Impact of the new rectal cancer definition on multimodality treatment and interhospital variability: Results from a nationwide cross-sectional study

AIM

This study aimed to determine the consequences of the new definition of rectal cancer for decision-making in multidisciplinary team meetings (MDT). The new definition of rectal cancer, the lower border of the tumour is located below the sigmoid take-off (STO), was implemented in the Dutch guideline in 2019 after an international Delphi consensus meeting to reduce interhospital variations.

METHOD

All patients with rectal cancer according to the local MDT, who underwent resection in 2016 in the Netherlands were eligible for this nationwide collaborative cross-sectional study. MRI-images were rereviewed, and the tumours were classified as above or on/below the STO.

RESULTS

This study registered 3107 of the eligible 3178 patients (98%), of which 2784 patients had an evaluable MRI. In 314 patients, the tumour was located above the STO (11%), with interhospital variation between 0% and 36%. Based on TN-stage, 175 reclassified patients with colon cancer (6%) would have received different treatment (e.g., omitting neoadjuvant radiotherapy, candidate for adjuvant chemotherapy). Tumour location above the STO was independently associated with lower risk of 4-year locoregional recurrence (HR 0.529; p = 0.030) and higher 4-year overall survival (HR 0.732; p = 0.037) compared to location under the STO.

CONCLUSION

By using the STO, 11% of the prior MDT-based diagnosis of rectal cancer were redefined as sigmoid cancer, with potential implications for multimodality treatment and prognostic value. Given the substantial interhospital variation in proportion of redefined cancers, the use of the STO will contribute to standardisation and comparability of outcomes in both daily practice and trial settings.

Hepatic arterial infusion pump chemotherapy combined with systemic chemotherapy for borderline resectable and unresectable colorectal liver metastases: phase II feasibility study

BACKGROUND

Hepatic arterial infusion pump chemotherapy combined with systemic chemotherapy (HAIP-SYS) for liver-only colorectal liver metastases (CRLMs) has shown promising results but has not been adopted worldwide. This study evaluated the feasibility of HAIP-SYS in the Netherlands.

METHODS

This was a single-arm phase II study of patients with CRLMs who received HAIP-SYS consisting of floxuridine with concomitant systemic FOLFOX or FOLFIRI. Main inclusion and exclusion criteria were borderline resectable or unresectable liver-only metastases, suitable arterial anatomy and no previous local treatment. Patients underwent laparotomy for pump implantation and primary tumour resection if in situ. Primary end point was feasibility, defined as ≥70% of patients completing two cycles of HAIP-SYS. Sample size calculations led to 31 patients. Secondary outcomes included safety and tumour response.

RESULTS

Thirty-one patients with median 13 CRLMs (i.q.r. 6-23) were included. Twenty-eight patients (90%) received two HAIP-SYS cycles. Three patients did not get two cycles due to extrahepatic disease at pump placement, definitive pathology of a recto-sigmoidal squamous cell carcinoma, and progressive disease. Five patients experienced grade 3 surgical or pump device-related complications (16%) and 11 patients experienced grade ≥3 chemotherapy toxicity (38%). At first radiological evaluation, disease control rate was 83% (24/29 patients) and hepatic disease control rate 93% (27/29 patients). At 6 months, 19 patients (66%) had experienced grade ≥3 chemotherapy toxicity and the disease control rate was 79%.

CONCLUSION

HAIP-SYS for borderline resectable and unresectable CRLMs was feasible and safe in the Netherlands. This has led to a successive multicentre phase III randomized trial investigating oncological benefit (EUDRA-CT 2023-506194-35-00). Current trial registration number: clinicaltrials.gov (NCT04552093).

Extrahepatic perfusion and incomplete hepatic perfusion after hepatic arterial infusion pump implantation: incidence and clinical implications

INTRODUCTION

This study investigates the incidence of extrahepatic perfusion and incomplete hepatic perfusion at intraoperative methylene blue testing and on postoperative nuclear imaging in patients undergoing hepatic arterial infusion pump (HAIP) chemotherapy.

METHODS

The first 150 consecutive patients who underwent pump implantation in the Netherlands were included. All patients underwent surgical pump implantation with the catheter in the gastroduodenal artery. All patients underwent intraoperative methylene blue testing and postoperative nuclear imaging (99mTc-Macroaggregated albumin SPECT/CT) to determine perfusion via the pump.

RESULTS

Patients were included between January-2018 and December-2021 across eight centers. During methylene blue testing, 29.3% had extrahepatic perfusion, all successfully managed intraoperatively. On nuclear imaging, no clinically relevant extrahepatic perfusion was detected (0%, 95%CI: 0.0-2.5%). During methylene blue testing, 2.0% had unresolved incomplete hepatic perfusion. On postoperative nuclear imaging, 8.1% had incomplete hepatic perfusion, leading to embolization in only 1.3%.

CONCLUSION

Methylene blue testing during pump placement for intra-arterial chemotherapy identified extrahepatic perfusion in 29.3% of patients, but could be resolved intraoperatively in all patients. Postoperative nuclear imaging found no clinically relevant extrahepatic perfusion and led to embolization in only 1.3% of patients. The role of routine nuclear imaging after HAIP implantation should be studied in a larger cohort.

Optimized whole-genome sequencing workflow for tumor diagnostics in routine pathology practice

Two decades after the genomics revolution, oncology is rapidly transforming into a genome-driven discipline, yet routine cancer diagnostics is still mainly microscopy based, except for tumor type-specific predictive molecular tests. Pathology laboratories struggle to quickly validate and adopt biomarkers identified by genomics studies of new targeted therapies. Consequently, clinical implementation of newly approved biomarkers suffers substantial delays, leading to unequal patient access to these therapies. Whole-genome sequencing (WGS) can successfully address these challenges by providing a stable molecular diagnostic platform that allows detection of a multitude of genomic alterations in a single cost-efficient assay and facilitating rapid implementation, as well as by the development of new genomic biomarkers. Recently, the Whole-genome sequencing Implementation in standard Diagnostics for Every cancer patient (WIDE) study demonstrated that WGS is a feasible and clinically valid technique in routine clinical practice with a turnaround time of 11 workdays. As a result, WGS was successfully implemented at the Netherlands Cancer Institute as part of routine diagnostics in January 2021. The success of implementing WGS has relied on adhering to a comprehensive protocol including recording patient information, sample collection, shipment and storage logistics, sequencing data interpretation and reporting, integration into clinical decision-making and data usage. This protocol describes the use of fresh-frozen samples that are necessary for WGS but can be challenging to implement in pathology laboratories accustomed to using formalin-fixed paraffin-embedded samples. In addition, the protocol outlines key considerations to guide uptake of WGS in routine clinical care in hospitals worldwide.

Abandonment of Routine Radiotherapy for Nonlocally Advanced Rectal Cancer and Oncological Outcomes

Importance

Neoadjuvant short-course radiotherapy was routinely applied for nonlocally advanced rectal cancer (cT1-3N0-1M0 with >1 mm distance to the mesorectal fascia) in the Netherlands following the Dutch total mesorectal excision trial. This policy has shifted toward selective application after guideline revision in 2014.

Objective

To determine the association of decreased use of neoadjuvant radiotherapy with cancer-related outcomes and overall survival at a national level.

Design, Setting, and Participants

This multicenter, population-based, nationwide cross-sectional cohort study analyzed Dutch patients with rectal cancer who were treated in 2011 with a 4-year follow-up. A similar study was performed in 2021, analyzing all patients that were surgically treated in 2016. From these cohorts, all patients with cT1-3N0-1M0 rectal cancer and radiologically unthreatened mesorectal fascia were included in the current study. The data of the 2011 cohort were collected between May and October 2015, and the data of the 2016 cohort were collected between October 2020 and November 2021. The data were analyzed between May and October 2022.

Main Outcomes and Measures

The main outcomes were 4-year local recurrence and overall survival rates.

Results

Among the 2011 and 2016 cohorts, 1199 (mean [SD] age, 68 [11] years; 430 women [36%]) of 2095 patients (57.2%) and 1576 (mean [SD] age, 68 [10] years; 547 women [35%]) of 3057 patients (51.6%) had cT1-3N0-1M0 rectal cancer and were included, with proportions of neoadjuvant radiotherapy of 87% (2011) and 37% (2016). Four-year local recurrence rates were 5.8% and 5.5%, respectively (P = .99). Compared with the 2011 cohort, 4-year overall survival was significantly higher in the 2016 cohort (79.6% vs 86.4%; P < .001), with lower non-cancer-related mortality (13.8% vs 6.3%; P < .001).

Conclusions and Relevance

The results of this cross-sectional study suggest that an absolute 50% reduction in radiotherapy use for nonlocally advanced rectal cancer did not compromise cancer-related outcomes at a national level. Optimizing clinical staging and surgery following the Dutch total mesorectal excision trial has potentially enabled safe deintensification of treatment.

Recurrent Colorectal Liver Metastases: Upfront Local Treatment versus Neoadjuvant Systemic Therapy Followed by Local Treatment (COLLISION RELAPSE): Study Protocol of a Phase III Prospective Randomized Controlled Trial

PURPOSE

The objective of the COLLISION RELAPSE trial is to prove or disprove superiority of neoadjuvant systemic therapy followed by repeat local treatment (either thermal ablation and/or surgical resection), compared to repeat local treatment alone, in patients with at least one recurrent locally treatable CRLM within one year and no extrahepatic disease.

METHODS

A total of 360 patients will be included in this phase III, multicentre randomized controlled trial. The primary endpoint is overall survival. Secondary endpoints are distant progression-free survival, local tumour progression-free survival analysed per patient and per tumour, systemic therapy-related toxicity, procedural morbidity and mortality, length of hospital stay, pain assessment and quality of life, cost-effectiveness ratio and quality-adjusted life years.

DISCUSSION

If the addition of neoadjuvant systemic therapy to repeat local treatment of CRLM proves to be superior compared to repeat local treatment alone, this may lead to a prolonged life expectancy and increased disease-free survival at the cost of possible systemic therapy-related side effects.

LEVEL OF EVIDENCE

Level 1, phase III randomized controlled trial.

TRIAL REGISTRATION

NCT05861505. May 17, 2023.

Challenging case of deficient mismatch repair right-sided locally advanced adenocarcinoma of the ascending colon with duodenal involvement: A case report including step-by-step video of operation

INTRODUCTION AND IMPORTANCE

Irresectable colon cancer presents a complex clinical challenge. Neoadjuvant immunotherapy has shown potential in improving resectability. Additionally, advancements in surgical techniques, including complete mesocolic excision (CME) with central vascular ligation (CVL), have contributed to better outcomes for right-sided colon cancer. This case report aims to demonstrate the successful laparoscopic resection of initial appearing irresectable colon cancer with suspected duodenal involvement.

