Phenotypic consequences of somatic mutations in the ataxia-telangiectasia mutated gene in non-small cell lung cancer

Mutations in the Ataxia-telangiectasia mutated (ATM) gene are frequently found in human cancers, including non-small cell lung cancer (NSCLC). Loss of ATM function confers sensitivity to ionising radiation (IR) and topoisomerase inhibitors and may thus define a subset of cancer patients that could get increased benefit from these therapies. In this study, we evaluated the phenotypic consequences of ATM missense changes reported in seven NSCLC cell lines with regard to radiosensitivity and functionality of ATM signalling. Our data demonstrate that only 2/7 NSCLC cell lines (H1395 and H23) harbouring ATM missense mutations show a functional impairment of ATM signalling following IR-exposure. In these two cell lines, the missense mutations caused a significant reduction in ATM protein levels, impairment of ATM signalling and marked radiosensitivity. Of note, only cell lines with homozygous mutations in the ATM gene showed significant impairment of ATM function. Based on these observations, we developed an immunohistochemistry-based assay to identify patients with loss or reduction of ATM protein expression in a clinical setting. In a set of 137 NSCLC and 154 colorectal cancer specimens we identified tumoral loss of ATM protein expression in 9.5% and 3.9% of cases, respectively, demonstrating the potential utility of this method.

Role of leucocytes in damage to the vascular endothelium during ischaemia-reperfusion injury

During this investigation, a model of tourniquet-induced forearm ischaemia-reperfusion injury is employed to investigate the role of leucocytes in damage to the vascular endothelium during ischaemia-reperfusion injury. Leucocyte entrapment is investigated by measuring the concentration of leucocytes in venous blood leaving the arm. Neutrophil and monocyte leucocyte subpopulations are isolated by density gradient centrifugation techniques. Cell surface expression of CD11b and the intracellular production of hydrogen peroxide are measured via flow cytometry. Plasma concentrations of elastase and von Willebrand factor (vWF) are measured using enzyme-linked immunosorbemt assay (ELISA) techniques. During ischaemia-reperfusion, there was an increase in CD11b cell surface expression on neutrophils (P=0.040) and monocytes (P=0.049), and a decrease in peripheral blood leucocytes (P=0.019). There was an increase in the intracellular production of hydrogen peroxide by leucocyte subpopulations (P=0.027 [neutrophils], P=0.091 [monocytes]) and in the plasma elastase concentration (P=0.05). There was also a trend to increasing plasma concentration of vWF (P=0.0562), which was measured as a marker of endothelial damage. Ischaemia-reperfusion results in increased adhesiveness, entrapment and activation of leucocytes. Even following a mild ischaemic insult, this leucocyte response was followed immediately by evidence of endothelial damage. These results may have important implications for understanding the development of chronic diseases that involve mild ischaemic episodes.

Prognostic value of isolated peritoneal versus other metastatic sites in colorectal cancer (CRC) patients treated by systemic chemotherapy: Findings from 9,265 pts in the ARCAD database

656

Background: Patients (pts) with peritoneal metastases from CRC (pmCRC) have reduced OS compared to mCRC pts without peritoneal involvement. Here we further investigated the impact of number and location of metastases among pts receiving first-line systemic chemotherapy. Methods: Individual patient data were available on 9,265 pts (median age 64; 63% male; 93% ECOG PS 0-1; 68% colon primary tumor; brain metastases excluded) enrolled onto 12 first-line randomized trials (4 tested targeted regimens). Stratified multivariable Cox models were used to assess the associations with overall survival (OS); adjusted hazard ratios (HRadj) and 95% confidence intervals are reported (CI). Results: There were 7,963 (86%) pts with non-pmCRC (3,904 with one disease site; 4,059 with ≥2 disease sites), 191 (2%) pts with isolated pmCRC, and 1,111 (12%) non-isolated pmCRC. These groups were similar in age, race, and use of targeted chemotherapy. Compared to non-pmCRC, pts with pmCRC were more likely to be female (41% vs. 36%, p<.001), have colon primary tumors (85% vs. 67%, p<.0001), and have PS2 (10% vs. 6%, p<.0001). Compared to isolated pmCRC, pts with solitary non-peritoneal sites (both M1a) had significantly better OS (HRadj=0.78; CI, 0.64-0.94, p=.009) while pts with ≥2 non-peritoneal sites had similar OS (HRadj=1.06; CI 0.88-1.28, p=.535). OS of pts with pmCRC with a single other disease site (n=446) was similar to isolated pmCRC (HRadj=1.13; CI 0.91-1.40, p=.28), but those with pmCRC + ≥2 additional disease sites (n=665) had shortest survival (HRadj=1.44; CI 1.17-1.77, p<.001). A combination of peritoneal and liver metastases (n=821; HRadj=1.37, CI 1.12-1.67, p=.002) was associated with poorer survival compared with isolated pmCRC; but combination with extrahepatic sites (n=290; HRadj=1.15, CI 0.91-1.45, p=.25) was not. Conclusions: pmCRC pts have significantly worse survival than those with other solitary site mCRC. Among those with multiple disease sites, poorer survival is a function of increased number of metastatic sites and peritoneal involvement, which indicates prognostic heterogeneities among M1b pts.

