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In recent years, it has been demonstrated that immunotherapy is an effective strategy for the management of solid tumors. The origins of immunotherapy can be traced back to the work of William Coley, who elicited an immune response against sarcoma by injecting patients with a mixture of dead bacteria. Significant progress has been made since, with immune markers within the tumor now being used as predictors of cancer prognosis and manipulated to improve patient survival. While surgery remains central to the management of most patients with solid malignancies, it is important that surgeons consider the different immunotherapy strategies that can be employed to manage disease. Here, we highlight how the immune system influences tumorigenesis and bring attention to how current and future immunotherapies can serve as an adjunct to surgery.

Several unanswered questions surround the management of retroperitoneal sarcoma (RPS). Guidelines recommend treatment by a multidisciplinary team at a specialized referral centre. The objective of this study was to describe the management of RPS at an Australian specialist sarcoma centre, comparing outcomes to international standards and analysing for predictors of local failure.A retrospective review of a prospectively maintained database was performed on patients with RPS treated between 2008 and 2016. A 5-year outcome analyses focussed on patients undergoing curative-intent surgery for primary, non-metastatic RPS.Eighty-eight patients underwent surgery for primary RPS. Five-year overall survival was 66%, 5-year freedom from local recurrence was 65% and 5-year freedom from distant metastasis was 71%. Overall survival was associated with tumour grade (hazard ratio (HR) 6.1, P 0.001) and histologic organ invasion (HR 5.7, P 0.001). Variables associated with improved freedom from local recurrence were macroscopically complete resection (HR 0.14, P 0.001) and neoadjuvant radiotherapy (HR 0.33, P = 0.014). Treatment at a specialist sarcoma centre was associated with a higher rate of preoperative biopsy and neoadjuvant radiotherapy (both with P 0.001). There was a trend towards improved local control for patients undergoing surgery at a specialist centre (P = 0.055).This is the largest Australian series of RPS and outcomes are comparable to major international sarcoma centres. Patients treated at a specialist centre had higher rates of preoperative diagnosis and tailored therapy which was associated with improved outcomes. Patients with suspected RPS should be referred to a specialist centre for optimal preoperative evaluation and multidisciplinary management.

Background Early drug development and phase 1 (P1) clinical trials have changed dramatically in the past decade, as targeted therapies and then immune-oncology evolved. Understanding the changing trends in P1 trials allows more targeted resource investment at the site level, but also at the industry level. We describe the changes in the P1 trial landscape in solid tumours over the past decade. Methods P1 trials registered on ClinicalTrials.gov to start between 1/1/2009-31/12/2018 were extracted using the parameters: cancer, ≥18 years (yr) old, active, recruiting, completed, (early) P1 and interventional. Of the 7,870 trials identified, 3,031 were excluded on the following basis: not conducted in patients with solid tumours, directed at supportive care, solely involving radiotherapy (RT), testing of a device or procedure or solely involving dietary interventions. The 4,839 eligible studies were categorized by treatment type, tumor type, start date and study location. Studies were independently reviewed by two clinicians. Results In the past decade, there was an average increase of 5%/yr in the number of P1 registered, reflected by substantial increases in trials investigating immune-oncology agents (IO) (average increase: 36%/year) and cell therapies (CT) (average increase: 17%/yr). P1 trials using chemotherapy (C) (average decrease: 1%/yr) or targeted therapies (T) (average decrease: 1%/yr) have plateaued. Clinical trials combining IO with T or C or RT increased by an average of 45%/yr. Most P1 studies (41%) enrolled multiple tumour types. Studies frequently involved North American (68.5%), European (29.3%) and Asia Pacific sites (34%). The inclusion of Asia Pacific sites increased most substantially (average increase: 8%/year). P1 Trials Classified by Type of Therapy (2009-2018) Table . 494P IO 1 C 1 T 1 CT 1 Total 2009-10 4% (30) 39% (324) 66% (557) 5% (39) 839 2011-12 12% (89) 36% (276) 64% (491) 3% (25) 767 2013-14 17% (141) 32% (258) 57% (467) 6% (47) 814 2015-16 33% (364) 29% (320) 48% (529) 9% (98) 1095 2017-18 44% (581) 23% (305) 40% (524) 11% (140) 1324 1 Includes P1 trials using a combination of treatments. Conclusions The conduct of P1 trials has increased markedly over the past decade, driven by growing interest in IO. Legal entity responsible for the study Peter MacCallum Cancer Centre. Funding Has not received any funding. Disclosure J. Desai: Research grant / Funding (institution): Genentech/Roche; Research grant / Funding (institution): GlaxoSmithKline; Research grant / Funding (institution): Novartis; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): Bionomics; Research grant / Funding (institution): MedImmune; Advisory / Consultancy, Research grant / Funding (institution): BeiGene; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): Lilly; Research grant / Funding (institution): Bristol-Myers Squibb; Honoraria (institution), Advisory / Consultancy: Eisai; Advisory / Consultancy: Ignyta. B. Tran: Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Amgen; Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Astella; Advisory / Consultancy, Travel / Accommodation / Expenses: Bayer; Advisory / Consultancy, Speaker Bureau / Expert testimony: Bristol-Myers Squibb; Advisory / Consultancy, Speaker Bureau / Expert testimony: Janssen-Cilag; Advisory / Consultancy: MSD; Advisory / Consultancy: Novartis; Advisory / Consultancy, Travel / Accommodation / Expenses: Sanofi; Advisory / Consultancy: Tolmar; Advisory / Consultancy: Ipsen. All other authors have declared no conflicts of interest.

In Stage II colon cancer, multiple independent studies have shown that a dense intratumoural immune infiltrate (local inflammation) is associated with improved outcomes, while systemic inflammation, measured by various markers, has been associated with poorer outcomes. However, previous studies have not considered the interaction between local and systemic inflammation, nor have they assessed the type of inflammatory response compared with standard clinicopathologic criteria. In order to evaluate the potential clinical utility of inflammatory markers in Stage II colon cancer, we examined local and systemic inflammation in a consecutive series of patients with resected Stage II colon cancer between 2000 and 2010 who were identified from a prospective clinical database. Increased intratumoural chronic inflammatory cell (CIC) density, as assessed by pathologist review of hematoxylin and eosin stained slides, was used to represent local inflammation. Neutrophil-to-lymphocyte ratio (NLR) >5, as calculated from pre-operative full blood counts, was used to represent systemic inflammation. In 396 eligible patients identified, there was a non-significant inverse relationship between local and systemic inflammation. Increased CIC density was significantly associated with improved overall (HR 0.45, p = 0.001) and recurrence-free survival (HR 0.37, p = 0.003). High NLR was significantly associated with poorer overall survival (HR 2.56, p < 0.001). The combination of these markers further stratified prognosis independent of standard high-risk criteria, with a dominant systemic inflammatory response (low CIC/high NLR) associated with the worst outcome (5-year overall survival 55.8%). With further validation this simple, inexpensive combined inflammatory biomarker might assist in patient selection for adjuvant chemotherapy in Stage II colon cancer.

