Phase III trial of irinotecan plus infusional 5-fluorouracil/folinic acid versus irinotecan plus oxaliplatin as first-line treatment of advanced colorectal cancer

Safety of first-line systemic therapy in patients with metastatic colorectal cancer: a network meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the safety of first-line systemic therapy for metastatic colorectal cancer through network meta-analysis.

METHODS

The literature from PubMed, Embase, Web of Science, and Cochrane Library databases was searched from the inception of the databases to August 15, 2023, and strict inclusion and exclusion criteria were applied to screen studies. The Cochrane Bias Risk Assessment Tool (RoB 2.0) was used to evaluate the quality of the included literature. Network meta-analysis was conducted using Stata 15.0 and R4.3.1 software to compare the incidence of adverse events (AEs) among different treatment regimens.

RESULTS

A total of 53 randomized controlled trials, involving 17,351 patients with metastatic colorectal cancer (mCRC), were ultimately included, encompassing 29 different therapeutic approaches. According to SUCRA rankings, the CAPOX regimen is most likely to rank first in terms of safety, while the FOLFOXIRI + panitumumab regimen is most likely to rank last. In terms of specific AEs, the CAPOX regimen, whether used alone or in combination with targeted drugs (bevacizumab and cetuximab), is associated with a reduced risk of neutropenia and febrile neutropenia, as well as an increased risk of thrombocytopenia and diarrhea. The FOLFOX regimen, with or without bevacizumab, is linked to an increased risk of neutropenia and peripheral sensory neuropathy. The FOLFIRI/CAPIRI + bevacizumab regimen is associated with a reduced risk of peripheral sensory neuropathy. S-1 and S-1 + oxaliplatin are well-tolerated in terms of gastrointestinal reactions. The FOLFOXIRI regimen, whether used alone or in combination with targeted drugs, is associated with various AEs.

CONCLUSION

In summary, the CAPOX regimen may be the safest option among the first-line systemic treatment regimens for mCRC patients, while the FOLFOXIRI + panitumumab regimen may be associated with a higher incidence of grade 3 or higher AEs.

The heterogeneity effect of surveillance intervals on progression free survival

Progression-free survival (PFS) is an increasingly important surrogate endpoint in cancer clinical trials. However, the true time of progression is typically unknown if the evaluation of progression status is only scheduled at given surveillance intervals. In addition, comparison between treatment arms under different surveillance schema is not uncommon. Our aim is to explore whether the heterogeneity of the surveillance intervals may interfere with the validity of the conclusion of efficacy based on PFS, and the extent to which the variation would bias the results. We conduct comprehensive simulation studies to explore the aforementioned goals in a two-arm randomized control trial. We introduce three steps to simulate survival data with predefined surveillance intervals under different censoring rate considerations. We report the estimated hazard ratios and examine false positive rate, power and bias under different surveillance intervals, given different baseline median PFS, hazard ratio and censoring rate settings. Results show that larger heterogeneous lengths of surveillance intervals lead to higher false positive rate and overestimate the power, and the effect of the heterogeneous surveillance intervals may depend upon both the life expectancy of the tumor prognoses and the censoring proportion of the survival data. We also demonstrate such heterogeneity effect of surveillance intervals on PFS in a phase III metastatic colorectal cancer trial. In our opinions, adherence to consistent surveillance intervals should be favored in designing the comparative trials. Otherwise, it needs to be appropriately taken into account when analyzing data.

A Systematic Review of Conversion to Resectability in Unresectable Metastatic Colorectal Cancer Chemotherapy Trials

OBJECTIVES

Metastasectomy in patients with metastatic colorectal cancer (mCRC) confers a significant survival benefit. We hypothesized that conversion to resectability (C2R) correlates with superior overall survival (OS) in patients with unresectable mCRC.

METHODS

A prospectively registered systematic review (PROSPERO CRD42015024104) of randomized clinical trials published after 2003 was conducted. Exposure of interest was C2R with a primary outcome of OS. Clinical trials were classified based on difference in C2R between study arms (<2%, 2% to 2.9%, ≥3%). Generalized estimating equations were used to measure associations while adjusting for multiple observations from the same trial.

RESULTS

Of 2902 studies reviewed, 30 satisfied selection criteria (n=13,618 patients). Median C2R was 7.3% (interquartile range [IQR]: 5% to 12.9%), with maximum C2R in the FOLFOX/FOLFIRI+cetuximab arm (28.6%). The median difference in C2R between 2 arms of the same study was 2.3% (IQR: 1.3% to 3.4%) with a maximum difference of 15.4% seen in FOLFOX/FOLFIRI+cetuximab versus FOLFOX/FOLFIRI. Median OS for the entire patient cohort was 20.7 months (IQR: 18.9 to 22.7 mo), with a between group difference of 1.3 months (IQR: -1.2 to 3.6 mo). The median survival difference between the 2 study arms with <2% C2R difference was 0.8 months versus 1.6 months with ≥3% C2R rates . Increasing C2R had an incremental dose-effect response on OS ( P =0.021), and higher response rates correlated with C2R rates ( P =0.003).

CONCLUSIONS

C2R occurs infrequently and variably in clinical trials enrolling patients with unresectable mCRC. Prioritization of chemotherapeutic agents that enhance C2R might improve OS of patients.

Efficacy and Safety of Systemic Treatments Among Colorectal Cancer Patients: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Systemic treatments, namely, either monotherapy or combination therapy, are commonly administered to patients with advanced or metastatic colorectal cancer (CRC). This study aimed to provide the complete efficacy and safety profiles and ranking of systemic therapies for the treatment of unresectable advanced or metastatic CRC.

