Early onset metastatic colorectal cancer in patients receiving panitumumab-based upfront strategy: Overall and sex-specific outcomes in the Valentino trial.

Anti-EGFRs plus doublet chemotherapy is considered the optimal upfront option for RAS/BRAF wild-type left-sided metastatic colorectal cancer (mCRC). Early-onset (EO) mCRC has an increasing incidence and its prognostic/predictive role and management is debatable. We performed a post hoc analysis of Valentino study, that randomized RAS wild-type mCRC patients to two panitumumab-based maintenance regimens after FOLFOX/panitumumab induction. We assessed the safety and efficacy outcomes in patients stratified for age (<50/≥50 years old). We assessed progression-free survival (PFS), overall survival (OS), response rate (ORR), rate of treatment-related and panitumumab-related adverse events (AEs) and quality of life (QoL). In 229 patients enrolled, 35 (15%) had EO mCRC, with a higher rate of female sex (P = .020) and lower rate of primary tumor resection (P = .001). Median PFS and OS were 10.9 vs 10.8 months (P = .593) and 28.1 vs 27.5 months (P = .865) in patients <50 and ≥50 years old, respectively, with no significant impact of maintenance arm. ORR and disease control rate were 74% vs 65% (P = .337) and 97% vs 81% (P = .013) in patients <50 or ≥50 years old. In younger patients, a trend for increased chemotherapy-related AEs (peculiarly anemia) was shown, while significantly decreased EGFR-related hypomagnesemia and increased skin rash were reported. No significant differences in treatment intensity or QoL were observed. In patients with EO mCRC and RAS wild-type status, we found no differences in terms of survival outcomes based on age when selecting maintenance strategies. Management of treatment-related AEs should consider the differential toxicity profile of age and sex.

Reinduction of an Anti-EGFR-based First-line Regimen in Patients with RAS Wild-type Metastatic Colorectal Cancer Enrolled in the Valentino Study.

BACKGROUND: In patients with RAS/BRAF wild-type metastatic colorectal cancer (mCRC), growing evidence supports anti-epidermal growth factor receptor (EGFR) retreatment, whereas little is known on the outcomes of anti-EGFR-based reinduction therapy during the upfront strategy. METHODS: We included patients enrolled in the Valentino study who had disease progression and received at least one dose of post-progression therapy. The Kaplan-Meier method and Cox proportional hazards regression were used for the survival analysis. When comparing the outcomes of anti-EGFR-based reinduction versus any second line, a propensity score-based matching was used. RESULTS: Liver-limited/single site of disease (P < .001 and P = .002), left-sidedness (P = .029), surgery of metastases (P = .003), early tumor shrinkage, and deeper responses (P = .018 and P = .036) were associated with the use of anti-EGFR-based reinduction versus any other second line. All patients treated with reinduction had an anti-EGFR-free interval of at least 3 months. In the propensity score-matched population, progression-free survival (PFS) was similar in the 2 treatment groups, the overall survival (OS) was significantly longer for patients treated with reinduction (P = .029), and the response rate was higher in patients treated with reinduction (P = .033). An oxaliplatin-free interval ≥12 months, left-sidedness, and molecular hyperselection beyond RAS/BRAF were associated with significantly better outcomes after anti-EGFR-based reinduction. CONCLUSIONS: Reinduction strategies with anti-EGFR-based regimens are commonly used in clinical practice. Our data highlight the importance of clinical-molecular selection for re-treatments and the need for prospective strategy trials in selected populations.

Baseline neutrophilia, derived neutrophil-to-lymphocyte ratio (dNLR), platelet-to-lymphocyte ratio (PLR), and outcome in non small cell lung cancer (NSCLC) treated with Nivolumab or Docetaxel.

Nivolumab is a novel therapeutic option in NSCLC, associated with a significant survival gain compared with Docetaxel. However, predictive biomarkers are lacking. The presence of systemic inflammation has been correlated with poor outcome in many cancer types. We aimed to evaluate whether there is a correlation between some indicators of inflammation and response to Nivolumab or Docetaxel in pre-treated NSCLCs. Data of 62 patients receiving Nivolumab or Docetaxel were analyzed. Baseline neutrophilia and thrombocytosis were not associated with response. High dNLR was associated with no response to Nivolumab, but not with Docetaxel, whereas high PLR correlated with low treatment response in both groups. Among refractory patients, a higher incidence of thrombocytosis, neutrophilia, high PLR, and high dNLR levels were observed compared with the overall population. This is one of the first reports in this field and suggests that indicators of inflammation might be included together with other predictive biomarkers in the baseline evaluation of patients candidate for immunotherapy.

