Current management of colorectal liver metastases

SUMMARY 

Colorectal cancer is common worldwide and is predicted to become more so in the coming years. The liver is the most common site of metastasis and management is increasingly complex. A multidisciplinary team approach to management is essential, and is associated with better outcomes. Patients with irresectable liver metastases can still benefit from the involvement of a liver specialist, as high secondary resection rates can be achieved with combination chemotherapy, incorporating novel biological therapies and liver-directed local and locoregional treatments. The application of an enhanced recovery model to perioperative care, alongside improvements in the assessment of patient fitness for surgery, should help to mitigate the challenges presented by an older population with increased comorbidity undergoing increasingly complex treatment.

PEAK: a randomized, multicenter phase II study of panitumumab plus modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) or bevacizumab plus mFOLFOX6 in patients with previously untreated, unresectable, wild-type KRAS exon 2 metastatic colorectal cancer

PURPOSE

To evaluate panitumumab plus modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) or bevacizumab plus mFOLFOX6 in patients with previously untreated wild-type (WT) KRAS exon 2 (codons 12 and 13) metastatic colorectal cancer (mCRC). A prespecified secondary objective was to assess treatment effects in an extended RAS analysis that included exons 2, 3, and 4 of KRAS and NRAS.

PATIENTS AND METHODS

Patients with WT KRAS exon 2 tumors were randomly assigned at a one-to-one ratio to panitumumab plus mFOLFOX6 or bevacizumab plus mFOLFOX6. The primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and safety.

RESULTS

Of 285 randomly assigned patients, 278 received treatment. In the WT KRAS exon 2 intent-to-treat group, PFS was similar between arms (hazard ratio [HR], 0.87; 95% CI, 0.65 to 1.17; P = .353). Median OS was 34.2 and 24.3 months in the panitumumab and bevacizumab arms, respectively (HR, 0.62; 95% CI, 0.44 to 0.89; P = .009). In the WT RAS subgroup (WT exons 2, 3, and 4 of KRAS and NRAS), PFS favored the panitumumab arm (HR, 0.65; 95% CI, 0.44 to 0.96; P = .029). Median OS was 41.3 and 28.9 months (HR, 0.63; 95% CI, 0.39 to 1.02; P = .058) in the panitumumab and bevacizumab arms, respectively. Treatment discontinuation rates because of adverse events were similar between arms.

CONCLUSION

PFS was similar and OS was improved with panitumumab relative to bevacizumab when combined with mFOLFOX6 in patients with WT KRAS exon 2 tumors. Patients with WT RAS tumors seemed to experience more clinical benefit with anti-epidermal growth factor receptor therapy.

Chemotherapy usage patterns in a US-wide cohort of patients with metastatic colorectal cancer

BACKGROUND

Since the introduction of biologic therapies for the treatment of metastatic colorectal cancer (mCRC), few studies have examined patterns of care or predictors of specific treatment approaches.

METHODS

We assessed 4877 mCRC patients who received chemotherapy between January 2004 and March 2011 at academic, private, and community-based oncology practices subscribing to a US-wide chemotherapy order entry (system capturing disease, patient, provider, and treatment data. Multivariable analyses of these prospectively recorded characteristics were used to identify independent predictors of specific therapeutic choices. All statistical tests were two-sided.

RESULTS

Throughout the study period, fluoropyrimidine/oxaliplatin combination was the most commonly used first-line chemotherapy regimen, representing 71% of first-line therapy by 2007. First-line bevacizumab use averaged 51%, peaking at 55% in 2006. Of those who received first-line bevacizumab, 34% continued to receive bevacizumab in the second-line. Only 26% of patients in our cohort ever received an anti-EGFR monoclonal antibody (cetuximab = 22%; panitumumab = 6%) at some point in their treatment course. Patients treated at academic centers, with longer duration of first-line therapy, and at sites in the western United States were statistically more likely to receive an anti-EGFR antibody. Anti-EGFR antibody use fell by 18% after the US Food and Drug Administration limited its use to patients with KRAS wild-type tumors in June 2009.

CONCLUSIONS

Analysis of this US-wide mCRC cohort demonstrates that bevacizumab has been more consistently integrated into treatment regimens than anti-EGFR antibody therapies, particularly in first-line therapy. However, treatment choices vary substantially according to specific patient, practice, and provider characteristics.

How to find the Ariadne's thread in the labyrinth of salvage treatment options for metastatic colorectal cancer?

