SPAR - a randomised, placebo-controlled phase II trial of simvastatin in addition to standard chemotherapy and radiation in preoperative treatment for rectal cancer: an AGITG clinical trial.

BACKGROUND: Retrospective studies show improved outcomes in colorectal cancer patients if taking statins, including overall survival, pathological response of rectal cancer to preoperative chemoradiotherapy (pCRT), and reduced acute and late toxicities of pelvic radiation. Major tumour regression following pCRT has strong prognostic significance and can be assessed in vivo using MRI-based tumour regression grading (mrTRG) or after surgery using pathological TRG (pathTRG). METHODS: A double-blind phase 2 trial will randomise 222 patients planned to receive long-course fluoropyrimidine-based pCRT for rectal adenocarcinoma at 18+ sites in New Zealand and Australia. Patients will receive simvastatin 40 mg or placebo daily for 90 days starting 1 week prior to standard pCRT. Pelvic MRI 6 weeks after pCRT will assess mrTRG grading prior to surgery. The primary objective is rates of favourable (grades 1-2) mrTRG following pCRT with simvastatin compared to placebo, considering mrTRG in 4 ordered categories (1, 2, 3, 4-5). Secondary objectives include comparison of: rates of favourable pathTRG in resected tumours; incidence of toxicity; compliance with intended pCRT and trial medication; proportion of patients undergoing surgical resection; cancer outcomes and pathological scores for radiation colitis. Tertiary objectives include: association between mrTRG and pathTRG grouping; inter-observer agreement on mrTRG scoring and pathTRG scoring; studies of T-cell infiltrates in diagnostic biopsies and irradiated resected normal and malignant tissue; and the effect of simvastatin on markers of systemic inflammation (modified Glasgow prognostic score and the neutrophil-lymphocyte ratio). Trial recruitment commenced April 2018. DISCUSSION: When completed this study will be able to observe meaningful differences in measurable tumour outcome parameters and/or toxicity from simvastatin. A positive result will require a larger RCT to confirm and validate the merit of statins in the preoperative management of rectal cancer. Such a finding could also lead to studies of statins in conjunction with chemoradiation in a range of other malignancies, as well as further exploration of possible mechanisms of action and interaction of statins with both radiation and chemotherapy. The translational substudies undertaken with this trial will provisionally explore some of these possible mechanisms, and the tissue and data can be made available for further investigations. TRIAL REGISTRATION: ANZ Clinical Trials Register ACTRN12617001087347. (www.anzctr.org.au, registered 26/7/2017) Protocol Version: 1.1 (June 2017).

A descriptive study of persistent oxaliplatin-induced peripheral neuropathy in patients with colorectal cancer.

BACKGROUND: Prolonged neurotoxicity after systemic chemotherapy has the potential to impact on quality of life. We explored the frequency of persistent peripheral neuropathy in patients who received oxaliplatin for colorectal cancer at two local centres. PATIENTS AND METHODS: Questionnaires were sent to patients who completed treatment with oxaliplatin for colorectal cancer at least 20 months prior to entering the study. Neuropathy questions were adapted from the FACT/GOG-Ntx (V.4) questionnaire. RESULTS: Of the 56 eligible patients, 27 returned the questionnaire. Twenty-five patients (93 %) experienced neuropathic symptoms during their treatment; 11 had grade-2, and two had grade-3 symptoms. At the time of completing the questionnaire, 17 patients (63.0 %; 95%CI 43.9-79.4 %) were still symptomatic with 12 patients (44.4 %; 95%CI 26.8-63.3) having grade-2 or grade-3 symptoms and three patients (11.1 %; 95%CI 2.9-27.3) having grade-3 neuropathic symptoms. Participants who received more than 900 mg/m2 oxaliplatin had a significantly higher risk of persistent grade-2 or grade-3 neuropathy (p = 0.031, RR = 8.3 95%CI = 1.2-57.4). There was a trend toward increased risk of persistent neuropathy of any grade among participants with a history of regular alcohol use (p = 0.051; RR = 1.7 95%CI 1.0-2.8). CONCLUSION: Persistent oxaliplatin-induced neuropathy is not as uncommon as previously suggested, and the rate of grade-2 and grade-3 symptoms could be considerably higher than previous reports.