METHODS

We searched PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov from inception until June 30, 2021, and also the bibliographies of relevant studies. Randomized controlled trials comparing two or more treatments, namely, at least capecitabine, 5-fluorouracil, leucovorin, irinotecan, bevacizumab, cetuximab, oxaliplatin, or panitumumab were investigated. A network meta-analysis using the Bayesian approach was performed to compare the efficacy and safety of treatments. The surface under the cumulative ranking curve (SUCRA) was calculated for the probability of each treatment as the most effective. The overall response rate (ORR), disease control rate (DCR), overall survival (OS), progression-free survival (PFS), adverse events (AEs) grade ≥3, and serious adverse events (SAEs) were evaluated.

RESULTS

One hundred two publications with 36,147 participants were assigned to 39 different treatments. Among 11 treatments with full information on six outcomes, FOLFIRI/FOLFOX/FOLFOXIRI + bevacizumab significantly improved both the ORR and DCR, compared to FOLFIRI. Although FOLFOX and FOLFIRI/FOLFOX + cetuximab significantly prolonged both OS and PFS, treatments were comparable in terms of AEs grade ≥3 and SAEs. The top highest SUCRA values were observed in the FOLFOXIRI + panitumumab group for ORR (96%) and DCR (99%), FOLFIRI + bevacizumab + panitumumab group for OS (62%) and PFS (54%), and FOLFOXIRI + bevacizumab group for AEs grade ≥3 (59%) and SAEs (59%) outcomes.

CONCLUSIONS

These findings suggest an available range of systemic treatment therapies with different efficacy and safety profiles with patients. Further investigations of the side effects and mutation status are required to confirm our findings.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42019127772.

Exact Primary Tumor Location in mCRC: Prognostic Value and Predictive Impact on Anti-EGFR mAb Efficacy

Simple Summary

Sidedness of primary tumor is a well-established prognostic marker and is predictive for anti-EGFR efficacy in RAS/BRAF wild-type metastatic colorectal cancer (mCRC) patients. As molecular markers change rather continuously throughout the colon, we ask whether the exact primary tumor location (PTL) is a better prognostic marker than sidedness and predictive for anti-EGFR efficacy in RAS/BRAF wild-type mCRC. We retrospectively analyzed five studies containing various therapy protocols concerning primary tumor location, dividing the colorectal frame into six segments. In our cohort, PTL has a prognostic impact on disease spread and overall survival. Only distal segments benefitted when receiving anti-EGFR containing therapy regarding overall survival. Intermediate segments were indifferent and caecal primaries had a detrimental effect receiving anti-EGFR based therapy. Being a retrospective analysis and challenging the standard of basing anti-EGFR treatment on sidedness in RAS/BRAF wild-type mCRC, future studies are necessary to confirm and further investigate our hypothesis-generating results.

Abstract

Primary tumor sidedness (left vs. right) has prognostic and predictive impact on anti-EGFR agent efficacy and thus management of metastatic colorectal cancer (mCRC). This analysis evaluates the relevance of primary tumor location (PTL) in RAS/BRAF wild-type mCRC patients, when dividing the colorectal frame into six segments. This pooled analysis, performed on a single-patient basis of five randomized first-line therapy trials, evaluates the impact of exact PTL classification on baseline characteristics, prognosis and prediction of anti-EGFR antibody efficacy by chi-square and log-rank tests, the Kaplan–Meier method, Cox and logistic regressions. The PTL was significantly associated with metastatic spread: liver (p = 0.001), lung (p = 0.047), peritoneal (p < 0.001) and lymph nodes (p = 0.048). A multivariate analysis indicated an impact on anti-EGFR agent efficacy in terms of overall survival depending on the exact primary tumor location: from detrimental in caecal (HR 2.63), rather neutral effects in the ascending colon (HR 1.24), right flexure/transverse colon (HR 0.99) and left flexure/descending colon (HR 0.91) to clear benefit in sigmoid (HR 0.71) and rectal (HR 0.58) primaries. Exact primary tumor location affects anti-EGFR antibody efficacy in a rather continuous than a dichotomous fashion in RAS/BRAF wild-type mCRC patients. This perspective might help to support clinical decisions when anti-EGFR antibodies are considered.

Managing 5FU Cardiotoxicity in Colorectal Cancer Treatment

Fluorouracil (5FU) is the backbone chemotherapy agent in the treatment of colorectal cancer (CRC). Cardiotoxicity represents an uncommon but serious side effect of treatment with 5FU. Here, we review the current literature on 5FU-cardiotoxicity in the setting of CRC specifically, with a focus on data from the modern era of combination chemotherapy. Despite decades of study, there is little consensus on risk factors and biomarkers for 5FU-cardiotoxicity, nor how patients with CRC should be managed following a cardiotoxicity event. Given the elevated risk of recurrent cardiotoxicity on rechallenge, the use of alternative regimens that do not contain 5FU is a critical aspect of management. Data on the cardiotoxicity risk and efficacy of non-5FU regimens in CRC are therefore reviewed in detail.

Amphiregulin Expression Is a Predictive Biomarker for EGFR Inhibition in Metastatic Colorectal Cancer: Combined Analysis of Three Randomized Trials

PURPOSE

Amphiregulin (AREG) and epiregulin (EREG) are ligands of EGFR. Predictive information for anti-EGFR treatment in metastatic colorectal cancer (mCRC) was observed, but data for other agents is limited.

EXPERIMENTAL DESIGN

Ligand mRNA expression; RAS, BRAF, PIK3CA mutations; and EGFR expression were assessed by qRT-PCR, pyrosequencing, and IHC, respectively, in mCRC tumor tissue of patients participating in the randomized controlled trials FIRE-1, CIOX, and FIRE-3. Normalized mRNA expression was dichotomized using median and third quartile. Overall (OS) and progression-free survival (PFS) were estimated by Kaplan-Meier method including univariate and multivariate Cox regression analyses. Penalized spline regression analysis tested interaction of mRNA expression and outcome.

