolerated therapy for

BACKGROUNDIn 2014, the COIN-B clinical trial demonstrated that intermittent cetuximab (IC) was a safe alternative to continuous cetuximab (CC), with less cytotoxic chemotherapy, in first-line treatment for KRAS wild-type metastatic colorectal cancer (mCRC). Cetuximab has been available for this indication in England since 2015, but treatment breaks beyond 6 weeks were prohibited, despite real-world evidence that therapy de-escalation maintains equivalent disease control, but with superior Quality-of-Life (QoL). We performed health economic analyses of IC versus CC and used this evidence to help underpin policy change and guide clinical practice through reduction in unnecessary treatment for mCRC patients.METHODSEmploying cost-minimization analysis, we conducted partitioned survival modelling (PSM) and Markov Chain Monte-Carlo (MCMC) simulation to determine costs and quality-adjusted-life-years for IC versus CC.RESULTSIC reduced costs by £35,763 (PSM; pCONCLUSIONSOur results highlight substantial cost savings achievable by treatment de-escalation, while also reinforcing the importance of therapy breaks to potentially increase tumour responsiveness and reduce treatment toxicity. Our study also highlights how health economic evidence can influence health policy, championing reduced treatment intensity approaches without compromising patient outcomes, which is of particular relevance when addressing the reduced capacity and treatment backlogs experienced during the pandemic.

BackgroundFirst-line therapeutic strategies for patients with BRAFV600E-mutated (BRAFmt) metastatic colorectal cancer (mCRC) mainly rely on subgroup analyses from randomized controlled trials (RCTs). We aimed to assess the prognostic and predictive impact of BRAFmt on the efficacy of targeted therapies with first-line chemotherapy.MethodsIndividual patient data from first-line RCTs with BRAF and KRAS status data in the ARCAD database were pooled. Progression-free survival and overall survival (OS) were assessed using Kaplan-Meier and Cox models. Outcomes were compared between treatment groups that were concurrently randomly assigned whenever possible.ResultsA total of 6391 patients from 10 RCTs were included: 573 BRAFmt (9.0%), 2059 KRASmt (32.2%), and 3759 double wild type (58.8%). BRAFmt mCRC patients experienced statistically significantly poorer OS than those with KRASmt (adjusted hazard ratio [HRadj] = 1.46, 95% confidence interval [CI] = 1.30 to 1.64) and patients with double wild-type tumors (HRadj = 2.14, 95% CI = 1.94 to 2.36). Anti-EGFR agents did not improve progression-free survival or OS of BRAFmt mCRC patients, based on 4 RCTs testing chemotherapy with or without anti-epidermal growth factor receptor (anti-EGFR) (HRadj = 0.96, 95% CI = 0.71 to 1.30; and HRadj = 0.85, 95% CI = 0.66 to 1.14, respectively).ConclusionsOur data suggest that the addition of anti-EGFR agents to chemotherapy is ineffective as first-line treatment for BRAFmt mCRC patients.

3572 Background: Early onset colorectal cancer (eoCRC: disease diagnosed < 50) has been increasing over the past 2 decades. Currently, standard treatment recommendations for eoCRC patients (pts) with metastatic disease does not differ from late-onset CRC (loCRC) pts although outcomes data in eoCRC pts is limited. Methods: Individual patient data on 5,761 treatment-naive metastatic eoCRC pts was pooled from 8 phase II and III randomized EGFRi studies (2000 - 2012) from the ARCAD mCRC database. The distribution of demographics, clinicopathological features, and biomarkers were summarized by age groups. Progression-free survival (PFS) was compared between age groups by stratified Cox models, adjusting for potential confounders. Predictive value of age group was evaluated by testing interaction effect between treatment and age variables based on a subset of trials with concurrent randomizations between regimens with and without EGFRi Results: eoCRC (n=756) were more evenly distributed between gender, had improved performance status (PS), increased likelihood of metastatic resection, and distant lymph node metastasis, but were less likely to have lung metastasis or KRAS mutation compared to loCRC (n=5,005, table 1). eoCRC and loCRC patients had similar distribution of primary tumor sidedness, primary resection, liver and/or peritoneal involvement, number of metastatic sites involved, and BRAF mutations (MT). No difference in PFS for eoCRC versus loCRC pts was noted (7.8 vs. 7.9 months [M], adjusted hazard ratio [HRadj], 1.02, 95% confidence interval [CI], 0.93-1.11). Among pts with KRAS wild type (WT) and left sided primary tumors, univariable analysis of EGFRi demonstrated improved mPFS in loCRC (9.9 vs 8.5M, HR = 0.74, p