Prognostic Differences of RAS Mutations: Results from the South Australian Metastatic Colorectal Registry.

BACKGROUND: Effective targeting of RAS mutations has proven elusive until recently. Novel agents directly targeting KRAS G12C have shown promise in early-phase clinical trials that included patients with metastatic colorectal cancer. Prior reports have suggested that G12C mutation may be predictive of poor outcome. OBJECTIVE: Assessment of the specific characteristics and prognostic implications of individual RAS mutation subtypes in patients with metastatic colorectal cancer. PATIENTS AND METHODS: Retrospective review of individual RAS mutation types from the South Australian Metastatic Colorectal Registry between 2006 and 2020. RESULTS: Of the 5165 patients entered onto the registry, 2305 (45%) had RAS mutation results available. 772 (33%) had a RAS mutation. The nature of the RAS mutation was available in 668 (87% of those with RAS mutation). Rare mutations (outside codons 12 and 13) made up 12.6% of the total. There were numerical differences in survival between the specific RAS mutation subgroups, with the longest median overall survival (30 months) observed in those with G12S mutations. However, there was no statistical difference in survival when comparing the various RAS mutations, including the comparison of G12C to G12S (p = 0.38). Patients with cancer harbouring rare RAS mutations had a median survival of 30 months. CONCLUSIONS: Whilst the G12S mutation was associated with the longest survival numerically, the observed survival for patients with the most common RAS mutations (G12C, G12V, G12A, G12D and G13D) did not significantly differ.

Phase I Trial of nab-Paclitaxel Administered Concurrently With Radiotherapy in Patients With Locally Advanced Inoperable Pancreatic Adenocarcinoma.

OBJECTIVES: Nab-paclitaxel has radiosensitizing antitumor efficacy in pancreatic cancer. We aimed to establish maximum tolerated dose (MTD) of nab-paclitaxel with radiotherapy in unresectable locally advanced pancreatic cancer. METHODS: In a phase I dose escalation trial patients received weekly nab-paclitaxel for 6 weeks with external beam radiotherapy (EBRT). 3 + 3 design was used with nab-paclitaxel doses: 25 mg/m 2 (cohort 1), 50 mg/m 2 (cohort 2), 75 mg/m 2 (cohort 3), and 100 mg/m 2 (cohort 4). Primary endpoint was MTD. Secondary objectives were progression-free survival and overall survival. RESULTS: Fourteen patients were recruited. Median age was 69 years (range, 40-86). Grade 1/2 toxicities were nausea (93%), vomiting (54%), diarrhea (57%), and fatigue (69%). There were no dose limiting toxicities (DLT) in cohorts 1 to 3. In cohort 4, DLTs of febrile neutropenia and enterocolitis were observed in patient 1. Subsequent DLT of febrile neutropenia and enterocolitis occurred in patient 5 in the expanded cohort. Following chemoradiotherapy median progression-free survival was 4.7 months (95% confidence interval, 2.5-27.5) and median overall survival was 10.8 months (95% confidence interval, 6.37-25.2). CONCLUSIONS: Nab-paclitaxel and EBRT was well-tolerated at doses below 100 mg/m 2 . The MTD and recommended phase II study dose for nab-paclitaxel with EBRT is 75 mg/m 2 in this disease.

Outcomes for Metastatic Colorectal Cancer Based on Microsatellite Instability: Results from the South Australian Metastatic Colorectal Cancer Registry.

