The importance of optimal drug sequencing in metastatic colorectal cancer: biological rationales for the observed survival benefit conferred by first-line treatment with EGFR inhibitors

Real-world treatment outcomes from nationwide Onco-colon Turkey registry in RAS wild-type patients treated with biologics second-line mCRC

BACKGROUNDS AND OBJECTIVES

Colorectal cancer is one of the leading causes of mortality both globally and in our country. In Turkey, we conducted a multicenter investigation into the effectiveness of second-line treatments and real-life data for patients with RAS wild-type metastatic colorectal cancer (NCT04757311).

MATERIALS AND METHODS

In this retrospective analysis, records from 28 centers were collected, and histopathological, molecular, and clinical characteristics were documented. Patients were categorized into groups based on their second-line biological treatments: anti-EGFR (Group A and Group B, panitumumab and cetuximab) and anti-VEGF (Group C, bevacizumab and aflibercept). They were then compared within these groups.

RESULTS

A total of 588 patients with documented RAS wild-type status were evaluated. The median OS was 15.7, 14.3 and 14.7 months in Group A, Group B and Group C, respectively (p  =  0.764). The median PFS of the patients in second-line setting that received panitumumab, cetuximab and bevacizumab/aflibercept were 7.8, 6.6 and 7.4 months, respectively (p  =  0.848).

CONCLUSION

According to the results of our real-life data study, there is no significant difference in efficiency between the combination of biological agent and chemotherapy used in the second-line treatments.

Synthesizing studies for comparing different treatment sequences in clinical trials

With advances in cancer treatments and improved patient survival, more patients may go through multiple lines of treatment. It is of clinical importance to choose a sequence of effective treatments (eg, lines of treatment) for individual patients with the goal of optimizing their long-term clinical outcome (eg, survival). Several important issues arise in cancer studies. First, cancer clinical trials are usually conducted by each line of treatment. For a treatment sequence, we may have first line and second line treatment data from two different studies. Second, there is typically a treatment initiation period varying from patient to patient between progression of disease and the start of the second line treatment due to administrative reasons. Additionally, the choice of the second line treatment for patients with progression of disease may depend on their characteristics. We address all these issues and develop semiparametric methods under the potential outcome framework for the estimation of the overall survival probability for a treatment sequence and for comparing different treatment sequences. We establish the large sample properties of the proposed inferential procedures. Simulation studies and an application to a colorectal clinical trial are provided.

Are All Anti-Angiogenic Drugs the Same in the Treatment of Second-Line Metastatic Colorectal Cancer? Expert Opinion on Clinical Practice

Targeting tumor-driven angiogenesis is an effective strategy in the management of metastatic colorectal cancer (mCRC); however, the choice of second-line therapy is complicated by the availability of several drugs, the occurrence of resistance and the lack of validated prognostic and predictive biomarkers. This review examines the use of angiogenesis-targeted therapies for the second-line management of mCRC patients. Mechanisms of resistance and anti-placental growth factor agents are discussed, and the role of aflibercept, a recombinant fusion protein consisting of portions of human vascular endothelial growth factor receptor (VEGFR)-1 and VEGFR-2, is highlighted. The novel mechanism of action of aflibercept makes it a useful second-line agent in mCRC patients progressing after oxaliplatin-based chemotherapy, as well as in those with resistance after bevacizumab.

Copanlisib promotes growth inhibition and apoptosis by modulating the AKT/FoxO3a/PUMA axis in colorectal cancer

Colorectal cancer (CRC) is the type of cancer with the third highest incidence and is associated with high mortality and low 5-year survival rates. We observed that copanlisib, an inhibitor of PI3K (pan-class I phosphoinositide 3-kinase) that preferentially inhibits PI3Kδ and PI3Kα, impedes the growth of CRC cells by inducing apoptosis via PUMA. There was a marked increase in the expression of PUMA independent of p53 after treatment with copanlisib. The response of CRC cells to copanlisib could be predicted by PUMA expression. Copanlisib was found to induce PUMA expression through FoxO3a by directly binding to the PUMA promoter after inhibiting AKT signaling. PUMA deficiency mitigated the apoptosis induced by copanlisib. Caspase activation and mitochondrial dysfunction led to copanlisib resistance, as observed through a clonogenic assay, whereas enhanced expression of PUMA increased the copanlisib-induced susceptibility to apoptosis. Moreover, the antitumor effects of copanlisib were suppressed by a deficiency of PUMA in a xenograft model, and caspase activation and reduced apoptosis were also observed in vivo. Copanlisib-mediated chemosensitization seemed to involve the concurrent induction of PUMA expression via mechanisms that were both dependent and independent of p53. These observations indicate that apoptosis mediated by PUMA is crucial for the anticancer effects of copanlisib and that manipulation of PUMA may aid in enhancing anticancer activities.