Background The true survival benefit of noncurative primary tumor resection in patients with de novo metastatic colorectal cancer (mCRC) remains uncertain. The present study examined the effect of primary tumor resection on systemic inflammation and survival in patients with mCRC. Materials and Methods Consecutive patients with de novo mCRC who had undergone primary tumor resection were identified from a prospective database. Patients were excluded if they had undergone resection of metastases, had undergone delayed primary resection, or if blood samples were unavailable. The neutrophil/lymphocyte ratio (NLR) was used as a biomarker of systemic inflammation. Overall survival (OS) was compared between patient groups according to the pre- and postprimary resection NLR. The associations between the reversal of an elevated NLR and primary tumor bulk or performance status were explored. Results A total of 145 eligible patients were identified from the database, with a median age of 70 years. The baseline NLR was elevated (> 5) in 65 patients, 36 (55%) of whom had a low NLR after surgery. The reversal of an elevated NLR was associated with significantly improved OS (hazard ratio, 0.53; P = .017). A similar benefit was seen after excluding patients undergoing emergency primary resection. NLR reversal was more frequent in patients with larger primary tumors or good performance status. Conclusion The present study is the first to demonstrate a relationship between the reversal of a systemic inflammatory response and the improved survival after primary resection in those with mCRC. A greater effect was seen in patients with large primary tumors. If validated, these observations could guide clinical decision-making in patients with mCRC at presentation.

Background: BRAF mutations are a validated target for cancer therapy. A second-generation BRAF inhibitor with an improved preclinical safety profile (RG7256) was evaluated in a first-in-man study in order to determine the safety, efficacy, pharmacokinetics and pharmacodynamics in patients with BRAF V600-mutated advanced solid tumors. Patients and Methods: Patients received RG7256 orally over 8 dose levels from 200 mg once a day (QD) to 2400 mg twice a day (BID) (50-, 100- and 150-mg tablets) using a classic 3 + 3 dose escalation design. Results: In total, 45 patients were enrolled; most (87 %) had advanced melanoma (94 % BRAF V600E). RG7256 was rapidly absorbed, with limited accumulation and dose-proportional increase in exposure up to 1950 mg BID. The maximal tolerated dose (MTD) was not reached. The most common drug-related adverse events (AEs) were dyspepsia (20 %), dry skin (18 %), rash (18 %), fatigue (16 %) and nausea (13 %), mainly grade 1. Three patients (7 %) developed cutaneous squamous cell carcinoma. Photosensitivity, arthralgia and increased liver enzyme levels were each observed in only one patient each. Of 44 evaluable patients, 14 (32 %) had a partial response (melanoma and thyroid cancer). At high dose levels (>1200 mg BID), 10 of 16 (63 %) patients had a partial response. A decrease in maximum standardized uptake value (SUVmax) on FDG-PET of ≥25 % was observed in 19 of 37 patients. On-treatment reductions in pERK were documented in eight of ten paired tumor samples. Conclusions: RG7256 has a favorable safety profile compared to other BRAF inhibitors while maintaining clinical activity, and MTD was not reached. The excessive pill burden needed to provide the desired exposure, and thus concerns about patient compliance, limited further development of this agent. Study Identifier: ClinicalTrials.gov (NCT01143753)[MediaObject not available: see fulltext.] Refereed/Peer-reviewed

Early indicators of treatment response in metastatic colorectal cancer (mCRC) could conceivably be used to optimize treatment. We explored early changes in circulating tumor DNA (ctDNA) levels as a marker of therapeutic efficacy.This prospective study involved 53 mCRC patients receiving standard first-line chemotherapy. Both ctDNA and CEA were assessed in plasma collected before treatment, 3 days after treatment and before cycle 2. Computed tomography (CT) scans were carried out at baseline and 8-10 weeks and were centrally assessed using RECIST v1.1 criteria. Tumors were sequenced using a panel of 15 genes frequently mutated in mCRC to identify candidate mutations for ctDNA analysis. For each patient, one tumor mutation was selected to assess the presence and the level of ctDNA in plasma samples using a digital genomic assay termed Safe-SeqS.Candidate mutations for ctDNA analysis were identified in 52 (98.1%) of the tumors. These patient-specific candidate tissue mutations were detectable in the cell-free DNA from the plasma of 48 of these 52 patients (concordance 92.3%). Significant reductions in ctDNA (median 5.7-fold; P0.001) levels were observed before cycle 2, which correlated with CT responses at 8-10 weeks (odds ratio = 5.25 with a 10-fold ctDNA reduction; P = 0.016). Major reductions (≥10-fold) versus lesser reductions in ctDNA precycle 2 were associated with a trend for increased progression-free survival (median 14.7 versus 8.1 months; HR = 1.87; P = 0.266).ctDNA is detectable in a high proportion of treatment naïve mCRC patients. Early changes in ctDNA during first-line chemotherapy predict the later radiologic response.

Desmoid tumors (DT) are rare clonal proliferations that arise from mesenchymal cells. These tumors do not metastasize but are locally aggressive, and their growth may lead to significant morbidity. Their clinical course is both variable and unpredictable; tumors may rapidly progress but in other instances remain stable or regress without intervention. To examine current treatment of DT and assist with decision-making at time of presentation. A literature search was conducted of MEDLINE and Cochrane databases for published studies (1995–July 2015) using the search terms fibromatosis aggressive, desmoid with drug therapy, radiation therapy, prevention and control, radiotherapy, surgery, and therapy. Articles were categorized as surgery, radiation, surgery + radiation, systemic therapy, and front-line observation. Articles were included if they reported a retrospective or prospective comparative or observational study with an analyzed sample size of 10 patients or more with confirmed diagnosis of desmoid tumor and described one of the following clinical outcomes: relapse- or progression-free survival, local control rate, response rate. 258 articles were reviewed; following screening for eligibility, 54 were identified; following full-text screen, 31 were included in final evaluation. The control rate for patients treated with a “wait and see” observational approach compared favorably with management with surgery and resulted in disease control rates of between 60 and 92%. Decision-making in this rare tumor is complicated by the range of treatment options available. Our evidence supports use of an upfront observational approach.

Combining process analytical technology (PAT) with continuous production provides a powerful tool to observe and control monoclonal antibody (mAb) fermentation and purification processes. This work demonstrates on-line liquid chromatography (on-line LC) as a PAT tool for monitoring a continuous biologics process and forced degradation studies. Specifically, this work focused on ion exchange chromatography (IEX), which is a critical separation technique to detect charge variants. Product-related impurities, including charge variants, that impact function are classified as critical quality attributes (CQAs). First, we confirmed no significant differences were observed in the charge heterogeneity profile of a mAb through both at-line and on-line sampling and that the on-line method has the ability to rapidly detect changes in protein quality over time. The robustness and versatility of the PAT methods were tested by sampling from two purification locations in a continuous mAb process. The PAT IEX methods used with on-line LC were a weak cation exchange (WCX) separation and a newly developed shorter strong cation exchange (SCX) assay. Both methods provided similar results with the distribution of percent acidic, main, and basic species remaining unchanged over a 2 week period. Second, a forced degradation study showed an increase in acidic species and a decrease in basic species when sampled on-line over 7 days. These applications further strengthen the use of on-line LC to monitor CQAs of a mAb continuously with various PAT IEX analytical methods. Implementation of on-line IEX will enable faster decision making during process development and could potentially be applied to control in biomanufacturing.