CASE PRESENTATION

A 70-year-old female presented with an irresectable mismatch repair deficient (dMMR) adenocarcinoma of the ascending colon with suspected duodenal ingrowth. Neoadjuvant treatment with pembrolizumab and ataluren resulted in a significant response, allowing for surgical resection. A laparoscopic right hemicolectomy with CME, including CVL, intracorporeal anastomosis and extraction through a Pfannenstiel incision, was performed. Additionally, the serosal layer of the duodenum was shaved after observing the absence of intraluminal invasion. Postoperatively, transient gastroparesis occurred, but overall outcomes were favourable.

CLINICAL DISCUSSION

This case emphasizes the potential of immunotherapy in improving resectability for irresectable dMMR colon cancer with suspected involvement of surrounding organs. The combination of neoadjuvant therapy and advanced surgical techniques, such as CME with CVL, shows promise in achieving favourable clinical outcomes. However, further studies are needed to validate the effectiveness and safety of this combined approach in a larger cohort of patients.

CONCLUSION

The successful laparoscopic resection of initially irresectable dMMR colon cancer with duodenal involvement, following neoadjuvant immunotherapy, demonstrated promising outcomes. This case advocates for further exploration of neoadjuvant treatments' efficacy, coupled with advanced surgical techniques, in managing locally advanced right-sided colon cancer.

Health-Related Quality of Life in Patients With Metastatic Colorectal Cancer Undergoing Systemic Therapy With or Without Maximal Tumor Debulking

BACKGROUND

Maintaining a sufficient health-related quality of life (HRQoL) is important in the palliative treatment of patients with metastatic colorectal cancer (mCRC). The ORCHESTRA trial (ClinicalTrials.gov identifier: NCT01792934) is designed to prospectively evaluate overall survival benefit and impact on HRQoL of tumor debulking when added to first-line palliative systemic therapy in patients with multiorgan mCRC. In the present study, we report the HRQoL associated with this combination treatment compared with standard systemic therapy.

METHODS

Patients included in the ORCHESTRA trial with clinical benefit after 3 or 4 cycles of first-line palliative systemic therapy with fluoropyrimidines and oxaliplatin with or without bevacizumab were randomly assigned to maximal tumor debulking followed by systemic therapy versus systemic therapy alone. Patients completed the EORTC Quality of Life Questionnaire-Core 30 and the Multidimensional Fatigue Inventory questionnaire at prespecified time points during treatment. Between-group differences in HRQoL over time were evaluated with linear mixed model analyses. A pattern mixture approach was applied to correct for missing questionnaires due to progressive disease.

RESULTS

A total of 300 patients were randomized to the intervention arm (n=148) or the standard arm (n=152). No statistically significant or clinically relevant differences in HRQoL and fatigue were observed when tumor debulking was added to systemic therapy. In patients of both study arms, HRQoL after 1 year of treatment was not significantly different from HRQoL at the time of randomization. Patients in the intervention arm experienced serious adverse events (SAEs) twice as often as patients in the standard arm (P≤.001).

CONCLUSIONS

Maximal tumor debulking in combination with palliative systemic therapy in patients with multiorgan mCRC was significantly associated with more SAEs resulting from local therapy but no difference in HRQoL compared with palliative systemic therapy alone. There is a remarkable lack of association between the occurrence of SAEs and impact on HRQoL.

Efficacy of Thermal Ablation for Small-Size (0-3 cm) versus Intermediate-Size (3-5 cm) Colorectal Liver Metastases: Results from the Amsterdam Colorectal Liver Met Registry (AmCORE)

PURPOSE

Thermal ablation is widely recognized as the standard of care for small-size unresectable colorectal liver metastases (CRLM). For larger CRLM safety, local control and overall efficacy are not well established and insufficiently validated. The purpose of this comparative series was to analyze outcomes for intermediate-size versus small-size CRLM.

MATERIAL AND METHODS

Patients treated with thermal ablation between December 2000 and November 2021 for small-size and intermediate-size CRLM were included. The primary endpoints were complication rate and local control (LC). Secondary endpoints included local tumor progression-free survival (LTPFS) and overall survival (OS).

RESULTS

In total, 59 patients were included in the intermediate-size (3-5 cm) group and 221 in the small-size (0-3 cm) group. Complications were not significantly different between the two groups (p = 0.546). No significant difference between the groups was found in an overall comparison of OS (HR 1.339; 95% CI 0.824-2.176; p = 0.239). LTPFS (HR 3.388; p < 0.001) and LC (HR 3.744; p = 0.004) were superior in the small-size group. Nevertheless, the 1-, 3-, and 5-year LC for intermediate-size CRLM was still 93.9%, 85.4%, and 81.5%, and technical efficacy improved over time.

CONCLUSIONS

Thermal ablation for intermediate-size unresectable CRLM is safe and induces long-term LC in the vast majority. The results of the COLLISION-XL trial (unresectable colorectal liver metastases: stereotactic body radiotherapy versus microwave ablation-a phase II randomized controlled trial for CRLM 3-5 cm) are required to provide further clarification of the role of local ablative methods for intermediate-size unresectable CRLM.

Unresectable Intermediate-Size (3-5 cm) Colorectal Liver Metastases: Stereotactic Ablative Body Radiotherapy Versus Microwave Ablation (COLLISION-XL): Protocol of a Phase II/III Multicentre Randomized Controlled Trial

BACKGROUND

Although microwave ablation (MWA) has a low complication rate and good efficacy for small-size (≤ 3 cm) colorectal liver metastases (CRLM), local control decreases with increasing size. Stereotactic body radiotherapy (SBRT) is gaining interest as a potential means to treat intermediate-size CRLM and might be less susceptible to increasing volume. The objective of this study is to compare the efficacy of MWA to SBRT in patients with unresectable, intermediate-size (3-5 cm) CRLM.

METHODS

In this two-arm, multicentre phase II/ III randomized controlled trial, 68 patients with 1-3 unresectable, intermediate-size CRLM suitable for both MWA and SBRT, will be included. Patients will be treated with MWA or SBRT as randomised. The Primary endpoint is local tumour progression-free survival (LTPFS) at 1 year (intention-to-treat analysis). Main secondary endpoints are overall survival, overall and distant progression-free survival (DPFS), local control (LC) and procedural morbidity and mortality and assessment of pain and quality of life.

DISCUSSION

Current guidelines lack clear recommendations for the local treatment of liver only intermediate-size, unresectable CRLM and studies comparing curative intent SBRT and thermal ablation are scarce. Although safety and feasibility to eradicate tumours ≤ 5 cm have been established, both techniques suffer from lower LTPFS and LC rates for larger-size tumours. For the treatment of unresectable intermediate-size CRLM clinical equipoise has been reached. We have designed a two-armed phase II/ III randomized controlled trial directly comparing SBRT to MWA for unresectable CRLM 3-5 cm.

LEVEL OF EVIDENCE

Level 1, phase II/ III Randomized controlled trial.

TRIAL REGISTRATION

NCT04081168, September 9th 2019.

Delphi Initiative for Early-Onset Colorectal Cancer (DIRECt) International Management Guidelines

BACKGROUND & AIMS

Patients with early-onset colorectal cancer (eoCRC) are managed according to guidelines that are not age-specific. A multidisciplinary international group (DIRECt), composed of 69 experts, was convened to develop the first evidence-based consensus recommendations for eoCRC.

METHODS

After reviewing the published literature, a Delphi methodology was used to draft and respond to clinically relevant questions. Each statement underwent 3 rounds of voting and reached a consensus level of agreement of ≥80%.

RESULTS

The DIRECt group produced 31 statements in 7 areas of interest: diagnosis, risk factors, genetics, pathology-oncology, endoscopy, therapy, and supportive care. There was strong consensus that all individuals younger than 50 should undergo CRC risk stratification and prompt symptom assessment. All newly diagnosed eoCRC patients should receive germline genetic testing, ideally before surgery. On the basis of current evidence, endoscopic, surgical, and oncologic treatment of eoCRC should not differ from later-onset CRC, except for individuals with pathogenic or likely pathogenic germline variants. The evidence on chemotherapy is not sufficient to recommend changes to established therapeutic protocols. Fertility preservation and sexual health are important to address in eoCRC survivors. The DIRECt group highlighted areas with knowledge gaps that should be prioritized in future research efforts, including age at first screening for the general population, use of fecal immunochemical tests, chemotherapy, endoscopic therapy, and post-treatment surveillance for eoCRC patients.

CONCLUSIONS

The DIRECt group produced the first consensus recommendations on eoCRC. All statements should be considered together with the accompanying comments and literature reviews. We highlighted areas where research should be prioritized. These guidelines represent a useful tool for clinicians caring for patients with eoCRC.

Neoadjuvant FOLFOXIRI prior to chemoradiotherapy for high-risk ("ugly") locally advanced rectal cancer: study protocol of a single-arm, multicentre, open-label, phase II trial (MEND-IT)

Background

The presence of mesorectal fascia (MRF) invasion, grade 4 extramural venous invasion (EMVI), tumour deposits (TD) or extensive or bilateral extramesorectal (lateral) lymph nodes (LLN) on MRI has been suggested to identify patients with indisputable, extensive locally advanced rectal cancer (LARC), at high risk of treatment failure. The aim of this study is to evaluate whether or not intensified chemotherapy prior to neoadjuvant chemoradiotherapy improves the complete response (CR) rate in these patients.

Methods

This multicentre, single-arm, open-label, phase II trial will include 128 patients with non-metastatic high-risk LARC (hr-LARC), fit for triplet chemotherapy. To ensure a study population with indisputable, unfavourable prognostic characteristics, hr-LARC is defined as LARC with on baseline MRI at least one of the following characteristics; MRF invasion, EMVI grade 4, enlarged bilateral or extensive LLN at high risk of an incomplete resection, or TD. Exclusion criteria are the presence of a homozygous DPD deficiency, distant metastases, any chemotherapy within the past 6 months, previous radiotherapy within the pelvic area precluding standard chemoradiotherapy, and any contraindication for the planned treatment. All patients will be planned for six two-weekly cycles of FOLFOXIRI (5-fluorouracil, leucovorin, oxaliplatin and irinotecan) prior to chemoradiotherapy (25 × 2 Gy or 28 × 1.8 Gy with concomitant capecitabine). A resection will be performed following radiological confirmation of resectable disease after the completion of chemoradiotherapy. A watch and wait strategy is allowed in case of a clinical complete response. The primary endpoint is the CR rate, described as a pathological CR or a sustained clinical CR one year after chemoradiotherapy. The main secondary objectives are long-term oncological outcomes, radiological and pathological response, the number of resections with clear margins, treatment-related toxicity, perioperative complications, health-related costs, and quality of life.

Discussion

This trial protocol describes the MEND-IT study. The MEND-IT study aims to evaluate the CR rate after intensified chemotherapy prior to concomitant chemoradiotherapy in a homogeneous group of patients with locally advanced rectal cancer and indisputably unfavourable characteristics, defined as hr-LARC, in order to improve their prognosis.

