Targeted Treatment against Cancer Stem Cells in Colorectal Cancer.

The cancer stem cell (SC) theory proposes that a population of SCs serves as the driving force behind fundamental tumor processes, including metastasis, recurrence, and resistance to therapy. The standard of care for patients with stage III and high-risk stage II colorectal cancer (CRC) includes surgery and adjuvant chemotherapy. Fluoropyrimidines and their combination with oxaliplatin increased the cure rates, being able to eradicate the occult metastatic SC in a fraction of patients. The treatment for unresectable metastatic CRC is based on chemotherapy, antibodies to VEGF and EGFR, and tyrosine-kinase inhibitors. Immunotherapy is used in MSI-H tumors. Currently used drugs target dividing cells and, while often effective at debulking tumor mass, these agents have largely failed to cure metastatic disease. SCs are generated either due to genetic and epigenetic alterations in stem/progenitor cells or to the dedifferentiation of somatic cells where diverse signaling pathways such as Wnt/ß-catenin, Hedgehog, Notch, TGF-ß/SMAD, PI3K/Akt/mTOR, NF-κB, JAK/STAT, DNA damage response, and Hippo-YAP play a key role. Anti-neoplastic treatments could be improved by elimination of SCs, becoming an attractive target for the design of novel agents. Here, we present a review of clinical trials assessing the efficacy of targeted treatment focusing on these pathways in CRC.

Hypertension as predictive factor for bevacizumab-containing first-line therapy in metastatic breast and colorectal cancer in BRECOL (GEICAM/2011-04) study.

BACKGROUND: Retrospective data suggest an association between bevacizumab efficacy and the incidence of arterial hypertension (AHT). Additionally, epigenetic mechanisms have been related to AHT. METHODS: This prospective observational study conducted by GEICAM Spanish Breast Cancer Research Group included metastatic breast (MBC) or colorectal (mCRC) cancer patients treated with bevacizumab-containing chemotherapy as first-line treatment. Blood pressure (BP) levels were measured (conventional and 24-h Holter monitoring) at baseline and up to cycle 3. Primary endpoint assessed BP levels increase as predictive factor for progression-free survival (PFS). Germline DNA methylation profile was explored in pre-treatment blood samples; principal component analysis was used to define an epigenetic predictive score for increased BP levels. RESULTS: From Oct-2012 to Jul-2016, 143 (78 MBC and 65 mCRC) patients were included. The incidence of AHT according to guidelines was neither predictive of PFS nor of best overall tumor response (BOR). No statistically significant association was observed with systolic BP nor diastolic BP increment for PFS or BOR. Grade 3 and 4 adverse events were observed in 37 and 5% of patients, respectively. We identified 27 sites which baseline methylation status was significantly associated to BP levels increase secondary to bevacizumab-containing chemotherapy. CONCLUSIONS: Neither the frequency of AHT nor the increase of BP levels were predictive of efficacy in MBC and mCRC patients treated with bevacizumab-containing chemotherapy. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov Identifier: NCT01733628.

Sequential RAS mutations evaluation in cell-free DNA of patients with tissue RAS wild-type metastatic colorectal cancer: the PERSEIDA (Cohort 2) study.