RESULTS

Of 688 patients with available material, high AREG expression was detected in 343 (>median) and 172 (>3rd quartile) patients. High AREG expression was associated with significantly higher OS [26.2 vs. 21.5 months, HR = 0.80; 95% confidence interval (CI), 0.68-0.94; P = 0.007], PFS (10.0 vs. 8.1 months, HR = 0.74; 95% CI, 0.63-0.86; P = 0.001), and objective response rate (63.1% vs. 51.6%, P = 0.004) compared to low expression at both threshold values. This effect remained significant in multivariate Cox regression analysis (OS: P = 0.01, PFS: P = 0.002). High AREG mRNA expression interacted significantly with the efficacy of cetuximab compared with bevacizumab (OS: P = 0.02, PFS: P = 0.04) in RAS WT mCRC.

CONCLUSIONS

High AREG mRNA expression is a favorable prognostic biomarker for mCRC which interacted significantly with efficacy of anti-EGFR treatment.

Analysis of response-related endpoints in trials of first-line medical treatment of metastatic colorectal cancer

BACKGROUND

Tumor radiologic response after systemic chemotherapy has been used as endpoint of trials of patients with metastatic colorectal cancer (mCRC), which can report the best overall response rate (ORR) and the disease control rate (DCR) by RECIST criteria as well as the early tumor shrinkage (ETS). The present study perform a trial-level analysis to verify whether such response-related endpoints are predictive of overall survival (OS).

METHODS

After a systematic search, randomized clinical trials (RCTs) were selected each time they evaluated the three response endpoints and progression-free survival (PFS). Two arms per trial were selected, and the correlation between the difference in each endpoint and the difference in OS was calculated. The analysis then evaluated the effects of treatment on ∆ORR, or ∆DCR, ∆ETS, ∆PFS, and on ∆OS, using separate linear regressions for each of them, and the proportion of variability explained (R²_trial) on OS for each of the four endpoints was calculated.

RESULTS

The systematic review of the literature led to the selection of 12 RCTs, 7 phase-3 and 5 phase-2. ETS reported a different performance in the entire sample compared to phase-3 trials (R²_trial = 0.172 vs. 0.842), differently from DCR (R²_trial = 0.541 vs. 0.816) and ORR (R²_trial = 0.349 vs. 0.740). Surprisingly, PFS predicted OS with a weak correlation, which was not significant in the subgroup of phase-3 studies (R²_trial = 0.455 vs. 0.466).

CONCLUSION

The results of the present trial-level analysis report a good performance of two response-related endpoints, DCR and ETS, and suggest that they could be differently used depending on the setting of disease and the type of medical treatment.

Early tumor shrinkage after first-line medical treatment of metastatic colorectal cancer: a meta-analysis

BACKGROUND

Early tumor shrinkage (ETS) is a response-related endpoint of clinical trials of chemotherapy (CHT) of patients with metastatic colorectal cancer (mCRC). It identifies a dimensional reduction of tumor size by at least 20-30% after 6-8 weeks of CHT.

METHODS

A literature search of randomized trials of systemic treatment including CHT with or without antiangiogenics or anti-EGFR inhibitors in patients with mCRC has been conducted, and studies reporting the results of the relationship of ETS with overall survival (OS) and progression-free survival (PFS) were selected.

RESULTS

Twelve trials, including 3117 patients, have been included; all data were retrospective and only 72% of the enrolled patients have been evaluated for ETS. Two meta-analyses, each including 20 study cohorts from the selected 12 trials, reported a strong relationship of ETS with OS (HR 0.62; CIs 0.55-0.69) and of ETS with PFS (HR 0.66; CIs 0.60-0.73). However, both meta-analyses displayed a high level of heterogeneity. Among nine possible moderators, three variables (median age, surgery of metastases, and publication year) were able to explain at least a part of this heterogeneity.

CONCLUSION

ETS is a simple and interesting intermediate endpoint for clinical practice and future trials of medical treatments of patients with mCRC, but a large prospective analysis and validation are mandatory.

First-line therapies in metastatic colorectal cancer: integrating clinical benefit with the costs of drugs

PURPOSE

In light of the relevant expenses of pharmacological interventions, it might be interesting to make a balance between the cost of the new drugs administered and the added value represented by the improvement in progression free survival (PFS) in first-line for metastatic colorectal cancer CRC (mCRC).

METHODS

Phase III randomized controlled trials (RCTs) that compared at least two first-line chemotherapy regimens for mCRC patients were evaluated. Differences in PFS between the different arms were compared with the pharmacological costs (at the pharmacy of our hospital). The European Society for Medical Oncology Magnitude of Clinical Benefit Scale (ESMO-MCBS) was applied to the above RCTs.

RESULTS

Overall 28 phase III RCTs, including 19,958 patients, were analyzed. The FOLFOX resulted the least expensive (56 € per month of PFS gained) while the addition of irinotecan to FOLFOX (FOLFOXIRI) increased only marginally the costs (90 € per month of PFS gained). Treatments including the monoclonal antibodies showed a cost per month of PFS gained of 2823 € (FOLFIRI with cetuximab in KRAS wild-type patients and liver-only metastases), of € 15,822 (FOLFOX with panitumumab in KRAS wild type), and of 13,383 € (FOLFOX with bevacizumab). According to the ESMO-MCBS, the treatments including an EGFR-inhibitor (cetuximab or panitumumab) were associated with a score of 4, while the inclusion of bevacizumab reached a score of 3.

CONCLUSIONS

Our data demonstrate a huge difference in cost per month of PFS gained in modern first-line treatments in mCRC.

Reporting of patient characteristics and stratification factors in phase 3 trials investigating first-line systemic treatment of metastatic colorectal cancer: A systematic review

BACKGROUND

Patient characteristics and stratification factors are important factors influencing trial outcomes. Uniform reporting on these parameters would facilitate cross-study comparisons and extrapolation of trial results to clinical practice. In 2007, standardisation on patient characteristics reporting and stratification in metastatic colorectal cancer (mCRC) trials was proposed. We investigated the reporting of prognostic factors and implementation of this proposal in mCRC trials published from 2005 to 2016.