Since a chance for cure was found out in metastatic colorectal cancer (mCRC) patients undergoing a resection of liver and lung metastases, high tumor shrinkage by chemotherapy regimens and their combination with targeted agents have been addressed in potentially resectable mCRC. However, most mCRC patients cannot reach this opportunity because of tumor burden or metastatic sites. For these patients a salvage systemic therapy could be offered to prolong survival. To date, a huge number of clinical trials provided some evidences for the achievement of this goal. A lot of chemotherapeutic regimens in combination with biological therapies are now available. We tried to propose a simple way to choose the best options and to plan an optimal sequence of treatments. This tool could help the oncologists worldwide to better and easily manage mCRC patients who need salvage systemic therapy.

Cytoreduction and heated intraperitoneal chemotherapy for colorectal cancer: are we excluding patients who may benefit?

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are increasingly used to treat peritoneal carcinomatosis from colorectal cancer. It is still relatively unknown which poor prognostic factors to avoid in order to optimize patient selection for CRS + HIPEC.

METHODS

Between February 2003 and October 2011, 68 consecutive colorectal cancer patients who underwent CRS + HIPEC with a complete cytoreduction were identified from a prospective database. Survival analysis was performed using the Kaplan-Meier method, with log rank testing of differences between groups. Multivariate analysis was conducted using Cox proportional hazard regression.

RESULTS

Median follow-up was 30.3 (range, 2-88) months amongst survivors. Patients with a peritoneal cancer index (PCI) of 10 or less showed improved survival over those with a PCI of 11 or higher (P = 0.03). No difference in survival was seen for the other potentially poor prognostic variables including lymph node status, synchronous peritoneal disease, peri-operative systemic chemotherapy, and rectal cancer primary.

CONCLUSIONS

A low PCI was associated with improved survival. Complete CRS + HIPEC appears to result in similar survival outcomes regardless of delivery of peri-operative systemic chemotherapy. Rectal origin, lymph node status, and synchronous peritoneal disease should not be used as an absolute exclusion criteria for CRS + HIPEC based on current data.

Multi-marker analysis of circulating cell-free DNA toward personalized medicine for colorectal cancer

Development of a Q-PCR-based assay for the high-performance analysis of circulating cell-free DNA (ccfDNA) requires good knowledge of its structure and size. In this work, we present the first visual determination of ccfDNA by Atomic Force Microscopy (AFM) on plasma samples from colorectal cancer (CRC) patients and healthy donors. In addition to the examination of fragment size distribution profile as performed by Q-PCR, this analysis confirms that ccfDNA is highly fragmented and that more than 80% of ccfDNA fragments in CRC plasma are below 145 bp. We adapted an Allele-Specific Blocker (ASB) Q-PCR to small ccfDNA fragments to determine simultaneously the total ccfDNA concentration, the presence of point mutation, the proportion of mutated allele, and a ccfDNA integrity index. The data validated analytically these four parameters in 124 CRC clinical samples and 71 healthy individuals. The multi-marker method, termed Intplex, enables sensitive and specific non-invasive analysis of tumor ccfDNA, which has great potential in terms of cost, quality control, and easy implementation in every clinical center laboratory.

Clinical validation of the detection of KRAS and BRAF mutations from circulating tumor DNA

Assessment of KRAS status is mandatory in patients with metastatic colorectal cancer (mCRC) before applying targeted therapy. We describe here a blinded prospective study to compare KRAS and BRAF mutation status data obtained from the analysis of tumor tissue by routine gold-standard methods and of plasma DNA using a quantitative PCR-based method specifically designed to analyze circulating cell-free DNA (cfDNA). The mutation status was determined by both methods from 106 patient samples. cfDNA analysis showed 100% specificity and sensitivity for the BRAF V600E mutation. For the seven tested KRAS point mutations, the method exhibited 98% specificity and 92% sensitivity with a concordance value of 96%. Mutation load, expressed as the proportion of mutant alleles in cfDNA, was highly variable (0.5-64.1%, median 10.5%) among mutated samples. CfDNA was detected in 100% of patients with mCRC. This study shows that liquid biopsy through cfDNA analysis could advantageously replace tumor-section analysis and expand the scope of personalized medicine for patients with cancer.

Comparison of KRAS genotype: therascreen assay vs. LNA-mediated qPCR clamping assay

BACKGROUND

Kirsten rat sarcoma virus (KRAS) wild-type status determined using a locked nucleic acid (LNA)-mediated quantitative polymerase chain reaction (qPCR) clamping assay (LNA assay) predicted response to therapy in the CRYSTAL (Cetuximab Combined With Irinotecan in First-Line Therapy for Metastatic Colorectal Cancer) study. A companion KRAS diagnostic tool has been developed for routine clinical use (QIAGEN therascreen kit) (QIAGEN Manchester Ltd, Manchester, UK). We wanted to assess the concordance between the validated US Food and Drug Administration (FDA)-approved therascreen assay and the LNA assay in determining the KRAS status of a subset of patients enrolled in the CRYSTAL study.

