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Background: Simulation models utilizing real-world data have potential to optimize treatment sequencing strategies for specific patient subpopulations, including when conducting clinical trials is not feasible. We aimed to develop a simulation model to estimate progression-free survival (PFS) and overall survival for first-line doublet chemotherapy with or without bevacizumab for specific subgroups of metastatic colorectal cancer (mCRC) patients based on registry data., Methods: Data from 867 patients were used to develop two survival models and one logistic regression model that populated a discrete event simulation (DES). Discrimination and calibration were used for internal validation of these models separately and predicted and observed medians and Kaplan-Meier plots were compared for the integrated DES. Bootstrapping was performed to correct for optimism in the internal validation and to generate correlated sets of model parameters for use in a probabilistic analysis to reflect parameter uncertainty., Results: The survival models showed good calibration based on the regression slopes and modified Hosmer-Lemeshow statistics at 1 and 2 years, but not for short-term predictions at 0.5 years. Modified C-statistics indicated acceptable discrimination. The simulation estimated that median first-line PFS (95% confidence interval) of 219 (25%) patients could be improved from 175 days (156-199) to 269 days (246-294) if treatment would be targeted based on the highest expected PFS., Conclusions: Extensive internal validation showed that DES accurately estimated the outcomes of treatment combination strategies for specific subpopulations, with outcomes suggesting treatment could be optimized. Although results based on real-world data are informative, they cannot replace randomized trials.

Background: Emerging evidence on the optimal use of chemotherapy and biologics in patients with metastatic colorectal cancer should impact management in routine care. Recent studies have demonstrated benefits for initial triplet chemotherapy (5-fluorouracil, oxaliplatin and irinotecan, FOLFOXIRI) and for initial treatment with an epidermal growth factor receptor inhibitor (EGFRi) in patients with a RAS wild-type tumour and a left-sided primary tumour., Aim: To explore evolving pattern of metastatic colorectal cancer care over time in Australia., Methods: We analysed data from the Treatment of Recurrent and Advanced Colorectal Cancer registry., Results: From July 2009 to December 2017, 2552 metastatic colorectal cancer patients were entered into the Treatment of Recurrent and Advanced Colorectal Cancer registry. Of 1585 patients who initially underwent chemotherapy, treatment was with a doublet in 76%. FOLFOXIRI was given to 22 patients (1.4%), mostly young patients and those with potentially resectable disease. Along with first-line chemotherapy, 61% received bevacizumab, while 3.3% received an EGFRi, predominantly over the last 2 years. Within the KRAS wild-type left-sided tumour cohort, EGFRi use increased from 9% in 2015 to 37% in 2017. Across treatment sites, there was a wide variation in the utilisation of FOLFOXIRI and EGFRi therapy; bevacizumab use was more consistent. A clear impact on survival outcomes from these regimens is not evident, potentially due to multiple confounders., Conclusion: Doublet chemotherapy + bevacizumab remains the dominant initial strategy, with limited uptake of triplet chemotherapy and of EGFRi. Potential explanations include uncertainty about the significance of post hoc analyses for EGFRi and concerns regarding adverse events for both strategies., (© 2018 Royal Australasian College of Physicians.)

Background: Debate continues regarding the benefits versus risks of initial resection of the primary tumor in metastatic colorectal cancer (mCRC) patients with an asymptomatic primary tumor. Although the benefit of the anti-vascular endothelial growth factor agent bevacizumab alongside first-line chemotherapy in mCRC is established, the impact of bevacizumab on the intact primary tumor (IPT) is less well understood., Methods: Data from an Australian mCRC registry were used to assess the impact of bevacizumab-based regimens in the presence of an IPT, to see if this differs from effects in resected primary tumor (RPT) patients and to understand the safety profile of bevacizumab in patients with IPT. Progression-free survival (PFS), overall survival (OS) and safety endpoints were analyzed., Results: Of 1204 mCRC patients, 826 (69%) were eligible for inclusion. Bevacizumab use was similar in both arms (IPT (64%) versus RPT (70%)); compared with chemotherapy alone, bevacizumab use was associated with significantly longer PFS (IPT: 8.5 months vs 4.7 months, P = 0.017; RPT: 10.8 months vs 5.8 months, P < 0.001) and OS (IPT: 20 months vs 14.8 months, P = 0.005; RPT: 24.4 months vs 17.3 months, P = 0.004)). 1 Bevacizumab use in an IPT was associated with more GI perforations (4.5% vs 1.8%, P = 0.210) but less frequent bleeding (1.5% vs 5.3%, P = 0.050) and thrombosis (1.5% vs 2.7%, P = 0.470), versus chemotherapy alone. Median survival was equivalent between patients that did or did not experience bevacizumab-related adverse events - 20.0 months versus 19.9 months, hazard ratio = 0.98, P = 0.623. 1 CONCLUSIONS: The addition of bevacizumab significantly improved survival outcomes in mCRC with an IPT. The occurrence of bevacizumab-related adverse events did not significantly impact survival outcomes., (© 2016 John Wiley & Sons Australia, Ltd.)