METHODS

We searched PubMed and Embase (January 2005 - June 2016) for first-line phase 3 mCRC trials. Patient characteristics reporting and use of stratification factors were extracted and analysed for adherence to the proposal from 2007.

RESULTS

Sixty-seven trials (35,315 patients) were identified, reporting 48 different patient characteristics (median: 9 [range: 5-18] per study). Age, gender, performance status (PS), primary tumour site and adjuvant chemotherapy were frequently reported (87%-100%), in contrast to laboratory values, such as alkaline phosphatase, lactate dehydrogenase and white blood cell count (10%-25%). We identified 29 different stratification factors (median: 3 [range: 1-9] per study). The most common strata were PS and treatment centre (>60%). A median of 8/12 (range: 4-11) of the proposed parameters was reported. Although the percentage of studies reporting each factor slightly increased over time, there was no significant correlation between publication year and adherence to the proposal from 2007.

CONCLUSIONS

We observed persistent heterogeneity in the reporting of patient characteristics and use of stratification factors in first-line mCRC trials. The proposal from 2007 has not led to increased uniformity of patient characteristics reporting and use of stratification over time. There is an urgent need to address this issue to improve the interpretation of trial results.

Wee1 inhibition can suppress tumor proliferation and sensitize p53 mutant colonic cancer cells to the anticancer effect of irinotecan

Wee1 is an oncogenic nuclear kinase, which can regulate the cell cycle as a crucial G2M checkpoint. Overexpression of Wee1 can be observed in various cancer types, which may lead to a poor prognosis, but the potential therapeutic value of Wee1 in colorectal cancer has not been fully studied. In the present study, the role of Wee1 in colonic cancer was investigated. Wee1 inhibition by small interfering RNA was demonstrated to significantly restrain cancer cell proliferation and sensitize the p53 mutant colonic cancer cell lines HT29 and SW480 to the effect of treatment with ionizing radiation. The anticancer effect of the Wee1 inhibitor MK1775 was investigated in these two colonic cancer cell lines. MK1775 was demonstrated to induce significant DNA damage, suppress cell viability and induce apoptosis. In addition, MK1775 sensitized HT29 and SW480 cells to the effect of irinotecan. Annexin V/propidium iodide staining demonstrated that combination therapy can induce increased apoptosis compared with MK1775 or irinotecan monotherapy. The results of western blot analysis also indicated increased expression of the DNA damage marker histone H2AX, and apoptosis‑associated protein cleaved caspase 3, in HT29 and SW480 cells. In conclusion, the present study indicated that Wee1 may be a valuable target for treatment of p53 mutant colonic cancer.

Prevalence and influence on outcome of HER2/neu, HER3 and NRG1 expression in patients with metastatic colorectal cancer

Our aim was to explore the impact of the HER2/neu, HER3 receptor as well as their ligands' neuregulin (NRG1) expression on the outcome of patients with metastatic colorectal cancer (mCRC). NRG1, HER2/neu and HER3 expression was evaluated in 208 patients with mCRC receiving 5-FU/LV plus irinotecan or irinotecan plus oxaliplatin as the first-line treatment. Biomarker expression was correlated with the outcome of patients. NRG1 (low: 192 vs. high: 16), HER2/neu (low: 201 vs. high: 7) and HER3 (low: 69 vs. high: 139) expressions were assessed in 208 patients. High versus low NRG1 expression significantly affected progression-free survival (PFS) [4.7 vs. 8.2 months, hazard ratio (HR): 2.45; 95% confidence interval (CI): 1.45-4.13; P=0.001], but not overall survival (OS) (15.5 vs. 20.7 months, HR: 1.33; 95% CI: 0.76-2.35; P=0.32). High versus low HER3 expression (PFS: 7.1 vs. 8.8 months, HR: 1.11; 95% CI: 0.82-1.50; P=0.50; OS: 19.8 vs. 21.1 months, HR: 0.95; 95% CI: 0.70-1.30; P=0.75) and high compared with low HER2/neu expression (PFS: 7.7 vs. 8.0 months, HR: 1.07; 95% CI: 0.71-1.60; P=0.75; OS: 16.6 vs. 21.1 months, HR: 1.13; 95% CI: 0.75-1.71; P=0.57) did not influence outcome. High NRG1 expression was associated with inferior PFS in the FIRE-1 trial. We did not detect a prognostic impact of HER2/neu and HER3 overexpression in mCRC. The frequency of overexpression was comparable with other studies.

Combination adjuvant chemotherapy with targeted drugs for treatment of colorectal cancer: A network meta-analysis

Colorectal cancer (CRC) is one of the most fatal diseases in the world. The efficacy of present chemotherapy treatments are limited and the addition of targeted drugs have been put into practice. However, the preferred treatments among adjuvant chemotherapies still remain controversial and uncertain. To evaluate the efficacy of different adjuvant chemotherapies combined with or without targeted drugs to determine the optimal treatment for patients with CRC in clinical practice. PubMed and Embase were searched for eligible articles and only randomized controlled trials (RCTs) were included. R (Version 3.2.5) software was utilized to conduct the Bayesian network meta-analysis (NMA). Outcomes including overall survival (OS) and progression-free survival (PFS) were displayed using hazard ratios. And the rank probabilities of each treatment were evaluated using the surface under cumulative ranking curve. A total of 75 RCTs published after 1997 were included in the data analysis. Overall, FOLFIRI+ cetuximab was found to be the most effective treatment in terms of long-term survival and FOLFOX was the most effective pure chemotherapy treatment. The addition of targeted drugs will greatly improve the efficacy of chemotherapy. Targeted drug cetuximab combined with the chemotherapy regiment FOLFIRI is the preferable treatment for patients with CRC in clinical practice.