Technology has progressed from single gene panel to large-scale genomic sequencing. This is raising expectations from clinicians and patients alike. The utility and performance of this technology in a clinical setting needs to be evaluated.This pilot study investigated the feasibility of using exome-scale sequencing (ESS) to identify molecular drivers within cancers in real-time for Precision Oncology in the clinic.Between March 2014 and March 2015, the Victorian Comprehensive Cancer Centre Alliance explored the feasibility and utility of ESS in a pilot study. DNA extracted from the tumour specimens underwent both ESS and targeted 'hotspot' sequencing (TS). Blood was taken for germline analysis. A multi-disciplinary molecular tumour board determined the clinical relevance of identified mutations; in particular, whether they were 'actionable' and/or 'druggable'.Of 23 patients screened, 15 (65%) met the tissue requirements for genomic analysis. TS and ESS were successful in all cases. ESS identified pathogenic somatic variants in 73% (11/15 cases) versus 53% (8/15 cases) using TS. Clinically focused ESS identified 63 variants, consisting of 30 somatic variants (including all 13 identified by TS) and 33 germline variants. Overall, there were 48 unique variants. ESS had a clinical impact in 53% (8/15 cases); 47% (7/15 cases) were referred to the familial cancer clinic, and 'druggable' targets were identified in 53% (8/15 cases).ESS of tumour DNA impacted clinical decision-making in 53%, with 20% more pathogenic variants identified through ESS than TS. The identification of germline variants in 47% was an unexpected finding.

Osteosarcoma is the most common primary bone cancer affecting adolescent and young adults. The majority of osteosarcomas occur sporadically, although increasing age is associated with a higher risk of secondary osteosarcoma. Common causes of secondary osteosarcoma include pre-existing Paget's disease and prior irradiation. Bone infarct-associated sarcoma (IAS) is a rare subset of secondary sarcoma with few reports to date. We present the case of a 28-year-old male who presented with IAS potentially related to previous steroid exposure from treated Hodgkin disease in childhood. He is currently undergoing neoadjuvant chemotherapy with consideration of a limb-sparing surgery after two cycles.

Background: Preoperative radiotherapy (RT) is commonly used to treat localised soft-tissue sarcomas (STS). Hypoxia is an important determinant of radioresistance. Whether antiangiogenic therapy can ‘normalise' tumour vasculature, thereby improving oxygenation, remains unknown. Methods: Two cohorts were prospectively enrolled. Cohort A evaluated the implications of hypoxia in STS, using the hypoxic tracer 18F-azomycin arabinoside (FAZA-PET). In cohort B, sunitinib was added to preoperative RT in a dose-finding phase 1b/2 design. Results: In cohort A, 13 out of 23 tumours were hypoxic (FAZA-PET), correlating with metabolic activity (r2=0.85; P

Aim As multiple new agents have been added to the treatment options for patients with metastatic colorectal cancer, survival outcomes in clinical trials have continued to improve. Similarly, improved outcomes in routine clinical care would be anticipated, but have yet to be demonstrated. Here, we aim to explore whether survival gains demonstrated in clinical trials are reproducible in routine practice, and whether factors beyond new therapies may be contributing to improved outcomes. Methods Comparison of comprehensive treatment and outcome data for consecutive patients diagnosed in 2003–2006 versus 2007–2010 at four specialist hospitals in Australia. Results Data were available on 965 patients; median age 66.1 years (range 19–93), 572 (59%) were male. For the latter time period, there was an increase in patients receiving any treatment (74% vs 66%, P = 0.014), initial combination chemotherapy (57% vs 44%, P

Aim: To carry out a nationwide study of KRAS testing in metastatic colorectal cancer as reported by nine major molecular pathology service providers in Australia, including mutation frequencies and turnaround times that might impact on patient care. Methods: Participating laboratories contributed information on KRAS mutation frequencies, including the G13D mutation type, as well as turnaround times for tumor block retrieval and testing. Results: The KRAS mutation frequency observed by nine different test sites for a total of 3688 metastatic colorectal cancers ranged from 34.4% to 40.7%, with an average across all sites of 38.8%. The average frequency of the G13D mutation type among all cases was 8.0%. The median turnaround time was 17 days (range 0-191), with 20% of cases requiring more than 4 weeks for a KRAS test result. The major contributor to long turnaround times was the time taken to retrieve archived blocks of primary tumor, particularly from sources external to the test site. Conclusion: The frequency of KRAS mutations in metastatic colorectal cancer reported by the major Australian test sites is very similar to that reported by other large overseas studies. More widespread introduction of routine testing at the time of initial diagnosis should eliminate the long turnaround times currently being experienced in a significant proportion of cases. Future expansion of testing to include other KRAS and NRAS mutation hotspots may spur the introduction of next-generation sequencing platforms.

The microsatellite instability-high (MSI-H) phenotype, present in 15% of early colorectal cancer (CRC), confers good prognosis. MSI-H metastatic CRC is rare and its impact on outcomes is unknown. We describe survival outcomes and the impact of chemotherapy, metastatectomy, and BRAF V600E mutation status in the largest reported cohort of MSI-H metastatic colorectal cancer (CRC).A retrospective review of 55 MSI-H metastatic CRC patients from two institutions, Royal Melbourne Hospital (Australia) and The University of Texas MD Anderson Cancer Center (United States), was conducted. Statistical analyses utilized Kaplan-Meier method, Log-rank test, and Cox proportional hazards models.Median age was 67 years (20-90), 58% had poor differentiation, and 45% had stage IV disease at presentation. Median overall survival (OS) from metastatic disease was 15.4 months. Thirteen patients underwent R0/R1 metastatectomies, with median OS from metastatectomy 33.8 months. Thirty-one patients received first-line systemic chemotherapy for metastatic disease with median OS from the start of chemotherapy 11.5 months. No statistically significant difference in progression-free survival or OS was seen between fluoropyrimidine, oxaliplatin, or irinotecan based chemotherapy. BRAF V600E mutation was present in 14 of 47 patients (30%). BRAF V600E patients demonstrated significantly worse median OS; 10.1 versus 17.3 months, P = 0.03. In multivariate analyses, BRAF V600E mutants had worse OS (HR 4.04; P = 0.005), while patients undergoing metastatectomy (HR 0.11; P =0.001) and patients who initially presented as stage IV disease had improved OS (HR 0.27; P = 0.003).Patients with MSI-H metastatic CRC do not appear to have improved outcomes. BRAF V600E mutation is a poor prognostic factor in MSI-H metastatic CRC.

Systems Biology & Personalised Medicine Division, Walter & Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia Faculty of Medicine, Dentistry & Health Sciences, Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia Department of Medical Oncology, Royal Melbourne Hospital, Parkville & Western Hospital, Footscray, Victoria, Australia *Author for correspondence: oliver.sieber@ludwig.edu.au Therapeutic options for treating patients with metastatic colorectal cancer (CRC) have increased markedly over the past decade. Recent improvements in overall survival rates from 10 to 24 months have been achieved through the introduction of molecularly targeted agents to complement traditional cytotoxics, including agents directed against the EGF receptor (EGFR) pathway (cetuximab and panitumumab) and angiogenesis (bevacizumab, aflibercept and regorafenib). This progress has spurred intense efforts to develop further compounds that target key molecular pathways driving carcinogenesis. One major focus has been on the inhibition of oncogenic PI3K signaling, with diverse inhibitors currently in Phase I/II clinical trials. While achieving clear responses in some cancers, activity in CRC has been modest, with disease stabilization observed in approximately 10% of patients. Here, we discuss the potential opportunities of targeting the PI3K pathway in treating patients with metastatic CRC. PI3K/AKT signaling is typically initiated via growth factors (e.g., EGF) or insulin, resulting in activation of receptor tyrosine kinases or G-protein coupled receptors. Activated receptor tyrosine kinases/G-protein coupled receptors recruit and activate class IA PI3K at the cell membrane, enabling PI3K to convert PIP2 to PIP3. PIP3 recruits the serene–threonine protein kinase AKT, which is rendered fully active through phosphorylation by PDK1 and mTORC2. Phosphorylated AKT transduces the signal to a range of downstream substrates (e.g., NF-κB, TSC1/2 complex, mTORC1, S6K, 4EBP1, BAD, GSK3β and MDM2) affecting cell proliferation, growth, survival, apoptosis, protein synthesis and glucose metabolism [1]. PI3K signaling is negatively regulated by the PTEN phosphatase, which removes the 3-phosphate from PIP3. In addition, PI3K can be stimulated by GTP-bound RAS, a crosstalk important for RAS mutation-induced transformation of mammalian cells. Michelle Palmieri1,2, Jayesh Desai1,3 & Oliver Sieber*,1