The identification of genetic determinants that underpin tumor radioresistance can help the development of targeted radiosensitizers or aid personalization of radiotherapy treatment. Here we identify signal recognition particle 72kDa (SRP72) as a novel gene involved in radioresistance. Knockdown of SRP72 resulted in significant radiosensitization of HeLa (cervical), PSN-1 (pancreatic), and T24 (bladder), BT-549 (breast) and MCF7 (breast) tumor lines as measured by colony formation assays. SRP72 depletion also resulted in the radiosensitization of normal lung fibroblast cell lines (HFL1 and MRC-5), demonstrating that the effect is not restricted to tumor cells. Increased radiosensitivity was not due to impaired DNA damage signaling or repair as assessed by γ-H2AX foci formation. Instead SRP72 depletion was associated with elevated levels of apoptosis after irradiation, as measured by caspase 3/7 activity, PARP-cleavage and Annexin-V staining, and with an induction of the unfolded protein response. Together, our results show that SRP72 is a novel gene involved in radioresistance.

Colorectal cancer (CRC) biopsies underpin accurate diagnosis, but are also relevant for patient stratification in molecularly-guided clinical trials. The consensus molecular subtypes (CMS) and colorectal cancer intrinsic subtypes (CRIS) transcriptional signatures have potential clinical utility for improving prognostic/predictive patient assignment. However, their ability to provide robust classification, in pre-treatment biopsies from multiple regions or at different time points remains untested. In this study, we undertook a comprehensive assessment of the robustness of CRC transcriptional signatures, including CRIS and CMS, using a range of tumour sampling methodologies currently employed in clinical and translational research. These include analyses using (i) laser-capture microdissected CRC tissue, (ii) eight publically available rectal cancer biopsy data sets (n=543), (iii) serial biopsies (from AXEBeam trial, NCT00828672; n=10), (iv) multi-regional biopsies from colon tumours (n=29 biopsies, n=7 tumours) and (v) pre-treatment biopsies from the phase II rectal cancer trial COPERNCIUS (NCT01263171; n=44). Compared to previous results obtained using CRC resection material, we now demonstrate that CMS classification in biopsy tissue is significantly less capable of reliably classifying patient subtype (43% unknown in biopsy versus 13% unknown in resections, p=0.0001). In contrast, there was no significant difference in classification rate between biopsies and resections when using the CRIS classifier. Additionally, we demonstrated that CRIS provides significantly better spatially- and temporally- robust classification of molecular subtypes in CRC primary tumour tissue compared to CMS (p= 0.003 and p=0.02, respectively). These findings may have potential to inform ongoing biopsy-based patient stratification in CRC, enabling robust and stable assignment of patients into clinically-informative arms of prospective multi-arm, multi-stage clinical trials. Citation Format: Matthew Alderdice, Susan D. Richman, Simon Gollins, Peter Stewart, Chris Hurt, Richard Adams, Amy M. McCorry, Aideen Roddy, Dale Vimalachandran, Claudio Isella, Enzo Medico, Tim Maughan, Darrgh G. McArt, Mark Lawler, Philip D. Dunne. Prospective patient stratification into robust cancer-cell intrinsic subtypes from colorectal cancer biopsies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5365.