Network meta-analysis of the efficacy of first-line chemotherapy regimens in patients with advanced colorectal cancer

This network meta-analysis compared the short-term and long-term efficacies of first-line chemotherapy regimens in patients with advanced colorectal cancer (CRC). The 10 regimens included folinic acid + 5-fluorouracil + oxaliplatin (FOLFOX), folinic acid + 5-fluorouracil + irinotecan (FOLFIRI), folinic acid + 5-fluorouracil + gemcitabine (FFG), folinic acid + 5-fluorouracil + trimetrexate (FFT), folinic acid + 5-fluorouracil (FF), irinotecan + oxaliplatin (IROX), raltitrexed + oxaliplatin (TOMOX), folinic acid + tegafur-uracil (FTU), raltitrexed, and capecitabine. Electronic searches were performed in the Cochrane Library, PubMed and Embase databases from inception to June 2017. Network meta-analysis combined direct and indirect evidence to obtain odds ratios (ORs) and surface under the cumulative ranking curves (SUCRA) of different chemotherapy regimens for advanced CRC. Fourteen randomized controlled trails (RCTs) covering 4,383 patients with advanced CRC were included. The results revealed that FOLFOX, FOLFIRI, IROX, and TOMOX all showed higher overall response rates (ORRs) than FF or raltitrexed. Compared with raltitrexed, the aforementioned four regimens also had higher 1-year progression-free survival (PFS) rates. In addition, FOLFOX and FOLFIRI exhibited higher disease control rates (DCRs) and 1-year PFS rates than FF or raltitrexed. Cluster analysis revealed that FOLFOX, FOLFIRI, and TOMOX had better short-term and long-term efficacies. These findings suggest FOLFOX, FOLFIRI, and TOMOX are superior to other regimens for advanced CRC. These three regimens are therefore recommended for clinical treatment of advanced CRC.

Outcome according to KRAS-, NRAS- and BRAF-mutation as well as KRAS mutation variants: pooled analysis of five randomized trials in metastatic colorectal cancer by the AIO colorectal cancer study group

In this pooled analysis of metastatic colorectal cancer patients, mutations in KRAS, and BRAF were associated with inferior progression-free and overall survival compared with patients with non-mutated tumors. KRAS exon 2 mutation variants were associated with heterogeneous outcome compared with unmutated tumors with KRAS G12C and G13D being associated with rather poor survival.

Background

To explore the impact of KRAS, NRAS and BRAF mutations as well as KRAS mutation variants in patients with metastatic colorectal cancer (mCRC) receiving first-line therapy.

Patients and methods

A total of 1239 patients from five randomized trials (FIRE-1, FIRE-3, AIOKRK0207, AIOKRK0604, RO91) were included into the analysis. Outcome was evaluated by the Kaplan–Meier method, log-rank tests and Cox models.

Results

In 664 tumors, no mutation was detected, 462 tumors were diagnosed with KRAS-, 39 patients with NRAS- and 74 patients with BRAF-mutation. Mutations in KRAS were associated with inferior progression-free survival (PFS) and overall survival (OS) [multivariate hazard ratio (HR) for PFS: 1.20 (1.02–1.42), P = 0.03; multivariate HR for OS: 1.41 (1.17–1.70), P < 0.001]. BRAF mutation was also associated with inferior PFS [multivariate HR: 2.19 (1.59–3.02), P < 0.001] and OS [multivariate HR: 2.99 (2.10–4.25), P < 0.001]. Among specific KRAS mutation variants, the KRAS G12C-variant (n = 28) correlated with inferior OS compared with unmutated tumors [multivariate HR 2.26 (1.25–4.1), P = 0.001]. A similar trend for OS was seen in the KRAS G13D-variant [n = 71, multivariate HR 1.46 (0.96–2.22), P = 0.10]. More frequent KRAS exon 2 variants like G12D [n = 152, multivariate HR 1.17 (0.86–1.6), P = 0.81] and G12V [n = 92, multivariate HR 1.27 (0.87–1.86), P = 0.57] did not have significant impact on OS.

Conclusion

Mutations in KRAS and BRAF were associated with inferior PFS and OS of mCRC patients compared with patients with non-mutated tumors. KRAS exon 2 mutation variants were associated with heterogeneous outcome compared with unmutated tumors with KRAS G12C and G13D (trend) being associated with rather poor survival.

Influence of mRNA expression of epiregulin and amphiregulin on outcome of patients with metastatic colorectal cancer treated with 5-FU/LV plus irinotecan or irinotecan plus oxaliplatin as first-line treatment (FIRE 1-trial)

Our aim was to investigate the impact of EREG and AREG mRNA expression (by RT-qPCR) in patients with metastatic colorectal cancer (mCRC). In addition, epidermal growth factor receptor (EGFR) expression (by immunohistochemistry) as well as RAS-and PIK3CA-mutations (by pyrosequencing) were assessed. Tumors of 208 mCRC patients receiving 5-fluorouracil/leucovorin plus irinotecan (FUFIRI) or irinotecan plus oxaliplatin (mIROX) within the FIRE-1 trial were analyzed for mutations. Molecular characteristics were correlated with response, progression-free survival (PFS), overall survival (OS). mRNA expression was evaluated using ROC-analysis in 192 tumors (AREG high n = 31 vs. low n = 161; EREG high n = 89 vs. low n = 103). High versus low AREG expression was associated with PFS of 10.0 versus 8.0 months (HR = 0.62, 95% CI: 0.402-0.940, p = 0.03) and OS of 24.6 versus 18.7 months (HR = 0.72, 95% CI: 0.476-1.078, p = 0.11). High versus low EREG expression correlated with prolonged PFS (9.4 vs. 6.8 months, HR = 0.62, 95% CI: 0.460-0.846, p = 0.002) and OS (25.8 vs. 15.5 months, HR = 0.48, 95% CI: 0.351-0.657, p < 0.001). The positive prognostic effect of high EREG expression was confirmed in a multivariate analysis and was neither affected by EGFR expression nor by mutations of RAS- and PIK3CA-genes. EREG expression appears as an independent prognostic marker in patients with mCRC receiving first-line irinotecan-based chemotherapy.

