Practice variation on hospital level in the systemic treatment of metastatic colorectal cancer in The Netherlands: a population-based study

Harnessing the Potential of Real-World Evidence in the Treatment of Colorectal Cancer: Where Do We Stand?

OPINION STATEMENT

Treatment guidelines for colorectal cancer (CRC) are primarily based on the results of randomized clinical trials (RCTs), the gold standard methodology to evaluate safety and efficacy of oncological treatments. However, generalizability of trial results is often limited due to stringent eligibility criteria, underrepresentation of specific populations, and more heterogeneity in clinical practice. This may result in an efficacy-effectiveness gap and uncertainty regarding meaningful benefit versus treatment harm. Meanwhile, conduct of traditional RCTs has become increasingly challenging due to identification of a growing number of (small) molecular subtypes. These challenges-combined with the digitalization of health records-have led to growing interest in use of real-world data (RWD) to complement evidence from RCTs. RWD is used to evaluate epidemiological trends, quality of care, treatment effectiveness, long-term (rare) safety, and quality of life (QoL) measures. In addition, RWD is increasingly considered in decision-making by clinicians, regulators, and payers. In this narrative review, we elaborate on these applications in CRC, and provide illustrative examples. As long as the quality of RWD is safeguarded, ongoing developments, such as common data models, federated learning, and predictive modelling, will further unfold its potential. First, whenever possible, we recommend conducting pragmatic trials, such as registry-based RCTs, to optimize generalizability and answer clinical questions that are not addressed in registrational trials. Second, we argue that marketing approval should be conditional for patients who would have been ineligible for the registrational trial, awaiting planned (non) randomized evaluation of outcomes in the real world. Third, high-quality effectiveness results should be incorporated in treatment guidelines to aid in patient counseling. We believe that a coordinated effort from all stakeholders is essential to improve the quality of RWD, create a learning healthcare system with optimal use of trials and real-world evidence (RWE), and ultimately ensure personalized care for every CRC patient.

Triplet chemotherapy with or without bevacizumab as first line treatment for metastatic colorectal cancer: An AGEO multicenter real-world study

BACKGROUND

Prior trials validated triplet chemotherapy (Tri-CT) with bevacizumab as first line treatment for metastatic colorectal cancer (mCRC) but real-world data are scarce and practices remain heterogeneous.

AIMS

To evaluate Tri-CT +/- bevacizumab efficacy and safety, and to identify factors influencing treatment decisions.

METHODS

The COLOTRIP retrospective study enrolled mCRC patients treated from 2014 to 2019 in 14 French centers.

RESULTS

Of 299 patients (81% PS 0-1, 58% RAS-mutated and 19% BRAF-mutated), 51% received Tri-CT and 49% Tri-CT + bevacizumab. Metastatic disease was classified as resectable (6.5%), potentially resectable (40%), and unresectable (54%). Bevacizumab use was associated with primary tumor location, mutational status and number of metastases. Median overall survival was 33.5 months in the Tri-CT group and 23.9 months in the Tri-CT + bevacizumab group, with median progression-free survival being 14.5 and 11.4 months. After adjusting for initial characteristics, no difference in survival was noted. Around 30% of patients experienced grade ≥3 adverse events.

CONCLUSIONS

This study highlights several factors influencing Tri-CT use +/- bevacizumab decision and confirms the real-world good oncological outcomes and tolerability of these regimens in mCRC patients. Our results suggest that Tri-CT alone may by an appropriate option for specific subgroups of patients.

Temporal development in survival, and gender and regional differences in the Swedish population of patients with synchronous and metachronous metastatic colorectal cancer

BACKGROUND

Survival in patients with metastatic colorectal cancer (mCRC) has markedly improved in patients included in clinical trials. In population-based materials, improvements were seen until about a decade ago, but it is unclear if survival has continued to improve. It is also unclear if regional or gender differences exist.

MATERIAL AND METHODS

All patients with mCRC (N = 19,566) in Sweden between 2007 and 2016 were identified from the national quality register, SCRCR, with almost complete coverage. Overall survival (OS) from diagnosis of metastatic disease was calculated in two calendar periods, 2007-2011 and 2012-2016. Differences between groups were compared using Cox regression.

RESULTS

Median age was 72 years, 55% were males, synchronous presentation was seen in 13,630 patients and metachronous in 5936. In synchronous disease, the primary tumour was removed more often during the first than the second period (51% vs 41%, p < 0.001). Median OS (mOS) was 14.0 months. It was longer in those with metachronous than synchronous disease (17.6 vs 13.1 months, p < 0.001) and in males (15.0 vs 12.8 months, p < 0.001), and markedly influenced by age and primary location. It was longer in patients diagnosed during the second period than during the first (14.9 vs 13.1 months, HR 0.89 (95% CI 0.86-0.92), p < 0.001). This difference was seen in all subgroups according to sex, age, presentation, and sidedness. mOS was about one month shorter in 1/6 healthcare regions, most pronounced during the first period. Differences in median of up to 5 months were seen between the region with the shortest and longest mOS.

CONCLUSIONS

Overall survival in Swedish patients with mCRC has improved during the past decade but is still substantially worse than reported from clinical trials/hospital-based series, reflecting the selection of patients to trials. Regional differences were seen, but they decreased with time. Women did not have a poorer prognosis in multivariable analyses.