BACKGROUND: Microsatellite instability (MSI) is the molecular marker for DNA mismatch repair deficiency (dMMR) in colorectal cancer (CRC) and has been associated with better survival outcomes in early stage disease. In metastatic CRC (mCRC), outcomes for patients with MSI are less clear. There is evolving evidence that treatment pathways for MSI CRC should include programmed-death 1 (PD-1) antibodies. OBJECTIVE: An analysis was performed to explore the impact of MSI status on overall survival (OS) in mCRC. PATIENTS AND METHODS: South Australian Metastatic CRC Registry data were analysed to assess patient characteristics and survival outcomes, comparing patients with MSI CRC with those whose tumours were microsatellite stable (MSS). Kaplan-Meier survival analysis was used to assess OS. Cox regression analysis was undertaken to assess the independence of MSI as a prognostic factor. RESULTS: Of 4359 patients registered on the database, 598 (14%) had been tested for, and 62 (10.1%) of these patients had, demonstrable MSI. There were significantly higher rates of right-sided primary (p < 0.001), poorly differentiated pathology (p = 0.002), and BRAF V600E mutation (p < 0.001) in the MSI group. The MSI group were also less likely to receive chemotherapy (p < 0.001) or to have liver surgery, but more likely to be diagnosed at an early stage. The median overall survival was 9.5 months for those with MSI CRC versus 21.3 months for MSS CRC patients (p = 0.052). Cox regression analysis indicated that MSI was not an independent predictor of OS. Independent predictors of better OS included having liver surgery for metastasis, having chemotherapy, and being initially diagnosed at an early stage. CONCLUSIONS: Only 14% of patients with mCRC were tested for MSI, and 1 in 10 were found to be MSI high. The clinical characteristics of MSI mCRC are in keeping with those previously reported. MSI in this population-based registry was associated with a numerically lower survival which did not attain statistical significance.

Adjuvant therapy for resected colon cancer 2017, including the IDEA analysis.

INTRODUCTION: Oxaliplatin-based adjuvant chemotherapy has been the standard of care for resected early colon cancer for over a decade. Recent results from the IDEA meta-analysis attempt to address the question of whether 3 or 6 months of adjuvant chemotherapy is preferable in Stage III colon cancer. Areas covered: A review of the literature and recent conference presentations was undertaken on the topic of adjuvant therapy for resected early colon cancers. This article reviews the current evidence for adjuvant treatment of Stage II and III colon cancer, as well as up-to-date data regarding optimal duration of therapy. This article reviews the evidence for lifestyle modifications in the management of early colorectal cancer and other future directions for research in early colon cancer. Expert commentary: In recent years, there have been no advances in the development of novel agents for adjuvant therapy in colorectal cancer. Although the IDEA meta-analysis was negative for its primary non-inferiority endpoint, the detailed results provide valuable information that allows personalisation of treatment regimen and duration.

Current challenges in optimizing systemic therapy for patients with pancreatic cancer: expert perspectives from the Australasian Gastrointestinal Trials Group (AGITG) with invited international faculty.

INTRODUCTION: Despite recent progress, the outlook for most patients with pancreatic cancer remains poor. There is variation in how patients are managed globally due to differing interpretations of the evidence, partly because studies in this disease are challenging to undertake. This article collates the evidence upon which current best practice is based and offers an expert opinion from an international faculty on how latest developments should influence current treatment paradigms. Areas covered: Optimal chemotherapy for first and subsequent lines of therapy; optimal management of locally advanced, non-metastatic cancer including the role of neoadjuvant chemo(radio)therapy, current evidence for adjuvant chemotherapy, major advances in pancreatic cancer genomics and challenges in supportive care particularly relevant to patients with pancreatic cancer. For each section, literature was reviewed by comprehensive search techniques, including clinical trial websites and abstracts from international cancer meetings. Expert commentary: For each section, a commentary is provided. Overall the challenges identified were: difficulties in diagnosing pancreatic cancer early, challenges for performing randomised clinical trials in all stages of the disease, some progress in systemic therapy with new agents and in identifying molecular subtypes that may be clinically relevant and move towards personalized therapy, but still, pancreatic cancer remains a very poor prognosis cancer with significant palliative care needs.

Systemic therapies for advanced gastroenteropancreatic neuroendocrine tumors.