Predictive and prognostic markers in the treatment of metastatic colorectal cancer (mCRC): personalized medicine at work

This article clarifies prognostic and predictive markers in the treatment of colorectal cancer. Multiple chemotherapeutic drugs are approved for metastatic colorectal cancer (mCRC), but available guidelines are often not helpful in directing drug selections. It would be desirable to define patient populations before chemotherapy by biomarkers that predict outcome and toxicities. RAS mutational evaluation remains the only established biomarker analysis in the treatment of mCRC. BRAF mutant tumors are associated with poor outcome. Chemotherapeutic combination therapies still remain the most active treatments in the armamentarium, and future trials should address the need to prospectively investigate and validate biomarkers.

Early tumour shrinkage (ETS) and depth of response (DpR) in the treatment of patients with metastatic colorectal cancer (mCRC)

BACKGROUND

Response evaluation criteria in solid tumours (RECIST) are used to define degrees of response to anti-tumour agents. In retrospective analyses, early tumour shrinkage (ETS) has been investigated as an alternative early-on-treatment predictor of treatment efficacy with regard to progression-free and overall survival. While cut-off based analysis of ETS facilitates the categorisation of patients into responders and non-responders after a defined period of treatment, depth of response (DpR) serves as a continuous measure, which defines the nadir of tumour response.

METHODS

A systematic literature search for 'early tumour shrinkage' or 'tumour size decrease' in 'metastatic colorectal cancer' reported from January 2000 to July 2014 was performed. The present review summarises available data concerning ETS and DpR and evaluates their potential as predictive markers for the clinical management of patients with metastatic colorectal cancer (mCRC).

RESULTS

A total of 10 clinical trials investigated the role of ETS as a marker of clinical outcome in patients with mCRC. In addition, DpR was investigated using the efficacy data from three of these trials. Available data show that ETS differentiates patients with high sensitivity to treatment and more favourable prognosis from a heterogeneous group of patients classified as non-ETS patients. ETS is an early indicator of the potentially achievable response. In contrast, DpR estimates the nadir of tumour response as a continuous measure, which may affect the subsequent disease history, thus translating into superior survival.

CONCLUSIONS

The concepts of ETS and DpR offer potential as clinical end-points to aid the clinical decision making process and thus further optimise mCRC patient management in the era of tailored therapy approaches.

Dilemma of dihydropyrimidine dehydrogenase deficiency in colorectal cancer patients: is Uftoral® the right answer?

SUMMARY 

Fluoropyrimidines (5-fluorouracil, capecitabine, S-1, Uftoral® [UFT; Merck, Germany]) and their derivatives are effective in management of colorectal cancer. DPD deficiency is not routinely tested and is usually diagnosed after a patient has severe/grade IV toxicity secondary to the use of 5-fluorouracil or capecitabine. Once DPD deficiency is diagnosed, there are sparse data on the use of UFT or raltitrexed and there are no comparable outcome data with well-known regimens like infusional 5-fluorouracil, leucovorin oxaliplatin (FOLFOX) and infusional 5-fluorouracil, leucovorin, irinotecan (FOLFIRI). Here we report the first case series from India of DPD deficiency and the use of UFT.

Evaluation of prognostic factors in liver-limited metastatic colorectal cancer: a preplanned analysis of the FIRE-1 trial

Background:

Liver-limited disease (LLD) denotes a specific subgroup of metastatic colorectal cancer (mCRC) patients.

Patients and Methods:

A total of 479 patients with unresectable mCRC from an irinotecan-based randomised phase III trial were evaluated. Patients with LLD and non-LLD and hepatic resection were differentiated. Based on baseline patient characteristic, prognostic factors for hepatic resection were evaluated. Furthermore, prognostic factors for median overall survival (OS) were estimated via Cox regression in LLD patients.

Results:

Secondary liver resection was performed in 38 out of 479 patients (resection rate: 7.9%). Prognostic factors for hepatic resection were LLD, lactate dehydrogenase (LDH), node-negative primary, alkaline phosphatase (AP) and Karnofsky performance status (PS). Median OS was significantly increased after hepatic resection (48 months), whereas OS in LLD (17 months) and non-LLD (19 months) was comparable in non-resected patients. With the inapplicability of Koehne's risk classification in LLD patients, a new score based on only the independent prognostic factors LDH and white blood cell (WBC) provided markedly improved information on the outcome.

Conclusion:

Patients undergoing hepatic resection showed favourable long-term survival, whereas non-resected LLD patients and non-LLD patients did not differ with regard to progression-free survival and OS. The LDH levels and WBC count were confirmed as prognostic factors and provide a useful and simple score for OS-related risk stratification also in LLD.

Early tumor shrinkage in metastatic colorectal cancer: retrospective analysis from an irinotecan-based randomized first-line trial

Early tumor shrinkage (ETS) has been highlighted as a favorable prognostic factor related to progression-free survival (PFS) and overall survival (OS) in cytotoxic treatment of metastatic colorectal cancer. Data from a randomized phase III study comparing infusional 5-fluorouracil plus irinotecan (FUFIRI) versus irinotecan plus oxaliplatin (mIROX) were evaluated. Patient groups were analyzed according to the relative change in maximum tumor diameter between baseline and after 7 weeks of treatment. The ETS cohort was defined as a decrease of ≥20%. Additionally, the non-ETS cohort was subdivided into "minor shrinkage" (0-19%), "tumor progression" (any increase) and development of "new metastatic lesions". Progression-free survival and OS were estimated in all patient subgroups. Assessment of ETS was possible in 201 patients. Early tumor shrinkage was observed in 47% (94/201) and non-ETS in 53% (107/201) of patients. Patients with ETS had a more favorable outcome with regard to PFS (9.9 months vs 6.1 months, P = 0.029) and OS (27.5 months vs 17.8 months, P = 0.002). In the non-ETS subgroups, patients with "minor shrinkage" (PFS 8.4 months, OS 21.6 months) showed a markedly better outcome than patients with "early tumor progression" (PFS 4.0 months, OS 15.3 months) or with "new metastatic lesions (PFS 2.2 months, OS 7.6 months). In conclusion, ETS assessment offers accelerated response evaluation when compared to RECIST. In patients treated with chemotherapy alone, ETS ≥20% is associated with excellent outcome. Non-ETS is a heterogeneous subgroup where patients with minor shrinkage clearly benefit from treatment, and patients with early progression or development of new lesions have an unfavorable prognosis.