PATIENTS AND METHODS

DNA extracted from paraffin-embedded tumor sections was tested for KRAS status using the therascreen assay. Efficacy data from the CRYSTAL study were assessed to determine if the overall survival (OS) hazard ratio for cetuximab in patients identified as having KRAS wild-type status using the therascreen assay was equivalent to that in patients identified as KRAS wild-type using the LNA assay. This was determined by assessing if the concordance between the therascreen assay and the LNA assay met the minimum threshold (prespecified as 0.8) to achieve a significant difference in the OS hazard ratio in favor of the cetuximab + FOLFIRI (5-fluorouracil, leucovorin [folinic acid], irinotecan) arm in the KRAS wild-type population as identified using the therascreen assay.

RESULTS

Of the 148 samples determined to be KRAS wild-type (therascreen assay), 141 (95.3%) samples were also KRAS wild-type (LNA assay) and 7 samples (4.7%) were KRAS mutant (LNA assay). The prespecified primary concordance measure p was 141/148 = 0.953 (95% confidence interval [CI], 0.905-0.981). The concordance was statistically significantly higher than the prespecified threshold of 0.8 for concordance between the therascreen assay and the LNA assay. Consistent with the concordance exceeding the prespecified threshold, the OS hazard ratio (cetuximab + FOLFIRI arm vs. FOLFIRI arm) in the KRAS wild-type population, determined by the therascreen assay, supported a significant benefit for cetuximab (ie, the 95% CI excluded 1) and was comparable to the OS hazard ratio observed in the CRYSTAL study KRAS wild-type population (LNA assay) even after adjustment for potentially confounding baseline variables.

CONCLUSION

These results support the utility of the therascreen assay for identifying patients who may benefit from cetuximab therapy for metastatic colorectal cancer.

Personalized oncology in interventional radiology

As personalized medicine becomes more applicable to oncologic practice, image-guided biopsies will be integral for enabling predictive and pharmacodynamic molecular pathology. Interventional radiology has a key role in defining patient-specific management. Advances in diagnostic techniques, genomics, and proteomics enable a window into subcellular mechanisms driving hyperproliferation, metastatic capabilities, and tumor angiogenesis. A new era of personalized medicine has evolved whereby clinical decisions are adjusted according to a patient's molecular profile. Several mutations and key markers already have been introduced into standard oncologic practice. A broader understanding of personalized oncology will help interventionalists play a greater role in therapy selection and discovery.

Cancer pharmacogenomics, adoption by oncologists and patient benefit

Aim: The study aim was to understand physician experience and factors influencing the adoption of cancer pharmacogenomic (caPGx) testing by oncologists practicing in academic and nonacademic settings. Method: Anonymous paper surveys were distributed to oncologists practicing in North Carolina (USA). Results: Although 98% of oncologists see promise in utilizing PGx tests in their practice, few were comfortable with their knowledge (33%) or interpreting test results (37%). At one site, the survey was not distributed due to clinician unfamiliarity with the term ‘pharmacogenomics’. Compared with oncologists in academia, community oncologists were more likely to order the new Oncotype Dx™ test for colon cancer (33% vs 0; p = 0.0071), more likely to indicate future use of caPGx tests (94 vs 75%; p = 0.012) and less likely to have never ordered a caPGx test (2 vs 35%%; p < 0.001). Nearly every oncologist was interested in additional PGx education. Conclusion: A critical need exists to disseminate accurate and updated caPGx information to oncologists practicing in both academic and nonacademic settings.

Monoclonal antibodies as therapeutics in human malignancies

ABSTRACT: 

Monoclonal antibodies (mAbs) are a proven effective therapeutic modality in human malignancy. Several mAbs are approved to targets critical in aberrant oncogenic signaling within tumors and their microenvironment. These targets include secreted ligands (e.g., VEGF and HGH), their receptors (e.g., HER2 and VEGFR2), cell surface counter receptors and their receptor-bound ligands (e.g., PD1 and PD1L, respectively). The ability to genetically engineer the structure and/or functions of mAbs has significantly improved their effectiveness. Furthermore, advances in gene expression profiling, proteomics, deep sequencing and deciphering of complex signaling networks have revealed novel therapeutic targets. We review target selection, approved indications and the rationale for mAb utilization in solid and hematologic malignancies. We also discuss novel mAbs in early- and late-phase clinical trials that are likely to change the natural history of disease and improve survival. The future challenge is to design mAb-based novel trial designs for diagnostics and therapeutics for human malignancies.