Trial registration

Clinicaltrials.gov: NCT04838496, registered on 02–04-2021 Netherlands Trial Register: NL9790.

Protocol version

Version 3 dd 11–4-2022.

Feasibility of whole genome sequencing based tumor diagnostics in routine pathology practice

The current increase in number and diversity of targeted anticancer agents poses challenges to the logistics and timeliness of molecular diagnostics (MolDx), resulting in underdiagnosis and treatment. Whole‐genome sequencing (WGS) may provide a sustainable solution for addressing current as well as future diagnostic challenges. The present study therefore aimed to prospectively assess feasibility, validity, and value of WGS in routine clinical practice. WGS was conducted independently of, and in parallel with, standard of care (SOC) diagnostics on routinely obtained tumor samples from 1,200 consecutive patients with metastatic cancer. Results from both tests were compared and discussed in a dedicated tumor board. From 1,200 patients, 1,302 samples were obtained, of which 1,216 contained tumor cells. WGS was successful in 70% (854/1,216) of samples with a median turnaround time of 11 days. Low tumor purity (<20%) was the main reason for not completing WGS. WGS identified 99.2% and SOC MolDx 99.7% of the total of 896 biomarkers found in genomic regions covered by both tests. Actionable biomarkers were found in 603/848 patients (71%). Of the 936 associated therapy options identified by WGS, 343 were identified with SOC MolDx (36.6%). Biomarker‐based therapy was started in 147 patients. WGS revealed 49 not previously identified pathogenic germline variants. Fresh‐frozen, instead of formalin‐fixed and paraffin‐embedded, sample logistics were easily adopted as experienced by the professionals involved. WGS for patients with metastatic cancer is well feasible in routine clinical practice, successfully yielding comprehensive genomic profiling for the vast majority of patients. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Development of a miRNA-based classifier for detection of colorectal cancer molecular subtypes

Previously, colorectal cancer (CRC) has been classified into four distinct molecular subtypes based on transcriptome data. These consensus molecular subtypes (CMSs) have implications for our understanding of tumor heterogeneity and the prognosis of patients. So far, this classification has been based on the use of messenger RNAs (mRNAs), although microRNAs (miRNAs) have also been shown to play a role in tumor heterogeneity and biological differences between CMSs. In contrast to mRNAs, miRNAs have a smaller size and increased stability, facilitating their detection. Therefore, we built a miRNA-based CMS classifier by converting the existing mRNA-based CMS classification using machine learning (training dataset of n = 271). The performance of this miRNA-assigned CMS classifier (CMS-miRaCl) was evaluated in several datasets, achieving an overall accuracy of ~ 0.72 (0.6329-0.7987) in the largest dataset (n = 158). To gain insight into the biological relevance of CMS-miRaCl, we evaluated the most important features in the classifier. We found that miRNAs previously reported to be relevant in microsatellite-instable CRCs or Wnt signaling were important features for CMS-miRaCl. Following further studies to validate its robustness, this miRNA-based alternative might simplify the implementation of CMS classification in clinical workflows.

Trends in Use and Perceptions About Triplet Chemotherapy Plus Bevacizumab for Metastatic Colorectal Cancer

Importance

Triplet chemotherapy with fluorouracil, folinic acid, oxaliplatin, and irinotecan plus bevacizumab (FOLFOXIRI-B) is an effective first-line treatment option for patients with metastatic colorectal cancer (mCRC). However, the degree of implementation of FOLFOXIRI-B in daily practice is unknown.

Objectives

To evaluate the current adoption rate of FOLFOXIRI-B in patients with mCRC and investigate the perspectives of medical oncologists toward this treatment option.

Design, Setting, and Participants

This 1-week, multicenter, cross-sectional study in the Netherlands used a flash mob design, which facilitates ultrafast data generation (flash) through the engagement of numerous researchers (mob). During the study week (March 1-5, 2021), patient data were retrieved from electronic health records of 47 hospitals on patients with mCRC who were referred to a medical oncologist between November 1, 2020, and January 31, 2021. Interviews were simultaneously conducted with 101 medical oncologists from 52 hospitals who regularly treat patients with mCRC.

Exposure

First-line systemic treatment as determined by the treating physician.

Main Outcomes and Measures

The FOLFOXIRI-B prescription rate was the main outcome. Current practice was compared with prescription rates in 2015 to 2018. Eligibility for treatment with FOLFOXIRI-B was estimated. An exploratory outcome was medical oncologists' reported perspectives on FOLFOXIRI-B.

Results

A total of 5948 patients in the Netherlands (median age [interquartile range], 66 [57-73] years; 3503 [59%] male; and 3712 [62%] with left-sided or rectal tumor) were treated with first-line systemic therapy for synchronous mCRC. A total of 282 patients with mCRC underwent systemic therapy during the study period (2021). Of these 282 patients, 199 (71%) were treated with intensive first-line therapy other than FOLFOXIRI-B, of whom 184 (65%) were treated with oxaliplatin doublets with or without bevacizumab; 14 (5%) with irinotecan doublets with or without bevacizumab, panitumumab, or cetuximab; and 1 (0.4%) with irinotecan with bevacizumab. Fifty-four patients (19%) were treated with fluoropyrimidine monotherapy with or without bevacizumab, 1 patient (0.4%) with panitumumab monotherapy, and 3 (1%) with immune checkpoint inhibitors. In total, 25 patients (9%; 95% CI, 6%-12%) were treated with first-line FOLFOXIRI-B compared with 142 (2%; 95% CI, 2%-3%) in 2015 to 2018. During the study period, 21 of 157 eligible patients (13.4%) in the Netherlands were treated with FOLFOXIRI-B. A total of 87 medical oncologists (86%) reported discussing FOLFOXIRI-B as a treatment option with eligible patients. A total of 47 of 85 (55%) generally communicated a preference for a chemotherapy doublet to patients. These oncologists reported a significantly lower awareness of guidelines and trial results. Toxic effects were the most reported reason to prefer an alternative regimen.

Conclusions and Relevance

The findings of this study suggest that FOLFOXIRI-B prescription rates have marginally increased in the last 5 years. Considering that most medical oncologists discuss this treatment option, the prescription rate found in this study was below expectations. Awareness of guidelines and trial data seems to contribute to the discussion of available treatment options by medical oncologists, and the findings of this study suggest a need for repeated and continuing medical education.

Perioperative Systemic Therapy vs Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Alone for Resectable Colorectal Peritoneal Metastases: A Phase 2 Randomized Clinical Trial

Importance

To date, no randomized clinical trials have investigated perioperative systemic therapy relative to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) alone for resectable colorectal peritoneal metastases (CPM).

Objective

To assess the feasibility and safety of perioperative systemic therapy in patients with resectable CPM and the response of CPM to neoadjuvant treatment.

Design, Setting, and Participants

An open-label, parallel-group phase 2 randomized clinical trial in all 9 Dutch tertiary centers for the surgical treatment of CPM enrolled participants between June 15, 2017, and January 9, 2019. Participants were patients with pathologically proven isolated resectable CPM who did not receive systemic therapy within 6 months before enrollment.

Interventions

Randomization to perioperative systemic therapy or CRS-HIPEC alone. Perioperative systemic therapy comprised either four 3-week neoadjuvant and adjuvant cycles of CAPOX (capecitabine and oxaliplatin), six 2-week neoadjuvant and adjuvant cycles of FOLFOX (fluorouracil, leucovorin, and oxaliplatin), or six 2-week neoadjuvant cycles of FOLFIRI (fluorouracil, leucovorin, and irinotecan) and either four 3-week adjuvant cycles of capecitabine or six 2-week adjuvant cycles of fluorouracil with leucovorin. Bevacizumab was added to the first 3 (CAPOX) or 4 (FOLFOX/FOLFIRI) neoadjuvant cycles.

Main Outcomes and Measures

Proportions of macroscopic complete CRS-HIPEC and Clavien-Dindo grade 3 or higher postoperative morbidity. Key secondary outcomes were centrally assessed rates of objective radiologic and major pathologic response of CPM to neoadjuvant treatment. Analyses were done modified intention-to-treat in patients starting neoadjuvant treatment (experimental arm) or undergoing upfront surgery (control arm).

Results

In 79 patients included in the analysis (43 [54%] men; mean [SD] age, 62 [10] years), experimental (n = 37) and control (n = 42) arms did not differ significantly regarding the proportions of macroscopic complete CRS-HIPEC (33 of 37 [89%] vs 36 of 42 [86%] patients; risk ratio, 1.04; 95% CI, 0.88-1.23; P = .74) and Clavien-Dindo grade 3 or higher postoperative morbidity (8 of 37 [22%] vs 14 of 42 [33%] patients; risk ratio, 0.65; 95% CI, 0.31-1.37; P = .25). No treatment-related deaths occurred. Objective radiologic and major pathologic response rates of CPM to neoadjuvant treatment were 28% (9 of 32 evaluable patients) and 38% (13 of 34 evaluable patients), respectively.

Conclusions and Relevance

In this randomized phase 2 trial in patients diagnosed with resectable CPM, perioperative systemic therapy seemed feasible, safe, and able to induce response of CPM, justifying a phase 3 trial.

Trial Registration

ClinicalTrials.gov Identifier: NCT02758951.

Detection of tumor-derived cell-free DNA from colorectal cancer peritoneal metastases in plasma and peritoneal fluid

Tumor-derived cell-free DNA (cfDNA) is an emerging biomarker for guiding the personalized treatment of patients with metastatic colorectal cancer (CRC). While patients with CRC liver metastases (CRC-LM) have relatively high levels of plasma cfDNA, little is known about patients with CRC peritoneal metastases (CRC-PM). This study evaluated the presence of tumor-derived cfDNA in plasma and peritoneal fluid (i.e. ascites or peritoneal washing) in 20 patients with isolated CRC-PM and in the plasma of 100 patients with isolated CRC-LM. Among tumor tissue KRAS/BRAF mutation carriers, tumor-derived cfDNA was detected by droplet digital polymerase chain reaction (ddPCR) in plasma of 93% of CRC-LM and 20% of CRC-PM patients and in peritoneal fluid in all CRC-PM patients. Mutant allele fraction (MAF) and mutant copies per ml (MTc/ml) were lower in CRC-PM plasma than in CRC-LM plasma (median MAF = 0.28 versus 18.9%, p < 0.0001; median MTc/ml = 21 versus 1,758, p < 0.0001). Within patients with CRC-PM, higher cfDNA levels were observed in peritoneal fluid than in plasma (median MAF = 16.4 versus 0.28%, p = 0.0019; median MTc/ml = 305 versus 21, p = 0.0034). These data imply that tumor-derived cfDNA in plasma is a poor biomarker to monitor CRC-PM. Instead, cfDNA detection in peritoneal fluid may offer an alternative to guide CRC-PM treatment decisions.