Major advances in the medical treatment of gastrointestinal tumors (GISTs) have improved survival for both patients with advanced disease and those diagnosed with high-risk primary tumors. The Consensus approaches to best practice management of gastrointestinal stromal tumors, published in this journal in 2008, provided guidance for the management of GIST to both clinicians and regulatory authorities. Since then, clinical trials have demonstrated the benefit of adjuvant imatinib in high-risk patients, and mature data from advanced GIST studies suggest that a small but significant proportion of patients with advanced disease can achieve long-term benefit with ongoing imatinib treatment. Other evolving management strategies include the controversial use of palliative or debulking surgery to improve outcomes in advanced GIST and the development of promising new multikinase inhibitors, such as regorafenib, which has established benefit in the third-line setting. This review provides an update of recent developments in GIST management and discusses new controversies that these advances have generated.

Nutlin-3a is a small-molecule antagonist of p53/MDM2 that is being explored as a treatment for sarcoma. In this study, we examined the molecular mechanisms underlying the sensitivity of sarcomas to Nutlin-3a. In an ex vivo tissue explant system, we found that TP53 pathway alterations (TP53 status, MDM2/MDM4 genomic amplification/mRNA overexpression, MDM2 SNP309, and TP53 SNP72) did not confer apoptotic or cytostatic responses in sarcoma tissue biopsies (n = 24). Unexpectedly, MDM2 status did not predict Nutlin-3a sensitivity. RNA sequencing revealed that the global transcriptomic profiles of these sarcomas provided a more robust prediction of apoptotic responses to Nutlin-3a. Expression profiling revealed a subset of TP53 target genes that were transactivated specifically in sarcomas that were highly sensitive to Nutlin-3a. Of these target genes, the GADD45A promoter region was shown to be hypermethylated in 82% of wild-type TP53 sarcomas that did not respond to Nutlin-3a, thereby providing mechanistic insight into the innate ability of sarcomas to resist apoptotic death following Nutlin-3a treatment. Collectively, our findings argue that the existing benchmark biomarker for MDM2 antagonist efficacy (MDM2 amplification) should not be used to predict outcome but rather global gene expression profiles and epigenetic status of sarcomas dictate their sensitivity to p53/MDM2 antagonists. Cancer Res; 74(3); 921–31. ©2013 AACR.

Background Colorectal cancer (CRC) is the second leading cause of cancer related mortality. Over 80% of CRC develop from adenomatous polyps. Hence, early treatment and prevention of adenomas would lead to a significant decrease of disease burden for CRC. MYB is a transcription factor that is over-expressed in both adenomatous polyp precursors and colorectal cancer and hence an ideal immunotherapeutic target. We have developed a cancer vaccine, TetMYB, that targets MYB and aim to evaluate its efficacy in the prophylactic and therapeutic management of adenomatous polyps. Material and Methods Six to eight-week-old Apcmin/+ (Familial Adenomatous Polyposis model) and Apc580S (sporadic model) C57BL/6 mice were used. The Apcmin/+ mice are carried a germline mutation of one Apc allele whereas the Apc580S model has an inducible silencing of one Apc allele, when exposed to Tamoxifen, via the Cre-Lox recombination enzyme system. In the prophylactic treatment group, Apcmin/+ and Apc580S C57BL/6 mice were vaccinated and then surveyed for clinical signs of distress according to animal ethical endpoints. Number of adenoma and survival were measured. In the therapeutic cohort, Apc580S C57BL/6 mice were given Tamoxifen-laced food to activate Cre-Lox recombinase mediated silencing of one Apc allele and thus inducing adenoma development. Following adenoma detection using mouse colonoscopy, mice were vaccinated with TetMYB and treated with anti-PD-1 antibody and were analyzed for adenoma growth rate. Results In both the prophylactic and therapeutic setting, mice vaccinated with TetMYB had a significantly improved outcome. In the prophylactic treatment group, the vaccinated Apcmin/+ mice had a median survival benefit of 70 days (p = 0.008) and the vaccinated Apc580S mice having a mean survival benefit of 134 days (p = 0.01) over the unvaccinated mice. In the prophylactic cohort, immunofluorescence confirmed a stronger cytotoxic CD8+ T-cell infiltrate in the vaccinated group, implying an anti-tumor immune response. In the therapeutic cohort, vaccinated Apc580S mice showed significantly reduced adenoma growth rate compared to the unvaccinated mice (p = 0.0005). Conclusion TetMYB vaccine has shown benefit in a prophylactic and therapeutic setting in the management of colonic adenoma in a murine model. This will form the basis for a future clinical trial to prevent and treat colonic adenomatous polyps, and perhaps colorectal cancer prevention. Citation Format: Toan D. Pham, Sandra Carpinteri, Shienny Sampurno, Lloyd Pereira, Sara Roth, Vignesh Narasimhan, Kasmira Wilson, Phillip Darcy, Jayesh Desai, Alexander G. Heriot, Robert G. Ramsay. Novel vaccine targeting colonic adenoma: A pre-clinical model [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 1472.

Background Tislelizumab (BGB-A317), an investigational monoclonal antibody with high affinity and specificity for PD-1, was engineered to minimize binding to FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, a potential mechanism of resistance to anti-PD-1 therapy. Previous reports from early phase studies suggest tislelizumab was generally well tolerated and had antitumor activity in patients (pts) with advanced solid tumors. Clinical effects of tislelizumab LTE (>12 mo) in pts enrolled in the first-in-human study (NCT02407990) are presented here. Methods Patients with advanced solid tumors received IV tislelizumab 0.5, 2, 5, or 10 mg/kg Q2W, 2 or 5 mg/kg administered Q2W or Q3W, or 200 mg IV Q3W. Antitumor activity was assessed by RECIST v1.1 criteria; PD-L1 expression was retrospectively assessed with the VENTANA PD-L1 (SP263) assay. Results As of 31 Aug 2018, 63 of the 451 pts received tislelizumab for >12 mo. In these 63 pts, median age was 64 yr and 70% had received ≥1 prior systemic therapy. Tislelizumab LTE was most common in NSCLC (n=9), HCC (n=7), and bladder and ovarian (n=5 each) cancers. Four of the 5 pts who achieved CR during this study had LTE to tislelizumab (Table); all 4 pts were PD-L1+ (≥1% expression on tumor cells). Across the LTE cohort, ORR was 66.7%; PR and SD were observed in both PD-L1+ and PD-L1- tumors. The median time to CR/PR (3.7 mo) and duration of CR/PR (21.1 mo) were longer in pts with LTE than pts who responded but did not remain on treatment for >12 mo (2.1 and 6.3 mo, respectively). Rash was the only treatment-related AE (TRAE) reported in ≥15% of pts. Most TRAEs were of mild or moderate severity; arthritis, diarrhea, fatigue, granuloma, hyperglycemia, and lichenoid keratosis (n=1 each) were the only grade ≥3 TRAEs reported with tislelizumab LTE. Conclusion Tislelizumab remained well tolerated for >12 mo and elicited durable responses in pts with a variety of tumor types regardless of PD-L1 status. PD-L1+ (n=35)PD-L1- (n=22)Missing (n=6)Total (N=63)CR4004 (6.3%)PR2113438 (60.3%)SD99220 (31.7%)PD1001 (1.6%)Abbreviations: CR, complete response; PD, progressive disease; PR, partial response; SD stable disease. Citation Format: Jayesh Desai, Benjamin Markman, Michael Friedlander, Hui Gan, Lisa Horvath, Amanda Townsend, Michael Millward, Michael Jameson, Chia-Jui Yen, Ming-Mo Hou, Jeannie Hou, John Wu, Liang Liang, Sanjeev Deva. Long-term exposure (LTE) to Tislelizumab, an investigational anti-PD-1 antibody, in a first-in-human Phase I study [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 CT084.