Post-treatment surveillance in locally advanced squamous cell carcinoma (SCCA) of the anal canal: A global subspecialist survey

573

Background: Squamous cell carcinoma of the anal canal will be diagnosed in 28,000 individuals globally. Considered a rare cancer, the incidence of anal carcinoma continues to rise annually. Majority of patients present with locally advanced disease in which concurrent chemoradiation (CRT) will be provided with curative intent. The Anal Cancer IRCI Working Group was created to pursue novel approaches to the diagnosis, treatment, and surveillance of patients. Yet, surveillance following completion of CRT is not well established and varies as per NCCN (v2.2015) and ESMO guidelines. Methods: A 22-question survey provided to anonymous international GI subspecialists in various fields. Questions pertained to timing and type of diagnostic imaging, surveillance interval, approach to detection of complete response (CR), and prevention of sexual dysfunction. Results: Survey distribution was initiated in March 2015 and still ongoing. Thus far, 96 physicians responded. Conclusions: Carcinoma of the anal canal continues to rise in incidence annually. Surveillance following completion of CRT is warranted; however, global variability in practice patterns for surveillance exists. As such, the IRCI Anal Cancer Working Group intends to provide an international consensus surveillance statement. [Table: see text]

Body Mass Index Is Prognostic in Metastatic Colorectal Cancer: Pooled Analysis of Patients From First-Line Clinical Trials in the ARCAD Database

PURPOSE

In recent retrospective analyses of early-stage colorectal cancer (CRC), low and high body mass index (BMI) scores were associated with worsened outcomes. Whether BMI is a prognostic or predictive factor in metastatic CRC (mCRC) is unclear.

PATIENTS AND METHODS

Individual data from 21,149 patients enrolled onto 25 first-line mCRC trials during 1997 to 2012 were pooled. We assessed both prognostic and predictive effects of BMI on overall survival and progression-free survival, and we accounted for patient and tumor characteristics and therapy type (targeted v nontargeted).

RESULTS

BMI was prognostic for overall survival (P < .001) and progression-free survival (P < .001), with an L-shaped pattern. That is, risk of progression and/or death was greatest for low BMI; risk decreased as BMI increased to approximately 28 kg/m(2), and then it plateaued. Relative to obese patients, patients with a BMI of 18.5 kg/m(2) had a 27% increased risk of having a PFS event (95% CI, 20% to 34%) and a 50% increased risk of death (95% CI, 43% to 56%). Low BMI was associated with poorer survival for men than women (interaction P < .001). BMI was not predictive of treatment effect.

CONCLUSION

Low BMI is associated with an increased risk of progression and death among the patients enrolled on the mCRC trials, with no increased risk for elevated BMI, in contrast to the adjuvant setting. Possible explanations include negative effects related to cancer cachexia in patients with low BMI, increased drug delivery or selection bias in patients with high BMI, and potential for an interaction between BMI and molecular signaling pathways.

Epidermal growth factor receptor immunohistochemistry: new opportunities in metastatic colorectal cancer

The treatment of cancer is becoming more precise, targeting specific oncogenic drivers with targeted molecular therapies. The epidermal growth factor receptor has been found to be over-expressed in a multitude of solid tumours. Immunohistochemistry is widely used in the fields of diagnostic and personalised medicine to localise and visualise disease specific proteins. To date the clinical utility of epidermal growth factor receptor immunohistochemistry in determining monoclonal antibody efficacy has remained somewhat inconclusive. The lack of an agreed reproducible scoring criteria for epidermal growth factor receptor immunohistochemistry has, in various clinical trials yielded conflicting results as to the use of epidermal growth factor receptor immunohistochemistry assay as a companion diagnostic. This has resulted in this test being removed from the licence for the drug panitumumab and not performed in clinical practice for cetuximab. In this review we explore the reasons behind this with a particular emphasis on colorectal cancer, and to suggest a way of resolving the situation through improving the precision of epidermal growth factor receptor immunohistochemistry with quantitative image analysis of digitised images complemented with companion molecular morphological techniques such as in situ hybridisation and section based gene mutation analysis.