Time dependent effect of cold ischemia on the phosphoproteome and protein kinase activity in fresh-frozen colorectal cancer tissue obtained from patients

Background

Based on their potential to analyze aberrant cellular signaling in relation to biological function, kinase activity profiling in tumor biopsies by peptide microarrays and mass spectrometry-based phosphoproteomics may guide selection of protein kinase inhibitors in patients with cancer. Variable tissue handling procedures in clinical practice may influence protein phosphorylation status and kinase activity and therewith may hamper biomarker discovery. Here, the effect of cold ischemia time (CIT) on the stability of kinase activity and protein phosphorylation status in fresh-frozen clinical tissue samples was studied using peptide microarrays and mass spectrometry-based phosphoproteomics.

Methods

Biopsies of colorectal cancer resection specimens from five patients were collected and snap frozen immediately after surgery and at 6 additional time points between 0 and 180 min of CIT. Kinase activity profiling was performed for all samples using a peptide microarray. MS-based global phosphoproteomics was performed in tumors from 3 patients at 4 time points. Statistical and cluster analyses were performed to analyze changes in kinase activity and phosphoproteome resulting from CIT.

Results

Unsupervised cluster analysis of kinase activity and phosphoproteome data revealed that samples from the same patients cluster together. Continuous ANOVA analysis of all 7 time points for 5 patient samples resulted in 4 peptides out of 210 (2%) with significantly (p < 0.01 and fold change > 2) altered signal intensity in time. In 4 out of 5 patients tumor kinase activity was stable with CIT. MS-based phosphoproteomics resulted in the detection of 10,488 different phosphopeptides with on average 6044 phosphopeptides per tumor sample. 2715 phosphopeptides were detected in all samples at time point 0, of which 90 (3.3%) phosphopeptides showed significant changes in intensity with CIT (p < 0.01). Only two phosphopeptides were significantly changed in all time points, including one peptide (PKP3) with a fold change > 2.

Conclusions

The vast majority of the phosphoproteome as well as the activity of protein kinases in colorectal cancer resection tissue is stable up to 180 min of CIT and reflects tumor characteristics. However, specific changes in kinase activity with increasing CIT were observed. Therefore, stringent tissue collection procedures are advised to minimize changes in kinase activity during CIT.

Study protocol: Whole genome sequencing Implementation in standard Diagnostics for Every cancer patient (WIDE)

BACKGROUND

'Precision oncology' can ensure the best suitable treatment at the right time by tailoring treatment towards individual patient and comprehensive tumour characteristics. In current molecular pathology, diagnostic tests which are part of the standard of care (SOC) only cover a limited part of the spectrum of genomic changes, and often are performed in an iterative way. This occurs at the expense of valuable patient time, available tissue sample, and interferes with 'first time right' treatment decisions. Whole Genome Sequencing (WGS) captures a near complete view of genomic characteristics of a tumour in a single test. Moreover, WGS facilitates faster implementation of new treatment relevant biomarkers. At present, WGS mainly has been applied in study settings, but its performance in a routine diagnostic setting remains to be evaluated. The WIDE study aims to investigate the feasibility and validity of WGS-based diagnostics in clinical practice.

METHODS

1200 consecutive patients in a single comprehensive cancer centre with (suspicion of) a metastasized solid tumour will be enrolled with the intention to analyse tumour tissue with WGS, in parallel to SOC diagnostics. Primary endpoints are (1) feasibility of implementation of WGS-based diagnostics into routine clinical care and (2) clinical validation of WGS by comparing identification of treatment-relevant variants between WGS and SOC molecular diagnostics. Secondary endpoints entail (1) added clinical value in terms of additional treatment options and (2) cost-effectiveness of WGS compared to SOC diagnostics through a Health Technology Assessment (HTA) analysis. Furthermore, the (3) perceived impact of WGS-based diagnostics on clinical decision making will be evaluated through questionnaires. The number of patients included in (experimental) therapies initiated based on SOC or WGS diagnostics will be reported with at least 3 months follow-up. The clinical efficacy is beyond the scope of WIDE. Key performance indicators will be evaluated after every 200 patients enrolled, and procedures optimized accordingly, to continuously improve the diagnostic performance of WGS in a routine clinical setting.

DISCUSSION

WIDE will yield the optimal conditions under which WGS can be implemented in a routine molecular diagnostics setting and establish the position of WGS compared to SOC diagnostics in routine clinical care.

A specific microRNA profile as predictive biomarker for systemic treatment in patients with metastatic colorectal cancer

Background

Palliative systemic therapy is currently standard of care for patients with extensive metastatic colorectal cancer (mCRC). A biomarker predicting chemotherapy benefit which prevents toxicity from ineffective treatment is urgently needed. Therefore, a previously developed tissue‐derived microRNA profile to predict clinical benefit from chemotherapy was evaluated in tissue biopsies and serum from patients with mCRC.

Methods

Samples were prospectively collected from patients (N = 132) who were treated with capecitabine or 5‐FU/LV with oxaliplatin ± bevacizumab. Response evaluation was performed according to RECIST 1.1 after three or four cycles, respectively. Baseline tissue and serum miRNAs expression levels of miR‐17‐5p, miR‐20a‐5p, miR‐30a‐5p, miR‐92a‐3p, miR‐92b‐3p, and miR‐98‐5p were quantified with RT‐qPCR and droplet digital PCR, respectively. Combined predictive performance of selected variables was tested using logistic regression analysis.

Results

From 132 patients, 81 fresh frozen tissue biopsies from metastases and 93 serum samples were available. Based on expression levels of miRNAs in tissue, progressive disease could be predicted with an AUC of 0.85 (95% CI:0.72‐0.91) and response could be predicted with an AUC of 0.70 (95% CI:0.56‐0.80). This did not outperform clinical parameters alone (respectively P = .14 and P = .27). Expression levels of miR‐92a‐3p and miR‐98‐5p in serum significantly improved the predictive value of clinical parameters for response to chemotherapy (AUC 0.74, 95% CI:0.64‐0.84, P = .003) in this cohort.

Conclusions

The additive predictive value to clinical parameters of the tissue‐derived six miRNA profile for clinical benefit could not be validated in patients with mCRC treated with first‐line systemic therapy. Although miR‐92a‐3p and miR‐98‐5p serum levels improved the predictive value of clinical parameters, it remained insufficient for clinical decision‐making.

Abstract 708: Limited release of circulating tumor DNA into the systemic circulation by peritoneal metastases from colorectal cancer

Introduction: Circulating tumor DNA (ctDNA) from plasma is a promising biomarker. Patients with metastatic colorectal cancer (CRC) often have high ctDNA levels compared to other cancer types. However, it is unclear whether this is also the case for patients with peritoneal metastases from CRC.

Aim: To compare the propensity of ctDNA shedding by isolated liver metastases and isolated peritoneal metastases from CRC.

Methods: Plasma was collected from 100 CRC patients (64% male, mean age of 60 [SD=10] years) with isolated unresectable liver metastasis (CRC-LM). Plasma and ascites were obtained from 20 CRC patients (60% male, mean age of 63 [SD=9.8] years) with isolated unresectable peritoneal metastases (CRC-PM). All liquid biopsies were obtained prior to treatment and cell-free DNA was isolated using the QIAsymphony (Qiagen, Germany) and assessed by droplet digital PCR (ddPCR; Bio-Rad, Hercules, USA). Patients with a KRAS or BRAF tumor tissue mutation were suited for plasma ctDNA ddPCR analysis, and were detected in 57 CRC-LM (57%) and 11 CRC-PM (55%) patients. The ability to shed ctDNA into the circulation was evaluated by comparing KRAS/BRAF mutation status in plasma and ascites with the mutation status based on tumor tissue. Regarding liquid biopsies, mutant allele fraction (MAF) and mutant copies per ml input (MTc/ml) were reported.

Results: Tissue mutations could be confirmed in plasma in 93% of CRC-LM and only 20% of CRC-PM patients, whereas mutations were detected in ascites in 100% of CRC-PM patients. The MAF and MTc/ml were both significantly lower in CRC-PM plasma ctDNA (median MAF=0.28% and MTc/ml=21) compared to CRC-LM plasma ctDNA (median MAF=18.9% and MTc/ml= 1758; P&lt;0.0001). In addition, the MAF and MTc/ml were significantly higher in CRC-PM ascites ctDNA (median MAF=16.4%, MTc/ml=305) compared to plasma ctDNA (median MAF=0.28%, MTc/ml=21; P&lt;0.0001).

Conclusion: To our knowledge, this is the first study showing a comprehensive comparison of tissue, blood and ascites derived genomic information in patients with CRC and extensive isolated peritoneal metastases. This study concludes that isolated peritoneal metastases from CRC is a malignancy with distinct clinical and biological characteristics, which should be taken into account when considering the clinical utility of ctDNA in different metastatic setting of CRC. To detect genomic alterations, the blood circulation is the preferred source of ctDNA in case of CRC liver metastases, whereas ascites offers an alternative to plasma in patients with peritoneal metastases, which might be suitable as diagnostic, prognostic, predictive or disease monitoring biomarker.

Citation Format: Iris van 't Erve, Koen P. Rovers, Alexander Constantinides, Karen Bolhuis, Emma C. Wassenaar, Robin J. Lurvink, Clément J. Huysentruyt, Petur Snaebjornsson, Daan van den Broek, Tineke E. Buffart, Niels F. Kok, Gerrit A. Meijer, Cornelis J. Punt, Onno Kranenburg, Ignace H. de Hingh, Remond J. Fijneman. Limited release of circulating tumor DNA into the systemic circulation by peritoneal metastases from colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 708.

Expression of let-7i and miR-192 is associated with resistance to cisplatin-based chemoradiotherapy in patients with larynx and hypopharynx cancer

OBJECTIVES

The majority of patients with locally advanced larynx or hypopharynx squamous cell carcinoma are treated with organ-preserving chemoradiotherapy (CRT). Clinical outcome following CRT varies greatly. We hypothesized that tumor microRNA (miRNA) expression is predictive for outcome following CRT.

METHODS

Next-generation sequencing (NGS) miRNA profiling was performed on 37 formalin-fixed paraffin-embedded (FFPE) tumor samples. Patients with a recurrence-free survival (RFS) of less than 2 years and patients with late/no recurrence within 2 years were compared by differential expression analysis. Tumor-specific miRNAs were selected based on normal mucosa miRNA expression data from The Cancer Genome Atlas database. A model was constructed to predict outcome using group-regularized penalized logistic ridge regression. Candidate miRNAs were validated by RT-qPCR in the initial sample set as well as in 46 additional samples.

RESULTS

Thirteen miRNAs were differentially expressed (p < 0.05, FDR < 0.1) according to outcome group. Initial class prediction in the NGS cohort (n = 37) resulted in a model combining five miRNAs and disease stage, able to predict CRT outcome with an area under the curve (AUC) of 0.82. In the RT-qPCR cohort (n = 83), 25 patients (30%) experienced early recurrence (median RFS 8 months; median follow-up 42 months). Class prediction resulted in a model combining let-7i-5p, miR-192-5p and disease stage, able to discriminate patients with good versus poor clinical outcome (AUC:0.80).

