The Early Impact of the IDEA Collaboration Results: How the Results Changed Prescribing Practice

Treatment Adherence to Adjuvant Chemotherapy According to the New Standard 3-month CAPOX Regimen in High-risk Stage II and Stage III Colon Cancer: A Population-based Evaluation in The Netherlands

BACKGROUND

A 3-month adjuvant treatment regimen with capecitabine and oxaliplatin (CAPOX) for high-risk stage II (T4N0) and stage III (node-positive) colon cancer was implemented in the Netherlands in 2017. The IDEA trial showed a clinically irrelevant difference in long-term outcomes in combination with a substantial decrease in toxicity in comparison with a 6-month regimen. A significantly increased dose intensity was observed in the 3-month arm, which might be essential to achieve optimal long-term outcomes. Hence, the aim of the present study was to evaluate if a similar dose intensity could be achieved in patients treated with adjuvant CAPOX for 3 months in daily practice.

MATERIALS AND METHODS

Patients scheduled for 3 months of adjuvant CAPOX for high-risk stage II or stage III colon cancer were selected from the Netherlands Cancer Registry. The number of administered cycles and the daily cumulative dose of capecitabine and oxaliplatin were extracted from the medical files. Relative dose intensity (RDI) was determined by comparing the administered dose intensity with the standard dose intensity.

RESULTS

In total, 802 (80.0%) of the 1002 patients completed 4 cycles of CAPOX. The overall mean RDI of adjuvant treatment was 82.9% for capecitabine, and 83.8% for oxaliplatin, based on the combination of dose reductions and omitting cycles.

CONCLUSION

One out of 5 patients did not complete 4 cycles of CAPOX. The administered dose of capecitabine and oxaliplatin in the first year after the update of the guideline was lower than the advised dose for the 3-month CAPOX regimen, and the administered dose in the IDEA study. The impact on long-term oncological outcomes should be awaited.

Impact of the IDEA Collaboration Study on Real-World Practice Patterns of Adjuvant Chemotherapy in Patients With Stage III Colon Cancer: A Population-Based Study

PURPOSE

The International Duration Evaluation of Adjuvant Chemotherapy (IDEA) collaboration showed no significant clinical difference in outcomes in patients with stage III colon cancer (CC) treated with 3 versus 6 months of oxaliplatin-based adjuvant chemotherapy (O-ACT). We aimed to assess change in real-world practice patterns before and after publication of the IDEA study.

METHODS

This retrospective cohort study included patients age ≥18 years with stage III CC diagnosed between January 1, 2012, and December 31, 2020. Eligible patients received >1 dose of ACT between March 20, 2012, and May 10, 2021 inclusive. They were categorized into pre-IDEA (diagnosed before March 31, 2018) and post-IDEA (diagnosed on or after April 1, 2018) groups. The primary outcome was the median duration and type of ACT and factors associated with a shorter duration. Secondary outcomes were 2-year overall survival (OS) and cancer-specific survival (CSS).

RESULTS

In total, 740 patients were included (median age, 64 years, range, 27-90; 52.7% male). 48.8% had pT4 and/or pN2 disease. 77% received O-ACT. In the post-IDEA era, capecitabine plus oxaliplatin (CAPOX) ACT use increased (22.8%-50.7%, P < .001), and median duration of treatment was significantly shorter (2.7 v 4.8 months, P < .001). Factors associated with shorter O-ACT duration included diagnosis in the post-IDEA era (odds ratio, 2.08, P = .002), absence of pT4 and/or pN2 disease (hazard ratio [HR], 1.71, P = .01), and receipt of CAPOX (HR, 2.58, P < .001). Two-year OS and CSS were comparable between pre- and post-IDEA eras (OS 95% v 94%; CSS 96% v 96%).

CONCLUSION

Our study shows that the results of the IDEA trial have been largely adopted in clinical practice with shorter duration of ACT in low-risk stage III CC.

The association of clinical and patient factors with chemotherapy-induced peripheral neuropathy (CIPN) in colorectal cancer: secondary analysis of the SCOT trial

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect of oxaliplatin. CIPN can impair long-term quality of life and limit the dose of chemotherapy. We investigated the association of CIPN over time with age, sex, body mass index, baseline neuropathy, and chemotherapy regimen in people treated with adjuvant oxaliplatin-containing chemotherapy for colorectal cancer.