InterAACT: An international multicenter open label randomized phase II advanced anal cancer trial comparing cisplatin (CDDP) plus 5-fluorouracil (5-FU) versus carboplatin (CBDCA) plus weekly paclitaxel (PTX) in patients with inoperable locally recurrent (ILR) or metastatic disease

TPS792

Background: Metastatic squamous cell carcinoma of the anus (SCCA) is a rare condition with 5-year overall survival (OS) rate of 32%. CDDP/5-FU is commonly used in the first-line treatment of patients with ILR or metastatic disease. This practice is based on retrospective series and data from randomised trials are lacking. Recent retrospective studies showed promising activity of CBDCA/PTX in this setting. Methods: InterAACT is an international, multicentre, open label, randomised phase II trial comparing two chemotherapy regimens in patients with ILR or metastatic SCCA. Eligible patients are randomised in a 1:1 ratio to CDDP (60 mg/mq, D1q21) plus 5-FU (1000 mg/mq/24h, D1-4q21) or CBDCA (AUC 5, D1q28) plus PTX (80 mg/mq, D1,8,15q28). Stratification factors are: performance status, extent of disease, HIV status and country. The primary endpoint is response rate (RR). Secondary endpoints include progression-free survival, OS, toxicity and quality of life. Based on a RR estimate of 40% in the CDDP/5-FU arm 80 patients are to be recruited to detect 10% difference in RR between the two arms with 80% power (phase II selection trial design). Correlative biomarker analyses are planned in tumour tissue and blood samples. The trial is sponsored by The Royal Marsden NHS Foundation Trust and endorsed by the International Rare Cancer Initiative (IRCI) group. Approximately 50 centres in the UK, Europe (EORTC), Scandinavia, US (ECOG-ACRIN) and Australia (AGITG) are estimated to participate and recruitment is anticipated to be completed within 3 years. Recruitment started in December 2013. As of September 16, 2014, 6 sites in the UK are open to recruitment and 6 patients have been randomised (3 to CDDP/5-FU and 3 to CBDCA/PTX). InterAACT aims to provide the first randomised evidence for the treatment of ILR and metastatic SCCA, to identify the optimal chemotherapy backbone to combine with targeted agents in future studies and to confirm the feasibility of conducting an international multicentre trial for this rare tumour. Clinical trial information: NCT02051868.

Regional variation in physicians’ awareness, understanding, and use of personalized medicine in the treatment of cancer and perception of patient (pt) education

574

Background: A multinational survey of oncologists was conducted to assess the awareness and use of biomarkers in clinical practice (Ciardiello et al, ESMO 2014). These data explore regional variations as well as perceived level of “cancer literacy” among pts. Methods: Ten-minute online interviews were conducted with practicing oncology specialists (3 to 35 years of experience, treating > 15 pts/month) from 12 representative countries in Europe, South America, and Asia. Results: In total, 895 interviews were completed; numerous regional differences were observed. While most physicians use biomarkers (90%), there were marked regional variations. KRAS was the most frequent test. Among the 10% of physicians not using biomarkers, local availability of testing, speed of obtaining results, and cost were cited as the main reasons. The majority of Chinese doctors indicated that physician training (82%) and better biomarker information for pts (83%) would enable them to use biomarkers more often (global averages: 38% and 34%, respectively). Striking variation was seen in physicians’ assessment of pts’ knowledge of cancer biology, treatment options, use of biomarkers, and involvement in their own treatment plans. Only 38% of German physicians believed their pts know that tumors can be tested to help decide which treatment to give (global average: 73%). Only 21% of Saudi Arabian physicians believed the treatment decision process is shared between the doctor and/or multidisciplinary team and pt (global average: 82%). While physicians felt specialist nurses were the best source of information for pts, only 45% globally believed pts had access to these nurses (ranging from 19% in Russia to 83% in the UK). Conclusions: These data demonstrate wide global use of biomarkers but with regional variations reflecting cultural and local practice. Perception of pt cancer literacy and pt access to information also differs widely. Most physicians agree, however, that pts require more information to understand their disease better and become involved in treatment decisions.

A feasibility study testing four hypotheses with phase II outcomes in advanced colorectal cancer (MRC FOCUS3): a model for randomised controlled trials in the era of personalised medicine?

BACKGROUND

Molecular characteristics of cancer vary between individuals. In future, most trials will require assessment of biomarkers to allocate patients into enriched populations in which targeted therapies are more likely to be effective. The MRC FOCUS3 trial is a feasibility study to assess key elements in the planning of such studies.

PATIENTS AND METHODS

Patients with advanced colorectal cancer were registered from 24 centres between February 2010 and April 2011. With their consent, patients' tumour samples were analysed for KRAS/BRAF oncogene mutation status and topoisomerase 1 (topo-1) immunohistochemistry. Patients were then classified into one of four molecular strata; within each strata patients were randomised to one of two hypothesis-driven experimental therapies or a common control arm (FOLFIRI chemotherapy). A 4-stage suite of patient information sheets (PISs) was developed to avoid patient overload.