Management of locally advanced and metastatic colon cancer in elderly patients

Colon cancer is the second leading cause of cancer mortality in the United States with a median age at diagnosis of 69 years. Sixty percent are diagnosed over the age of 65 years and 36% are 75 years or older. At diagnosis, approximately 58% of patients will have locally advanced and metastatic disease, for which systemic chemotherapy has been shown to improve survival. Treatment of cancer in elderly patients is more challenging due to multiple factors, including disabling co-morbidities as well as a decline in organ function. Cancer treatment of elderly patients is often associated with more toxicities that may lead to frequent hospitalizations. In locally advanced disease, fewer older patients receive adjuvant chemotherapy despite survival benefit and similar toxicity when compared to their younger counterparts. A survival benefit is also observed in the palliative chemotherapy setting for elderly patients with metastatic disease. When treating elderly patients with colon cancer, one has to consider drug pharmacokinetics and pharmacodynamics. Since chronological age is a poor marker of a patient’s functional status, several methods of functional assessment including performance status and activities of daily living (ADL) or instrumental ADL, or even a comprehensive geriatric assessment, may be used. There is no ideal chemotherapy regimen that fits all elderly patients and so a regimen needs to be tailored for each individual. Important considerations when treating elderly patients include convenience and tolerability. This review will discuss approaches to the management of elderly patients with locally advanced and metastatic colon cancer.

Survival of patients with initially unresectable colorectal liver metastases treated with FOLFOX/cetuximab or FOLFIRI/cetuximab in a multidisciplinary concept (CELIM study)

BACKGROUND

Initially, unresectable colorectal liver metastases can be resected after response to chemotherapy. While cetuximab has been shown to increase response and resection rates, the survival outcome for this conversion strategy needs further evaluation.

PATIENTS AND METHODS

Patients with technically unresectable and/or ≥5 liver metastases were treated with FOLFOX/cetuximab (arm A) or FOLFIRI/cetuximab (arm B) and evaluated with regard to resectability every 2 months. Tumour response and secondary resection data have been reported previously. A final analysis of overall survival (OS) and progression-free survival (PFS) was carried out in December 2012.

RESULTS

Between December 2004 and March 2008, 56 patients were randomised to arm A, 55 to arm B. The median OS was 35.7 [95% confidence interval (CI) 27.2-44.2] months [arm A: 35.8 (95% CI 28.1-43.6), arm B: 29.0 (95% CI 16.0-41.9) months, HR 1.03 (95% CI 0.66-1.61), P = 0.9]. The median PFS was 10.8 (95% CI 9.3-12.2) months [arm A: 11.2 (95% CI 7.2-15.3), arm B: 10.5 (95% CI 8.9-12.2) months, HR 1.18 (95% CI 0.79-1.74), P = 0.4]. Patients who underwent R0 resection (n = 36) achieved a better median OS [53.9 (95% CI 35.9-71.9) months] than those who did not [21.9 (95% CI 17.1-26.7) months, P < 0.001]. The median disease-free survival for R0 resected patients was 9.9 (95% CI 5.8-14.0) months, and the 5-year OS rate was 46.2% (95% CI 29.5% to 62.9%).

CONCLUSIONS

This study confirms a favourable long-term survival for patients with initially sub-optimal or unresectable colorectal liver metastases who respond to conversion therapy and undergo secondary resection. Both FOLFOX/FOLFIRI plus cetuximab, appear to be appropriate regimens for 'conversion' treatment in patients with K-RAS codon 12/13/61 wild-type tumours. Thus, liver surgery can be considered curative or alternatively as an additional 'line of therapy' in those patients who are not cured.

CLINICAL TRIAL NUMBER

NCT00153998, www.clinicaltrials.gov.

A phase II open-label randomized multicenter trial of TSU-68 in combination with S-1 and oxaliplatin versus S-1 in combination with oxaliplatin in patients with metastatic colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the fourth leading cause of cancer-related deaths worldwide. The combination of oxaliplatin-based treatments (oxaliplatin plus infusional 5-fluorouracil and leucovorin [FOLFOX] or oxaliplatin plus capecitabine [CapeOX]) and bevacizumab is a standard chemotherapy regimen for metastatic CRC (mCRC). However, several clinical studies that tested S-1 plus oxaliplatin (SOX) indicate that SOX is also a treatment option for mCRC. TSU-68 is an oral compound that inhibits vascular endothelial growth factor receptor and platelet-derived growth factor receptor. The recommended dose of TSU-68 + SOX was previously determined in a phase I study of mCRC patients. The goal of this trial was to evaluate the efficacy of TSU-68 in combination with SOX.