CONCLUSION

The combined miRNA expression and disease stage prediction model for CRT outcome is superior to using either factor alone. This study indicates NGS miRNA profiling using FFPE specimens is feasible, resulting in clinically relevant biomarkers.

Safety and Feasibility of Additional Tumor Debulking to First-Line Palliative Combination Chemotherapy for Patients with Multiorgan Metastatic Colorectal Cancer

Introduction

Local treatment of metastases is frequently performed in patients with multiorgan metastatic colorectal carcinoma (mCRC) analogous to selected patients with oligometastatic disease for whom this is standard of care. The ORCHESTRA trial (NCT01792934) was designed to prospectively evaluate overall survival benefit from tumor debulking in addition to chemotherapy in patients with multiorgan mCRC. Here, we report the preplanned safety and feasibility evaluation after inclusion of the first 100 patients.

Methods

Patients were eligible if at least 80% tumor debulking was deemed feasible by resection, radiotherapy and/or thermal ablative therapy. In case of clinical benefit after three or four cycles of respectively 5‐fluorouracil/leucovorin or capecitabine and oxaliplatin ± bevacizumab patients were randomized to tumor debulking followed by chemotherapy in the intervention arm, or standard treatment with chemotherapy.

Results

Twelve patients dropped out prior to randomization for various reasons. Eighty‐eight patients were randomized to the standard (n = 43) or intervention arm (n = 45). No patients withdrew after randomization. Debulking was performed in 82% (n = 37). Two patients had no lesions left to treat, five had progressive disease, and one patient died prior to local treatment. In 15 patients (40%) 21 serious adverse events related to debulking were reported. Postoperative mortality was 2.7% (n = 1). After debulking chemotherapy was resumed in 89% of patients.

Conclusion

Tumor debulking is feasible and does not prohibit administration of palliative chemotherapy in the majority of patients with multiorgan mCRC, despite the occurrence of serious adverse events related to local treatment.

Implications for Practice

This first prospective randomized trial on tumor debulking in addition to chemotherapy shows that local treatment of metastases is feasible in patients with multiorgan metastatic colorectal cancer and does not prohibit administration of palliative systemic therapy, despite the occurrence of serious adverse events related to local treatment. The trial continues accrual, and overall survival (OS) data and quality of life assessment are collected to determine whether the primary aim of >6 months OS benefit with preserved quality of life will be met. This will support evidence‐based decision making in multidisciplinary colorectal cancer care and can be readily implemented in daily practice.

The ORCHESTRA trial was designed to prospectively evaluate overall survival benefit from tumor debulking in addition to chemotherapy in patients with multi‐organ metastatic colorectal cancer. This article reports the preplanned safety and feasibility evaluation after inclusion of the first 100 patients.

CD276-Positive Circulating Endothelial Cells Do Not Predict Response to Systemic Therapy in Advanced Colorectal Cancer

CD276 can discriminate between tumor derived and normal CECs (circulating endothelial cells). We evaluated whether CD276⁺CEC is a clinically relevant biomarker to predict response to palliative systemic therapy in patients with metastatic colorectal cancer (mCRC). Samples were prospectively collected from patients with mCRC enrolled in the ORCHESTRA trial (NCT01792934). At baseline and after three cycles of 5-fluorouracil/leucovorin and oxaliplatin ± bevacizumab, CECs were measured by flowcytometry (CD34⁺CD45^negCD146⁺DNA⁺; and CD276⁺). A clinically relevant cut-off value of (CD276⁺)CECs was determined as 100% sensitivity (and 80% specificity in 95% confidence interval) identifying patients with progressive disease within 6 months. There were 182 baseline samples and 133 follow up samples available for analysis. CEC and CD276⁺CEC counts significantly increased during treatment from 48 to 90 CEC/4 mL (p = 0.00) and from 14 to 33 CD276⁺CEC/4 mL (p = 0.00) at baseline and at first evaluation, respectively. CEC and CD276⁺CEC counts were not predictive for poor response (area under the curve (AUC) 0.53 for CEC and AUC 0.52 for CD276⁺CEC). Despite numerical changes during therapy, CEC and CD276⁺CEC counts do not adequately predict poor response to first line palliative systemic therapy in patients with mCRC.

Proteomic Analysis of miR-195 and miR-497 Replacement Reveals Potential Candidates that Increase Sensitivity to Oxaliplatin in MSI/P53wt Colorectal Cancer Cells

Most patients with advanced colorectal cancer (CRC) eventually develop resistance to systemic combination therapy. miR-195-5p and miR-497-5p are downregulated in CRC tissues and associated with drug resistance. Sensitization to 5-FU, oxaliplatin, and irinotecan by transfection with miR-195-5p and miR-497-5p mimics was studied using cell viability and clonogenic assays in cell lines HCT116, RKO, DLD-1, and SW480. In addition, proteomic analysis of transfected cells was implemented to identify potential targets. Significantly altered proteins were subjected to STRING (protein-protein interaction networks) database analysis to study the potential mechanisms of drug resistance. Cell viability analysis of transfected cells revealed increased sensitivity to oxaliplatin in microsatellite instable (MSI)/P53 wild-type HCT116 and RKO cells. HCT116 transfected cells formed significantly fewer colonies when treated with oxaliplatin. In sensitized cells, proteomic analysis showed 158 and 202 proteins with significantly altered expression after transfection with miR-195-5p and miR-497-5p mimics respectively, of which CHUK and LUZP1 proved to be coinciding downregulated proteins. Resistance mechanisms of these proteins may be associated with nuclear factor kappa-B signaling and G1 cell-cycle arrest. In conclusion, miR-195-5p and miR-497-5p replacement enhanced sensitivity to oxaliplatin in treatment naïve MSI/P53 wild-type CRC cells. Proteomic analysis revealed potential miRNA targets associated with the cell-cycle which possibly bare a relation with chemotherapy sensitivity.

Abstract 2588: Restoring downregulated microRNAs miR-195-5p and miR-497-5p increases sensitivity to chemotherapy in colorectal cancer cells

Background: Patients with advanced colorectal cancer (CRC) are commonly treated with systemic combination therapy, however the success of treatment is hampered by drug resistance. MicroRNAs (miRNAs) have recently emerged as important players in therapy resistance in CRC. The aim of this study was to improve therapy efficacy by sensitizing CRC cells to the chemotherapeutics currently used in clinical practice for patients with advanced CRC by restoring downregulated miR-195-5p and miR-497-5p.

Methods: Sensitivity to 5FU, oxaliplatin (OHP) and irinotecan before and after transfection with miR-195-5p and miR-497-5p mimics was analyzed using tetrazolium reduction and clonogenic assays in CRC cell lines HCT116, RKO, DLD1 and SW480. Transfection with cel-miR-39-3p and untransfected cells were used as controls. Proteomic analyses of transfected and untransfected cells were implemented to identify possible targets involved in sensitivity to chemotherapy. Group comparisons by beta-binomial statistics were performed to analyze significantly altered peptides after restoring miRNA expression.

Results: After transfection with miR-195-5p and miR-497-5p mimics, RKO showed an increased sensitivity to OHP (IC50 decreased from 1100 nM to 900 nM and 800 nM, respectively) and HCT116 showed increased sensitivity to OHP (IC50 decreased from 600 nM to 200 nM and 180 nM, respectively) and 5FU (IC50 decreased from 3500 nM to 2900 nM and 2800 nM, respectively). No increased sensitivity to irinotecan was observed. Clonogenic assay revealed that HCT116 formed 20% and 50% less colonies when treated with 5FU after transfection with miR-195-5p and miR-497-5p mimics, respectively, and 60% less colonies when treated with OHP after transfection with either mimic. RKO showed a 20% decrease in colonies when treated with OHP after transfection with miR-497-5p mimic. No differences in sensitivity to OHP, 5FU or irinotecan were found in transfected SW480 and DLD1. Unsupervised clustering of the proteome showed that HCT116 and RKO cells transfected with miR-195-5p and miR-497-5p mimics could be distinguished from the cells transfected with a control mimic and the untransfected cells. Transfected and control SW480 and DLD1 could not be distinguished based on the proteome profiles. In the combined analyses of HCT116 and RKO 12 peptides showed significantly altered expression (FDR&lt;0.1) after transfection. No significantly altered peptides were detected in transfected SW480 and DLD1 cell lines.

Conclusion: Restoring miR-195-5p and miR-497-5p expression enhanced sensitivity to OHP in HCT116 and RKO cells and to 5FU in HCT116 cells. Proteomics revealed 12 peptides with significantly altered expression after restoring expression of these miRNAs. Treatment with miRNA mimics to sensitize tumor cells to chemotherapy could be an alternative systemic treatment strategy for patients with advanced CRC.

Citation Format: Lenka N. Boyd, Dennis Poel, Tim Schelfhorst, Thang V. Pham, Sander R. Piersma, Jaco C. Knol, Connie R. Jimenez, Henk M. Verheul, Tineke E. Buffart. Restoring downregulated microRNAs miR-195-5p and miR-497-5p increases sensitivity to chemotherapy in colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2588.

Abstract 1801: MicroRNA expression profiling predicts clinical outcome in patients with locally advanced larynx and hypopharynx cancer treated with chemoradiotherapy

Background

For patients with locally advanced larynx and hypopharynx cancer, organ preservation chemoradiotherapy (CRT) protocols are frequently applied. However, some tumors are resistant to CRT or will recur within a short time frame. For these patients upfront surgical resection may result in an improved cure rate. Currently, there are no molecular markers that can predict CRT response. In this study, tumor microRNA (miRNA) profiling was performed to predict clinical outcome in patients with locally advanced larynx or hypopharynx cancer treated with CRT.

Methods

First, matched fresh frozen (FF) and formalin-fixed paraffin-embedded (FFPE) tumor biopsies from 12 patients were profiled by Next Generation Sequencing (NGS) to ensure valid miRNA results from FFPE. Next, miRNA profiles of FFPE tumor biopsies from 37 patients with larynx or hypopharynx cancer, treated with primary CRT, were determined. Clinicopathological data, including response to CRT, tumor stage and nodal stage, was collected of all patients. Differential expression analysis was performed to compare patients with poor clinical outcome, i.e residual tumor after treatment or progression free survival (PFS) &lt; 2 years versus patients with good clinical outcome, i.e. complete response and PFS &gt; 2 years. The median follow up of this cohort was 60 months (range 6 - 118). The Cancer Genome Atlas (TCGA) head and neck miRNA expression data of larynx and hypopharynx tumors and normal squamous cell tissues were used to select tumor specific miRNAs. By group-regularized penalized logistic ridge regression analysis, a model to predict clinical outcome was generated using tumor specific miRNAs combined with clinical covariates.