Emergence of MET hyper-amplification at progression to MET and BRAF inhibition in colorectal cancer.

BACKGROUND: Combined MET and BRAF inhibition showed clinical benefit in a patient with rectal cancer carrying BRAFV600E and MET amplification. However after 4 months, acquired resistance emerged and the patient deceased shortly after disease progression. The mechanism of resistance to this drug combination is unknown. METHODS: We analysed plasma circulating tumour DNA obtained at progression by exome sequencing and digital PCR. MET gene and mRNA in situ hybridisation analyses in two bioptic specimens obtained at progression were used to confirm the plasma data. RESULTS: We identified in plasma MET gene hyper-amplification as a potential mechanism underlying therapy resistance. Increased MET gene copy and transcript levels were detected in liver and lymph node metastatic biopsies. Finally, transduction of MET in BRAF mutant colorectal cancer cells conferred refractoriness to BRAF and MET inhibition. CONCLUSIONS: We identified in a rectal cancer patient MET gene hyper-amplification as mechanism of resistance to dual BRAF and MET inhibition.

Preoperative Capecitabine, Oxaliplatin, and Irinotecan in Resectable Gastric or Gastroesophageal Junction Cancer: Pathological Response as Primary Endpoint and FDG-PET Predictions.

OBJECTIVES: This phase II trial was aimed at assessing the safety and activity of capecitabine, oxaliplatin, and irinotecan (COI regimen) as a preoperative treatment for resectable gastric cancer (GC) or gastroesophageal junction (GEJ) cancer. METHODS: Patients affected by T3-T4/N0-N+/M0 GC/GEJ cancer were treated with the COI regimen for 4 cycles followed by restaging and gastroresection with D2 lymphadenectomy. Four postoperative cycles were scheduled. The primary endpoint was pathological response rate according to Becker et al. [Cancer 2003;98:1521-1530]. The potential role of fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) as a predictive biomarker of pathological tumor response was assessed in a subgroup of 19 evaluable patients. RESULTS: Between January 2011 and October 2015, a total of 40 patients were enrolled. After the preoperative phase, 36 out of 40 patients (90%) were considered eligible for surgery: 12 patients (30%) achieved a pathological response. The most frequent grade 3/4 adverse events were diarrhea (27%), nausea (25%), and fatigue (17%). Grade 3 neutropenia occurred in 7.5% of patients. A lower standard uptake value at baseline FDG-PET/CT was associated with pathological response. CONCLUSION: COI combination is active with a manageable toxicity profile in patients with resectable GC or GEJ cancer. FDG-PET/CT imaging as a surrogate biomarker of pathological response in this setting appears fascinating but should be further investigated.

Location of Primary Tumor and Benefit From Anti-Epidermal Growth Factor Receptor Monoclonal Antibodies in Patients With RAS and BRAF Wild-Type Metastatic Colorectal Cancer.

INTRODUCTION: Right- and left-sided colorectal cancers (CRCs) differ in clinical and molecular characteristics. Some retrospective analyses suggested that patients with right-sided tumors derive less benefit from anti-epidermal growth factor receptor (EGFR) antibodies; however, molecular selection in those studies was not extensive. PATIENTS AND METHODS: Patients with RAS and BRAF wild-type metastatic CRC (mCRC) who were treated with single-agent anti-EGFRs or with cetuximab-irinotecan (if refractory to previous irinotecan) were included in the study. Differences in outcome between patients with right- and left-sided tumors were investigated. RESULTS: Of 75 patients, 14 and 61 had right- and left-sided tumors, respectively. None of the right-sided tumors responded according to RECIST, compared with 24 left-sided tumors (overall response rate: 0% vs. 41%; p = .0032), and only 2 patients with right-sided tumors (15%) versus 47 patients with left-sided tumors (80%) achieved disease control (p < .0001). The median duration of progression-free survival was 2.3 and 6.6 months in patients with right-sided and left-sided tumors, respectively (hazard ratio: 3.97; 95% confidence interval: 2.09-7.53; p < .0001). CONCLUSION: Patients with right-sided RAS and BRAF wild-type mCRC seemed to derive no benefit from single-agent anti-EGFRs. IMPLICATIONS FOR PRACTICE: Right- and left-sided colorectal tumors have peculiar epidemiological and clinicopathological characteristics, distinct gene expression profiles and genetic alterations, and different prognoses. This study assessed the potential predictive impact of primary tumor site with regard to anti-epidermal growth factor receptor (EGFR) monoclonal antibody treatment in patients with RAS and BRAF wild-type metastatic colorectal cancer. The results demonstrated the lack of activity of anti-EGFRs in RAS and BRAF wild-type, right-sided tumors, thus suggesting a potential role for primary tumor location in driving treatment choices.