Progression-free survival as a surrogate endpoint for median overall survival in metastatic colorectal cancer: literature-based analysis from 50 randomized first-line trials

PURPOSE

To evaluate progression-free survival (PFS) as a potential surrogate endpoint (SEP) for overall survival (OS) in metastatic colorectal cancer (mCRC) with a focus on applicability to trials containing targeted therapy with anti-VEGF- or anti-EGF receptor (EGFR)-directed monoclonal antibodies.

EXPERIMENTAL DESIGN

A systematic literature search of randomized trials of first-line chemotherapy for mCRC reported from January 2000 to January 2012 was conducted. Adjusted weighted linear regression was used to calculate correlations within PFS and OS (endpoints; R(EP)) and between treatment effects on PFS and on OS (treatment effects; R(TE)).

RESULTS

Fifty trials reflecting 22,736 patients met the inclusion criteria. Correlation between treatment effects on PFS and OS and between the endpoints PFS and OS was high across all studies (R(TE) = 0.87, R(EP) = 0.86). This was also observed in chemotherapy-only trials (R(TE) = 0.93, R(EP) = 0.81) but less so for trials containing monoclonal antibodies (R(TE) = 0.47; R(EP) = 0.52). Limiting the analysis to bevacizumab-based studies (11 trials, 3,310 patients) again yielded high correlations between treatment effects on PFS and on OS (R(TE) = 0.84), whereas correlation within PFS and OS was low (R(EP) = 0.45). In 7 trials (1,335 patients) investigating cetuximab- or panitumumab-based studies, contrasting correlations with very wide confidence intervals were observed (R(TE) = 0.28; R(EP) = 0.96).

CONCLUSIONS

PFS showed consistently high correlation with OS of an order that would justify its use as an SEP in chemotherapy regimens. For validation of surrogacy in anti-VEGF and anti-EGFR-directed therapies, further research and a larger set of trials is needed.

Alternative treatment options in colorectal cancer patients with 5-fluorouracil- or capecitabine-induced cardiotoxicity

Most chemotherapy regimens in colorectal cancer treatment are 5-fluorouracil (5-FU)/leucovorin or capecitabine-based. Cardiotoxicity is a less common but potentially lethal complication of 5-FU or capecitabine treatment, and some physicians might be unfamiliar with treatment alternatives. Rechallenging should be avoided because it carries a high risk of recurrence of the cardiac symptoms and prophylactic treatment is not always protective. Possible alternative treatment options to be considered are to replace the oral capecitabine or intravenous 5-FU by a 5-FU bolus regimen, by uracil-tegafur or tegafur/gimeracil/oteracil, both oral fluoropyrimidines combining a 5-FU prodrug with a dihydropyrimidine dehydrogenase (DPD) inhibitor, or by raltitrexed, a thymidilate synthase inhibitor whose metabolism is independent of DPD. Patients with advanced colorectal cancer and fluoropyrimidine-induced cardiotoxicity can be treated with other non-fluoropyrimidine related chemotherapy, either as a single agent, combined, or in combination with biological agents. In this report we discuss the different alternative treatment options.

Correlation of progression-free and post-progression survival with overall survival in advanced colorectal cancer

BACKGROUND

Polychemotherapy and biological drugs have increased therapeutic options and outcomes of advanced colorectal cancer (CRC). We examined the relation between progression-free survival (PFS), post-progression survival (PPS) and overall survival (OS) in trials of modern (oxaliplatin- and irinotecan-based) chemotherapy alone or with targeted therapies for advanced CRC. We also evaluated surrogacy of PFS and OS.

PATIENTS AND METHODS

A PubMed search identified 34 randomized trials. We split the OS, PFS and PPS and evaluated the correlation between OS and either PFS or PPS.

RESULTS

The median PPS and PFS were 10.75 and 8.4 months, respectively. For all trials, PPS was strongly associated with OS [regression coefficient (R2)=0.8; Spearman's rank correlation coefficient (r)=0.88], whereas PFS was moderately associated with OS (R2)=0.43; r=0.64). In trials with targeted therapies, the correlation of PPS with OS was 0.88. However, across all trials, correlation between differences in median PFS (ΔPFS) and median OS (ΔOS) is 0.59 (P=0.0007), confirming PFS/OS surrogacy.

CONCLUSION

Our findings indicate that in recent first-line, phase III, trials, OS becomes more associated with PPS than PFS. However, improvements in PFS are strongly associated with improvements in OS. In this setting so, PFS may be an appropriate surrogate for OS.

Optimizing first-line chemotherapy for metastatic colorectal cancer

SUMMARY Up to half of all patients who develop colorectal cancer will be treated for metastatic disease; some can be cured but most are simply palliated. The optimum use of the available drugs tailored to the patient should be informed by evidence, where it is available, and are of much current debate. Treatment objectives must be clear in making these decisions. Improved response rate may be appropriate where disease may become resectable, with an aim for cure. Tolerability and quality of life balanced with long-term survival may be most relevant where this is not feasible. A good start appropriate to the individual in the first-line metastatic setting is of both physical and psychological importance and may affect subsequent therapeutic decisions. Where Phase III randomized controlled trial evidence is missing, clinical decisions must still be made. Here we explore the data available for optimized first-line therapy, the options created from this data and balance this against the benefits to the patient as a whole.