PURPOSE: RAS (KRAS/NRAS) mutational status on a tumor biopsy is mandatory to guide the best treatment in metastatic colorectal cancer (mCRC). Determining the RAS mutational status by tumor-tissue biopsy is essential in guiding the optimal treatment decision for mCRC. RAS mutations are negative predictive factors for the use of EGFR monoclonal antibodies. Cell-free DNA (cfDNA) analysis enables minimally invasive monitoring of tumor evolution. METHODS/PATIENTS: PERSEIDA was an observational, prospective study assessing cfDNA RAS, BRAF and EGFR mutations (using Idylla™) in first-line mCRC, RAS wild-type (baseline tumor-tissue biopsy) patients (cohort 2). Plasma samples were collected before first-line treatment, after 20 ± 2 weeks, and at disease progression. RESULTS: 117 patients were included (103 received panitumumab + chemotherapy as first-line treatment). At baseline, 7 (6.8%) patients had RAS mutations, 4 (3.9%) BRAF mutations and no EGFR mutations were detected (cfDNA, panitumumab + chemotherapy subpopulation [panitumumab + Ch]). The baseline RAS mutational status concordance between tissue and liquid biopsies was 94.0% (93.2%, panitumumab + Ch). At 20 weeks, only one patient in the study (included in the panitumumab + Ch) had an emerging cfDNA RAS mutation. No emerging BRAF or EGFR mutations were reported. At disease progression, 6 patients had emergent mutations not present at baseline (RAS conversion rate: 13.3% [6/45]; 15.0% [6/40], panitumumab + Ch). CONCLUSIONS: The concordance rate between liquid and solid biopsies at baseline was very high, as previously reported, while our results suggest a considerable emergence of RAS mutations during disease progression. Thus, the dynamics of the genomic landscape in ctDNA may provide relevant information for the management of mCRC patients.

Evolution of RAS Mutations in Cell-Free DNA of Patients with Tissue RAS Wild-Type Metastatic Colorectal Cancer Receiving First-Line Treatment: The PERSEIDA Study.

The serial analysis of cell-free DNA (cfDNA) enables minimally invasive monitoring of tumor evolution, providing continuous genetic information. PERSEIDA was an observational, prospective study assessing the cfDNA RAS (KRAS/NRAS) mutational status evolution in first-line, metastatic CRC, RAS wild-type (according to baseline tumor tissue biopsy) patients. Plasma samples were collected before first-line treatment, after 20 ± 2 weeks, and at disease progression. One hundred and nineteen patients were included (102 received panitumumab and chemotherapy as first-line treatment-panitumumab subpopulation). Fifteen (12.6%) patients presented baseline cfDNA RAS mutations (n = 14 [13.7%], panitumumab subpopulation) (mutant allele fraction ≥0.02 for all results). No patients presented emergent mutations (cfDNA RAS mutations not present at baseline) at 20 weeks. At disease progression, 11 patients (n = 9; panitumumab subpopulation) presented emergent mutations (RAS conversion rate: 19.0% [11/58]; 17.7% [9/51], panitumumab subpopulation). In contrast, three (5.2%) patients presenting baseline cfDNA RAS mutations were RAS wild-type at disease progression. No significant associations were observed between overall response rate or progression-free survival and cfDNA RAS mutational status in the total panitumumab subpopulation. Although, in patients with left-sided tumors, a significantly longer progression-free survival was observed in cfDNA RAS wild-type patients compared to those presenting cfDNA RAS mutations at any time. Continuous evaluation of RAS mutations may provide valuable insights on tumor molecular dynamics that can help clinical practice.

A randomised phase 2 study comparing different dose approaches of induction treatment of regorafenib in previously treated metastatic colorectal cancer patients (REARRANGE trial).

PURPOSE: The purpose of this article is to evaluate the safety of two regorafenib dose-escalation approaches in refractory metastatic colorectal cancer (mCRC) patients. PATIENTS AND METHODS: Patients with mCRC and progression during or within 3 months following their last standard chemotherapy regimen were randomised to receive the approved dose of regorafenib of 160 mg QD (arm A) or 120 mg QD (arm B) administered as 3 weeks of treatment followed by 1 week off, or 160 mg QD 1 week on/1 week off (arm C). The primary end-point was the percentage of patients with G3/G4 treatment-related adverse events (AEs) in each arm. RESULTS: There were 299 patients randomly assigned to arm A (n = 101), arm B (n = 99), or arm C (n = 99); 297 initiated treatments (arm A n = 100, arm B n = 98, arm C n = 99: population for safety analyses). G3/4 treatment-related AEs occurred in 60%, 55%, and 54% of patients in arms A, B, and C, respectively. The most common G3/4 AEs were hypertension (19, 12, and 20 patients), fatigue (20, 14, and 15 patients), hypokalemia (11, 7, and 10 patients), and hand-foot skin reaction (8, 7, and 3 patients). Median overall survival was 7.4 (IQR 4.0-13.7) months in arm A, 8.6 (IQR 3.8-13.4) in arm B, and 7.1 (IQR 4.4-12.4) in arm C. CONCLUSIONS: The alternative regorafenib dosing schedules were feasible and safe in patients with mCRC who had been previously treated with standard therapy. There was a higher numerical improvement on the most clinically relevant AEs in the intermittent dosing arm, particularly during the relevant first two cycles. GOV IDENTIFIER: NCT02835924.