GNAS mutations as prognostic biomarker in patients with relapsed peritoneal pseudomyxoma receiving metronomic capecitabine and bevacizumab: a clinical and translational study.

BACKGROUND: There is lack of evidence about systemic treatment of pseudomyxoma peritonei (PMP) relapsing after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. There is also lack of biomarkers able to predict outcomes beyond known clinical and pathological prognostic features. METHODS: Fifteen patients with relapsed PMP and progressive disease within the last 6 months were included and received metronomic capecitabine (625 mg/mq/day b.i.d.) and bevacizumab (7.5 mg/Kg three-weekly) until progressive disease/unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Ion Torrent(®) next generation sequencing technology (Hot-spot Cancer Panel) was used to characterize molecular features. RESULTS: At a median follow up of 12 months, median PFS was 8.2 months and 1-year overall survival was 91 %. Partial responses were observed in 20 % of cases, but a significant reduction of tumor markers in up to 79 %. Treatment was very well tolerated without no new safety signals. All tumor samples except one had KRAS mutations. Patients with GNAS mutations had a significantly shorter median PFS as compared to GNAS wild-type ones (5.3 months vs. not reached; p < 0.007). The results were externally validated on our previous series of PMP patients. GNAS mutations were rare in a parallel cohort of 121 advanced colorectal cancers (2.5 %), but were associated with peculiar clinical-pathological features and aggressive course. CONCLUSIONS: Metronomic capecitabine and bevacizumab is an active and well tolerated option in patients with relapsed PMP. The negative prognostic effect of GNAS mutations in gastrointestinal cancers warrants further confirmatory studies and may prompt the development of effective targeted strategies.

Single-Agent Panitumumab in Frail Elderly Patients With Advanced RAS and BRAF Wild-Type Colorectal Cancer: Challenging Drug Label to Light Up New Hope.

BACKGROUND: No prospective trials have specifically addressed the efficacy and safety of panitumumab in elderly patients with metastatic colorectal cancer (CRC). We aimed at assessing the efficacy and safety of single agent panitumumab in "frail" elderly patients diagnosed with metastatic RAS and BRAF wild-type CRC. MATERIALS AND METHODS: Forty elderly patients (aged ≥ 75 years) with metastatic RAS-BRAF wild-type CRC received off-label prescriptions of single-agent panitumumab at seven Italian institutions. Treatment was administered as first line in patients with absolute contraindication to any chemotherapy or as second-line treatment after failure of a fluoropyrimidine-based treatment, in the presence of contraindication to irinotecan. The outcome measures included objective response rate (ORR), as well as progression-free survival (PFS), disease control rate (DCR), overall survival (OS), and safety. RESULTS: The median PFS and OS were 6.4 months (95% confidence interval [CI]: 4.9-8 months) and 14.3 months (95% CI: 10.9-17.7 months), respectively. ORR was 32.5%, and DCR was 72.5%. Dose reductions related to adverse events (AEs) were reported in 9 (23%) patients, but no permanent treatment discontinuation caused by was reported. The most frequent grade 3 AE was skin rash, with an incidence of 20%. CONCLUSION: Panitumumab is effective and well-tolerated in frail elderly patients with RAS-BRAF wild-type metastatic CRC and deemed unfit for chemotherapy. A randomized study is needed to confirm these data. IMPLICATIONS FOR PRACTICE: Treatment of elderly patients with metastatic colorectal cancer represents a difficult challenge in clinical practice. A significant proportion of frail elderly patients do not receive treatment, reflecting ongoing uncertainty of clinical benefit and toxicity of chemotherapy. Unfit condition in this cohort of patients further limits antineoplastic prescription and consequently patient survival. RAS and BRAF wild-type status could help select an elderly and unfit population that could benefit from anti-epidermal growth factor receptor single agent therapy. In the present study, single-agent off-label panitumumab was effective and well-tolerated as first-line treatment in frail elderly patients deemed unfit for chemotherapy for metastatic RAS and BRAF wild-type colorectal cancer.