INTRODUCTION: Neuroendocrine tumors are a heterogeneous group of malignancies, characterised by production of hormones and vasoactive peptides. The incidence of gastroenteropancreatic neuroendocrine tumors (GEP-NET) is rising, and they have the highest prevalence amongst upper gastro-intestinal tumors. Diagnosis remains challenging due to wide variations in presentation and slow onset of symptoms. A multi-disciplinary approach is vital in appropriately managing the diverse spectrum of GEP-NET. Areas covered: Investigations in GEP-NET and biomarkers are described. Moreover, all available therapeutic options for GEP-NET including surgery, somatostatin analogues, targeted agents, Peptide Receptor Radionuclide Therapy and chemotherapy are also discussed. Expert commentary: The landscape of management has changed significantly in the last decade as a result of many practice-changing clinical trials. Long- acting somatostatin analogues are used not only for symptom control but also for their anti-proliferative effect. Targeted agents, such as everolimus and sunitinib, have improved PFS in GEP-NET. The recently presented NETTER-1 trial confirms the place of peptide receptor radionuclide treatment (PRRT) in treating NET. While chemotherapy remained an important option for high grade tumors. Despite promising results from recent trials, challenges include establishing the optimal sequencing of therapies to optimize outcome and preserve the quality of life.

Cetuximab in metastatic colorectal cancer.

Management of metastatic colorectal cancer has evolved in the last 10 years, with the availability of targeted therapies resulting in improvement in quality of life and overall survival. Cetuximab is a chimeric monoclonal antibody that binds to the EGF receptor, and the net effects are inhibition of tumor growth, invasion, angiogenesis and metastasis. Cetuximab binding to the EGF receptor is also known to augment the effects of chemotherapy and radiotherapy. Only tumors expressing wild-type KRAS respond to cetuximab and improvements in progression-free survival and overall survival are seen, whereas patients with mutant KRAS are considered to be resistant. Cetuximab is currently available worldwide for use as monotherapy or in combination with chemotherapy in first-, second- or third-line settings in metastatic colorectal cancer patients with wild-type KRAS.

Randomized phase III study of panitumumab with fluorouracil, leucovorin, and irinotecan (FOLFIRI) compared with FOLFIRI alone as second-line treatment in patients with metastatic colorectal cancer.

PURPOSE: Panitumumab is a fully human anti-epidermal growth factor receptor (EGFR) monoclonal antibody that improves progression-free survival (PFS) in chemotherapy-refractory metastatic colorectal cancer (mCRC). This trial evaluated the efficacy and safety of panitumumab plus fluorouracil, leucovorin, and irinotecan (FOLFIRI) compared with FOLFIRI alone after failure of initial treatment for mCRC by tumor KRAS status. PATIENTS AND METHODS: Patients with mCRC, one prior chemotherapy regimen for mCRC, Eastern Cooperative Oncology Group performance status 0 to 2, and available tumor tissue for biomarker testing were randomly assigned 1:1 to panitumumab 6.0 mg/kg plus FOLFIRI versus FOLFIRI every 2 weeks. The coprimary end points of PFS and overall survival (OS) were independently tested and prospectively analyzed by KRAS status. RESULTS: From June 2006 to March 2008, 1,186 patients were randomly assigned 1:1 and received treatment. KRAS status was available for 91% of patients: 597 (55%) with wild-type (WT) KRAS tumors, and 486 (45%) with mutant (MT) KRAS tumors. In the WT KRAS subpopulation, when panitumumab was added to chemotherapy, a significant improvement in PFS was observed (hazard ratio [HR] = 0.73; 95% CI, 0.59 to 0.90; P = .004); median PFS was 5.9 months for panitumumab-FOLFIRI versus 3.9 months for FOLFIRI. A nonsignificant trend toward increased OS was observed; median OS was 14.5 months versus 12.5 months, respectively (HR = 0.85, 95% CI, 0.70 to 1.04; P = .12); response rate was improved to 35% versus 10% with the addition of panitumumab. In patients with MT KRAS, there was no difference in efficacy. Adverse event rates were generally comparable across arms with the exception of known toxicities associated with anti-EGFR therapy. CONCLUSION: Panitumumab plus FOLFIRI significantly improved PFS and is well-tolerated as second-line treatment in patients with WT KRAS mCRC.