Controversies in the treatment of RAS wild-type metastatic colorectal cancer

Objective

To provide guidance for the management of RAS wild-type (wt) metastatic colorectal cancer (mCRC) in daily practice.

Methods

Nominal group and Delphi techniques were used. A steering committee of seven experts analyzed the current management of RAS wt mCRC, through which they identified controversies, critically analyzed the available evidence, and formulated several guiding statements for clinicians. Subsequently, a group of 30 experts (the expert panel) was selected to test agreement with the statements, through two Delphi rounds. The following response categories were established in both rounds: 1 = totally agree, 2 = basically agree, 3 = basically disagree, 4 = totally disagree. Agreement was defined if ≥ 75% of answers were in categories 1 and 2 (consensus with the agreement) or 3 and 4 (consensus with the disagreement).

Results

Overall, 71 statements were proposed, which incorporated the following areas: (1) overarching principles; (2) tumor location; (3) triplets; (4) maintenance; (5) second-line and beyond treatments; (6) Rechallenge and liquid biopsy. After the two Delphi rounds, only six statements maintained a lack of clear consensus.

Conclusions

This document aims to describe the expert’s attitude when dealing with several common clinical questions regarding patients with RAS wt mCRC.

Electronic supplementary material

The online version of this article (10.1007/s12094-020-02475-8) contains supplementary material, which is available to authorized users.

Metastatic colorectal cancer (mCRC): French intergroup clinical practice guidelines for diagnosis, treatments and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, SFR)

INTRODUCTION

This document is a summary of the French intergroup guidelines regarding the management of metastatic colorectal cancer (mCRC) published in January 2019, and available on the French Society of Gastroenterology website (SNFGE) (www.tncd.org).

METHODS

This collaborative work was realized by all French medical and surgical societies involved in the management of mCRC. Recommendations are graded in three categories (A, B and C), according to the level of evidence found in the literature, up until December 2018.

RESULTS

The management of metastatic colorectal cancer has become complex because of increasing available medical, radiological and surgical treatments alone or in combination. The therapeutic strategy should be defined before the first-line treatment, mostly depending on the presentation of the disease (resectability of the metastases, symptomatic and/or threatening disease), of the patient's condition (ECOG PS, comorbidities), and tumor biology (RAS, BRAF, MSI). The sequence of targeted therapies also seems to have an impact on the outcome (angiogenesis inhibition beyond progression). Surgical resection of metastases was the only curative intent treatment to date, joined recently by percutaneous tumor ablation tools (radiofrequency, microwave). Localized therapies such as hepatic intra-arterial infusion, radioembolization and hyperthermic intraperitoneal chemotherapy, also have seen their indications specified (liver-dominant disease and resectable peritoneal carcinomatosis). New treatments have been developed in heavily pretreated patients, increasing overall survival and preserving quality of life (regorafenib and trifluridine/tipiracil). Finally, immune checkpoint inhibitors have demonstrated high efficacy in MSI mCRC.

CONCLUSION

French guidelines for mCRC management are put together to help offer the best personalized therapeutic strategy in daily clinical practice, as the mCRC therapeutic landscape is complexifying. These recommendations are permanently being reviewed and updated. Each individual case must be discussed within a multidisciplinary team (MDT).

Sequential cetuximab/bevacizumab therapy is associated with improved outcomes in patients with wild-type KRAS exon 2 metastatic colorectal cancer

Purpose

Combination of biological therapy and chemotherapy improves the survival of patients with metastatic colorectal cancer (mCRC). However, the optimal biological therapy sequence remains unclear. In this retrospective study, we evaluated the clinical outcomes of patients with mCRC treated with different sequences of biological therapies as first‐ and third‐line therapy.