Undetected toxicity risk in pharmacogenetic testing for dihydropyrimidine dehydrogenase.

Fluoropyrimidines, the mainstay agents for the treatment of colorectal cancer, alone or as a part of combination therapies, cause severe adverse reactions in about 10%-30% of patients. Dihydropyrimidine dehydrogenase (DPD), a key enzyme in the catabolism of 5-fluorouracil, has been intensively investigated in relation to fluoropyrimidine toxicity, and several DPD gene (DPYD) polymorphisms are associated with decreased enzyme activity and increased risk of fluoropyrimidine-related toxicity. In patients carrying non-functional DPYD variants (c.1905+1G>A, c.1679T>G, c.2846A>T), fluoropyrimidines should be avoided or reduced according to the patients' homozygous or heterozygous status, respectively. For other common DPYD variants (c.496A>G, c.1129-5923C>G, c.1896T>C), conflicting data are reported and their use in clinical practice still needs to be validated. The high frequency of DPYD polymorphism and the lack of large prospective trials may explain differences in studies' results. The epigenetic regulation of DPD expression has been recently investigated to explain the variable activity of the enzyme. DPYD promoter methylation and its regulation by microRNAs may affect the toxicity risk of fluoropyrimidines. The studies we reviewed indicate that pharmacogenetic testing is promising to direct personalised dosing of fluoropyrimidines, although further investigations are needed to establish the role of DPD in severe toxicity in patients treated for colorectal cancer.

Maintenance Therapy With Panitumumab Alone vs Panitumumab Plus Fluorouracil-Leucovorin in Patients With RAS Wild-Type Metastatic Colorectal Cancer: A Phase 2 Randomized Clinical Trial.

IMPORTANCE: Few studies are available on the role of maintenance strategies after induction treatment regimens based on anti-epidermal growth factor receptors, and the optimal regimen for an anti-epidermal growth factor receptors-based maintenance treatment in patients with RAS wild-type metastatic colorectal cancer is still to be defined. OBJECTIVE: To determine whether maintenance therapy with single-agent panitumumab was noninferior to panitumumab plus fluorouracil and leucovorin after a 4-month induction treatment regimen. DESIGN, SETTING, AND PARTICIPANTS: This open-label, randomized phase 2 noninferiority trial was conducted from July 7, 2015, through October 27, 2017, at multiple Italian centers. Patients with RAS wild-type, unresectable metastatic colorectal adenocarcinoma who had not received previous treatment for metastatic disease were eligible. Induction therapy consisted of panitumumab plus FOLFOX-4 (panitumumab, 6 mg/kg, oxaliplatin, 85 mg/m2 at day 1, leucovorin calcium, 200 mg/m2, and fluorouracil, 400-mg/m2 bolus, followed by 600-mg/m2 continuous 24-hour infusion at days 1 and 2, every 2 weeks). Cutoff date for analyses was July 30, 2018. INTERVENTIONS: Patients were randomized (1:1) to first-line panitumumab plus FOLFOX-4 for 8 cycles followed by maintenance therapy with panitumumab plus fluorouracil-leucovorin (arm A) or panitumumab (arm B) until progressive disease, unacceptable toxic effects, or consent withdrawal. The minimization method was used to stratify randomization by previous adjuvant treatment and number of metastatic sites. MAIN OUTCOMES AND MEASURES: The prespecified primary end point was 10-month progression-free survival (PFS) analyzed on an intention-to-treat basis with a noninferiority margin of 1.515 for the upper limit of the 1-sided 90% CI of the hazard ratio (HR) of arm B vs A. RESULTS: Overall, 229 patients (153 male [66.8%]; median age, 64 years [interquartile range (IQR), 56-70 years]) were randomly assigned to arm A (n = 117) or arm B (n = 112). At a median follow-up of 18.0 months (IQR, 13.1-23.3 months]), a total of 169 disease progression or death events occurred. Arm B was inferior (upper limit of 1-sided 90% CI of the HR, 1.857). Ten-month PFS was 59.9% (95% CI, 51.5%-69.8%) in arm A vs 49.0% (95% CI, 40.5%-59.4%) in arm B (HR, 1.51; 95% CI, 1.11-2.07; P = .01). During maintenance, arm A had a higher incidence of grade 3 or greater treatment-related adverse events (36 [42.4%] vs 16 [20.3%]) and panitumumab-related adverse events (27 [31.8%] vs 13 [16.4%]), compared with arm B. CONCLUSIONS AND RELEVANCE: In patients with RAS wild-type metastatic colorectal cancer, maintenance therapy with single-agent panitumumab was inferior in terms of PFS compared with panitumumab plus fluorouracil-leucovorin, which slightly increased the treatment toxic effects. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02476045.