PATIENTS AND METHODS

We carried out secondary analysis of data from the SCOT randomised controlled trial. SCOT compared 3 months to 6 months of oxaliplatin-containing adjuvant chemotherapy in 6088 people with colorectal cancer recruited between March 2008 and November 2013. Two different chemotherapy regimens were used: capecitabine with oxaliplatin (CAPOX) or fluorouracil with oxaliplatin (FOLFOX). CIPN was recorded with the Functional Assessment of Cancer Therapy/Gynaecologic Oncology Group-Neurotoxicity 4 tool in 2871 participants from baseline (randomisation) for up to 8 years. Longitudinal trends in CIPN [averages with 95% confidence intervals (CIs)] were plotted stratified by the investigated factors. Analysis of covariance (ANCOVA) was used to analyse the association of factors with CIPN adjusting for the SCOT randomisation arm and oxaliplatin dose. P < 0.01 was adopted as cut-off for statistical significance to account for multiple testing.

RESULTS

Patients receiving CAPOX had lower CIPN scores than those receiving FOLFOX. Chemotherapy regimen was associated with CIPN from 6 months (P < 0.001) to 2 years (P = 0.001). The adjusted ANCOVA coefficient for CAPOX at 6 months was -1.6 (95% CIs -2.2 to -0.9) and at 2 years it was -1.6 (95% CIs -2.5 to -0.7). People with baseline neuropathy scores ≥1 experienced higher CIPN than people with baseline neuropathy scores of 0 (P < 0.01 for all timepoints apart from 18 months). Age, sex, and body mass index did not link with CIPN.

CONCLUSIONS

A neuropathy assessment before treatment with oxaliplatin can help identify people with an increased risk of CIPN. More research is needed to understand the CIPN-inducing effect of different chemotherapy regimens.

ctDNA guided adjuvant chemotherapy versus standard of care adjuvant chemotherapy after curative surgery in patients with high risk stage II or stage III colorectal cancer: a multi-centre, prospective, randomised control trial (TRACC Part C)

BACKGROUND

Circulating tumour DNA (ctDNA) to detect minimal residual disease (MRD) is emerging as a biomarker to predict recurrence in patients with curatively treated early stage colorectal cancer (CRC). ctDNA risk stratifies patients to guide adjuvant treatment decisions. We are conducting the UK's first multi-centre, prospective, randomised study to determine whether a de-escalation strategy using ctDNA to guide adjuvant chemotherapy (ACT) decisions is non-inferior to standard of care (SOC) chemotherapy, as measured by 3-year disease free survival (DFS) in patients with resected CRC with no evidence of MRD (ctDNA negative post-operatively). In doing so we may be able to spare patients unnecessary chemotherapy and associated toxicity and achieve significant cost savings for the National Health Service (NHS).

METHODS

We are recruiting patients with fully resected high risk stage II and stage III CRC who are being considered for ACT into the study which uses results from a plasma-only ctDNA assay to guide treatment decisions. Eligible patients are randomised 1:1 to receive ctDNA-guided chemotherapy versus SOC chemotherapy. The primary endpoint is the difference in DFS at 3 years between the trial arms. Secondary endpoints include the proportion of patients in the ctDNA-guided arm who are ctDNA negative post-operatively and receive de-escalated ACT compared to the standard arm, the difference in overall survival (OS), neurotoxicity and quality of life between the arms, and the cost-effectiveness of ctDNA-guided therapy compared to SOC treatment. We hypothesise that using a ctDNA-guided approach to ACT decisions is non-inferior to SOC. Target accrual is 1621 patients over 4 years, which will provide a power of 80% with an alpha of 0.1 to demonstrate non-inferiority with a margin of 1.25 in survival of the ctDNA-guided approach compared to SOC. We anticipate approximately 50 UK centres will participate. The study opened with the Guardant Reveal plasma-only ctDNA assay in August 2022.

DISCUSSION

The trial will determine whether ctDNA guided ACT is non-inferior to SOC ACT in patients with fully resected high risk stage II and stage III resected CRC, with the potential to significantly reduce unnecessary ACT and the toxicity associated with it.

TRIAL REGISTRATION

NCT04050345.