Upfront primary tumour resection and survival in synchronous metastatic colorectal cancer according to primary tumour location and RAS status: Pooled analysis of the Spanish Cooperative Group for the Treatment of Digestive Tumours (TTD).

INTRODUCTION: Retrospective studies and meta-analyses suggest that upfront primary tumour resection (UPTR) confers a survival benefit in patients with asymptomatic unresectable metastatic colorectal cancer (mCRC) undergoing chemotherapy, however a consensus of its role in routine clinical practice in the current era of targeted therapies is lacking. This retrospective study aimed to analyse the survival benefit of UPTR in terms of tumour location and mutational status, in patients with synchronous mCRC receiving chemotherapy and targeted therapy. PATIENTS AND METHODS: Survival was analysed in a pooled cohort of synchronous mCRC patients treated with a first-line anti-VEGF or anti-EGFR inhibitor in seven trials of the Spanish TTD group, according to UPTR, tumour-sidedness and mutational profiling. RESULTS: Of 1334 eligible patients, 642 (48%) had undergone UPTR. UPTR was associated with significantly longer overall survival (OS; 25.0 vs 20.3 months; HR 1.30, 95%CI 1.15-1.48; p < 0.0001). UPTR was associated with significant OS benefit in both left-sided (HR 1.38, 95%CI 1.13-1.69; p = 0.002) and right-sided (HR 1.39, 95%CI 1.00-1.94; p = 0.049) tumours, RASwt (HR 1.29, 95%CI 1.05-1.60; p = 0.016) and BRAFwt (HR 1.49, 95%CI 1.21-1.84; p = 0.0002) tumours, and treatment with anti-EGFRs (HR 1.47, 95%CI 1.13-1.92; p = 0.004) and anti-VEGFs (HR 1.25, 95%CI 1.08-1.44; p = 0.003). Multivariate analysis identified number of metastatic sites, RAS status, primary tumour location and UPTR as independent prognostic factors for OS. CONCLUSION: Considering the selection bias inherent to this study, our results support UPTR before first-line anti-EGFR or anti-VEGF targeted therapy in right and left-sided asymptomatic unresectable synchronous mCRC patients. RAS/BRAF mutational status may also influence UPTR function.

Effect of aflibercept plus FOLFIRI and potential efficacy biomarkers in patients with metastatic colorectal cancer: the POLAF trial.

BACKGROUND: Aflibercept is an antiangiogenic drug against metastatic colorectal cancer (mCRC) combined with 5-fluorouracil/leucovorin/irinotecan (FOLFIRI); however, no antiangiogenic biomarker has yet been validated. We assessed aflibercept plus FOLFIRI, investigating the biomarker role of baseline vascular endothelial growth factor A (VEGF-A) and angiotensin-converting enzyme (ACE). METHODS: Phase II trial in oxaliplatin-treated mCRC patients who received aflibercept plus FOLFIRI. The reported 135 ng/mL ACE cut-off was used and ROC analysis was performed to assess the optimal VEGF-A cut-off for progression-free survival (PFS). Overall survival (OS), time to progression (TTP), time to treatment failure (TTF), overall response rate (ORR) and disease control rate (DCR) were also assessed. RESULTS: In total, 101 patients were followed for a median of 12 (6-17) months. The 1941 pg/mL VEGF-A was an optimal cut-off, with a longer median PFS when VEGF-A was <1941 versus ≥1941 pg/mL (9 versus 4 months). Patients with VEGF-A < 1941 pg/mL showed longer median OS (19 versus 8 months), TTP (9 versus 4 months) and TTF (8 versus 4 months), along with higher ORR (26% versus 9%) and DCR (81% versus 55%). No differences were identified according to ACE levels. CONCLUSIONS: This study supports aflibercept plus FOLFIRI benefits, suggesting VEGF-A as a potential biomarker to predict better outcomes.