Ramucirumab as Second-Line Therapy in Metastatic Gastric Cancer: Real-World Data from the RAMoss Study.

BACKGROUND: Ramucirumab-alone or combined with paclitaxel-represents one of the main options for patients failing first-line treatment for advanced gastric cancer. OBJECTIVE: The RAMoss study aimed to evaluate the safety and efficacy profile of ramucirumab in the "real-life setting". PATIENTS AND METHODS: Patients from 25 Italian hospitals started therapy consisting of ramucirumab 8 mg/kg i.v. d1,15q28 with or without paclitaxel 80 mg/m2 i.v. d1,8,15q28. The primary endpoint was safety, and secondary endpoints were overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). RESULTS: One hundred sixty-seven patients with disease progression on first-line therapy received ramucirumab as monotherapy (10%) or combined with paclitaxel (90%). Median treatment duration was 4 months (1-17 months). Global incidence of grade (G) 3-4 toxicity was 9.6%, and for neutropenia 5.4%; treatment was discontinued due to toxicity in 3% of patients. The most frequent adverse events (AE) were G1-2 fatigue (27.5%), G1-2 neuropathy (26.3%), and G1-2 neutropenia (14.9%). ORR was 20.2%. Stable disease was observed in 39.2% of patients, with a disease control rate of 59.4%. With a median follow-up of 11 months, median PFS was 4.3 months (95% confidence interval [CI] 4.1-4.7), whereas median OS was 8.0 months (95% CI: 7.09-8.9). In a multivariate analysis, ECOG performance status <1 or ≥1 (HR 1.13, 95% CI 1.0-1.27, p = 0.04) and the presence versus absence of peritoneal metastases (HR 1.57, 95% CI 1.63-2.39, p = 0.03) were independent poor prognostic factors. CONCLUSIONS: These "real-life" efficacy data on ramucirumab treatment are in line with previous randomized trials. Ramucirumab is well tolerated in daily clinical practice.

Molecular classifications of gastric cancers: Novel insights and possible future applications.

Despite some notable advances in the systemic management of gastric cancer (GC), the prognosis of patients with advanced disease remains overall poor and their chance of cure is anecdotic. In a molecularly selected population, a median overall survival of 13.8 mo has been reached with the use of human epidermal growth factor 2 (HER2) inhibitors in combination with chemotherapy, which has soon after become the standard of care for patients with HER2-overexpressing GC. Moreover, oncologists have recognized the clinical utility of conceiving cancers as a collection of different molecularly-driven entities rather than a single disease. Several molecular drivers have been identified as having crucial roles in other tumors and new molecular classifications have been recently proposed for gastric cancer as well. Not only these classifications allow the identification of different tumor subtypes with unique features, but also they serve as springboard for the development of different therapeutic strategies. Hopefully, the application of standard systemic chemotherapy, specific targeted agents, immunotherapy or even surgery in specific cancer subgroups will help maximizing treatment outcomes and will avoid treating patients with minimal chance to respond, therefore diluting the average benefit. In this review, we aim at elucidating the aspects of GC molecular subtypes, and the possible future applications of such molecular analyses.

Digital PCR assessment of MGMT promoter methylation coupled with reduced protein expression optimises prediction of response to alkylating agents in metastatic colorectal cancer patients.