The aim of palliative chemotherapy is to increase survival whilst maintaining maximum quality of life for the individual concerned. It is evident that the survival advantage offered by palliative chemotherapy for metastatic colorectal cancer has increased incrementally with the addition of each newly licensed therapeutic agent. More recently, advances in the field have led to the introduction of targeted monoclonal antibodies, whose benefits are documented in clinical trials and are acknowledged in their approval and licensing. Whilst we are continuing to explore the optimum use of the more traditional chemotherapy agents, with respect to both quantity and quality of life, these novel agents are battling to find their optimum place in the armamentarium. It is evident that a continuing add-one-in policy is likely to be detrimental to both patient and budget. Defining the positioning and duration of these combination therapies has become the subject of much debate and numerous current clinical trials. The Medical Research Council COIN trial is one of these trials, with a remit to explore further the optimum use of both standard agents and novel agents in the first-line setting for metastatic colorectal cancer.

Purpose This study addressed whether age is prognostic for overall survival (OS) or progression-free survival (PFS) in patients with metastatic colorectal cancer (mCRC). Patients and Methods A total of 20,023 patients from 24 first-line clinical trials in the ARCAD (Aide et Recherche en Cancérologie Digestive) database were analyzed. Primary age effects and interactions with age, sex, performance status (PS), and metastatic site were modeled using Cox proportional hazards stratified by treatment arm within study. Results Of total patients, 3,051 (15%) were age ≤ 50 years. Age was prognostic for both OS (P < .001) and PFS (P < .001), with U-shaped risk (ie, highest risk was evident in youngest and oldest patients). Relative to patients of middle age, the youngest patients experienced 19% (95% CI, 7% to 33%) increased risk of death and 22% (95% CI, 10% to 35%) increased risk of progression. The oldest patients experienced 42% (95% CI, 31% to 54%) increased risk of death and 15% (95% CI, 7% to 24%) increased risk of progression or death. This relationship was more pronounced in the first year of follow-up. Age remained marginally significant for OS (P = .08) when adjusted for PS, sex, and presence of liver, lung, or peritoneal metastases, and age was significant in an adjusted model for PFS (P = .005). The age effect did not differ by site of metastatic disease, year of enrollment, type of therapy received, or biomarker mutational status. Conclusion Younger and older age are associated with poorer OS and PFS among treated patients with mCRC. Younger and older patients may represent higher-risk populations, and additional studies are warranted.

Biallelic inherited mutations in the oxidative DNA damage repair gene MUTYH predispose to colorectal adenomas and colorectal carcinoma (CRC) with high penetrance. We investigated whether rare inherited variants in other oxidative DNA damage repair genes predisposed to CRC. Single marker association analyses were assessed under an allelic model with Bonferroni correction for multiple testing. All statistical tests were two-sided. A rare inherited nonsynonymous variant in OGG1 (Gly308Glu), the functional partner of MUTYH, was over-represented in case patients with advanced CRC compared with population-based control subjects (n = 36 of 2142 case patients vs n = 15 of 2175 control subjects in the training phase, P = 1.8×10(-3); and n = 22 of 1005 case patients vs n = 8 of 1389 control subjects in the validation phase, P = 4.8×10(-4); P = 1.4×10(-5) combined; odds ratio = 2.92, 95% confidence interval = 1.80 to 4.74). Glycine at residue 308 was highly conserved through evolution, and the glutamic acid substitution was predicted as likely to interfere with function. Biallelic inherited and somatic OGG1 mutations were rarely observed in OGG1 (Gly308Glu) carriers, nor did we find any associated somatic mutator phenotype. These data suggest that OGG1 (Gly308Glu) may act as a low-penetrance allele that contributes to colorectal tumorigenesis.