Relationships Between Köhne Category/Baseline Tumor Load and Early Tumor Shrinkage, Depth of Response, and Outcomes in Metastatic Colorectal Cancer.

BACKGROUND: In metastatic colorectal cancer (mCRC), there are limited data on associations between early tumor shrinkage (ETS), depth of response (DpR), and patient characteristics. METHODS: Data from patients with RAS wild-type mCRC who had participated in the PRIME (NCT00364013) and PEAK (NCT00819780) studies were analyzed retrospectively. ETS and DpR were assessed by baseline Köhne category/BRAF status (PRIME) and baseline tumor load (pooled PRIME and PEAK). RESULTS: Analysis populations included 436 to 665 patients. Patients' chances of achieving ETS of 30% or greater were 63.8%, 50.4%, and 41.9% in the low-, medium-, and high-risk Köhne categories, and 21.7% in those with BRAF mutations. Corresponding percentages for the highest DpR classification (71%-100%) were 47.7% (low risk), 23.6% (medium risk), 10.0% (high risk), and 4.2% (BRAF mutant). No clear relationship was observed between baseline tumor load and ETS or DpR. An ETS of 30% or greater and higher DpR values were associated with statistically significant prolongation of median progression-free survival and overall survival. CONCLUSION: Patients with mCRC categorized at baseline by the Köhne criteria as high risk or with BRAF mutations have lower chances of achieving an ETS of 30% or greater or a high DpR. Baseline tumor load was not predictive of ETS or DpR. Favorable ETS or DpR is associated with improved progression-free and overall survival.

First-Line Biological Agents Plus Chemotherapy in Older Patients with Metastatic Colorectal Cancer: A Retrospective Pooled Analysis.

BACKGROUND: Biologicals, in combination with chemotherapy, are recommended as first-line treatment of metastatic colorectal cancer (mCRC); however, evidence guiding the appropriate management of older patients with mCRC is limited. OBJECTIVE: This study was undertaken to compare the efficacy and safety outcomes in older versus younger patients with mCRC who received first-line biological therapy. METHODS: This retrospective analysis used pooled data from five trials undertaken by the Spanish Cooperative Group for the Treatment of Digestive Tumours. All were studies of adults with advanced CRC who received first-line treatment with chemotherapy plus bevacizumab, cetuximab or panitumumab, stratified by age (≥ 65 vs. < 65 years). Endpoints included progression-free survival (PFS), overall survival (OS), overall response rate (ORR) and safety. RESULTS: In total, 999 patients from five studies were included in the analysis: 480 (48%) were aged ≥ 65 years, and 519 (52%) were aged < 65 years. Median PFS did not differ significantly between patients aged ≥ 65 and < 65 years (9.9 vs. 9.4 months; hazard ratio [HR] 1.01; 95% confidence interval [CI] 0.88-1.17). Median OS was significantly shorter in older than in younger patients (21.3 vs. 25.0 months; HR 1.21; 95% CI 1.04-1.41). There was no significant difference between older and younger patients in ORR (59 vs. 62%). Patients aged ≥ 65 years experienced significantly more treatment-related grade 3 or higher adverse events (61.67%) than did patients aged < 65 years (45.86%). CONCLUSIONS: Biologicals plus chemotherapy is an effective first-line treatment option for selected patients aged ≥ 65 years with mCRC and has a manageable safety profile and efficacy comparable to that observed in younger patients.

Phase II clinical trial of nab-paclitaxel plus gemcitabine in elderly patients with previously untreated locally advanced or metastatic pancreatic adenocarcinoma: the BIBABRAX study.