Methods

We only included patients with wild‐type KRAS exon 2 mCRC who had received cetuximab, bevacizumab, and standard chemotherapy. The patients were treated with cetuximab or bevacizumab as first‐ or third‐line therapy combined with a similar chemotherapy backbone.

Results

In total, 102 patients were included. Forty‐six patients received first‐line cetuximab therapy followed by third‐line bevacizumab therapy (cetuximab → bevacizumab group) and 56 patients received first‐line bevacizumab therapy followed by third‐line cetuximab therapy (bevacizumab → cetuximab group). The cetuximab → bevacizumab group was associated with increased survival (OS) compared with the bevacizumab → cetuximab group (median OS: 30.4 months vs 25.7 months, hazard ratio (HR): 0.55, 95% confidence interval (CI): 0.36‐0.86). When calculated from the start of second‐ and third‐line therapies, OS was also higher in the cetuximab → bevacizumab group (second‐line: 20.6 months vs 14.8 months, HR: 0.54, 95% CI: 0.34‐0.81; third‐line: 12.5 months vs 9.9 months, HR: 0.53, 95% CI: 0.35‐0.83). The cetuximab → bevacizumab group was also associated with better progression‐free survival than the bevacizumab → cetuximab group (8.8 vs 4.5 months, HR: 0.43, 95% CI: 0.25‐0.58) in the third‐line setting, but not in the first‐ or second‐line settings.

Conclusions

Our study demonstrated that first‐line cetuximab therapy followed by third‐line bevacizumab therapy was associated with favorable clinical outcomes as compared to the reverse sequence.

Sequential therapy with bevacizumab and EGFR inhibitors for metastatic colorectal carcinoma: a national registry-based analysis

Purpose

Although inhibitors of vascular endothelial growth factor and inhibitors of epidermal growth factor receptor (EGFRi) are commonly used for the treatment of metastatic colorectal cancer (mCRC), the optimal sequencing of these agents is currently unclear.

Methods

A national registry of targeted therapies was used to analyze baseline characteristics and outcomes of patients with mCRC and wild-type KRAS exon 2 status who received bevacizumab and EGFRi (cetuximab or panitumumab) as a part of first- and second-line treatment in either sequence.

Results

The cohort included 490 patients (181 patients treated with first-line EGFRi and second-line bevacizumab and 309 patients treated with first-line bevacizumab and second-line EGFRi). Median overall survival (OS) from the initiation on first-line therapy was similar for patients treated with either sequence, reaching 31.8 (95% CI 27.5-36.1) vs 31.4 months (95% CI 27.8-35.0) for EGFRi → bevacizumab vs bevacizumab → EGFRi cohort, respectively. Time from first-line initiation to progression on the second-line therapy [progression-free survival (PFS)] was 21.1 (95% CI 19.3-23.0) vs 19.3 months (95% CI 17.3-21.3) for bevacizumab → EGFRi vs EGFRi → bevacizumab cohort, respectively (P=0.016).

Conclusion

This retrospective analysis of real-world data of patients with wild-type KRAS exon 2 mCRC showed no differences in OS between cohorts treated with bevacizumab → EGFRi vs the reverse sequence while combined PFS favored the bevacizumab → EGFRi sequence.

Biologic Response of Colorectal Cancer Xenograft Tumors to Sequential Treatment with Panitumumab and Bevacizumab

Recent studies in RAS wild-type (WT) metastatic colorectal cancer (mCRC) suggest that the survival benefits of therapy using anti-epidermal growth factor receptor (anti-EGFR) and anti-vascular endothelial growth factor (anti-VEGF) antibodies combined with chemotherapy are maximized when the anti-EGFR antibody is given as first-line, followed by subsequent anti-VEGF antibody therapy. We report reverse-translational research using LIM1215 xenografts of RAS WT mCRC to elucidate the biologic mechanisms underlying this clinical observation. Sequential administration of panitumumab then bevacizumab (PB) demonstrated a stronger tendency to inhibit tumor growth than bevacizumab then panitumumab (BP). Cell proliferation was reduced significantly with PB (P < .01) but not with BP based on Ki-67 index. Phosphoproteomic analysis demonstrated reduced phosphorylation of EGFR and EPHA2 with PB and BP compared with control. Western blotting showed reduced EPHA2 expression and S897-phosphorylation with PB; RSK phosphorylation was largely unaffected by PB but increased significantly with BP. In quantitative real-time PCR analyses, PB significantly reduced the expression of both lipogenic (FASN, MVD) and hypoxia-related (CA9, TGFBI) genes versus control. These results suggest that numerous mechanisms at the levels of gene expression, protein expression, and protein phosphorylation may explain the improved clinical activity of PB over BP in patients with RAS WT mCRC.