Summary Background In the Medical Research Council (MRC) COIN trial, the epidermal growth factor receptor (EGFR)-targeted antibody cetuximab was added to standard chemotherapy in first-line treatment of advanced colorectal cancer with the aim of assessing effect on overall survival. Methods In this randomised controlled trial, patients who were fit for but had not received previous chemotherapy for advanced colorectal cancer were randomly assigned to oxaliplatin and fluoropyrimidine chemotherapy (arm A), the same combination plus cetuximab (arm B), or intermittent chemotherapy (arm C). The choice of fluoropyrimidine therapy (capecitabine or infused fluouroracil plus leucovorin) was decided before randomisation. Randomisation was done centrally (via telephone) by the MRC Clinical Trials Unit using minimisation. Treatment allocation was not masked. The comparison of arms A and C is described in a companion paper. Here, we present the comparison of arm A and B, for which the primary outcome was overall survival in patients with KRAS wild-type tumours. Analysis was by intention to treat. Further analyses with respect to NRAS, BRAF , and EGFR status were done. The trial is registered, ISRCTN27286448. Findings 1630 patients were randomly assigned to treatment groups (815 to standard therapy and 815 to addition of cetuximab). Tumour samples from 1316 (81%) patients were used for somatic molecular analyses; 565 (43%) had KRAS mutations. In patients with KRAS wild-type tumours (arm A, n=367; arm B, n=362), overall survival did not differ between treatment groups (median survival 17·9 months [IQR 10·3–29·2] in the control group vs 17·0 months [9·4–30·1] in the cetuximab group; HR 1·04, 95% CI 0·87–1·23, p=0·67). Similarly, there was no effect on progression-free survival (8·6 months [IQR 5·0–12·5] in the control group vs 8·6 months [5·1–13·8] in the cetuximab group; HR 0·96, 0·82–1·12, p=0·60). Overall response rate increased from 57% (n=209) with chemotherapy alone to 64% (n=232) with addition of cetuximab (p=0·049). Grade 3 and higher skin and gastrointestinal toxic effects were increased with cetuximab (14 vs 114 and 67 vs 97 patients in the control group vs the cetuximab group with KRAS wild-type tumours, respectively). Overall survival differs by somatic mutation status irrespective of treatment received: BRAF mutant, 8·8 months (IQR 4·5–27·4); KRAS mutant, 14·4 months (8·5–24·0); all wild-type, 20·1 months (11·5–31·7). Interpretation This trial has not confirmed a benefit of addition of cetuximab to oxaliplatin-based chemotherapy in first-line treatment of patients with advanced colorectal cancer. Cetuximab increases response rate, with no evidence of benefit in progression-free or overall survival in KRAS wild-type patients or even in patients selected by additional mutational analysis of their tumours. The use of cetuximab in combination with oxaliplatin and capecitabine in first-line chemotherapy in patients with widespread metastases cannot be recommended. Funding Cancer Research UK, Cancer Research Wales, UK Medical Research Council, Merck KGgA.