PURPOSE: To evaluate the health-related quality of life (HRQoL), global health status (GHS), and deterioration-free survival of an elderly population (> 70 years) with unresectable locally advanced (LAPC) or metastatic pancreatic cancer (mPC) treated with nab-paclitaxel in combination with gemcitabine. METHODS: In this open-label, single-arm, multicenter, phase II trial, patients received 4-week cycles of intravenous (i.v.) nab-paclitaxel at a dose of 125 mg/m2, followed by i.v. injections of gemcitabine at a dose of 1000 mg/m2 on days 1, 8 and 15 until disease progression or unacceptable toxicity was observed. The primary outcome was the HRQoL (deterioration-free rate at 3 months as evaluated with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30. RESULTS: Eighty patients (median age: 74.6 years) were enrolled (56 with mPC, 24 with LAPC). The percentage of patients who had not experienced deterioration at 3 months was 54.3% (95% CI 41.6-67.0%). The median (interquartile range) time until definite deterioration was 1.6 (1.1-3.7) months. The objective response rate and clinical benefit rate were achieved by 11 (13.8%, 95% CI 6.2-21.3%) and 54 patients (67.5%, 95% CI 57.2-77.8%), respectively. The median overall survival was 9.2 months (95% CI 6.9-11.5), and the median progression-free survival was 7.2 months (95% CI 5.8-8.5). Only fatigue and neutropenia demonstrated a grade 3-4 toxicity incidence > 20%. CONCLUSIONS: Our study confirms the clinical benefit of the combination of nab-paclitaxel and gemcitabine in an elderly population with pancreatic cancer in terms of improved survival and clinical response. However, we were unable to confirm a benefit in terms of quality-of-life.

First-line panitumumab plus capecitabine for the treatment of older patients with wild-type RAS metastatic colorectal cancer. The phase II, PANEL study.

BACKGROUND: Despite the high morbidity and mortality of metastatic colorectal cancer (mCRC) in older patients, they have been underrepresented in clinical trials and their optimal treatment is yet to be determined. This open-label phase II study evaluated the benefits of panitumumab and capecitabine as a first-line chemotherapy regimen in older patients with wild-type [WT] RAS mCRC. PATIENTS AND METHODS: Patients (≥70 years; ECOG≤2) received 3-week cycles of panitumumab (9 mg/kg on day 1) plus capecitabine (850 mg/m2 twice daily on days 1-14) until disease progression or unacceptable toxicity. Response was evaluated every 9 weeks according to RECIST_1.1. Outcome measures were: objective response rate (ORR), duration of response (DoR), time to response (TTR), progression (TTP) and treatment failure (TTF), progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Twenty-seven patients (11 women; median age: 78 years; ECOG: 0 [26%], 1 [67%], 2 [7%]) were evaluated. Median follow-up was 17.7 months. Confirmed ORR (95%CI) was 44.4% (25.7-63.2), with 25.9% of patients achieving at least stable disease. Median (95%CI) DoR was 8.7 (5.5-10.4) months, and median TTR was 2.2 (1.9-2.8) months. Median TTP was 9.6 (4.8-11.5) months, with a median TTF of 5.2 (2.8-7.2) months. The median PFS was 7.5 (4.4-10.4) months, and the median OS was 23.7 (7.4-27.5) months. Seventeen (63%) patients reported panitumumab and/or capecitabine-related adverse events grade 3-4, with skin toxicity (18.5%) being the most common. Two (7.4%) deaths were treatment-related. CONCLUSION: This study suggests that panitumumab plus capecitabine is a safe and effective regimen in older patients with WT RAS mCRC.

A phase 2 study of panitumumab with irinotecan as salvage therapy in chemorefractory KRAS exon 2 wild-type metastatic colorectal cancer patients.