Development and utilization of a combined LC-UV and LC-MS/MS method for the simultaneous analysis of tegafur and 5-fluorouracil in human plasma to support a phase I clinical study of oral UFT®/leucovorin

Tegafur is a 5-fluorouracil (5-FU) prodrug widely used outside the United States to treat colorectal cancer as well as cancers of the head and neck. The resulting plasma concentrations of tegafur are much higher than those of 5-FU; thus, analytical methods are needed that are sensitive enough to detect low plasma concentrations of 5-FU and robust enough to simultaneously analyze tegafur. Previous LC-MS/MS methods have either failed to demonstrate the ability to simultaneously measure low 5-FU and high tegafur plasma levels, or failed to be applicable in clinical studies. Our goal was to develop a method capable of measuring low concentrations of 5-FU (8-200 ng/ml) and high concentrations of tegafur (800-20,000 ng/ml) in human plasma and to subsequently evaluate the utility of the method in patient samples collected during a phase I clinical study where oral doses of either 200mg or 300 mg UF®/LV (uracil and tegafur in a 4:1 molar ratio plus leucovorin) were administered. A combined LC-MS/MS and LC-UV method was developed utilizing negative ion atmospheric pressure ionization (API). The method provides an accuracy and precision of <10% and <6%, respectively, for both analytes. Material recoveries from the liquid-liquid extraction technique were 97-110% and 86-91% for tegafur and 5-FU, respectively. Utilization of this method to determine tegafur and 5-FU plasma concentrations followed by noncompartmental pharmacokinetic analyses successfully estimated pharmacokinetic parameters (C(MAX), t(MAX) and AUC(0-10h)) in the clinical study patients. Overall, this method is ideal for the simultaneous bioanalysis of low levels of 5-FU and relatively higher levels of its prodrug, tegafur, in human plasma for clinical pharmacokinetic analysis.

Progression-free Survival Decreases with Each Subsequent Therapy in Patients Presenting for Phase I Clinical Trials

Background: There is often a finite progression-free interval of time between one systemic therapy and the next when treating patients with advanced cancer. While it appears that progression-free survival (PFS) between systemic therapies tends to get shorter for a number of factors, there has not been a formal evaluation of diverse tumor types in an advanced cancer population treated with commercially-available systemic therapies.

Methods: In an attempt to clarify the relationship between PFS between subsequent systemic therapies, we analyzed the records of 165 advanced cancer patients coming to our clinic for consideration for participation in six different phase I clinical trials requiring detailed and extensive past medical treatment history documentation.

Results: There were 77 men and 65 women meeting inclusion criteria with a median age at diagnosis of 55.3 years (range 9.4-81.6). The most common cancer types were colorectal (13.9%), other gastrointestinal (11.8%), prostate (11.8%). A median of 3 (range 1-11) systemic therapies were received prior to phase I evaluation. There was a significant decrease in PFS in systemic therapy for advanced disease from treatment 1 to treatment 2 to treatment 3 (p = 0.002), as well as, from treatment 1 through treatment 5 (p < 0.001).

Conclusions: In an advanced cancer population of diverse tumor types, we observe a statistically significant decrease in PFS with each successive standard therapy. Identification of new therapies that reverse this trend of decreasing PFS may lead to improved clinical outcomes.

Progression-free survival as a primary endpoint in clinical trials of metastatic colorectal cancer

In recent years, significant advances have been made in the management of metastatic colorectal cancer. Traditionally, an improvement in overall survival has been considered the "gold standard"-the most convincing measure of efficacy. However, overall survival requires larger patient numbers and longer follow-up and may often be confounded by other factors, including subsequent therapies and crossover. Given the number of active therapies for potential investigation, demand for rapid evaluation and early availability of new therapies is growing. Progression-free survival is regarded as an important measure of treatment benefit and, compared with overall survival, can be evaluated earlier, with fewer patients and no confounding by subsequent lines of therapy. The present paper reviews the advantages, limitations, and relevance of progression-free survival as a primary endpoint in randomized trials of metastatic colorectal cancer.

Analysis for prognostic factors of 60-day mortality: evaluation of an irinotecan-based phase III trial performed in the first-line treatment of metastatic colorectal cancer

BACKGROUND

Mortality rates in published irinotecan-based trials range between 1.7% and 5.0%. This analysis aimed to evaluate clinical and histopathologic factors associated with 60-day mortality in first-line therapy for metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

Sixty-day all-cause and disease-specific mortality rates from 479 patients who participated in a randomized phase III study comparing FUFIRI (5-fluorouracil [5-FU], leucovorin, irinotecan) (n = 238) vs. mIROX (modified irinotecan plus oxaliplatin (n = 241) were evaluated for association with prognostic factors such as platelet counts, alkaline phosphatase (AP) levels, white blood cell (WBC) counts, hemoglobin values, lactate dehydrogenase (LDH) levels, carcinoembryonic antigen (CEA) levels, and several other baseline parameters using univariate and multivariate logistic regression analyses applied to patients combined from both treatment groups.

RESULTS

The all-cause 60-day mortality rate was 5.0% (24/479). Thirteen patients (5.5%) in the FUFIRI arm died within the first 60 days of treatment compared with 11 (4.6%) patients in the mIROX arm (P = .68). Among the 24 patients in both treatment arms, mortality was qualified as disease related in 15 (63%) patients and treatment related in 7 (29%) patients (P = .695). In multivariate analyses, high LDH levels (P = .010) and an elevated WBC count (P = .006) remained as significant independent prognostic factors. Low Karnofsky performance status (KPS) showed a strong trend but failed to reach statistical significance (P = .057) as did AP levels and the number of metastatic sites.

CONCLUSION

In this study 63% of the early deaths were disease related, whereas only 29% were possibly related to study medication. Independent prognostic factors for early mortality were LDH levels and WBC counts. KPS showed a strong trend in the multivariate analysis. Future investigation may consider LDH levels and WBC counts for exclusion criteria.