METHODS

This open-label multicenter randomized phase II trial was performed in Korea. Treatment-naive mCRC patients with a performance status of 0 or 1 were randomized in a 1:1 ratio to receive either TSU-68 + SOX or SOX alone. The primary endpoint was progression-free survival (PFS).

RESULTS

A total of 105 patients (TSU-68 + SOX, 52 patients; SOX alone, 53 patients) were randomized. The median PFS was 7.0 months in the TSU-68 + SOX group (hazard ratio [HR], 1.057) and 7.2 months in the SOX group (p = 0.8401). The most frequent grade 3 and 4 adverse events were thrombocytopenia (9.6 % [TSU-68 + SOX] vs. 26.4 % [SOX]), neutropenia (13.5 % [TSU-68 + SOX] vs. 15.1 % [SOX]), and anemia (3.8 % [TSU-68 + SOX] vs. 13.2 % [SOX]). We observed a difference between the 2 groups for all grades of anemia (15.4 % [TSU-68 + SOX] vs. 32.1 % [SOX]), diarrhea (30.8 % [TSU-68 + SOX] vs. 47.2 % [SOX]), vomiting (50.0 % [TSU-68 + SOX] vs. 26.4 % [SOX]), and chromaturia (23.1 % [TSU-68 + SOX] vs. 0.0 % [SOX]). Analysis using a Cox proportional hazard model showed that baseline interleukin 6 (IL-6) levels were associated with a survival benefit of TSU-68 (p = 0.012).

CONCLUSION

TSU-68 + SOX had a favorable safety profile. However, TSU-68 did not have a synergistic effect on the efficacy of SOX. The baseline serum IL-6 level could be a prognostic factor for TSU-68 efficacy.

Can we accurately report PTEN status in advanced colorectal cancer?

BACKGROUND

Loss of phosphatase and tensin homologue (PTEN) function evaluated by loss of PTEN protein expression on immunohistochemistry (IHC) has been reported as both prognostic in metastatic colorectal cancer and predictive of response to anti-EGFR monoclonal antibodies although results remain uncertain. Difficulties in the methodological assessment of PTEN are likely to be a major contributor to recent conflicting results.

METHODS

We assessed loss of PTEN function in 51 colorectal cancer specimens using Taqman® copy number variation (CNV) and IHC. Two blinded pathologists performed independent IHC assessment on each specimen and inter-observer variability of IHC assessment and concordance of IHC versus Taqman® CNV was assessed.

RESULTS

Concordance between pathologists (PTEN loss vs no loss) on IHC assessment was 37/51 (73%). In specimens with concordant IHC assessment, concordance between IHC and Taqman® copy number in PTEN loss assessment was 25/37 (68%).

CONCLUSION

Assessment PTEN loss in colorectal cancer is limited by the inter-observer variability of IHC, and discordance of CNV with loss of protein expression. An understanding of the genetic mechanisms of PTEN loss and implementation of improved and standardized methodologies of PTEN assessment are required to clarify the role of PTEN as a biomarker in colorectal cancer.

Safety and efficacy of addition of VEGFR and EGFR-family oral small-molecule tyrosine kinase inhibitors to cytotoxic chemotherapy in solid cancers: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The approach of combining cytotoxic chemotherapy with oral small molecule tyrosine kinase inhibitors (TKIs) has been explored in a large number of randomized trials, in a variety of tumor. We performed a systematic review and meta-analysis to evaluate the safety and efficacy of this therapeutic approach.

PATIENTS AND METHODS

PubMed and the ASCO databases were searched up to March 2013. We included randomized trials in which the FDA approved vascular endothelial growth factor receptor (VEGFR) or epidermal growth factor receptor-family (EGFR)-targeted TKI in combination with chemotherapy was compared with chemotherapy alone in patients with any type of solid cancer. The endpoints included safety [fatal adverse events (FAEs), treatment discontinuation, any severe (grade 3 or 4) adverse events (AEs), and individual severe AEs] and efficacy [progression-free survival (PFS), and overall survival (OS)]. The pooled relative risk (RR) or hazard ratio (HR) were calculated.

RESULTS

A total of 16,011 patients from 43 trials were included. Compared with chemotherapy alone, the addition of a TKI significantly increased the risk of FAEs (RR, 1.63; 95% CI, 1.32-2.01), treatment discontinuation (RR, 1.80; 95% CI, 1.58-2.06), and any severe AE (RR, 1.25; 95% CI, 1.16-1.36). The addition of a TKI was associated with a significant improvement in PFS (HR, 0.82; 95% CI, 0.76-0.89), but not OS (HR, 0.99; 95% CI, 0.95-1.03).

CONCLUSIONS

It is important for physicians to weigh the risk of toxicity versus the modest PFS benefit associated with chemotherapy plus TKI in patients with solid cancers.