Measuring variation in the quality of systemic anti-cancer therapy delivery across hospitals: A national population-based evaluation

AIM

To date, there has been little systematic assessment of the quality of care associated with systemic anti-cancer therapy (SACT) delivery across national healthcare systems. We evaluated hospital-level toxicity rates during SACT treatment as a means of identifying variation in care quality.

METHODS

All colorectal cancer (CRC) patients receiving SACT within 106 English National Health Service (NHS) hospitals between 2016 and 2019 were included. Severe acute toxicity rates were derived from hospital administrative data using a validated coding framework. Variation in hospital-level toxicity rates was assessed separately in the adjuvant and metastatic settings. Toxicity rates were adjusted for age, sex, comorbidity, performance status, tumour site, and TNM staging.

RESULTS

Eight thousand one hundred and seventy three patients received SACT in the adjuvant setting, and 7,683 patients in the metastatic setting. Adjusted severe acute toxicity rates varied between hospitals from 11% to 49% for the adjuvant cohort, and from 25% to 67% for the metastatic cohort. Compared to the national mean toxicity rate in the adjuvant cohort, six hospitals were more than two standard deviations (2SD) above, and four hospitals were more than 2SD below. In the metastatic cohort, six hospitals were more than 2SD above, and seven hospitals were more than 2SD below the national mean toxicity rate. Overall, 12 hospitals (12%) had toxicity rates more than 2SD above the national mean, and 11 (10%) had rates more than 2SD below.

CONCLUSION

There is substantial variation in hospital-level severe acute toxicity rates in both the adjuvant and metastatic settings, despite risk-adjustment. Ongoing reporting of this performance indicator can be used to focus further investigation of toxicity rates and stimulate quality improvement initiatives to improve care.

Cancer Trial Impact: Understanding Implementation of the Short Course Oncology Treatment (SCOT) Trial Findings in colorectal cancer at a National Level

AIMS

The Short Course Oncology Treatment (SCOT) trial indicated that 3 months of adjuvant doublet chemotherapy was non-inferior to 6 months of treatment for patients with colorectal cancer, with considerably less toxicity. The SCOT trial results were disseminated in June 2017. The aim of this study was to understand if SCOT trial findings were implemented in Scotland.

MATERIALS AND METHODS

A retrospective analysis was carried out on a dataset derived from a source population of 5.4 million people. Eligible patients were those with stage II or III colorectal cancer who received adjuvant chemotherapy. Logistic regression was applied to understand the extent of practice change to a 3-month adjuvant chemotherapy duration after the SCOT trial results were disseminated. Interrupted time series analysis was used to visualise differences in prescribing trends before and after June 2017 for the overall cohort, and by SCOT trial eligibility.

RESULTS

In total, 2310 patients were included in the study; 1957 and 353 treated pre- and post-June 2017, respectively. The median treatment duration decreased from 21 weeks (interquartile range 14-24) prior to June 2017 to 12 weeks (interquartile range 12-21 weeks) after June 2017 (P < 0.001). The proportion of patients receiving over 3 months of adjuvant treatment decreased from 75% to 42% (P < 0.001). This change was most noticeable for patients who met the SCOT trial eligibility criteria, and specifically for those with low-risk stage III disease and those treated with capecitabine and oxaliplatin (CAPOX). Although practice change occurred in all locations, there were differences between regions that could be explained by pre-SCOT trial prescribing trends.

DISCUSSION

A significant change in chemotherapy prescribing occurred after dissemination of the SCOT trial results. National, real-world data can be used to capture the extent of implementation of clinical trial results. In this case, implementation was aligned with clinical trial subgroup findings. This type of analysis could be conducted to evaluate the impact of other clinical trials.

Finding Waldo: The Evolving Paradigm of Circulating Tumor DNA (ctDNA)-Guided Minimal Residual Disease (MRD) Assessment in Colorectal Cancer (CRC)