BACKGROUND: Targeted agents are standard treatment for RAS wild-type metastatic colorectal cancer in the first- and second-line settings. This phase 2 study determined the benefit of targeting the epidermal growth factor receptor (EGFR) with panitumumab plus irinotecan in irinotecan-refractory patients. METHODS: KRAS exon-2 wild-type patients failing prior irinotecan received panitumumab (6 mg/kg) and irinotecan (180 mg/m²) every 2 weeks. The primary endpoint was the overall response rate (ORR). Secondary endpoints included safety, progression-free survival (PFS) and overall survival (OS). KRAS exon-2 status was evaluated centrally, along with NRAS, BRAF mutations, epiregulin, amphiregulin, PTEN and EGFR copy number status, and correlated with efficacy. RESULTS: Sixty-one patients were treated. Among the 46 wild-type RAS patients, the ORR was 15.2% (seven partial responses), with median PFS of 3.8 months (95% CI 2.7-4.3) and median OS of 12.5 months (95% CI 6.7-15.9). Wild-type BRAF patients showed a 13.0% response rate. No significant correlations between response and baseline biomarker expression were identified. Common grade 3-4 adverse events were diarrhoea and rash (18.0% each), hypomagnesaemia and asthenia (8.2% each). CONCLUSIONS: The addition of panitumumab to irinotecan as salvage therapy is feasible but has limited activity in irinotecan-refractory metastatic colorectal cancer. No biomarkers predictive of response were identified.

In Vitro Anti-proliferative and Anti-invasive Effect of Polysaccharide-rich Extracts from Trametes Versicolor and Grifola Frondosa in Colon Cancer Cells.

Colorectal cancer (CRC) is one of leading causes of mortality in western countries and novel treatment strategies are required. The medicinal application of mushrooms has been used in traditional medicine in many oriental countries. Polysaccharide-rich extracts obtained from certain medicinal mushroom species have shown antitumor effects in different experimental models. In the present study, we have developed polysaccharide-rich extracts from Trametes versicolor (TV) and Grifola frondosa (GF) fruit bodies. We aim to evaluate the anticancer effects of these polysaccharide-rich extracts in LoVo and HT-29 human colon cancer cells. The in vitro effects were determined by cytotoxicity assay, proliferation assay, wound healing assay and invasion assay. Moreover, the effect on anchorage independent-cell growth was also determined. Our results showed that TV and GF extracts did inhibit human colon cell proliferation and induce cytotoxicity. Furthermore, both fungal extracts significantly inhibited oncogenic potential, cell migration and invasion in colon cancer cells. In addition, extracts induce a more epithelial phenotype, observed by phase contrast images, together with an increase expression of the E-cadherin epithelial marker, detected by western-blotting analyses. Moreover, by using gelatin zymography assays, it was detected a decrease of MMP-2 enzyme activity, a crucial metalloproteinase important for the degradation of the extracellular matrix. Finally, the combination of the extracts with one the most clinical used agents for colorectal cancer, 5-fluorouracil, increases cell cytotoxicity. Taken together our results underscore a potential antitumor effect of polysaccharide-rich extracts obtained from TV and GF in human colon cancer cells lines. These finding may contribute to the reported health effects of fungal extracts.

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.

A Randomized Phase II Study of Axitinib as Maintenance Therapy After First-line Treatment for Metastatic Colorectal Cancer.

INTRODUCTION: The aim of this study was to evaluate the efficacy and safety of maintenance therapy with axitinib versus placebo following induction therapy in patients with metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: In this double-blinded, phase II trial, patients with mCRC who had not progressed after 6 to 8 months of first-line chemotherapy were randomized to receive axitinib (5 mg twice a day) (arm A) or placebo (arm B). RESULTS: Forty-nine patients were included: 25 in arm A and 24 in arm B. The median follow-up was 26.07 months (95% confidence interval [CI], 18.44-31.73 months). Progression-free survival (PFS) rate at 6 months was 40.00% (95% CI, 21.28%-58.12%) in the axitinib arm versus 8.33% (95% CI, 1.44%-23.30%) in the placebo arm (P = .0141). The median PFS was statistically significantly longer in the axitinib group than in the placebo group (4.96 vs. 3.16 months; hazard ratio, 0.46; 95% CI, 0.25-0.86; P = .0116). Median overall survival was also longer in the axitinib arm but did not reach statistical significance (27.61 vs. 19.99 months; hazard ratio, 0.68; 95% CI, 0.31-1.48; P = .3279). Grade 3 to 4 treatment-related toxicities were experienced by 7 patients (28%) in cohort A and 1 patient (4%) in cohort B (P = .0488). The most frequent grade 3 to 4 treatment-related toxicities were hypertension, diarrhea, and asthenia. There were no toxic deaths. The study was prematurely closed because of slow recruitment. CONCLUSIONS: In our study, maintenance treatment with axitinib monotherapy showed a significant increase in PFS and a good safety profile. Axitinib should be further explored as a possible option for first-line chemotherapy maintenance treatment in patients with mCRC.