Results

In total, 324 novel candidate and 2,262 mature miRNAs were detected. A comparative analysis of miRNA profiles generated using matched FF and FFPE tumor biopsies showed a high correlation (mean r2=0.75). Using only FFPE samples, 13 miRNAs were significantly differentially expressed between patients with good versus poor clinical outcome (p&lt;0.05, FDR&lt;0.1). Class prediction resulted in a model of three miRNAs combined with AJCC stage, able to predict recurrence with an area under the curve of 0.83. Further validation of the model is ongoing in an additional cohort of patients with larynx or hypopharynx cancer treated with CRT.

Conclusion

NGS miRNA profiling using FFPE tumor biopsies from patients with head and neck cancer is technically feasible, resulting in high quality miRNA expression data comparable to fresh frozen tissue. Based on miRNA expression profiling, candidate miRNAs were identified predictive for clinical outcome following treatment with CRT. A validation study is ongoing.

Citation Format: Dennis Poel, Francois Rustenburg, Daoud Sie, Hendrik F. van Essen, Paul P. Eijk, Elisabeth Bloemena, Teresita E. Benites, Bauke Ylstra, Brakenhoff H. Ruud, René C. Leemans, Tineke E. Buffart, Henk M. Verheul, Jens Voortman. MicroRNA expression profiling predicts clinical outcome in patients with locally advanced larynx and hypopharynx cancer treated with chemoradiotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1801.

Abstract 1793: Optimal quantification of a circulating miRNA profile predictive for treatment response with droplet digital PCR in patients with multi-organ metastatic colorectal cancer

Introduction: Presence of microRNAs (miRNAs) in blood specimens hold promise for a predictive biomarker for treatment response in clinical practice as they are relatively resistant to degradation. Previously, we identified a six miRNA expression signature from tumor tissue that predicted response to first line systemic treatment in patients with metastatic colorectal cancer (mCRC) when combined with clinicopathological factors. The six miRNA expression signature consists of miR-17-5p, miR-20a-5p, miR-30a-5p, miR-92a-3p, miR-92b-3p and miR-98-5p. The aim of this study is to determine whether circulating levels of these miRNAs will be predictive for treatment outcome as well. Therefore we first studied whether these six miRNAs can be adequately measured in blood samples of patients with mCRC undergoing first line chemotherapy. Droplet digital PCR (ddPCR) technology was used for optimal quantification of miRNAs compared to normal quantitative PCR, because of low abundance of tumor specific miRNAs in blood.

Methods: Serum samples of 120 patients with multi-organ mCRC who participated in a multi-center randomized controlled clinical trial were analyzed. RNA was isolated with miRNeasy Serum/Plasma Advanced Kit of Qiagen. Expression levels of the six miRNA expression signature was determined with ddPCR by using the miRCURY LNA miRNA PCR system combined with EvaGreen. Primer concentration and annealing temperature were first optimized per specific miRNA assay for ddPCR. RNA spike cel-miR-39-3p was used for quality control. Analysis was performed on samples with at least a minimal amount of 10.000 obtained droplets. Absolute quantification per patient is displayed as copies per µl (cop/µl) as defined by Quantasoft software.

Results: In 120 blood samples miRNAs were measured by ddPCR. The most optimal primer concentrations for the different miRNAs was 0,5 µl for cel-miR-39-3p and 1,0 µl for the other 6 miRNAs. For cel-miR-39-3p, miR-17-5p, miR-20a-5p and miR-92a-3p the most efficient annealing temperature was 53 °C and for miR-30a-5p, miR-92b-3p and miR-98-5p this was 58 °C. The mean number of obtained droplets was 15.044 (SD 1922). The highest amount of detected copies were observed in miR-17-5p (644,4 cop/µl), miR-20a-5p (1037,1 cop/µl) and miR-92a-3p (1136,0 cop/µl). Lower expression levels were observed in miR-30a-5p (9,88 cop/µl), miR-92b-3p (1,6 cop/µl) and miR-98-5p (6,9 cop/µl).

Conclusion: We demonstrated that with ddPCR absolute quantification of these six miRNAs in serum samples was efficient and reliable. Further analysis will reveal whether circulating miRNA expression levels can be used as a liquid biomarker for response to first line systemic treatment in patients with multi-organ mCRC.

Citation Format: Lotte Bakkerus, Dennis Poel, Elske C. Gootjes, Cornelis Verhoef, Tineke E. Buffart, Hendrik M. Verheul. Optimal quantification of a circulating miRNA profile predictive for treatment response with droplet digital PCR in patients with multi-organ metastatic colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1793.

The value of tumour debulking for patients with extensive multi-organ metastatic colorectal cancer

Local treatment of metastases by surgical resection or other ablative therapies is technically feasible in an increasing number of patients with multi-organ metastatic cancer. This results in a growing debate on whether patients with extensive disease, that is traditionally deemed unresectable, may benefit from local treatment of metastases when added to standard palliative systemic therapy. For selected patients with oligometastatic colorectal cancer, local treatment of metastases has become the standard of care based on retrospective reports showing long-term survival rates. In addition to systemic therapy, preliminary evidence suggests that patients with extensive metastatic colorectal cancer may also benefit from local treatment. Here, we present the future perspectives based on the available literature on local treatment approaches in colorectal cancer.

Combination of a six microRNA expression profile with four clinicopathological factors for response prediction of systemic treatment in patients with advanced colorectal cancer

Background

First line chemotherapy is effective in 75 to 80% of patients with metastatic colorectal cancer (mCRC). We studied whether microRNA (miR) expression profiles can predict treatment outcome for first line fluoropyrimidine containing systemic therapy in patients with mCRC.

Methods

MiR expression levels were determined by next generation sequencing from snap frozen tumor samples of 88 patients with mCRC. Predictive miRs were selected with penalized logistic regression and posterior forward selection. The prediction co-efficients of the miRs were re-estimated and validated by real-time quantitative PCR in an independent cohort of 81 patients with mCRC.

Results

Expression levels of miR-17-5p, miR-20a-5p, miR-30a-5p, miR-92a-3p, miR-92b-3p and miR-98-5p in combination with age, tumor differentiation, adjuvant therapy and type of systemic treatment, were predictive for clinical benefit in the training cohort with an AUC of 0.78. In the validation cohort the addition of the six miR signature to the four clinicopathological factors demonstrated a significant increased AUC for predicting treatment response versus those with stable disease (SD) from 0.79 to 0.90. The increase for predicting treatment response versus progressive disease (PD) and for patients with SD versus those with PD was not significant. in the validation cohort. MiR-17-5p, miR-20a-5p and miR-92a-3p were significantly upregulated in patients with treatment response in both the training and validation cohorts.

Conclusion

A six miR expression signature was identified that predicted treatment response to fluoropyrimidine containing first line systemic treatment in patients with mCRC when combined with four clinicopathological factors. Independent validation demonstrated added predictive value of this miR-signature for predicting treatment response versus SD. However, added predicted value for separating patients with PD could not be validated. The clinical relevance of the identified miRs for predicting treatment response has to be further explored.

Evaluation of several methodological challenges in circulating miRNA qPCR studies in patients with head and neck cancer

Circulating microRNAs (ci-miRNAs) in blood have emerged as promising diagnostic, prognostic and predictive biomarkers in cancer. Many clinical studies currently incorporate studies that assess ci-miRNAs. Validation of the clinical significance of candidate biomarker miRNAs has proven to be difficult, potentially resulting from vast discrepancies in the detection methodology as well as biological variability. In the current study, the influence of several methodological factors on ci-miRNA detection was evaluated as well as short-term biological variability in patients with head and neck cancer. RNA was isolated from 124 serum and plasma samples originating from patients with head and neck cancer and healthy volunteers. The miRNA levels were measured using RT-qPCR and the influence of pre-analytical factors, different normalization strategies and temporal reproducibility was assessed. RNA carriers improved ci-miRNA detection in serum and plasma specimens. A prolonged pre-processing time correlated with an increased hemolytic index in serum samples only. Hemolysis differentially affected the detection of individual miRNAs. Optimal normalization was achieved using the averaged detection values of spike-in cel-miR-39-3p and endogenous miR-16-5p. Comparing biological replicates from patients with head and neck cancer, the intra-individual miRNA levels were relatively stable (average interval 7 days). Differences in the ci-miRNA detection methodology and limitations of currently used technologies can greatly affect the results and may explain inconsistent outcomes between studies. Prior to the implementation of ci-miRNAs as useful clinical biomarkers, further advances in the standardization of the detection methodology and reduction of technical variability are needed.

Safety and feasibility of adding tumor debulking to palliative chemotherapy in multi-organ metastatic colorectal cancer: The ORCHESTRA trial

3553

Background: For selected patients with oligometastatic colorectal cancer (mCRC), local treatment of metastases is standard of care based on retrospective reports showing long term survival rates. Local treatment of metastases is technically feasible in an increasing number of patients with multi-organ mCRC. It is unknown if patients with extensive disease will benefit from tumor debulking when added to first line palliative chemotherapy. The ORCHESTRA trial (NCT01792934) was designed to prospectively evaluate overall survival (OS) benefit from tumor debulking in patients with multi-organ mCRC. Methods: Patients with multi-organ mCRC were eligible if > 80% tumor debulking was deemed feasible by resection, radiotherapy and/or thermal ablative therapy. All patients received oxaliplatin based chemotherapy ± bevacizumab. In case of stable disease or response at first evaluation (9 weeks), patients were randomized to continuation of chemotherapy or tumor debulking followed by chemotherapy. Adverse events were reported. If patient withdrawal after randomization was < 10%, the study was deemed feasible. Study continuation was based on the interim report on safety and feasibility after inclusion of 100 (of 478) patients. Results: Patients were randomized to the standard (N = 43) or intervention arm (N = 45). No patients withdrew after randomization. In 6.8% of patients debulking was not performed due to progressive disease (N = 5) or death (N = 1) prior to local treatment. Two patients had no lesions left to treat, 37 patients underwent tumor debulking. In 15 patients (40%) 21 serious adverse events related to debulking were reported, 83.7% of patients had no SAEs or recovered within 30 days. Postoperative 90-day mortality was 2.7% (N = 1). Chemotherapy was resumed in 86.5% of patients, median time to restart was 12.7 weeks (SD 5.6) and 78.4% completed ≥24 weeks of chemotherapy. Conclusions: Tumor debulking is feasible and safe and does not prohibit administration of palliative chemotherapy in the majority of patients with multi-organ mCRC. The ORCHESTRA trial will continue accrual to determine whether the aim of > 6 months OS benefit from tumor debulking will be achieved. Clinical trial information: NCT01792934.

Abstract 4928: MiR expression profiles can predict response to systemic treatment in patients with advanced colorectal cancer

Background and aim: Patients with advanced colorectal cancer (mCRC) are commonly treated with systemic treatment consisting of fluoropyrimidine-based regimens being ineffective in 20-25% of the patients. Currently, selection criteria for patients to predict who will respond to this treatment is lacking. The aim of this study is to identify which patients will respond to first line fluoropyrimidine-based treatment based using microRNA (miR) expression profiles in order to avoid ineffective treatment.