A prospective observational study to examine the relationship between quality of life and adverse events of first-line chemotherapy plus cetuximab in patients with KRAS wild-type unresectable metastatic colorectal cancer: QUACK Trial

We have planned a multicentre prospective study to examine the relative impact of the efficacy and adverse events of cetuximab plus first-line chemotherapy on the quality of life in Japanese patients with KRAS wild-type unresectable colorectal cancer. The Dermatology Life Quality Index and the European Organization for Research Treatment of Cancer Quality of Life Questionnaire Core 30 will be used to assess dermatology-specific and health-related quality of life. The severity of adverse events will be assessed by using the National Cancer Institute Common Terminology Criteria for adverse Events ver. 4.0. The endpoints will be the following associations: adverse events, including skin toxicity and quality of life; efficacy and skin toxicity; efficacy and quality of life; and skin-related quality of life and health-related quality of life. A total of 140 patients are considered to be appropriate for inclusion in this study. The results of this study will provide more information to both patients and physicians regarding the practical use of cetuximab and its impact on quality of life in patients with unresectable colorectal cancer in Japan. This study was registered at the University Hospital Medical Information Network Clinical Trial Registry as UMIN000010985.

KRAS mutations: analytical considerations

Colorectal cancer (CRC) is the third most common cancer and the second most common cause of cancer death globally. Significant improvements in survival have been made in patients with metastasis by new therapies. For example, Cetuximab and Panitumumab are monoclonal antibodies that inhibit the epidermal growth receptor (EGFR). KRAS mutations in codon 12 and 13 are the recognized biomarkers that are analyzed in clinics before the administration of anti-EGFR therapy. Genetic analyses have revealed that mutations in KRAS predict a lack of response to Panitumumab and Cetuximab in patients with metastatic CRC (mCRC). Notably, it is estimated that 35-45% of CRC patients harbor KRAS mutations. Therefore, KRAS mutation testing should be performed in all individuals with the advanced CRC in order to identify the patients who will not respond to the monoclonal EGFR antibody inhibitors. New techniques for KRAS testing have arisen rapidly, and each technique has advantages and disadvantages. Herein, we review the latest published literature specific to KRAS mutation testing techniques. Since reliability and feasibility are important issues in clinical analyses. Therefore, this review also summarizes the effectiveness and limitations of numerous KRAS mutation testing techniques.

High-sensitivity PCR method for detecting BRAF V600E mutations in metastatic colorectal cancer using LNA/DNA chimeras to block wild-type alleles

The response to epidermal growth factor receptor (EGFR)-targeted therapy in metastatic colorectal cancer (mCRC) is variable because of intra-tumor heterogeneity at the genetic level, and consequently, it is important to develop sensitive and selective assays to predict patient responses to therapy. Low-abundance BRAF V600E mutations are associated with poor response to treatment with EGFR inhibitors. We developed a method for the detection of BRAF V600E mutations in mCRC using real-time wild-type blocking PCR (WTB-PCR), in which a chimera composed of locked nucleic acids and DNA is incorporated to amplify the mutant allele at high efficiency while simultaneously inhibiting the amplification of wild-type alleles. Mixing experiments showed that this method is exquisitely sensitive, with detection of the mutated allele at a mutant/wild-type ratio of 1:10,000. To demonstrate the applicability of this approach for mCRC patients, we assessed the V600E mutations in 50 clinical cases of mCRC by real-time WTB-PCR. The percentage of patients with V600E mutation as determined by WTB-PCR (16%, 8/50) was higher than by traditional PCR (10%, 5/50), suggesting an increased sensitivity for WTB-PCR. By calculating the ΔC q for real-time traditional PCR, which amplifies all BRAF alleles, versus WTB-PCR, which selectively amplifies mutant BRAF, we demonstrated that among the V600E-positive mCRC patient samples, the percentage of BRAF DNA with the V600E mutation ranged from 0.05 to 52.32%. In conclusion, WTB-PCR provides a rapid, simple, and low-cost method to detect trace amounts of mutated BRAF V600E gene.