Author Correction: Exploratory analyses assessing the impact of early tumour shrinkage and depth of response on survival outcomes in patients with RAS wild-type metastatic colorectal cancer receiving treatment in three randomised panitumumab trials.

The authors would like to include the following changes in the published article.

Hakai overexpression effectively induces tumour progression and metastasis in vivo.

At early stages of carcinoma progression, epithelial cells undergo a program named epithelial-to-mesenchymal transition characterized by the loss of the major component of the adherens junctions, E-cadherin, which in consequence causes the disruption of cell-cell contacts. Hakai is an E3 ubiquitin-ligase that binds to E-cadherin in a phosphorylated-dependent manner and induces its degradation; thus modulating cell adhesions. Here, we show that Hakai expression is gradually increased in adenoma and in different TNM stages (I-IV) from colon adenocarcinomas compared to human colon healthy tissues. Moreover, we confirm that Hakai overexpression in epithelial cells drives transformation in cells, a mesenchymal and invasive phenotype, accompanied by the downregulation of E-cadherin and the upregulation of N-cadherin, and an increased proliferation and an oncogenic potential. More importantly, for the first time, we have studied the role of Hakai during cancer progression in vivo. We show that Hakai-transformed MDCK cells dramatically induce tumour growth and local invasion in nude mice and tumour cells exhibit a mesenchymal phenotype. Furthermore, we have detected the presence of micrometastasis in the lung mice, further confirming Hakai role during tumour metastasis in vivo. These results lead to the consideration of Hakai as a potential new therapeutic target to block tumour development and metastasis.

Exploratory analyses assessing the impact of early tumour shrinkage and depth of response on survival outcomes in patients with RAS wild-type metastatic colorectal cancer receiving treatment in three randomised panitumumab trials.

PURPOSE: To report exploratory analyses of early tumour shrinkage (ETS) and depth of response (DpR) in patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC), receiving the first-line treatment in three randomised panitumumab trials. METHODS: Data from the PRIME (NCT00364013), PEAK (NCT00819780) and PLANET (NCT00885885) studies were included. Median DpR, the proportion of patients achieving ETS ≥ 20% or ≥ 30% at week 8, and the impact of ETS and DpR (including by category) on outcome were analysed. Factors associated with ETS and DpR and the optimal ETS/DpR cut-off values for predicting improved overall survival (OS) were assessed. RESULTS: Overall, 505, 170 and 53 patients had RAS WT mCRC in PRIME, PEAK and PLANET, respectively. Patients receiving panitumumab had higher ETS rates (≥ 30%: PRIME 59% vs. 38%; PEAK 64% vs. 45%) and greater DpR (PRIME: 54% vs. 46%; PEAK: 65% vs. 46%) than those receiving treatment without panitumumab. In multiple regression analyses, panitumumab treatment, liver-only metastases and WT BRAF status were consistently associated with improved ETS and DpR outcomes. Irrespective of treatment, ETS and DpR were associated with improved progression-free survival, overall survival and resection rates; most resections occurred in patients in the two highest DpR categories. In PRIME and PEAK, respectively, the optimal cut-offs for predicting improved OS were 32 and 34% for ETS, and 59 and 70% for DpR. CONCLUSIONS: These exploratory analyses suggest that panitumumab is associated ETS and DpR benefits in patients with RAS WT mCRC and that achieving these endpoints during first-line treatment is linked with favourable outcomes.

Proteomic Analysis of the E3 Ubiquitin-Ligase Hakai Highlights a Role in Plasticity of the Cytoskeleton Dynamics and in the Proteasome System.