Material and methods: Total RNA was isolated from 88 fresh frozen colorectal cancer tissue samples consisting of ≥ 70% tumor cells, collected from patients with mCRC. MiR expression profiles were generated by next generation sequencing using the Illumina High Seq 2000 platform. Of all patients clinical and pathological data, including treatment response based on RECIST criteria, were collected. Class prediction and miR selection were performed using the GRidge package in R. Penalized selection and internal cross validation were used to select miRs predictive for treatment response.

RESULTS: Next generation sequencing resulted in a mean of 10.087.107 (range 6.114.932 to 74.313.067) reads per sample corresponding to 2567 unique mature miR sequences, including 457 novel candidate and 2110 known miRs sequences (miRbase version 19). Penalized regression analysis on tumor specific miRs identified an expression profile which was predictive for clinical benefit (defined as response and stable disease) from first line treatment.

Conclusion: With miR profiling of CRC tissue samples response prediction to first line fluoropyrimidine-based treatment in patients with mCRC is possible. We foresee that selection of treatment using miR expression profiling will avoid unnecessary treatment related toxicity and improve outcome for patients with mCRC

Citation Format: Dennis Poel, Maarten Neerincx, Daoud L.S. Sie, Nicole C.T. van Grieken, R Shankaraiah, F. S.W. van der Wolf, J. H.T.M van Waesberghe, J. D. Burggraaf, Paul P. Eijk, Bauke Ylstra, Cees Verhoef, Mark A. van de Wiel, Henk M.W. Verheul, Tineke E. Buffart. MiR expression profiles can predict response to systemic treatment in patients with advanced colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4928.

The ORCHESTRA trial: A phase III trial of adding tumor debulking to systemic therapy versus systemic therapy alone in multi-organ metastatic colorectal cancer (mCRC)

TPS788

Background: In the current multidisciplinary approach of mCRC, local treatment of oligometastases is common practice. Results of large case series of selected patients treated with complete surgical resection of metastatic lesions suggest that this approach substantially improves survival rates to around 30-60%. Other techniques such as radiofrequency or microwave ablation (RFA, MWA), transarterial chemoembolization (TACE) or radiotherapy can also be applied in local treatment. Curative treatment options are generally not available for patients with extensive hepatic and/or extrahepatic mCRC. These patients primarily receive palliative systemic treatment consisting of combination chemotherapy as well as targeted agents. So far, reports on the benefit of local treatment for metastases in multi-organ mCRC have major limitations, including being small, non-randomized, single-center and retrospective. The benefit from local treatment of metastases for these patients should be established to allow for interruption of the standard systemic therapy and exposure to possible adverse events from local treatment. Methods: The ‘ORCHESTRA’ trial is a randomized multicenter clinical trial for patients with multi-organ mCRC, comparing the combination of chemotherapy and maximal tumor debulking versuschemotherapy alone (NCT01792934). We will examine the interplay of both efficacy and toxicity for the combination of systemic chemotherapy and locoregional therapy. Our study design incorporates systemic as well as local therapy in the experimental arm and combines local treatment modalities to pursue maximal tumor debulking. We aim to improve overall survival of patients with multi-organ mCRC by maximal tumor debulking after induction chemotherapy with at least six months. A total of 478 patients will be included to meet the primary endpoint (power 80%, type I error rate 5%). We define local treatments feasible when they can be performed within a 3-month time period to prevent extensive delay of systemic therapy. Currently, 60 patients are included in 22 participating Dutch hospitals. Clinical trial information: NCT01792934.

ShrinkBayes: a versatile R-package for analysis of count-based sequencing data in complex study designs

Background

Complex designs are common in (observational) clinical studies. Sequencing data for such studies are produced more and more often, implying challenges for the analysis, such as excess of zeros, presence of random effects and multi-parameter inference. Moreover, when sample sizes are small, inference is likely to be too liberal when, in a Bayesian setting, applying a non-appropriate prior or to lack power when not carefully borrowing information across features.

Results

We show on microRNA sequencing data from a clinical cancer study how our software ShrinkBayes tackles the aforementioned challenges. In addition, we illustrate its comparatively good performance on multi-parameter inference for groups using a data-based simulation. Finally, in the small sample size setting, we demonstrate its high power and improved FDR estimation by use of Gaussian mixture priors that include a point mass.

Conclusion

ShrinkBayes is a versatile software package for the analysis of count-based sequencing data, which is particularly useful for studies with small sample sizes or complex designs.

High-level copy number gains of established and potential drug target genes in gastric cancer as a lead for treatment development and selection

PURPOSE

The overall survival rate of patients with advanced gastric cancer is poor. Therefore, there is an urgent need for new treatment options for these patients. The identification of drug target genes located on DNA regions exhibiting high-level copy number gains (CNG) may be an effective approach, as has e.g. previously been shown for HER2. The aim of the present study was to identify putative drug targets in patients with gastric cancer by applying this strategy.

METHODS

Genome-wide array comparative genomic hybridization (array CGH) data available from 183 primary gastric cancer samples were analyzed through Ingenuity Pathway Analysis (IPA) to assess whether any established or potential anticancer drug target genes showed high-level CNG, including focal amplifications.

RESULTS

A total of 147 high-level gained regions were identified in the gastric cancer samples, harboring 167 genes that had previously been annotated as drug target genes. Thirty (18 %) of these genes showed high-level gains in at least 2 % of the tumors. The identified drug target genes included those for drugs known to be active in advanced (gastric) cancer, targets for targeted therapies in clinical development, as well as targets for drugs currently used for other indications but of potential interest for anticancer treatment. In addition, 12 potential drug target genes were identified, including genes involved in growth factor signaling and cell cycle regulation.

CONCLUSION

The majority of gastric cancers carried one or more high-level CNGs or focal amplifications encompassing putative drug target genes. A number of the associated drugs are currently not being considered for treatment of gastric cancer. Based on these results we hypothesize that DNA copy number profiling may be a useful tool to identify new drug targets and to guide individualized treatment strategies in patients with gastric cancer.

[Liver disorders in adults: ALT and AST]

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are commonly used biomarkers for liver damage. As well as in liver tissue, AST is also present in cardiac and skeletal muscle and in erythrocytes, making ALT the most specific marker for liver damage. Here, we describe two patients with sustained increases in ALT and AST levels. The first patient is a 79-year-old woman who developed elevated serum transaminases shortly after having a myocardial infarction. The second patient, an obese 40-year-old woman presented with increased ALT and AST levels in the absence of physical symptoms. Notably, her father died of liver cirrhosis without a history of alcohol abuse. Based upon these case reports we discuss the differential diagnostic work-up of elevated serum transaminase levels. Furthermore, we explain monitoring, test performance, reference values and analytical pitfalls of these biomarkers.

Lack of microRNA-101 causes E-cadherin functional deregulation through EZH2 up-regulation in intestinal gastric cancer

E-cadherin expression disruption is commonly observed in metastatic epithelial cancers and is a crucial step in gastric cancer (GC) initiation and progression. As aberrant expression of microRNAs often perturb the normal expression/function of pivotal cancer-related genes, we characterized and dissected a pathway that causes E-cadherin dysfunction via loss of microRNA-101 and up-regulation of EZH2 expression in GC. MicroRNA microarray expression profiling and array-CGH were used to reinforce miR-101 involvement in GC. By using quantitative real-time PCR and quantitative SNaPshot genomic PCR, we confirmed that miR-101 was significantly down-regulated in GC (p < 0.0089) in comparison with normal gastric mucosas and, at least in 65% of the GC cases analysed, this down-regulation was caused by deletions and/or microdeletions at miR-101 genomic loci. Moreover, around 40% of cases showing miR-101 down-regulation displayed concomitant EZH2 over-expression (at the RNA and protein levels), which, in turn, was associated with loss/aberrant expression of E-cadherin. Interestingly, this occurred preferentially in intestinal-type GCs, retaining allele(s) untargeted by classical CDH1-inactivating mechanisms. We also demonstrated that miR-101 gain of function or direct inhibition of EZH2 in Kato III GC cells led to a strong depletion of endogenous EZH2 and consequent rescue of E-cadherin membranous localization, mimicking results obtained in clinical GC samples. In conclusion, we show that deletions and/or microdeletions at both miR-101 genomic loci cause mature miR-101 down-regulation, subsequent EZH2 over-expression and E-cadherin dysfunction, specifically in intestinal-type GC.

Losses of chromosome 5q and 14q are associated with favorable clinical outcome of patients with gastric cancer

PURPOSE

To improve the clinical outcome of patients with gastric cancer, intensified combination strategies are currently in clinical development, including combinations of more extensive surgery, (neo)adjuvant chemotherapy, and radiotherapy. The present study used DNA copy number profiling to identify subgroups of patients with different clinical outcomes. We hypothesize that, by identification of subgroups, individual treatment strategies can be selected to improve clinical outcome and to reduce unnecessary treatment toxicity for patients with gastric cancer.

EXPERIMENTAL DESIGN

DNA from 206 gastric cancer patients was isolated and analyzed by genomewide array comparative genomic hybridization. DNA copy number profiles were correlated with lymph node status and patient survival. In addition, heat shock protein 90 (HSP90) expression was analyzed and correlated with survival in 230 gastric cancer patients.

RESULTS

Frequent (>20%) DNA copy number gains and losses were observed on several chromosomal regions. Losses on 5q11.2-q31.3 and 14q32.11-q32.33 (14% of patients) were correlated with good clinical outcome in univariate and multivariate analyses, with a median disease-free survival interval of 9.2 years. In addition, loss of expression of HSP90, located on chromosome 14q32.2, was correlated with better patient survival.

CONCLUSION

Genomewide DNA copy number profiling allowed the identification of a subgroup of gastric cancer patients, marked by losses on chromosomes 5q11.2-q31.3 and 14q32.11-q32.33 or low HSP90 protein expression, with an excellent clinical outcome after surgery alone. We hypothesize that this subgroup of patients most likely will not benefit from (neo)adjuvant systemic treatment and/or radiotherapy, whereas anti-HSP90 therapy may have clinical potential in patients with HSP90-expressing gastric cancer, pending validation in an independent dataset.

Small bowel adenocarcinoma copy number profiles are more closely related to colorectal than to gastric cancers

BACKGROUND

Small bowel adenocarcinoma (SBA) is a rare cancer and consequently, the options for clinical trials are limited. As they are treated according to either a colorectal or a gastric cancer regimen and the molecular biology of a tumor is a pivotal determinant for therapy response, chromosomal copy number aberrations were compared with the colorectal and gastric adenocarcinomas.