RESULTS

A total of 332 patients were registered, 244 randomised. Among randomised patients, biomarker results were provided within 10 working days (w.d.) in 71%, 15 w.d. in 91% and 20 w.d. in 99%. DNA mutation analysis was 100% concordant between two laboratories. Over 90% of participants reported excellent understanding of all aspects of the trial. In this randomised phase II setting, omission of irinotecan in the low topo-1 group was associated with increased response rate and addition of cetuximab in the KRAS, BRAF wild-type cohort was associated with longer progression-free survival.

CONCLUSIONS

Patient samples can be collected and analysed within workable time frames and with reproducible mutation results. Complex multi-arm designs are acceptable to patients with good PIS. Randomisation within each cohort provides outcome data that can inform clinical practice.

Somatic profiling of the epidermal growth factor receptor pathway in tumors from patients with advanced colorectal cancer treated with chemotherapy ± cetuximab

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 (BRAF(WT)) with nodal-only metastases (P = 2.9 × 10(-4)). MSI (BRAF(WT)) 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.

Comprehensive pharmacogenetic profiling of advanced colorectal cancer

3509

Background: Inherited genetic factors may influence a patient’s response to, and side effects from, chemotherapy and biological therapies. Here, we sought to generate a comprehensive inherited pharmacogenetic profile for advanced colorectal cancer (aCRC). Methods: We analysed 260 potentially functional coding region and promoter variants in genes within the 5-FU, capecitabine, oxaliplatin, EGFR and DNA repair pathways in 2183 patients with aCRC treated with oxaliplatin-fluoropyrimidine chemotherapy ± cetuximab (from the MRC COIN and COIN-B trials). Primary outcomes assessed were 12-week response, skin rash (SR) (for those receiving cetuximab), dose-reduction or delay in treatment due to any toxicity and peripheral neuropathy (PN). Results: For variants with minor allele frequencies >20%, we had >85% power to detect an effect on response / toxicity with an OR of 1.3. In patients treated with chemotherapy + cetuximab, 5 and 4 coding region variants in the EGFR pathway were associated with response and SR, respectively. The most significant associations were with variants in members of phosphatidylinositol 3-kinase regulatory subunit. In patients treated with chemotherapy ± cetuximab, 8 coding region variants in the 5-FU, capecitabine, oxaliplatin or DNA repair pathways were associated with response, 8 with any toxicity and 5 with PN. The most significant associations for response were with variants in DNA repair genes and, for any toxicity, with common variants in DPYD. Conclusions: Our study highlights the difficulty in identifying inherited biomarkers for the treatment of aCRC - despite using samples from the largest reported randomised trial for aCRC, with considerable power to detect alleles of small effects, none of the associations remained significant after rigorous correction for multiple testing.

FOCUS4: A prospective molecularly stratified, adaptive multicenter program of randomized controlled trials for patients with colorectal cancer (CRC)

TPS3645

Background: Targeted therapies based on somatic gene mutations or activated pathways have inhibited progression of some cancers. However, although various targets are identifiable in CRC, KRAS mutation is currently the only validated predictive biomarker for selection of a targeted therapy. FOCUS4 is a rolling phase II-III trial for testing in a staged way both the utility of molecular stratification and the efficacy of novel agents in subpopulations of mCRC patients. It is also a trial of a new strategy for testing stratified approaches to therapy in any biologically complex tumour type using a Multi-Arm, Multi-Stage design. Methods: The study population consists of subjects with newly diagnosed inoperable mCRC. Subjects receive first-line chemotherapy for 16 weeks. During this time the tumour is tested for BRAF/PIK3CA/KRAS/NRAS mutations and PTEN loss. Subjects with responding or stable disease on CT, who would normally be candidates for a treatment break, are then randomised to four coherent biomarker-based subgroups: FOCUS4-A: BRAF mutant, FOCUS4-B: PIK3CA mutant or complete loss of PTEN on IHC, FOCUS4-C: KRAS or NRAS mutant, FOCUS4-D: All wild type (no mutations of BRAF, PIK3CA, KRAS or NRAS). For each subgroup, a relevant novel agent or combination is to be tested in an adaptive double-blind placebo controlled randomised trial design with multiple interim analyses for early termination if there is no strong evidence of worthwhile activity. There will also be a 5thsubgroup FOCUS4-N testing maintenance capecitabine for unclassifiable tumours or for patients whose marker defined cohort is temporarily suspended. The primary endpoint is progression free survival. Promising results in any biomarker defined cohort will then be tested for response in cohorts without the biomarker. Within the overall trial, biomarker developments can be accommodated with changes in the distribution of the cohorts or testing of new targeted agents. Enrolment will commence in May 2013. Upto 3400 patients will be registered over a 4-5 year period depending on which cohorts pass their staged interim analyses and proceed to later stages, including an overall survival endpoint. Clinical trial information: 2012-005111-12.