Background. Elderly and frail patients with cancer, although often treated with chemotherapy, are under-represented in clinical trials. We designed FOCUS2 to investigate reduced-dose chemotherapy options and to seek objective predictors of outcome in frail patients with advanced colorectal cancer. Methods. We undertook an open, 2 × 2 factorial trial in 61 UK centres for patients with previously untreated advanced colorectal cancer who were considered unfit for full-dose chemotherapy. After comprehensive health assessment (CHA), patients were randomly assigned by minimisation to: 48-h intravenous fluorouracil with levofolinate (group A); oxaliplatin and fluorouracil (group B); capecitabine (group C); or oxaliplatin and capecitabine (group D). Treatment allocation was not masked. Starting doses were 80% of standard doses, with discretionary escalation to full dose after 6 weeks. The two primary outcome measures were: addition of oxaliplatin ([A vs B] + [C vs D]), assessed with progression-free survival (PFS); and substitution of fluorouracil with capecitabine ([A vs C] + [B vs D]), assessed by change from baseline to 12 weeks in global quality of life (QoL). Analysis was by intention to treat. Baseline clinical and CHA data were modelled against outcomes with a novel composite measure, overall treatment utility (OTU). This study is registered, number ISRCTN21221452. Findings. 459 patients were randomly assigned (115 to each of groups A–C, 114 to group D). Factorial comparison of addition of oxaliplatin versus no addition suggested some improvement in PFS, but the finding was not significant (median 5·8 months [IQR 3·3–7·5] vs 4·5 months [2·8–6·4]; hazard ratio 0·84, 95% CI 0·69–1·01, p=0·07). Replacement of fluorouracil with capecitabine did not improve global QoL: 69 of 124 (56%) patients receiving fluorouracil reported improvement in global QoL compared with 69 of 123 (56%) receiving capecitabine. The risk of having any grade 3 or worse toxic effect was not significantly increased with oxaliplatin (83/219 [38%] vs 70/221 [32%]; p=0·17), but was higher with capecitabine than with fluorouracil (88/222 [40%] vs 65/218 [30%]; p=0·03). In multivariable analysis, fewer baseline symptoms (odds ratio 1·32, 95% CI 1·14–1·52), less widespread disease (1·51, 1·05–2·19), and use of oxaliplatin (0·57, 0·39–0·82) were predictive of better OTU. Interpretation. FOCUS2 shows that with an appropriate design, including reduced starting doses of chemotherapy, frail and elderly patients can participate in a randomised controlled trial. On balance, a combination including oxaliplatin was preferable to single-agent fluoropyrimidines, although the primary endpoint of PFS was not met. Capecitabine did not improve QoL compared with fluorouracil. Comprehensive baseline assessment holds promise as an objective predictor of treatment benefit. Funding. Cancer Research UK and the Medical Research Council.

The hypoxic cell radiosensitizers Ro 03-8799 (pimonidazole) and SR 2508 (etanidazole) are under evaluation as single agents (Phase III) and in combination (Phase I). Ro 03-8799 produces an acute, transient central nervous system syndrome, whereas SR 2508 causes cumulative, peripheral neurotoxicity; both effects are dose-limiting. Pharmacokinetic studies have shown the importance of area under the plasma drug concentration versus time curve (AUC) in predicting the risk of peripheral neuropathy. Most patients have very similar pharmacokinetic parameters. This study reports 2/25 patients receiving 0.75 g/m2 Ro 03-8799 plus 2.0 g/m2 SR 2508 who showed significant discrepancies in drug handling. One patient exhibited a markedly elevated AUC and prolonged t1/2 beta for SR 2508 and this was associated with an unusually rapid onset of peripheral neuropathy. A second patient showed normal handling of SR 2508 but prolonged values for both t1/2 alpha and t1/2 beta for Ro 03-8799 and unusually low levels of its N-oxide metabolite. In addition a low peak Ro 03-8799 concentration combined with a very high volume of distribution was found in this patient, leading to a normal AUC value and toxicity profile. Both patients exhibited a relatively low creatinine clearance. The mechanisms which may underlie these findings are discussed, and the importance of pharmacokinetic monitoring in the use of these agents is emphasized.

The discovery over 20 years ago by the Nobel Laureate Stanley Cohen of epidermal growth factor and its receptor, followed by the recognition that this receptor is overexpressed in multiple cancer types, has been of phenomenal significance. From these events the ‘Holy Grail’ of targeted therapy has looked increasingly realistic. Over the last 5 years this work has come of age with the licensing of multiple agents targeting this important mitogenic pathway in multiple tumor types. However, these agents and the technology behind them, while impressive, have resulted in lower clinical response rates than anticipated. In this review we will focus on the epidermal growth factor receptor-targeted therapies in colorectal cancer, why our expectations from these therapies have not yet been fulfilled and how we may predict those cancers that are likely to respond or be resistant to these therapies through a greater appreciation of the intricacy, diversity and dynamism of cellular signaling mechanisms.