e18236 Background: The double-blind, randomized, placebo-controlled phase 3 ENLIVEN study in TGCT demonstrated a significant tumor response at week 25 by RECIST for pexidartinib (39% vs. 0% for placebo) and improvement in joint function and symptoms. The aim of this analysis was to identify a threshold score for responder definitions for PROMIS-PF scale and Worst Stiffness Numerical Rating Scale (WS-NRS) and compared responder rates for pexidartinib versus placebo. Methods: Anchor- and distribution-based estimates were calculated, and cumulative distribution function (CDF) plots were generated to derive responder definition threshold estimates. Anchor- and distribution-based results and CDFs were evaluated through triangulation, following FDA PRO Guidance, to determine a single responder definition threshold (i.e., meaningful change) for each instrument. The proportion of responders at Week 25 between treatments was compared with Fisher’s Exact Test (2-sided). Results: 120 patients were randomized to pexidartinib (n = 61) and placebo (n = 59) and assessed through 25 weeks of treatment. Anchor-based analysis showed one-level improvement on the patient global rating of PF item was associated with a mean change of 4.0 on PROMIS-PF. Distribution-based estimates (0.5 SD and 1 SEM) for PROMIS-PF were 2.8 and 2.5, respectively. For WS-NRS, a response of “A little improved” by patients on the perception of stiffness item was associated with a mean change of 1.1. The distribution-based estimates for the WS-NRS item were 0.9 and 0.5, respectively. This resulted in the following responder definition thresholds: ≥3 points for PROMIS-PF and ≥1 for WS-NRS improvement. A greater proportion of pexidartinib as compared to placebo patients were responders by PROMIS-PF (30% vs. 5%, p < 0.001) and WS-NRS (39% vs. 19%, p = 0.02) at week 25, respectively. Conclusions: Triangulation yielded responder definitions of ≥3 points for PROMIS-PF and ≥1 for WS-NRS. With these definitions, a greater proportion of patients treated with pexidartinib compared to placebo had meaningful improvement in physical function and stiffness.

11042 Background: TGCT is a rare, locally aggressive neoplasm of the joint/tendon sheath linked to colony-stimulating factor 1 (CSF1) overexpression. Pexidartinib (pex), a selective inhibitor of CSF1 receptor, KIT, and FLT3-ITD, had a compelling tumor response rate in the TGCT cohort of a phase 1 study (NCT01004861) and significant tumor response vs placebo by RECIST v1.1 (39% vs 0%, P< 0.0001) and tumor volume score (TVS) (56% vs 0%, P< 0.0001) in the randomized, 2-part, crossover phase 3 ENLIVEN study (NCT02371369). Updated efficacy and safety with longer treatment are reported. Methods: Patients (pts) were ≥18 y with TGCT that was inoperable or for which surgery would likely be associated with worsening functional limitation or severe morbidity. Best overall response (complete or partial [CR/PR]) and duration of response (DOR) by RECIST and TVS were assessed by independent central review. Data cutoff was Jan 31, 2018, 16-67 mo after pts’ first dose. Results: In both studies 130 pts received pex, 61 ongoing at data cutoff. Median treatment duration was 17 mo (1, 60+). CR/PR rates were high and consistent and, together with DOR, improved with prolongation of treatment (Table). Most frequent adverse events were hair color change (75%), fatigue (60%), nausea (45%), arthralgia (38%), AST increase (30%), and diarrhea (30%). In ENLIVEN part 1, 3 of 61 (5%) pts had reversible ALT and AST ≥3 × ULN with TBil and ALP ≥2 × ULN; all started in the first 8 weeks of treatment, and no new cases emerged with continuation of treatment. Conclusions: Tumor response rate increased with continuation of pex treatment. The safety profile remained similar, with no new mixed or cholestatic hepatotoxicity. Clinical trial information: NCT01004861 and NCT02371369. [Table: see text]

3003 Background: The KRASG12C mutation is found in approximately 13% of lung adenocarcinomas and 1–3% of other solid tumors, but there is no approved therapy that targets this mutation. AMG 510 is a novel small molecule that specifically and irreversibly inhibits KRASG12C by locking it in an inactive GDP-bound state. Methods: This phase 1, first-in-human, open-label, multicenter study (NCT03600883) is evaluating the safety, tolerability, PK, and efficacy of AMG 510 in adult patients (pts) with locally-advanced or metastatic KRASG12C mutant solid tumors. The primary endpoint is safety; key secondary endpoints include PK, ORR (assessed every 6 weeks [wks]), DOR, and PFS. Key inclusion criteria: KRASG12C mutation identified through DNA sequencing, measurable or evaluable disease, ECOG PS ≤2, life expectancy >3 months (mo). Key exclusion criteria: active brain metastases, myocardial infarction within 6 mo. A dose exploration will determine the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D). A dose expansion will enroll pts with NSCLC, CRC, and other advanced solid tumors carrying the KRASG12C mutation. AMG 510 will be given PO until disease progression, intolerance, or withdrawal of consent. Results: 22 pts (8 men, 14 women; median age 55.5 y) were enrolled in the first 3 dose cohorts. Tumor types: 6 NSCLC, 15 CRC, 1 other. Most pts (n=17) had ≥3 prior lines of treatment (tx). Median tx duration was 28 d (range: 8–134). 5 pts reported 10 treatment-related AEs (grade 1, n=9; grade 2, n=1); there were no DLTs. Tumor response was evaluated in 9 pts (4 with ≥2 assessments); 13 pts have not reached their first assessment.1 pt had a PR (NSCLC at wks 6 and 12, tx ongoing), 6 pts had SD (4 CRC and 2 NSCLC; median tx duration 9.7 wks [range: 6.3–19.1], tx ongoing), 2 pts had PD. 20 pts are continuing to receive AMG 510. A second PR (NSCLC at wk 6, tx ongoing) was reported after data cutoff. Conclusions: AMG 510 has been well tolerated at the dose levels tested and has shown antitumor activity when administered as monotherapy to patients with advanced KRAS G12C mutant solid tumors. MTD has not been determined, and enrollment into the dose exploration is ongoing. Clinical trial information: NCT03600883.