BACKGROUND: O(6)-methylguanine-DNA-methyltransferase (MGMT) is a repair protein, and its deficiency makes tumours more susceptible to the cytotoxic effect of alkylating agents. Five clinical trials with temozolomide or dacarbazine have been performed in metastatic colorectal cancer (mCRC) with selection based on methyl-specific PCR (MSP) testing with modest results. We hypothesised that mitigated results are consequences of unspecific patient selection and that alternative methodologies for MGMT testing such as immunohistochemistry (IHC) and digital polymerase chain reaction (PCR) could enhance patient enrolment. PATIENTS AND METHODS: Formalin-fixed paraffin embedded archival tumour tissue samples from four phase II studies of temozolomide or dacarbazine in MGMT MSP-positive mCRCs were analysed by IHC for MGMT protein expression and by methyl-BEAMing (MB) for percentage of promoter methylation. Pooled data were then retrospectively analysed according to objective response rate, progression-free survival (PFS) and overall survival (OS). RESULTS: One hundred and five patients were included in the study. Twelve had achieved partial response (PR) (11.4%), 24 stable disease (SD; 22.9%) and 69 progressive disease (PD; 65.7%). Patients with PR/SD had lower IHC scores and higher MB levels than those with PD. MGMT expression by IHC was negatively and MB levels positively associated with PFS (p < 0.001 and 0.004, respectively), but not with OS. By combining both assays, IHC low/MB high patients displayed an 87% reduction in the hazard of progression (p < 0.001) and a 77% in the hazard for death (p = 0.001). CONCLUSION: In mCRC selected for MGMT deficiency by MSP, IHC and MB testing improve clinical outcome to alkylating agents. Their combination could enhance patient selection in this setting.

Surrogate Endpoints in Second-Line Trials of Targeted Agents in Metastatic Colorectal Cancer: A Literature-Based Systematic Review and Meta-Analysis.

PURPOSE: The purpose of this study was to evaluate progression-free survival (PFS) and objective response rate (ORR) as surrogate endpoints of overall survival (OS) in modern clinical trials investigating the efficacy of targeted agents in the second-line treatment of metastatic colorectal cancer (mCRC). MATERIALS AND METHODS: A systematic search of literature pertaining to randomized phase II and III trials evaluating targeted agents as second-line treatments for mCRC was performed. The strength of the correlation between both PFS and ORR and OS was assessed based on the Pearson's correlation coefficient (R) and the coefficient of determination (R2). RESULTS: Twenty trials, including a total of 7,571 patients, met the search criteria. The median duration of post-progression survival (PPS) was 7.6 months. The median differences between experimental and control arms were 0.65 months (range, -2.4 to 3.4) for the median PFS and 0.7 months (range, -5.8 to 3.9) for the median OS. PFS and ORR showed moderate (R=0.734, R2=0.539, p < 0.001) and poor correlation (R=0.169, R2=0.029, p=0.476) with OS, respectively. No differences between anti-angiogenic agents and other drugs were evident. CONCLUSION: Targeted agents investigated in the second-line treatment of mCRC provided minimal PFS gains translating into modest OS improvements. Considering both the moderate correlation between PFS and OS and the short duration of PPS, the OS should remain the preferred primary endpoint for randomized clinical trials in the second-line treatment of mCRC.

Prognostic value of diffuse versus intestinal histotype in patients with gastric cancer: a systematic review and meta-analysis.

BACKGROUND: There are two distinct types of gastric carcinoma (GC), intestinal, more frequently sporadic and linked to environmental factors, and diffuse (undifferentiated) that is highly metastatic and characterized by rapid disease progression and a poor prognosis. However, there are many conflicting data in the literature concerning the association between histology and prognosis in GC. This meta-analysis was performed to provide demonstration if histology according to Lauren classification is associated with different prognosis in patients with GC. METHODS: We searched PubMed, the Cochrane Library, SCOPUS, Web of Science, CINAHL, and EMBASE for all eligible studies. The combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) in terms of overall survival (OS) were evaluated. RESULTS: A total of 73 published studies including 61,468 patients with GC were included in this meta-analysis. Our analysis indicates that GC patients with diffuse-type histology have a worst prognosis than those with intestinal subgroup in all studies (HR 1.23; 95% CI, 1.17-1.29; P<0.0001), in both loco-regional confined (HR 1.21; 95% CI, 1.12-1.30; P<0.0001) and advanced disease (HR 1.25; 95% CI, 1.046-1.50; P=0.014), in Asiatic (HR 1.2; 95% CI, 1.14-1.27; P<0.0001) and Western patients (HR 1.3; 95% CI, 1.19-1.41; P<0.0001), and in those not exposed (HR 1.15; 95% CI, 1.07-1.24; P<0.0001) or exposed (HR 1.27; 95% CI, 1.17-1.37; P<0.0001) to (neo)adjuvant therapy. CONCLUSIONS: Our results indicated that histology might be a useful prognostic marker for both early and advanced GC patients, with intestinal-type associated with a better outcome. This information could be used for stratification purpose in future clinical trials.