Circulating tumor DNA (ctDNA), the tumor-derived cell-free DNA fragments in the bloodstream carrying tumor-specific genetic and epigenetic alterations, represents an emerging novel tool for minimal residual disease (MRD) assessment in patients with resected colorectal cancer (CRC). For many decades, precise risk-stratification following curative-intent colorectal surgery has remained an enduring challenge. The current risk stratification strategy relies on clinicopathologic characteristics of the tumors that lacks precision and results in over-and undertreatment in a significant proportion of patients. Consequently, a biomarker that can reliably identify patients harboring MRD would be of critical importance in refining patient selection for adjuvant therapy. Several prospective cohort studies have provided compelling data suggesting that ctDNA could be a robust biomarker for MRD that outperforms all existing clinicopathologic criteria. Numerous clinical trials are currently underway to validate the ctDNA-guided MRD assessment and adjuvant treatment strategies. Once validated, the ctDNA technology will likely transform the adjuvant therapy paradigm of colorectal cancer, supporting ctDNA-guided treatment escalation and de-escalation. The current article presents a comprehensive overview of the published studies supporting the utility of ctDNA for MRD assessment in patients with CRC. We also discuss ongoing ctDNA-guided adjuvant clinical trials that will likely shape future adjuvant therapy strategies for patients with CRC.

Survival outcomes associated with completion of adjuvant oxaliplatin-based chemotherapy for stage III colon cancer: A national population-based study

The impact of cycle completion rates of oxaliplatin-based adjuvant chemotherapy for stage III colon cancer in real-world practice is unknown. We assessed its impact, and that of treatment modification, on 3-year cancer-specific mortality. Four thousand one hundred and forty-seven patients with pathological stage III colon cancer undergoing major resection from 2014 to 2017 in the English National Health Service were included. Chemotherapy data came from linked national administrative datasets. Competing risk regression analysis for 3-year cancer-specific mortality was performed according to completion of <6, 6-11, or 12 5-fluoropyrimidine and oxaliplatin (FOLFOX) cycles, or <4, 4-7, or 8 capecitabine and oxaliplatin (CAPOX) cycles, adjusted for patient, tumour and hospital-level characteristics. Median age was 64 years. Thirty-two per cent of patients had at least one comorbidity. Forty-two per cent of patients had T4 disease, and 40% had N2 disease. Compared to completion of 12 FOLFOX cycles, cancer-specific mortality was higher in patients completing <6 cycles [subdistribution hazard ratios (sHR) 2.17; 95% CI 1.56-3.03] or 6-11 cycles (sHR 1.40; 95% CI 1.09-1.78) (P < .001). Compared to completion of 8 CAPOX cycles, cancer-specific mortality was higher in patients completing <4 cycles (sHR 2.02; 95% CI 1.53-2.67) or 4-7 cycles (sHR 1.63; 95% CI 1.27-2.10) (P < .001). Dose reduction and early oxaliplatin discontinuation did not impact mortality in patients completing all cycles. Completion of all cycles of chemotherapy was associated with improved cancer-specific survival in real-world practice. Poor prognostic factors may have affected findings, however, patients completing <50% of cycles had poor outcomes. Clinicians may wish to facilitate completion with treatment modification in those able to tolerate it.

Do clinical trials change practice? A longitudinal, international assessment of colorectal cancer prescribing practices

INTRODUCTION

Over half of the 1.5 million individuals globally who are diagnosed with colorectal cancer (CRC) present with stage II-III disease. Understanding clinician attitudes towards treatment for this group is paramount to contextualise real-world outcomes and plan future trials. The aim of this study was to assess clinician awareness of trials assessing the optimal duration of CRC adjuvant therapy, their attitudes towards shorter treatment and their self-reported practice.

METHODS

A survey was developed using OnlineSurveys® and distributed to clinicians in April 2019, with a follow-up survey disseminated to a subset of respondents in August 2020. Microsoft Excel® and Stata® were used for analysis.

RESULTS

265 clinicians replied to the first survey, with the majority aware of findings from the International Duration Evaluation of Adjuvant Therapy collaboration and contributory trials. Practice change was greatest for patients under 70 with low-risk stage III CRC, with most uncertainty around using 3-months of doublet chemotherapy for high-risk stage II disease. In August 2020, clinicians (n = 106) were more likely to use 3-months of FOLFOX for low-risk stage III disease and 3-months of CAPOX for stage II disease compared to April 2019. There was no indication that the COVID-19 pandemic had enduring changes on treatment decisions beyond those made in response to trial evidence.

DISCUSSION

Clinicians use a risk-stratified approach to treat CRC the adjuvant setting. Lower utilisation of doublet chemotherapy for older and stage II patients has affected the extent of trial implementation. Active dialogue regarding how trial results apply to these groups may improve consensus.