358 Background: Nivo (anti–PD-1) has shown durable responses and manageable safety (ORR, 19.6%; grade 3‒4 treatment-related AEs [TRAEs], 18%) in advBC (Sharma et al. Lancet Oncol 2017), but prolonging survival in more pts requires additional approaches to overcome tumor evasion mechanisms. IDO1 allows tumor escape through kynurenine (KYN) production, which stimulates regulatory T cells and suppresses effector T-cell proliferation. Anti─PD-1 can upregulate IDO1, supporting the rationale for combining nivo with an IDO1i. BMS-986205 is a selective, potent, once-daily (QD) oral IDO1i that works early in the IDO1 pathway to reduce KYN production. BMS-986205 + nivo showed favorable safety and efficacy in heavily pretreated pts with select solid tumors (Luke et al. SITC 2017; NCT02658890). Updated safety across all tumor cohorts and efficacy in the immuno-oncology (I-O)–naive advBC cohort are reported. Methods: Dose-escalation methods in this phase 1/2a, open-label study were previously described; during expansion, pts received BMS-986205 100 or 200 mg QD + nivo 240 mg IV Q2W or 480 mg IV Q4W. Objectives included safety and ORR by RECIST v1.1 (includes unconfirmed responses). Results: As of Mar 2018, 516 pts received BMS-986205 + nivo; 45% had ≥2 prior regimens. TRAEs occurred in 57% of pts (grade 3‒4, 12%), the most common being fatigue (15%) and nausea (12%); 19 pts (4%) discontinued due to TRAEs, and 3 pts ( < 1%) died due to a TRAE (myocarditis, Stevens-Johnson syndrome, and hepatic failure). In all treated pts and within the advBC cohort (n = 30), the frequency and severity of TRAEs and rate of discontinuation due to TRAEs was lower with the 100- vs 200-mg BMS-986205 dose. Among the 27 pts with I-O–naive advBC, with a median duration of follow-up of 24 wk, ORR was 37% (3 CRs, 7 PRs), and the DCR was 56%; ORR in pts with tumor PD-L1 ≥1% (Dako PD-L1 IHC 28-8 pharmDx assay; n = 14) vs < 1% (n = 10) was 50% vs 30%. Conclusions: BMS-986205 + nivo was well tolerated in heavily pretreated pts, and tolerability was improved with the 100-mg BMS-986205 dose. Preliminary evidence of efficacy was observed in advBC, supporting further evaluation of BMS-986205 + nivo. Clinical trial information: NCT02658890.

TPS467 Background: CIT has significant survival benefits across multiple tumor types, but durable response is experienced by only subsets of patients (pts). To extend clinical benefit to more pts, efficacious CIT combinations (combos) targeting multiple cancer immune escape mechanisms need to be identified. The MORPHEUS platform includes multiple ph Ib/II trials designed to identify early signals of safety and efficacy of CIT combos. Using a randomized trial design, multiple treatment (tx) arms are compared with a single control arm in each pt cohort. We present three GI-specific MORPHEUS trials, each assessing CIT combos that could concurrently enhance multiple aspects of the cancer immune response. Methods: The MORPHEUS trials described here are global, open-label, randomized, Ph Ib/II trials enrolling pts with pancreatic ductal adenocarcinoma (PDAC), gastric or gastroesophageal junction cancers or colorectal cancer (CRC). New arms with novel CIT combos (table) are opened as new txs become available, and arms with minimal efficacy or unacceptable toxicity are closed. Studies include multiple cohorts for pts receiving different lines of tx (1L and 2L PDAC and gastric; 3L CRC). Pts with loss of clinical benefit or unacceptable toxicity may be eligible to enroll in a different CIT combo arm. Primary endpoints include safety and investigator-assessed ORR (RECIST v1.1); secondary endpoints: PFS, OS, DCR and DOR. Clinical trial information: NCT03193190, NCT03281369, NCT03555149. [Table: see text]

688 Background: BRAFV600E mutation occurs in 10%-–15% of patients (pts) with mCRC and confers a poor prognosis. After first-line therapy, standard second-line therapies provide limited benefit, with objective response rates (ORRs) < 10%, and overall survival (OS) of 4–6 months (mo). BEACON CRC (NCT02928224) is a 3-arm phase 3 trial of triplet therapy with the BRAF inhibitor ENCO + MEK inhibitor BINI + anti–EGFR antibody CETUX vs ENCO + CETUX vs a control arm (irinotecan/FOLFIRI + CETUX) in pts with BRAFV600E mCRC in the second or third-line setting. A safety lead-in (SLI) of the triplet therapy was conducted in 30 pts prior to initiation of the randomized part of the trial. Previously reported confirmed ORR in 29 pts with BRAFV600E mCRC was 48% and median progression-free survival (PFS) was 8.0 mo (Van Cutsem E, et al. Ann Oncol. 2018;29:O-027). Here we present updated safety and efficacy results including mature OS. Methods: All pts in the SLI received ENCO 300 mg once daily + BINI 45 mg twice daily + CETUX standard weekly dose. Assessments included efficacy (ORR, duration of response, time to response, PFS, and OS), safety, and tolerability. Results: Among 30 pts treated, 1 had a BRAF non-V600E mutation and is not included in the efficacy analyses. At data cutoff, the median follow-up time for survival was 18.2 mo and median exposure was 7.8 mo (range 0.5–21.4 mo). The confirmed ORR and median PFS remain unchanged from the previous report (ORR, 48% [95%CI, 29.4–67.5]; PFS, 8.0 mo [95% CI, 5.6–9.3 mo]). Mature median OS is 15.3 mo (95% CI, 9.6 mo–not reached). The triplet continues to be well-tolerated with no unexpected toxicities. The most common grade 3/4 toxicities were fatigue (13%), anemia, increases in creatine phosphokinase and/or aspartate aminotransferase, and urinary tract infections (each 10%). The rate of grade 3/4 skin toxicities continues to be lower than generally observed with CETUX in mCRC. Conclusions: With longer follow-up, triplet therapy with ENCO + BINI + CETUX continues to be well tolerated. Median PFS and now mature median OS are substantially improved over historical data for current standard-of-care options. Clinical trial information: NCT02928224.

Historically, patients with inoperable gastrointestinal stromal tumors (GISTs) had a very poor prognosis because of the highly resistant nature of these tumors to conventional chemotherapy. The rational and progressive development of tyrosine kinase inhibitors (TKIs) since the initial proof-of-concept studies with imatinib mesylate in the late 1990s, all designed to exploit key pathways that lead to GISTs being so oncogenically addicted, have revolutionized the treatment of GIST. Median overall survival has improved from less than a year to at least 5 years in patients with advanced or metastatic disease. Imatinib remains the standard first-line treatment in advanced GIST; however, resistance to imatinib and subsequent other TKIs inevitably develops in most but not all patients. As much as efforts will continue to identify new drugs for patients with disease that becomes refractory to these agents, there has also been a need to focus on optimizing the use of currently available therapies by using a combination of molecular tools to stratify patients more effectively, pharmacodynamic markers and pharmacokinetic modeling to maximize these agents' activity in individual patients, and reappraising the role of surgery in the management of patients with metastatic disease. These all form part of a modern, multidisciplinary approach to the management of GIST patients.