Exploratory pooled analysis evaluating the effect of sequence of biological therapies on overall survival in patients with RAS wild-type metastatic colorectal carcinoma

Background

The aim of this study was to evaluate the optimal sequence of targeted therapies (epidermal growth factor receptor inhibitors (EGFRi) and vascular endothelial growth factor inhibitors (VEGFi)), combined with chemotherapy, in patients with RAS wild-type (WT) metastatic colorectal carcinoma (mCRC). Exploratory analyses of overall survival (OS) for patients treated with either first-line panitumumab (EGFRi) and second-line VEGFi therapy, or first-line bevacizumab (VEGFi) and second-line EGFRi, were conducted.

Methods

Patients from PEAK (NCT00819780), PRIME (NCT00364013) and Study 181 (NCT00339183), with RAS WT or RAS WT/BRAF WT tumours, were included in the analyses. OS data were pooled for patients receiving first-line panitumumab (PEAK and PRIME) or first-line bevacizumab (PEAK and 181), followed by second-line VEGFi or EGFRi, respectively.

Results

Overall, 104 RAS WT patients were included (n=66 panitumumab→VEGFi, n=38 bevacizumab→EGFRi). At the time of final data analysis, 63.6% versus 92.1% of patients in the panitumumab→VEGFi versus bevacizumab→EGFRi arms had died; median OS was 36.8 versus 27.8 months, respectively (HR 0.65; 95% CI 0.42 to 1.03). The OS HR for patients with RAS WT/BRAF WT mCRC overall was 0.58 (95% CI 0.36 to 0.95) and was 0.56 (95% CI 0.30 to 1.04) in those with left-sided tumours.

Conclusion

Although numbers are small, these exploratory analyses suggest a trend towards improved OS for first-line panitumumab plus chemotherapy followed by second-line VEGFi, compared with first-line bevacizumab followed by second-line EGFRi in patients with RAS WT and RAS WT/BRAF WT mCRC. Large prospective randomised trials are needed to further evaluate the optimum sequence of EGFRi/VEGFi in mCRC.

Relevance of liver-limited disease in metastatic colorectal cancer: Subgroup findings of the FIRE-3/AIO KRK0306 trial

In metastatic colorectal cancer (mCRC), liver-limited disease (LLD) is associated with a higher chance of metastectomy leading to long-term survival. However, limited data describes the prognostic and predictive relevance of initially unresectable LLD with regard to targeted first-line therapy. The present analysis investigated the relevance of initially unresectable LLD in mCRC patients treated with targeted therapy against either the epidermal growth factor receptor (EGFR) or vascular epithelial growth factor (VEGF). The analysis was performed based on FIRE-3, a randomized phase III trial comparing first-line chemotherapy with FOLFIRI plus either cetuximab (anti-EGFR) or bevacizumab (anti-VEGF) in RAS wild-type (WT) mCRC. Of 400 patients, 133 (33.3%) had LLD and 267 (66.8%) had non-LLD. Median overall survival (OS) was significantly longer in LLD compared to non-LLD patients (36.0 vs. 25.4 months; hazard ratio [HR] = 0.66; 95% confidence interval [CI]: 0.51-0.87; p = 0.002). In a multivariate analysis also including secondary hepatic resection as time-dependent variable, LLD status was independently prognostic for OS (HR = 0.67; 95% CI: 0.50-0.91; p = 0.01). As assessed by interaction tests, treatment benefit from FOLFIRI plus cetuximab compared to FOLFIRI plus bevacizumab was independent of LLD status with regard to objective response rate (ORR), early tumour shrinkage ≥20% (ETS), depth of response (DpR) and OS (all p > 0.05). In conclusion, LLD could be identified as a prognostic factor in RAS-WT mCRC, which was independent of hepatic resection in patients treated with targeted therapy. LLD had no predictive relevance since benefit from FOLFIRI plus cetuximab over bevacizumab was independent of LLD status.