Carcinoma, the most common type of cancer, arises from epithelial cells. The transition from adenoma to carcinoma is associated with the loss of E-cadherin and, in consequence, the disruption of cell-cell contacts. E-cadherin is a tumor suppressor, and it is down-regulated during epithelial-to-mesenchymal transition (EMT); indeed, its loss is a predictor of poor prognosis. Hakai is an E3 ubiquitin-ligase protein that mediates E-cadherin ubiquitination, endocytosis and finally degradation, leading the alterations of cell-cell contacts. Although E-cadherin is the most established substrate for Hakai activity, other regulated molecular targets for Hakai may be involved in cancer cell plasticity during tumor progression. In this work we employed an iTRAQ approach to explore novel molecular pathways involved in Hakai-driven EMT during tumor progression. Our results show that Hakai may have an important influence on cytoskeleton-related proteins, extracellular exosome-associated proteins, RNA-related proteins and proteins involved in metabolism. Moreover, a profound decreased expression in several proteasome subunits during Hakai-driven EMT was highlighted. Since proteasome inhibitors are becoming increasingly used in cancer treatment, our findings suggest that the E3 ubiquitin-ligase, such as Hakai, may be a better target than proteasome for using novel specific inhibitors in tumor subtypes that follow EMT.

First-line panitumumab plus FOLFOX4 or FOLFIRI in colorectal cancer with multiple or unresectable liver metastases: A randomised, phase II trial (PLANET-TTD).

BACKGROUND: In first-line wild-type (WT)-Kirsten rat sarcoma viral oncogene homologue (KRAS) metastatic colorectal cancer (mCRC), panitumumab (Pmab) improves outcomes when added to FOLFOX [folinic acid, 5-fluorouracil, and oxaliplatin] or FOLFIRI [folinic acid, 5-fluorouracil, and irinotecan]. However no trial has directly compared these combinations. METHODS: Multicentre, open-label study in untreated patients ≥ 18 years with (WT)-KRAS mCRC and multiple or unresectable liver-limited disease (LLD) randomised to either Pmab-FOLFOX4 or Pmab-FOLFIRI. The primary end-point was objective response rate (ORR). Secondary end-points included liver metastases resection rate (R0 + R1), progression-free survival (PFS), overall survival (OS), adverse events and perioperative safety. Exploratory end-points were: response by RAS status, early tumour shrinkage (ETS) and depth of response (DpR) in WT-RAS patients. RESULTS: Data on 77 patients were analysed (38 Pmab-FOLFOX4; 39 Pmab-FOLFIRI; WT-RAS: 27/26, respectively). ORR was 74% with Pmab-FOLFOX4 and 67% with Pmab-FOLFIRI (WT-RAS: 78%/73%). Out of the above, 45% and 59% underwent surgical resection, respectively (WT-RAS: 37%/69%). The R0-R1 resection rate was 34%/46% (WT-RAS:26%/54%). Median PFS was 13/14 months (hazard ratio [HR] Pmab-FOLFIRI versus Pmab-FOLFOX4: 0.9; 95% confidence interval: [0.6-1.5]; WT-RAS:13/15; HR: 0.7 [0.4-1.3]). Median OS was 37/41 months (HR:1.0 [0.6-1.8]; WT-RAS: 39/49; HR:0.9 [0.4-1.9]). In WT-RAS patients with confirmed response, median DpR was 71%/66%, and 65%/77% of patients showed ETS ≥ 30%/ ≥ 20% at week 8, without significant differences between arms; these patients had longer median PFS and OS and higher resectability rates. Surgery was associated with longer survival. Perioperative and overall safety were similar, except for higher grade 3/4 neutropenia (40%/10%; p = 0.003) and neuropathy (13%/0%; p = 0.025) in the Pmab-FOLFOX4 arm. CONCLUSIONS: In patients with WT-KRAS mCRC and LLD, both first-line Pmab-FOLFOX4 and Pmab-FOLFIRI resulted in high ORR and ETS, allowing potentially curative resection. No significant differences in efficacy were observed between the two regimens. (clinicaltrials.gov:NCT00885885).