Options for metastatic colorectal cancer beyond the second line of treatment

Colorectal cancer is the third most common cancer, with recent advances in the management of unresectable metastatic lesions. The aim of this review is to discuss the remaining options for heavily pretreated patients with unresectable metastatic colorectal cancer. Beyond second-line treatment, two epidermal growth factor receptor (EGFR) inhibitors, cetuximab and panitumumab, have a demonstrated clinical interest in patients with KRAS wild-type tumours. However, few data exist in patients pretreated with an anti-EFGR and who are being rechallenged with anti-EGFR drugs. Reintroduction of chemotherapy should be considered. In September 2012, regorafenib, a multi-kinase inhibitor was approved by the US Federal Drug Administration for patients refractory to other standard treatments. In the case of metastases limited to the liver, transarterial chemoembolization, hepatic artery infusion and radioembolization could also be discussed in selected patients. With the multiplication of therapeutic options in first-line, second-line treatment, and beyond, the concept of subsequent lines of chemotherapy should be replaced by a multiline strategy, dependent on the patient and on tumour biology. A better understanding of the tumour biology and predictive factors for the response to these therapies is needed, and further strategic trials are urgently warranted.

Perfusion CT imaging of colorectal cancer

Imaging plays an important role in the assessment of colorectal cancer, including diagnosis, staging, selection of treatment, assessment of treatment response, surveillance and investigation of suspected disease relapse. Anatomical imaging remains the mainstay for size measurement and structural evaluation; however, functional imaging techniques may provide additional insights into the tumour microenvironment. With dynamic contrast-enhanced CT techniques, iodinated contrast agent kinetics may inform on regional tumour perfusion, shunting and microvascular function and provide a surrogate measure of tumour hypoxia and angiogenesis. In colorectal cancer, this may be relevant for clinical practice in terms of tumour phenotyping, prognostication, selection of individualized treatment and therapy response assessment.

Predictive and prognostic biomarkers with therapeutic targets in breast, colorectal, and non-small cell lung cancers: a systemic review of current development, evidence, and recommendation

Appropriate evidence-based roles of prognostic and predictive biomarkers of known therapeutic targets in breast, colorectal, and non-small cell lung cancers in adults are reviewed, with summary of evidence for use and recommendation. Current development in biomarker studies is also discussed. Computerized literature searches of PubMed (National Library of Medicine), the Cochrane Collaboration Library, and commonly accepted US and international guidelines (American Society of Clinical Oncology, European Society for Medical Oncology, and National Comprehensive Cancer Network) were performed from 2001 to 2012. Literature published before 2001 was noted for historical interest but not evaluated. Literature review was focused on available systematic reviews and meta-analyses of published predictive (associated with treatment response and/or efficacy) and prognostic (associated with disease outcome) biomarkers of known therapeutic targets in colorectal, breast, and non-small cell lung cancers. In general, significant health outcomes (e.g. predicted response to therapy, overall survival, disease-free survival, quality of life, lesser toxicity, and cost-effectiveness) were used for making recommendations. Four breast cancer biomarkers were evaluated, two of which (2D6 genotyping, Oncotype Dx) were considered emerging with insufficient evidence. Seven colorectal cancer biomarkers were evaluated, five of which (EGFR gene expression, K-ras G13D gene mutation, B-raf V600E gene mutation, dihydropyrimidine dehydrogenase deficiency, and UGT1A1 genotyping) were considered emerging. Seven non-small cell lung cancer biomarkers were evaluated, five of which were emerging (EGFR gene expression, ERCC gene expression, RRM1 gene expression, K-ras gene mutation, and TS gene expression). Of all 18 biomarkers evaluated, the following showed evidence of clinical utility and were recommended for routine use in practice: ER/PR and HER2 for breast cancer; K-ras gene mutation (except G13D gene mutation) for colorectal cancer; mismatch repair deficiency or microsatellite instability for colorectal cancer; and EGFR and EML4-ALK gene mutations for non-small cell lung. Not all recommendations for these biomarkers were uniformly supported by all guidelines.

Economic outcomes of sequences which include monoclonal antibodies against vascular endothelial growth factor and/or epidermal growth factor receptor for the treatment of unresectable metastatic colorectal cancer

BACKGROUND

Patients with unresectable, metastatic colorectal cancer with wild type Kirsten ras mutational status are eligible for sequential treatments which include monoclonal antibodies as first line (1L), second line (2L), or third line (3L) regimens.

OBJECTIVE

To compare the economic outcomes of different sequences which include monoclonal antibodies for the treatment of unresectable metastatic colorectal cancer.

METHODS

Individual drug regimens for 1L, 2L, and 3L treatments were compiled according to the clinical studies in the Summary of Product Characteristics for monoclonal antibodies. They were combined into plausible treatment sequences. Health outcomes were approximated using additive median PFS benefit, and economic outcomes were calculated with a treatment sequencing costing tool. Limitations of the analysis include the clinical trial data sources, cost assumptions, and the additive PFS approach.