Heterogeneity of Acquired Resistance to Anti-EGFR Monoclonal Antibodies in Patients with Metastatic Colorectal Cancer.

Purpose: Even if RAS-BRAF wild-type and HER2/MET-negative metastatic colorectal cancer (mCRC) patients frequently respond to anti-EGFR mAbs, acquired resistance almost invariably occurs. Mechanisms of resistance to EGFR blockade include the emergence of KRAS, NRAS, and EGFR extracellular domain mutations as well as HER2/MET alterations. However, these findings derive from retrospective studies that analyzed one single resistance mechanism at a time; moreover, it is still unclear how molecular heterogeneity affects clonal evolution in patients. In this work, we aimed at extensively characterizing and correlating the molecular characteristics of tissue- and blood-based data in a prospective cohort of patients with mCRC who received anti-EGFR antibodies.Experimental design: Twenty-two RAS-BRAF wild-type, HER2/MET-negative mCRC patients progressing on anti-EGFR therapy after initial response underwent rebiopsy. Next-generation sequencing and silver in situ hybridization (SISH)/IHC analyses were performed both on archival tumors and postprogression samples. Circulating tumor (ctDNA) molecular profiles were obtained in matched tissue-plasma samples.Results:RAS mutations and HER2/MET amplification were the most frequently detected resistance mechanisms in both tissue and blood sample analysis. On the other hand, BRAF and EGFR ectodomain mutations were much rarer. Patients with acquired MET amplification showed worse PFS on anti-EGFRs. We detected both intralesion heterogeneity, as suggested by co-occurrence of different resistance mechanisms in the same sample, and interlesion heterogeneity. The combined analysis of tissue and blood (ctDNA) results highlights the complexity of clonal evolution triggered by EGFR blockade.Conclusions: Our results indicate that it may be extremely challenging to target the complex landscape of molecular heterogeneity associated with emergence of resistance to targeted therapies in patients with mCRC. Clin Cancer Res; 23(10); 2414-22. ©2016 AACR.

Perioperative Triplet Chemotherapy and Cetuximab in Patients With RAS Wild Type High Recurrence Risk or Borderline Resectable Colorectal Cancer Liver Metastases.

BACKGROUND: For borderline resectable colorectal cancer liver metastases (CLM), systemic treatment can help to achieve R0 resection and reduce the risk of relapse. We assessed the role of perioperative triplet chemotherapy in combination with cetuximab in patients with RAS wild type high recurrence risk and/or borderline resectable CLM. PATIENTS AND METHODS: This was a monocenter, open-label phase II study. Borderline resectability was defined technically as tumor involvement of >1 hepatic vein, or >4 hepatic segments, need for 2-stage hepatectomy or radiofrequency ablation, and/or biologically (high risk): ≥4 metastatic nodules, or synchronous metastases. Patients were treated with 4 pre- and postoperative cycles of biweekly COI-E (cetuximab 500 mg/m2 and irinotecan 180 mg/m2 on day 1, oxaliplatin 85 mg/m2 on day 2, and capecitabine 1000 mg/m2 twice per day on days 2-6). The primary end point was overall response rate. RESULTS: Forty patients were enrolled. Nine patients with KRAS mutation were excluded after amendment in 2010. In an extended RAS test we did not find additional RAS mutations. The final population was comprised of 31 patients with RAS wild type CLM (technically borderline resectable 39%; synchronous 84%; ≥4 metastatic nodules 29%). The overall response, R0 resection, and pathological response rates were 87%, 84%, and 33%, respectively. At a median follow-up of 4 years, median progression-free survival and overall survival were 17.8 and 62.5 months, respectively. Treatment toxicity was relevant but did not jeopardize the surgical plan. CONCLUSION: The COI-E regimen was associated with high response and R0 resection rates in patients with RAS wild type CLM with borderline resectability and/or high-risk features.