Final analysis of the randomised PEAK trial: overall survival and tumour responses during first-line treatment with mFOLFOX6 plus either panitumumab or bevacizumab in patients with metastatic colorectal carcinoma

PURPOSE

To report planned final overall (OS) and progression-free survival (PFS) analyses from the phase II PEAK trial (NCT00819780).

METHODS

Patients with previously untreated, KRAS exon 2 wild-type (WT) metastatic colorectal cancer (mCRC) were randomised to mFOLFOX6 plus panitumumab or bevacizumab. The primary endpoint was PFS; secondary endpoints included OS, objective response rate, duration of response (DoR), time to response, resection and safety. Treatment effect by tumour RAS status was a prespecified objective. Exploratory analyses included early tumour shrinkage (ETS) and depth of response (DpR).

RESULTS

One hundred seventy patients had RAS WT and 156 had RAS WT/BRAF WT mCRC. Median PFS was longer for panitumumab versus bevacizumab in the RAS WT (12.8 vs 10.1 months; hazard ratio (HR) = 0.68 [95% confidence intervals (CI) = 0.48-0.96]; p = 0.029) and RAS WT/BRAF WT (13.1 vs 10.1 months; HR = 0.61 [95% CI = 0.42-0.88]; p = 0.0075) populations. Median OS (68% OS events) for panitumumab versus bevacizumab was 36.9 versus 28.9 months (HR = 0.76 [95% CI = 0.53-1.11]; p = 0.15) and 41.3 versus 28.9 months (HR = 0.70 [95% CI = 0.48-1.04]; p = 0.08), in the RAS WT and RAS WT/BRAF WT populations, respectively. Median DoR (11.4 vs 9.0 months; HR = 0.59 [95% CI = 0.39-0.88]; p = 0.011) and DpR (65.0 vs 46.3%; p = 0.0018) were improved in the panitumumab group. More panitumumab patients experienced ≥30% ETS at week 8 (64 vs 45%; p = 0.052); ETS was associated with improved PFS/OS. No new safety signals occurred.

CONCLUSIONS

First-line panitumumab + mFOLFOX6 increases PFS versus bevacizumab + mFOLFOX6 in patients with RAS WT mCRC.

Evidence-Based Treatment Options in Recurrent and/or Metastatic Squamous Cell Carcinoma of the Head and Neck

The major development of the past decade in the first-line treatment of recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) was the introduction of cetuximab in combination with platinum plus 5-fluorouracil chemotherapy (CT), followed by maintenance cetuximab (the "EXTREME" regimen). This regimen is supported by a phase 3 randomized trial and subsequent observational studies, and it confers well-documented survival benefits, with median survival ranging between approximately 10 and 14 months, overall response rates between 36 and 44%, and disease control rates of over 80%. Furthermore, as indicated by patient-reported outcome measures, the addition of cetuximab to platinum-based CT leads to a significant reduction in pain and problems with social eating and speech. Conversely, until very recently, there has been a lack of evidence-based second-line treatment options, and the therapies that have been available have shown low response rates and poor survival outcomes. Presently, a promising new treatment option in R/M SCCHN has emerged: immune checkpoint inhibitors (ICIs), which have demonstrated favorable results in second-line clinical trials. Nivolumab and pembrolizumab are the first two ICIs that were approved by the US Food and Drug Administration. We note that the trials that showed benefit with ICIs included not only patients who previously received ≥1 platinum-based regimens for R/M SCCHN but also patients who experienced recurrence within 6 months after combined modality therapy with a platinum agent for locally advanced disease. In this review, we outline the available clinical and observational evidence for the EXTREME regimen and the initial results from clinical trials for ICIs in patients with R/M SCCHN. We propose that these treatment options can be integrated into a new continuum of care paradigm, with first-line EXTREME regimen followed by second-line ICIs. A number of ongoing clinical trials are comparing regimens with ICIs, alone and in combination with other ICIs or CT, with the EXTREME regimen for first-line treatment of R/M SCCHN. As we eagerly await the results of these trials, the EXTREME regimen remains the standard of care for the first-line treatment of R/M SCCHN.