Soft-tissue sarcomas require tailored and multidisciplinary treatment and management. However, little is known about how sarcomas are treated and managed throughout the Asia-Pacific region.MEDLINE was systematically searched using prespecified criteria. Publications (previous 10 years) that reported tumour characteristics, treatment patterns, survival outcomes, and/or safety outcomes of patients with soft-tissue sarcoma were selected. Exclusion criteria were studies of patients18 years of age; ≤ 10 patients; countries other than Australia, Hong Kong, Indonesia, Korea, Malaysia, New Zealand, Philippines, Singapore, Taiwan, or Thailand;20% benign tumours; sarcomas located in bones or joints; gastrointestinal stromal tumour; Kaposi's sarcoma; or not reporting relevant outcomes.Of the 1,822 publications retrieved, 35 (32 studies) were included. Nearly all patients (98%, 1,992/2,024; 31 studies) were treated with surgery, and more studies used adjuvant radiotherapy than chemotherapy (24 vs 17 studies). Survival outcomes and recurrence rates varied among the studies because of the different histotypes, sites, and disease stages assessed. Only 5 studies reported safety findings.These findings highlight the lack of specific data available about soft-tissue sarcomas in the Asia-Pacific region. Better efforts to understand how the sarcoma is managed and treated will help improve patient outcomes in the region.

Background: The changing treatment landscape for metastatic colorectal cancer creates multiple potential treatment strategies. An Australian-centric database capturing comprehensive information across a range of treatment locations would create a valuable resource enabling multiple important research questions to be addressed. Aims: To establish a collection of a consensus dataset capturing treatment and outcomes at multiple public and private hospitals across Australia. Methods: An electronic database was developed by a panel of clinicians, to capture an agreed dataset for patients with newly diagnosed metastatic colorectal cancer. Of particular interest were clinician decision-making, the impact of comorbidities and the frequency of major adverse events. Results: Since July 2009, data collection has been established at six public and eight private hospitals across three Australian states and territories. Successful linkage and analysis, with support from BioGrid Australia, of selected data on the initial 864 patients demonstrates that data can be captured from diverse sites, including public and private practice, that multiple factors impact on treatment delivered and outcomes achieved and that comprehensive data on rare but important adverse events can be captured. As a clinical research tool, the project has been highly successful, generating multiple presentations at national and international conferences related to a diverse range of research questions. Conclusions: Multistate, project-specific data collection involving large numbers of patients is achievable. Providing invaluable insight into the routine clinical management of metastatic colorectal cancer in the era of targeted therapies, this also creates a significant resource for research, including many questions not being addressed by clinical trials.

The individual rarity of the many subtypes of soft tissue sarcomas has historically mandated an empiric approach to systemic therapy. Doxorubicin, first reported to have activity in sarcomas 40 years ago, remains the generalizable first-line treatment of choice for many subtypes, with no other drug or combination having shown an overall-survival advantage. Other cytotoxic agents, such as paclitaxel for angiosarcoma or gemcitabine with docetaxel for leiomyosarcoma, are commonly used for certain histologic subtypes based on relatively small studies. Trabectedin, particularly active against leiomyosarcoma and myxoid liposarcoma, is approved in many countries worldwide but not yet in the United States or Australia. Newer cytotoxic agents, including ifosfamide derivatives, are in current phase III testing. Although advances is systemic therapy of soft-tissue sarcomas have been hampered by their biologic heterogeneity, this diversity also serves as fertile ground for discovery and validation of targetable molecular drivers. The most notable success in this regard has been the development of small molecule therapies for gastrointestinal stromal tumors. Other targets of recent interest include mouse double minute 2 homolog (MDM2) in dedifferentiated liposarcoma and anaplastic lymphoma kinase (ALK) in inflammatory myofibroblastic tumor. Molecular therapies that have shown activity in diverse sarcoma populations include mammalian target of rapamycin (mTOR) inhibitors and vascular endothelial growth factor (VEGF-R) inhibitors. Among the latter, pazopanib demonstrated a progression-free survival over placebo in prior-treated patients with advanced sarcoma, and is now approved for use in the sarcomas in many countries. Efforts to understand the key molecular aberrations in any particular tumor continue towards a goal of individualized sarcoma therapy.

During the last 20 years there have been major therapeutic developments in colorectal cancer (CRC) with the introduction of multiple novel therapeutic agents into routine clinical practice. This has improved survival in both the adjuvant and advanced disease settings. However, improvements have come with substantial increases in expense to the community and potential toxicity to the patient. There has been substantial research to identify tumour factors in CRC that predict treatment response and survival outcomes. This research has identified clinically useful predictive biomarkers to aid clinical decision making, such as the presence or absence of KRAS gene mutations which can determine the benefit of using epidermal growth factor receptor (EGFR) inhibiting antibodies. However, less attention has been paid to the identification and impact of predictive patient-derived factors such as age, gender and the presence of comorbid conditions or evidence of a systemic inflammatory response. In this article, the current concepts of tumour and patient-related predictive factors in CRC management are reviewed.

Introduction. After treatment, bone sarcoma patients carry a high chance of relapse and late effects from multimodal therapy. We hypothesize that significant variation in surveillance practice exists between pediatric medical oncology (PO) and nonpediatric medical oncology (NP) sarcoma disciplines.Methods. Australian sarcoma clinicians were approached to do a web based survey that assessed radiologic surveillance (RS) strategies, late toxicity assessment, and posttreatment psychosocial interventions. Results. In total, 51 clinicians responded. No differences were identified in local disease RS. In metastatic disease response assessment, 100% of POs (23/23) and 93% of NPs (24/26) conducted CT chest. However, this was more likely to occur for NPs in the context of a CT chest/abdomen/pelvis (NP: 10/26; PO: 1/23;p=0.006). POs were more likely to use CXR for RS (p=0.006). POs showed more prescriptive intensity in assessment of heart function (p=0.001), hearing (p<0.001), and fertility (p=0.02). POs were more likely to deliver written information for health maintenance/treatment summary (p=0.04). The majority of respondents described enquiring about psychosocial aspects of health (n=33/37, 89%), but a routine formal psychosocial screen was only used by 23% (n=6/26).Conclusion. There is high variability in bone sarcoma surveillance between PO and NP clinicians. Efforts to harmonize approaches would allow early and late effects recognition/intervention and facilitate improved patient care/transition and research.

Purpose: Vemurafenib, a selective inhibitor of BRAFV600, has shown significant activity in BRAFV600 melanoma but not in less than 10% of metastatic BRAFV600 colorectal cancers (CRC), suggesting that studies of the unique hypermethylated phenotype and concurrent oncogenic activation of BRAFmut CRC may provide combinatorial strategies. Experimental Design: We conducted comparative proteomic analysis of BRAFV600E melanoma and CRC cell lines, followed by correlation of phosphoinositide 3-kinase (PI3K) pathway activation and sensitivity to the vemurafenib analogue PLX4720. Pharmacologic inhibitors and siRNA were used in combination with PLX4720 to inhibit PI3K and methyltransferase in cell lines and murine models. Results: Compared with melanoma, CRC lines show higher levels of PI3K/AKT pathway activation. CRC cell lines with mutations in PTEN or PIK3CA were less sensitive to growth inhibition by PLX4720 (P = 0.03), and knockdown of PTEN expression in sensitive CRC cells reduced growth inhibition by the drug. Combined treatment of PLX4720 with PI3K inhibitors caused synergistic growth inhibition in BRAF-mutant CRC cells with both primary and secondary resistance. In addition, methyltransferase inhibition was synergistic with PLX4720 and decreased AKT activation. In vivo, PLX4720 combined with either inhibitors of AKT or methyltransferase showed greater tumor growth inhibition than PLX4720 alone. Clones with acquired resistance to PLX4720 in vitro showed PI3K/AKT activation with EGF receptor (EGFR) or KRAS amplification. Conclusions: We show that activation of the PI3K/AKT pathway is a mechanism of both innate and acquired resistance to BRAF inhibitors in BRAFV600E CRC and suggest combinatorial approaches to improve outcomes in this poor prognosis subset of patients. Clin Cancer Res; 19(3); 657–67. ©2012 AACR.