MATERIALS AND METHODS

A total of 85 microsatellite stable (MSS) adenocarcinomas from the stomach, colorectum and small bowel were selected from existing array comparative genomic hybridization (aCGH) datasets. We compared the aCGH profiles of the three tumor sites by supervised analysis and hierarchical clustering.

RESULTS

Hierarchical clustering revealed substantial overlap of 27 SBA copy number profiles with matched colorectal adenocarcinomas but less overlap with profiles of gastric adenocarcinomas. DNA copy number aberrations located at chromosomes 1p36.3-p34.3, 4p15.3-q35.2, 9p24.3-p11.1, 13q13.2-q31.3 and 17p13.3-p13.2 were the strongest features discriminating SBAs and colorectal adenocarcinomas from gastric adenocarcinomas.

CONCLUSIONS

We show that MSS SBAs are more similar to colorectal than to gastric cancer, based on the 27 genome-wide DNA copy number profiles that are currently available. These molecular similarities provide added support for treatment of MSS small bowel cancers according to colorectal cancer regimens.

Abstract 3941: Amplifications of drug target genes in gastric cancer: Potential clinical implications

Background: The treatment of advanced gastric cancer remains a challenge for the clinical oncologist. Once distant metastases are present, median survival is around one year with the most active chemotherapeutic regimen. Besides the recent approval of trastuzumab in combination with chemotherapy, thus far no other molecular targeted agents have been approved for the treatment of this disease. There is an urgent need to improve selection of effective treatment for individual patients. A potentially promising approach for selecting active antitumor agents in individual patients could be the evaluation of tumor DNA for amplifications of genes coding for drug targets.

Material and Methods: 183 primary gastric adenocarcinomas were analyzed by genome wide array Comparative Genomic Hybridization (arrayCGH) using microarrays consisting of 5000 BAC clones. High level amplifications were defined as a minimum of 2 consecutive clones showing a log2 tumor to normal ratio of &gt; 1. Amplification frequencies for each BAC clone were calculated among the 183 tumors, and genes located within the amplicons were identified by using the RefSeq genes in the UCSC genome browser, version hg16/NCBI34. Drug target genes were selected with Ingenuity Pathway Analysis (IPA) and the Pharmacogenomics Knowledge Base (PharmGKB). Genes amplified in at least 4 patients (2%) were classified according to the mechanism of action of the drug interacting with this specific gene.

Results: In 183 gastric cancers a mean number of 2.0 amplifications per tumor (range 0-21) was found. 167 genes out of more than 6000 at these loci were annotated as drug target genes by IPA, with 30 genes having an amplification frequency of at least 4 (2%). Most frequently amplified regions were located on chromosome 6, 8, 11, 16, 17 and 20. Genes for molecular targeting agents included VEGFA (6.5%), ERBB2 (6%), HSP90AB1 (5.5%) and EGFR (3.8%). Interestingly, also genes for non-anticancer agents, including HRH3 (10.4 %) and RARA (4.9%), and potential therapeutic targets such as TNFRSF4B (7.1%) were found. Conclusion: ArrayCGH analysis of a large series of gastric tumors revealed many non-randomly amplified gene loci, including substrates for targeted agents with potential antitumor activity in advanced gastric cancer. Moreover, targets of agents without established anticancer activity were identified as well. Our results provide a molecular rationale for the investigation of new treatment strategies in advanced gastric cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3941. doi:10.1158/1538-7445.AM2011-3941

Gastric cancers of Western European and African patients show different patterns of genomic instability

Background

Infection with H. pylori is important in the etiology of gastric cancer. Gastric cancer is infrequent in Africa, despite high frequencies of H. pylori infection, referred to as the African enigma. Variation in environmental and host factors influencing gastric cancer risk between different populations have been reported but little is known about the biological differences between gastric cancers from different geographic locations. We aim to study genomic instability patterns of gastric cancers obtained from patients from United Kingdom (UK) and South Africa (SA), in an attempt to support the African enigma hypothesis at the biological level.

Methods

DNA was isolated from 67 gastric adenocarcinomas, 33 UK patients, 9 Caucasian SA patients and 25 native SA patients. Microsatellite instability and chromosomal instability were analyzed by PCR and microarray comparative genomic hybridization, respectively. Data was analyzed by supervised univariate and multivariate analyses as well as unsupervised hierarchical cluster analysis.

Results

Tumors from Caucasian and native SA patients showed significantly more microsatellite instable tumors (p < 0.05). For the microsatellite stable tumors, geographical origin of the patients correlated with cluster membership, derived from unsupervised hierarchical cluster analysis (p = 0.001). Several chromosomal alterations showed significantly different frequencies in tumors from UK patients and native SA patients, but not between UK and Caucasian SA patients and between native and Caucasian SA patients.

Conclusions

Gastric cancers from SA and UK patients show differences in genetic instability patterns, indicating possible different biological mechanisms in patients from different geographical origin. This is of future clinical relevance for stratification of gastric cancer therapy.

High-resolution array comparative genomic hybridization in sporadic and celiac disease-related small bowel adenocarcinomas

PURPOSE

The molecular pathogenesis of small intestinal adenocarcinomas is not well understood. Understanding the molecular characteristics of small bowel adenocarcinoma may lead to more effective patient treatment.

EXPERIMENTAL DESIGN

Forty-eight small bowel adenocarcinomas (33 non-celiac disease related and 15 celiac disease related) were characterized for chromosomal aberrations by high-resolution array comparative hybridization, microsatellite instability, and APC promoter methylation and mutation status. Findings were compared with clinicopathologic and survival data. Furthermore, molecular alterations were compared between celiac disease-related and non-celiac disease-related small bowel adenocarcinomas.

RESULTS

DNA copy number changes were observed in 77% small bowel adenocarcinomas. The most frequent DNA copy number changes found were gains on 5p15.33-5p12, 7p22.3-7q11.21, 7q21.2-7q21.3, 7q22.1-7q34, 7q36.1, 7q36.3, 8q11.21-8q24.3, 9q34.11-9q34.3, 13q11-13q34, 16p13.3, 16p11.2, 19q13.2, and 20p13-20q13.33, and losses on 4p13-4q35.2, 5q15-5q21.1, and 21p11.2-21q22.11. Seven highly amplified regions were identified on 6p21.1, 7q21.1, 8p23.1, 11p13, 16p11.2, 17q12-q21.1, and 19q13.2. Celiac disease-related and non-celiac disease-related small bowel adenocarcinomas displayed similar chromosomal aberrations. Promoter hypermethylation of the APC gene was found in 48% non-celiac disease-related and 73% celiac disease-related small bowel adenocarcinomas. No nonsense mutations were found. Thirty-three percent of non-celiac disease-related small bowel adenocarcinomas showed microsatellite instability, whereas 67% of celiac disease-related small bowel adenocarcinomas were microsatellite unstable.

CONCLUSIONS

Our study characterized chromosomal aberrations and amplifications involved in small bowel adenocarcinoma. At the chromosomal level, celiac disease-related and non-celiac disease-related small bowel adenocarcinomas did not differ. A defect in the mismatch repair pathways seems to be more common in celiac disease-related than in non-celiac disease-related small bowel adenocarcinomas. In contrast to colon and gastric cancers, no APC nonsense mutations were found in small bowel adenocarcinoma. However, APC promoter methylation seems to be a common event in celiac disease-related small bowel adenocarcinoma. Clin Cancer Res; 16(5); 1391-401.

High resolution analysis of DNA copy-number aberrations of chromosomes 8, 13, and 20 in gastric cancers

DNA copy-number gains of chromosomes 8q, 13q, and 20q are frequently observed in gastric cancers. Moreover gain of chromosome 20q has been associated with lymph node metastasis. The aim of this study was to correlate DNA copy-number changes of individual genes on chromosomes 8q, 13q, and 20q in gastric adenocarcinomas to clinicopathological data. DNA isolated from 63 formalin-fixed and paraffin-embedded gastric adenocarcinoma tissue samples was analyzed by whole-genome microarray comparative genomic hybridization and by multiplex ligation-dependent probe amplification (MLPA), targeting 58 individual genes on chromosomes 8, 13, and 20. Using array comparative genomic hybridization, gains on 8q, 13q, and 20q were observed in 49 (77.8%), 25 (39.7%), and 49 (77.8%) gastric adenocarcinomas, respectively. Gain of chromosome 20q was significantly correlated with lymph node metastases (p = 0.05) and histological type (p = 0.02). MLPA revealed several genes to be frequently gained in DNA copy number. The oncogene c-myc on 8q was gained in 73% of the cancers, while FOXO1A and ATP7B on 13q were both gained in 28.6% of the cases. Multiple genes on chromosome 20q showed gains in more than 60% of the cancers. DNA copy-number gains of TNFRSF6B (20q13.3) and ZNF217 (20q13.2) were significantly associated with lymph node metastasis (p = 0.02) and histological type (p = 0.02), respectively. In summary, gains of chromosomes 8q, 13q, and 20q in gastric adenocarcinomas harbor DNA copy-number gains of known and putative oncogenes. ZNF217 and TNFRSF6B are associated with important clinicopathological variables, including lymph node status.

NMD inhibition fails to identify tumour suppressor genes in microsatellite stable gastric cancer cell lines

Background

Gastric cancers frequently show chromosomal alterations which can cause activation of oncogenes, and/or inactivation of tumour suppressor genes. In gastric cancer several chromosomal regions are described to be frequently lost, but for most of the regions, no tumour suppressor genes have been identified yet. The present study aimed to identify tumour suppressor genes inactivated by nonsense mutation and deletion in gastric cancer by means of GINI (gene identification by nonsense mediated decay inhibition) and whole genome copy number analysis.

Methods

Two non-commercial gastric cancer cell lines, GP202 and IPA220, were transfected with siRNA directed against UPF1, to specifically inhibit the nonsense mediated decay (NMD) pathway, and with siRNA directed against non-specific siRNA duplexes (CVII) as a control. Microarray expression experiments were performed in triplicate on 4 × 44 K Agilent arrays by hybridizing RNA from UPF1-transfected cells against non-specific CVII-transfected cells. In addition, array CGH of the two cell lines was performed on 4 × 44K agilent arrays to obtain the DNA copy number profiles. Mutation analysis of GINI candidates was performed by sequencing.

Results

UPF1 expression was reduced for >70% and >80% in the GP202 and IPA220 gastric cancer cell lines, respectively. Integration of array CGH and microarray expression data provided a list of 134 and 50 candidate genes inactivated by nonsense mutation and deletion for GP202 and IPA220, respectively. We selected 12 candidate genes for mutation analysis. Of these, sequence analysis was performed on 11 genes. One gene, PLA2G4A, showed a silent mutation, and in two genes, CTSA and PTPRJ, missense mutations were detected. No nonsense mutations were detected in any of the 11 genes tested.

Conclusion

Although UPF1 was substantially repressed, thus resulting in the inhibition of the NMD system, we did not find genes inactivated by nonsense mutations. Our results show that the GINI strategy leads to a high number of false positives.