MicroR-545 mediates colorectal cancer cells proliferation through up-regulating epidermal growth factor receptor expression in HOTAIR long non-coding RNA dependent

The functional impact of recently discovered miRNAs in human cancer remains to be clarified. One miRNA in colorectal cancer which has attracted attention is miR-545. In this study, we examined the function of miR-545 in proliferation of colorectal cancer cells. Expressions of HOTAIR, miRNA-545, and epidermal growth factor receptor (EGFR) mRNA were measured in 100 paired cancerous and non-cancerous tissues as well as in SW480 and LOVO colorectal cancer cell (CRC) lines by quantitative RT-PCR. The relative protein level of EGFR was measured using western blotting. Effects of miRNA-545 and HOTAIR on gastric cancer cells were studied by overexpression and RNA interference approaches. Insight of mechanism of promotion cancer by miR-545 was gained from luciferase reporter assay and gene expression analysis. CRC proliferation was evaluated using clone formation and MTT assay. Differential expressions of HOTAIR, miR-545, and EGFR were observed in cancerous tissues in comparison to non-cancerous tissues. By expressional management of miR-545, we observed that miR-545 negatively regulated cell proliferation. Also luciferase reporter assay revealed that miR-545 inhibited regulated EGFR expression by affecting its 3'-UTR activity. In addition, miR-545 expression was suppressed by HOTAIR overexpression whereas enhanced by HOTAIR silence. Suppression of EGFR expression by miR-545 mimic was abrogated by HOTAIR overexpression. Monitoring of tumor growth in mice showed that miR-545 overexpression suppressed LOVO tumor growth. Our data suggested that HOTAIR long non-coding RNA mediates microR-545 regulating colorectal cancer cells proliferation.

Relation of early tumor shrinkage (ETS) observed in first-line treatment to efficacy parameters of subsequent treatment in FIRE-3 (AIOKRK0306)

We explored the association of early tumor shrinkage (ETS) and non-ETS with efficacy of first-line and consecutive second-line treatment in patients with KRAS wild-type metastatic colorectal cancer treated in FIRE-3. Assessment of tumor shrinkage was based on the sum of longest diameters of target lesions, evaluated after 6 weeks of treatment. Shrinkage was classified as ETS (shrinkage by ≥ 20%), mETS (shrinkage by 0 to <20%), mPD (minor progression >0 to <20%) and PD (progression ≥20%). Overall survival (OS) was 33.2 (95% CI 28.0-38.4) months in ETS patients, while non-ETS was associated with less favorable outcome (mETS 24.0 (95% CI 21.2-26.9) months, mPD 19.0 (95% CI 13.0-25.0) months, PD 12.8 (95% CI 11.1-14.5) months). Differences in PFS of first-line therapy were less pronounced. ETS subgroups defined in first-line therapy also correlated with efficacy of second-line therapy. Progression-free survival in second-line (PFS2nd) was 6.5 months (5.8-7.2) for ETS, and was 5.6 (95% CI 4.7-6.5) months for mETS, 4.9 (95% CI 3.7-6.1) months for mPD and 3.3 (95% CI 2.3-4.3) months for PD. PFS of first-line and PFS2nd showed a linear correlation (Bravais-Pearson coefficient: 0.16, p = 0.006). While ETS is associated with the most favorable outcome, non-ETS represents a heterogeneous subgroup with distinct characteristics of less favorable initial tumor response to treatment. This is the first analysis to demonstrate that early tumor response observed during first-line FOLFIRI-based therapy may also relate to efficacy of second-line treatment. Early response parameters may serve as stratification factors in trials recruiting pretreated patients.

Chemotherapy plus bevacizumab versus chemotherapy plus cetuximab as first-line treatment for patients with metastatic colorectal cancer: Results of a registry-based cohort analysis

The present observational cohort study was designed to elucidate the efficacy and safety profile of bevacizumab or cetuximab with chemotherapy as the first-line treatment in Chinese patients with metastatic colorectal cancer (mCRC). Clinical data were collected from a single-center registry study where mCRC patients received first-line fluoropyrimidine-based chemotherapy combined with either bevacizumab (188 patients with KRAS wild-type or mutated tumors) or cetuximab (101 patients with KRAS wild-type tumors) between January 2009 and December 2013. The Kaplan-Meier method was used for survival analysis. Cox proportional hazards model was used for estimating the prognostic and predictive values of clinicopathological characteristics. No statistically significant difference was observed between the bevacizumab and cetuximab groups in terms of median progression-free survival (PFS) (10.6 vs 8.7 months, P = 0.317), median overall survival (OS) (27.7 vs 28.3 months, P = 0.525), or overall response rate (43.1% vs 53.5%, P = 0.108). For the subset of patients with peritoneal dissemination, bevacizumab-based triplet appears to be superior to cetuximab-based triplet as measured by PFS (9.6 vs 6.1 months) and OS (26.3 vs 12.7 months), but not for patients without peritoneal dissemination (PFS, 10.6 vs 9.1 months; OS, 27.9 vs 30.7 months) (all unadjusted and adjusted interaction P < 0.05). Our study suggests that bevacizumab- or cetuximab-based regimens have similar effectiveness as first-line treatment of mCRC in Chinese population. Patients with peritoneal dissemination were likely to gain more benefit from bevacizumab than cetuximab treatment. Future prospective studies are required to further confirm these results.