Background: With an ever-increasing focus on personalized medicine, all factors known to affect treatment response need to be considered when defining optimal therapy for individual patients. While the prognostic impact of primary tumor site on colorectal cancer (CRC) outcomes is established, emerging data suggest potential differences in response to biologic therapies. We studied the impact of tumor site on bevacizumab efficacy in patients with metastatic CRC., Patients and Methods: We analyzed data of patients in an Australian prospective multicenter metastatic CRC (mCRC) registry who received first-line chemotherapy. Tumor site was defined as right colon, cecum to transverse; left colon, splenic flexure to rectosigmoid; and rectum. Kaplan-Meier and Cox models were used for survival analyses., Results: Of 926 patients, 297 had right colon, 354 left colon, and 275 rectum primary disease. Median age was 68.6, 65.9, and 63.3 years, respectively (P = .001). Right colon disease was significantly associated with intraperitoneal spread (P < .0001), while left colon and rectum disease preferentially metastasized to the liver and lungs, respectively (P < .0001 in both settings). A total of 636 patients (68.7%) received bevacizumab. Progression-free survival was superior for bevacizumab-treated patients in all groups but appeared greatest in right colon disease (hazard ratio, 0.46; 95% confidence interval, 0.36-0.60; P ≤ .001). Overall survival was longest in patients with disease of the rectum, followed by left colon and right colon (median, 26.2, 23.6, and 18.2 months, respectively; P = .0004)., Conclusion: Tumor site appears to be prognostic in mCRC, with rectum and right colon disease associated with the best and worst outcomes, respectively. Patients who received bevacizumab in addition to chemotherapy had superior outcomes, with the effect appearing greatest in patients with right colon disease., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Aim: To investigate the safety and efficacy of adding bevacizumab to first-line chemotherapy in metastatic colorectal cancer patients with peritoneal disease., Methods: We compared rates of gastrointestinal perforation in patients with metastatic colorectal cancer and peritoneal disease receiving first-line chemotherapy with and without bevacizumab in three distinct cohorts: (1) the AGITG MAX trial (Phase III randomised clinical trial comparing capecitabine vs capecitabine and bevacizumab vs capecitabine, bevacizumab and mitomycinC); (2) the prospective Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) registry (any first-line regimen ± bevacizumab); and (3) two cancer centres in New South Wales, Australia [Macarthur Cancer Therapy Centre and Liverpool Cancer Therapy Centre (NSWCC) from January 2005 to Decenber 2012, (any first-line regimen ± bevacizumab). For the AGITG MAX trial capecitabine was compared to the other two arms (capecitabine/bevacizumab and capecitabine/bevacizumab/mitomycinC). In the AGITG MAX trial and the TRACC registry rates of gastrointestinal perforation were also collected in patients who did not have peritoneal metastases. Secondary endpoints included progression-free survival, chemotherapy duration, and overall survival. Time-to-event outcomes were estimated using the Kaplan-Meier method and compared using the log-rank test., Results: Eighty-four MAX, 179 TRACC and 69 NSWCC patients had peritoneal disease. There were no gastrointestinal perforations recorded in either the MAX subgroup or the NSWCC cohorts. Of the patients without peritoneal disease in the MAX trial, 4/300 (1.3%) in the bevacizumab arms had gastrointestinal perforations compared to 1/123 (0.8%) in the capecitabine alone arm. In the TRACC registry 3/126 (2.4%) patients who had received bevacizumab had a gastrointestinal perforation compared to 1/53 (1.9%) in the chemotherapy alone arm. In a further analysis of patients without peritoneal metastases in the TRACC registry, the rate of gastrointestinal perforations was 9/369 (2.4%) in the chemotherapy/bevacizumab group and 5/177 (2.8%) in the chemotherapy alone group. The addition of bevacizumab to chemotherapy was associated with improved progression-free survival in all three cohorts: MAX 6.9 m vs 4.9 m, HR = 0.64 (95%CI: 0.42-1.02); P = 0.063; TRACC 9.1 m vs 5.5 m, HR = 0.61 (95%CI: 0.37-0.86); P = 0.009; NSWCC 8.7 m vs 6.8 m, HR = 0.75 (95%CI: 0.43-1.32); P = 0.32. Chemotherapy duration was similar across the groups., Conclusion: Patients with peritoneal disease do not appear to have an increased risk of gastrointestinal perforations when receiving first-line therapy with bevacizumab compared to systemic therapy alone.

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 Bio Grid 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. [ABSTRACT FROM AUTHOR]