Predictive value of chromosome 18q11.2-q12.1 loss for benefit from bevacizumab in metastatic colorectal cancer; a post-hoc analysis of the randomized phase III-trial AGITG-MAX

The VEGF‐A monoclonal antibody bevacizumab is currently recommended for first‐line treatment of all metastatic colorectal cancer (mCRC) patients. Cost‐benefit ratio and side‐effects however necessitate patient selection. A large retrospective yet nonrandomized study showed that patients with loss of chromosome 18q11.2‐q12.1 in the tumor and treated with bevacizumab have 3 months improved median progression‐free (PFS) and overall survival (OS) benefit compared to patients without this loss and/or treatment modality. Implementation for loss of chromosome 18q11.2‐q12.1 as a marker in clinical practice mandates evidence in a randomized controlled trial for bevacizumab. Of the trials with randomization of chemotherapy vs chemotherapy with bevacizumab, the AGITG‐MAX trial was the only one with tumor materials available. Chromosome 18q11.2‐q12.1 copy number status was measured for 256 AGITG‐MAX trial patients and correlated with PFS according to a predefined analysis plan with marker‐treatment interaction as the primary end‐point. Chromosome 18q11.2‐q12.1 losses were detected in 71% of patients (181/256) characteristic for mCRC. Consistent with the nonrandomized study, significant PFS benefit of bevacizumab was observed in patients with chromosome 18q11.2‐q12.1 loss (P = .009), and not in patients without 18q loss (P = .67). Although significance for marker‐treatment interaction was not reached (P_interaction = .28), hazard ratio and 95% confidence interval of this randomized cohort (HR_interaction = 0.72; 95% CI = 0.39‐1.32) shows striking overlap with the nonrandomized study cohorts (HR_interaction = 0.41; 95% CI = 0.32‐0.8) supported by a nonsignificant Cochrane χ² test (P = .11) for heterogeneity. We conclude that post hoc analysis of the AGITG‐MAX RCT provides supportive evidence for chromosome 18q11.2‐q12.1 as a predictive marker for bevacizumab in mCRC patients.

Conversion of a colorectal cancer guideline into clinical decision trees with assessment of validity

Objective

The interpretation and clinical application of guidelines can be challenging and time-consuming, which may result in noncompliance to guidelines. The aim of this study was to convert the Dutch guideline for colorectal cancer (CRC) into decision trees and subsequently implement decision trees in an online decision support environment to facilitate guideline application.

Methods

The recommendations of the Dutch CRC guidelines (published in 2014) were translated into decision trees consisting of decision nodes, branches and leaves that represent data items, data item values and recommendations, respectively. Decision trees were discussed with experts in the field and published as interactive open access decision support software (available at www.oncoguide.nl). Decision tree validation and a concordance analysis were performed using consecutive reports (January 2016–January 2017) from CRC multidisciplinary tumour boards (MTBs) at Amsterdam University Medical Centers, location AMC.

Results

In total, we developed 34 decision trees driven by 101 decision nodes based on the guideline recommendations. Decision trees represented recommendations for diagnostics (n = 1), staging (n = 10), primary treatment (colon: n = 1, rectum: n = 5, colorectal: n = 9), pathology (n = 4) and follow-up (n = 3) and included one overview decision tree for optimal navigation. We identified several guideline information gaps and areas of inconclusive evidence. A total of 158 patients’ MTB reports were eligible for decision tree validation and resulted in treatment recommendations in 80% of cases. The concordance rate between decision tree treatment recommendations and MTB advices was 81%. Decision trees reported in 22 out of 24 non-concordant cases (92%) that no guideline recommendation was available.

Conclusions

We successfully converted the Dutch CRC guideline into decision trees and identified several information gaps and areas of inconclusive evidence, the latter being the main cause of the observed disagreement between decision tree recommendations and MTB advices. Decision trees may contribute to future strategies to optimize quality of care for CRC patients.

Informing metastatic colorectal cancer patients by quantifying multiple scenarios for survival time based on real-life data

Reported median overall survival (mOS) in metastatic colorectal cancer (mCRC) patients participating in systemic therapy trials has increased to over 30 months. It is uncertain whether trial results translate to real-life populations. Moreover, patients prefer presentation of multiple survival scenarios. Population-based data of all stage IV CRC patients diagnosed between 2008 and 2016 were obtained from the Netherlands Cancer Registry, which has a case ascertainment completeness surpassing 95%. We calculated the following percentiles (scenarios) of OS per year of diagnosis for the total population, and for treatment subgroups: 10th (best-case), 25th (upper-typical), 50th (median), 75th (lower-typical) and 90th (worst-case). Twenty-five percent of patients did not receive any antitumor treatment. From 2008 to 2016, mOS of the total population (n = 27275) remained unchanged at approximately 12 months. OS improved only for the upper-typical and best-case patients; by 4.2 to 29.1 months (P < .001), and by 6 to 62 months (P < .001), respectively. No clinically relevant change was observed among patients who received systemic therapy, with mOS close to 15 months and best-case scenario approximately 40 months. A clinically relevant improvement in survival over time was observed in patients who initially received metastasectomy and/or HIPEC only. In contrast to the wide belief based on trial data that mOS of mCRC patients receiving systemic therapy has improved substantially, improvement could not be demonstrated in our real-life population. Clinicians should consider quoting multiple survival scenarios based on real-life data instead of point estimates from clinical trials, when informing patients about their life expectancy.