A study-level meta-analysis of efficacy data from head-to-head first-line trials of epidermal growth factor receptor inhibitors versus bevacizumab in patients with RAS wild-type metastatic colorectal cancer

BACKGROUND

Head-to-head trials comparing first-line epidermal growth factor receptor inhibitor (EGFRI) versus vascular endothelial growth factor inhibitor (bevacizumab) therapy yielded differing results, and debate remains over optimal first-line therapy for patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC).

METHODS

A PubMed search identified first-line mCRC trials comparing EGFRI plus chemotherapy versus bevacizumab plus chemotherapy; data were subsequently updated using recent congress presentations. This study-level meta-analysis estimated the overall survival (OS) treatment effect of first-line chemotherapy plus EGFRIs or bevacizumab in patients with RAS WT mCRC. Secondary end-points were progression-free survival (PFS), objective response rate (ORR), resection rate and safety. Early tumour shrinkage (ETS) of ≥20% at week 8 was an exploratory end-point.

RESULTS

Three trials comprising data from 1096 patients with RAS WT mCRC were included. OS (hazard ratio [HR]: 0.80 [95% confidence interval: 0.68-0.93]), ORR (odds ratio [OR]: 0.57) and ETS (OR: 0.48) favoured EGFRIs plus chemotherapy versus bevacizumab plus chemotherapy. PFS (HR: 0.98) and resections (OR: 0.93) were similar between treatments. For patients with KRAS exon 2 WT/'other' RAS mutant mCRC the OS HR was 0.70. A safety meta-analysis was not possible due to a lack of data; in the individual studies, skin toxicities and hypomagnesaemia were more common with EGFRIs, nausea and hypertension were more common with bevacizumab.

CONCLUSIONS

This meta-analysis supports a potential benefit for first-line EGFRI plus chemotherapy versus bevacizumab plus chemotherapy with respect to OS, ORR and ETS in patients with RAS WT mCRC. A patient-level meta-analysis is awaited.

Association between FOXM1 and hedgehog signaling pathway in human cervical carcinoma by tissue microarray analysis

Forkhead box M1 (FOXM1) and hedgehog (Hh) signaling pathway are implicated in the formation and development of human tumors, including cervical cancer. Previous studies have indicated that FOXM1 may be a downstream target gene of the Hh signaling pathway, but their association in cervical cancer is largely unknown. In the present study, the expression of FOXM1 and Hh signaling molecules was evaluated by immunohistochemical analysis in a tissue microarray that contained 70 cervical cancer tissues and 10 normal cervical tissues. In addition, the association of these molecules with clinicopathological parameters, and the association between FOXM1 and various molecules involved in the Hh signaling pathway was investigated. The results indicated that FOXM1 and Hh signaling molecules were overexpressed in cervical cancer tissues. The protein expression levels of FOXM1, glioma-associated oncogene 1 (GLI1) and smoothened (SMO) correlated with the clinical stage of the tumors, while the protein expression levels of Sonic Hh (SHh), patched 1 (PTCH1) and GLI1 correlated with the pathological grade of the tumors. The expression levels of GLI1 were lower in tissues without lymph node metastasis than in tissues with lymph node metastasis. In addition, FOXM1 expression correlated with GLI1, SHh and PTCH1 expression in cancer tissues. These findings confirmed the participation of FOXM1 and the Hh signaling pathway in cervical cancer. Furthermore, the finding that FOXM1 may be a downstream target gene of the Hh signaling pathway in cervical cancer provides a potential novel diagnostic and therapeutic target for cervical cancer.