Activation of the canonical TGF-β signaling pathway provides growth inhibitory signals in the normal intestinal epithelium. Colorectal cancers (CRCs) frequently harbor somatic mutations in the pathway members TGFBR2 and SMAD4, but to what extent mutations in SMAD2 or SMAD3 contribute to tumorigenesis is unclear. A cohort of 744 primary CRCs and 36 CRC cell lines were sequenced for SMAD4, SMAD2, and SMAD3 and analyzed for allelic loss by single-nucleotide polymorphism (SNP) microarray analysis. Mutation spectra were compared between the genes, the pathogenicity of mutations was assessed, and relationships with clinicopathologic features were examined. The prevalence of SMAD4, SMAD2, and SMAD3 mutations in sporadic CRCs was 8.6% (64 of 744), 3.4% (25 of 744), and 4.3% (32 of 744), respectively. A significant overrepresentation of two genetic hits was detected for SMAD4 and SMAD3, consistent with these genes acting as tumor suppressors. SMAD4 mutations were associated with mucinous histology. The mutation spectra of SMAD2 and SMAD3 were highly similar to that of SMAD4, both in mutation type and location within the encoded proteins. In silico analyses suggested the majority of the mutations were pathogenic, with most missense changes predicted to reduce protein stability or hinder SMAD complex formation. The latter altered interface residues or disrupted the phosphorylation-regulated Ser-Ser-X-Ser motifs within SMAD2 and SMAD3. Functional analyses of selected mutations showed reductions in SMAD3 transcriptional activity and SMAD2–SMAD4 complex formation. Joint biallelic hits in SMAD2 and SMAD3 were overrepresented and mutually exclusive to SMAD4 mutation, underlining the critical roles of these three proteins within the TGF-β signaling pathway. Cancer Res; 73(2); 725–35. ©2012 AACR.

Background There is a paucity of data on the current management of patients with advanced soft tissue sarcoma (STS) in the Australian health care setting. This study utilised the Australian sarcoma database to evaluate the patterns of care delivered to patients with advanced STS at Australian sarcoma services. Methods Prospectively collected data from six sarcoma centres in Australia were sourced to identify patients diagnosed with advanced STS between 1 January 2010 and 31 December 2012. Descriptive statistics were analysed for patient demographics, clinicopathological characteristics and treatment patterns. Overall survival was estimated using the Kaplan–Meier product limit method. Results Of 253 patients with advanced STS, four major STS subtypes were identified: undifferentiated pleomorphic sarcoma (23 %), leiomyosarcoma (17 %), liposarcoma (14 %), and synovial sarcoma (8 %); with the rest grouped as “other STS” (38 %). Approximately one-third of patients received palliative systemic therapy with the most common first-line therapy being doxorubicin alone (50 %). A small percentage of patients participated in clinical trials (20 %). Palliative radiotherapy was utilised mostly for treatment of symptomatic distant metastases and one-third of patients underwent metastasectomy, most commonly for pulmonary metastases. The median overall survival (OS) in this series was 18 months and no significant difference in OS was observed across different STS histological subtypes. Conclusions This is the first detailed study outlining patterns of care for Australian patients with advanced STS managed at sarcoma services. These data highlight a particular area of weakness in the lack of clinical trials for sarcoma patients and also serve as an important reference point for understanding how practice may change over time as treatment options evolve.

Data suggest aspirin improves survival in colorectal cancer (CRC) harbouring PIK3CA mutations. The impact of aspirin is thought predominantly to be through an anti-inflammatory effect. The aim of this study is to explore the effect of aspirin use on survival in a real-world cohort of stage 2 colon cancer (CC) patients.A prospective CRC database identified patients diagnosed with stage 2 CC between 2000 and 2011. PIK3CA mutation status was determined by next generation sequencing. Neutrophil-lymphocyte ratio greater than 5 at diagnosis represented systemic inflammation. Chart review was used to record regular aspirin use at diagnosis. Clinico-pathological features and survival data were available. Survival analyses used the Cox proportional hazards method.Of 488 patients with stage 2 CC, 95 patients were aspirin users and 70 patients had PIK3CA mutations. Aspirin users were more likely to be older (median: 76.4 years vs 68.3 years, P 0.001), to be less fit (American Society of Anaesthetists Score 3-4: 58% vs 31%, P 0.001) and to have systemic inflammation (neutrophil-lymphocyte ratio 5: 39% vs 27%, P = 0.027). Regular aspirin use did not significantly improve recurrence-free survival. In the PIK3CA mutated group, there was a trend towards improved recurrence-free survival (hazard ratio: 0.45, P = 0.42).Our study did not demonstrate a significant survival advantage from aspirin use in stage 2 PIK3CA mutated CC. The 'real-world' nature of our cohort and the subsequent uncontrolled differences in age and fitness in aspirin users are likely to have contributed to this result. Defining the true impact of aspirin in CRC requires prospective randomised clinical trials.

Background Patients with metastatic colorectal cancer whose disease has progressed on oxaliplatin- and irinotecan-containing regimens may benefit from EGFR-inhibiting monoclonal antibodies if they do not contain mutations in the KRAS gene (are “wild type”). It is unknown whether these antibodies, such as cetuximab, are more efficacious in refractory metastatic colorectal cancer as monotherapy, or in combination with irinotecan. Lack of mutation in KRAS, BRAF and PIK3CA predicts response to EFGR-inhibitors. The ICECREAM trial examines the question of monotherapy versus combination with chemotherapy in two groups of patients: those with a “quadruple wild type” tumour genotype (no mutations in KRAS, NRAS, PI3KCA or BRAF genes) and those with the specific KRAS mutation in codon G13D, for whom possibly EGFR-inhibitor efficacy may be equivalent. Methods and design ICECREAM is a randomised, phase II, open-label, controlled trial comparing the efficacy of cetuximab alone or with irinotecan in patients with “quadruple wild type” or G13D-mutated metastatic colorectal cancer, whose disease has progressed on, or who are intolerant of oxaliplatin- and fluoropyrimidine-based chemotherapy. The primary endpoint is the 6-month progression-free survival benefit of the treatment regimen. Secondary endpoints are response rate, overall survival, and quality of life. The tertiary endpoint is prediction of outcome with further biological markers. International collaboration has facilitated recruitment in this prospective trial of treatment in these infrequently found molecular subsets of colorectal cancer. Discussion This unique trial will yield prospective information on the efficacy of cetuximab and whether this is further enhanced with chemotherapy in two distinct populations of patients with metastatic colorectal cancer: the “quadruple wild type”, which may ‘superselect’ for tumours sensitive to EGFR-inhibition, and the rare KRAS G13D mutated tumours, which are also postulated to be sensitive to the drug. The focus on establishing both positive and negative predictive factors for the response to targeted therapy is an attempt to improve outcomes, reduce toxicity and contain treatment costs. Tissue and blood will yield a resource for molecular studies. Recruitment, particularly of patients with the rare G13D mutation, will demonstrate the ability for international collaboration to run prospective trials in small colorectal cancer molecular subgroups. Trial registration Australian and New Zealand Clinical Trials Registry: ACTRN12612000901808, registered 16 August 2012.