IL-8 and eNOS polymorphisms predict bevacizumab-based first line treatment outcomes in RAS mutant metastatic colorectal cancer patients.

BACKGROUND: Predictive biomarkers of efficacy and toxicity of bevacizumab have not yet been validated. This study assessed the influence of IL-8, eNOS and VEGF-A polymorphisms in RAS mutated metastatic colorectal cancer patients receiving bevacizumab-based chemotherapy. METHODS: 120 patients treated with first-line combination FOLFOX6 plus bevacizumab were included. A historical cohort of 112 RAS mutated colorectal cancer patients treated with FOLFOX6 alone served as control group. The following SNPs were analyzed: IL-8 c.-251T>A; eNOS c.-786T>C and c.-894G>T; VEGF-A c.936C>T, c.958T>C, c.1154A>G and c.2578C>A. Correlation of SNPs, baseline IL-8 serum levels and bevacizumab-efficacy was done. RESULTS: In the bevacizumab group, carriers of the IL-8 alleles c.-251TA+AA showed a shorter PFS (P=0.002) and OS (P=0.03) compared to TT alleles. Patients with pre-treatment IL-8 < 18.25 pg/ml showed significantly longer median PFS and OS (PFS: 10.9 vs 7.6 months, P=0.005; OS: 30.7 vs 18.2 months, P<0.001) compared to patients with IL-8 higher levels (>18,25 pg/ml). IL-8 c.-251TA+AA carriers had significantly higher IL-8 levels (P<0.0001). Multivariate analysis confirmed association of IL-8 polymorphism with PFS, and of IL-8 baseline levels with both PFS and OS. IL-8 SNP did not affect the outcome in the control group. The eNOS polymorphism c.-894G>T was found associated with higher severe toxicity (P=0.0002) in patients carrying the c.-894TT genotype. CONCLUSIONS: Although our data need prospective validation, IL-8 and eNOS SNPs may be have a role as predictive biomarkers for bevacizumab efficacy and toxicity.

ALK, ROS1, and NTRK Rearrangements in Metastatic Colorectal Cancer.

Background: ALK, ROS1, and NTRK fusions occur in 0.2% to 2.4% of colorectal cancers. Pioneer cases of metastatic colorectal cancer (mCRC) patients bearing rearrangements who benefited from anti-ALK, ROS, and TrkA-B-C therapies have been reported previously. Here we aimed at characterizing the clinical and molecular landscape of ALK, ROS1, and NTRK rearranged mCRC. Methods: Clinical features and molecular characteristics of 27 mCRC patients bearing ALK, ROS1, and NTRK rearranged tumors were compared with those of a cohort of 319 patients not bearing rearrangements by means of Fisher's exact, χ2 test, or Mann-Whitney test as appropriate. Overall survival curves were estimated with the Kaplan-Meier method and compared using the log-rank test. A Cox proportional hazard model was adopted in the multivariable analysis. Deep molecular and immunophenotypic characterizations of rearranged cases, including those described in The Cancer Genome Atlas database, were performed. All statistical tests were two-sided. Results: Closely recalling the "BRAF history," ALK, ROS1, and NTRK rearrangements more frequently occurred in elderly patients (P = .02) with right-sided tumors (P < .001) and node-spreading (P = .03), RAS wild-type (P < .001), and MSI-high (P < .001) cancers. All patients bearing ALK, ROS1, and NTRK fusions had shorter overall survival (15.6 months, 95% confidence interval [CI] = 0.0 to 20.4 months) than negative patients (33.7 months, 95% CI = 28.3 to 42.1 months), both in the univariate (hazard ratio [HR] = 2.17, 95% CI = 1.03 to 4.57, P < .001) and multivariable models (HR = 2.33, 95% CI = 1.10 to 4.95, P = .02). All four evaluable patients with rearrangements showed primary resistance to anti-epidermal growth factor receptor agents. Frequent association with potentially targetable RNF43 mutations was observed in MSI-high rearranged tumors. Conclusions: ALK, ROS1, and NTRK rearrangements define a new rare subtype of mCRC with extremely poor prognosis. Primary tumor site, MSI-high, and RAS and BRAF wild-type status may help to identify patients bearing these alterations. While sensitivity to available treatments is limited, targeted strategies inhibiting ALK, ROS, and TrkA-B-C provided encouraging results.