RESULTS

Seventeen sequences were evaluated. Results of the analysis show that sequences including 1L anti-EGFRs generally have relatively low-to-medium health outcomes at the highest comparative sequence costs compared to sequences including 2L anti-EGFRs, which have lower health outcomes at the lowest cost. Sequences including 3L anti-EGFRs (sequential bevazicumab-based 1L and 2L) have the highest health outcomes, with potential cost savings of €5972-€11,676 if replacing 2L anti-EGFRs or an additional cost of €5909-€12,708 if replacing 1L anti-EGFR regimens.

CONCLUSION

Clinical sequences consisting of 1L and 2L line bevacizumab followed by 3L anti-EGFR potentially yield the greatest health outcomes associated with a reasonable trade-off in additional cost when replacing 1L anti-EGFRs and are potentially cost-saving if replacing 2L anti-EGFRs, per patient per lifetime. To maximize health outcomes, optimal sequences include anti-EGFRs as 3L regimen, with an approximately equivalent trade-off in costs between the most costly (anti-EGFR 2L) and least costly (anti-EGFR 1L) sequences.

Molecular profiling in colorectal cancer: current state of play and future directions

SUMMARY In the era of molecular scientific discovery, there is a continuing gap between our growing scientific knowledge and its utility at the bedside. This phenomenon probably occurs more frequently in colorectal cancer than in other cancer streams, with thousands of scientific studies having produced only a handful of molecular interventions. This review examines our current practices of molecular profiling in colorectal cancer and the scientific research that may impact on this area in the future.

Figitumumab in patients with refractory metastatic colorectal cancer previously treated with standard therapies: a nonrandomized, open-label, phase II trial

PURPOSE

Figitumumab (CP-751,871) is a human IgG2 monoclonal antibody that binds and down-regulates insulin-like growth factor receptor-1 (IGF-1R) and inhibits activation of this receptor by IGF-1 and IGF-2. This nonrandomized, open-label, single-arm, phase II trial evaluated the antitumor activity and safety of figitumumab in patients with metastatic colorectal cancer that was refractory to ≥2 systemic therapies.

METHODS

Cohorts A and B received intravenous figitumumab 20 and 30 mg/kg in 3-week cycles, respectively. Both received loading doses (20 or 30 mg/kg) on days 1 and 2 of cycle 1. The primary endpoint was 6-month survival (null hypothesis for each cohort, H0: p6 mo surv = 0.45). Secondary endpoints included progression-free survival (PFS), overall survival (OS), objective response, safety, and pharmacokinetics.

RESULTS

A total of 168 patients (Cohort A, n = 85; Cohort B, n = 83) received figitumumab. Estimated 6-month survival was 49.4 % (95 % CI 38.8-60.0) in Cohort A and 44.1 % (95 % CI 33.4-54.9) in Cohort B. Median OS was 5.8 and 5.6 months, respectively; median PFS was 1.4 months in both cohorts. No objective partial or complete responses occurred. The respective rates of treatment discontinuation due to treatment-related adverse events (AEs) were 5 and 7 %. The most common grade 3/4 nonhematologic AEs in both cohorts were hyperglycemia and asthenia. No grade 4 hematologic laboratory abnormalities occurred. Most deaths were reported as due to progressive disease; none were due to figitumumab.

CONCLUSION

Six-month survival data do not support further study of figitumumab 20 or 30 mg/kg in this patient population.

Predictive biomarker candidates for the response of gastric cancer to targeted and cytotoxic agents

Gastric cancer is the second most common cause of cancer death worldwide. Recent development of targeted agents provides clinicians with additional systemic treatment options to conventional cytotoxic agents. Predictive markers are undoubtedly important for guiding the appropriate use of targeted and cytotoxic agents. Currently, however, HER2 is the only predictive biomarker validated for gastric cancer. In this review, candidate predictive markers for response to other targeted agents and cytotoxic chemotherapeutic agents are discussed.

Impact of cetuximab in current treatment of metastatic colorectal cancer

INTRODUCTION

Cetuximab is a chimeric monoclonal antibody targeting the EGFR, which has proven effective in patients with metastatic colorectal cancer (mCRC), wild-type Kirsten rat sarcoma viral oncogene homolog (KRAS).

AREAS COVERED

The aim of this manuscript is to discuss the current impact of cetuximab in the most important scenarios of mCRC. We review the currently available data regarding the role of other biomarkers, such as the mutational status of neuroblastoma RAS viral (v-ras) oncogene homolog in identifying patients who could benefit most from anti-EGFR. In addition, a review is included of the most relevant clinical trials that have assessed the effectiveness of cetuximab in the management of patients with potentially resectable metastatic disease and in the first-line treatment of wild-type KRAS mCRC, as well as the impact of this anti-EGFR agent on patient quality of life.

EXPERT OPINION

Cetuximab has had a progressive clinical development from the earliest to the later stages of the evolution of mCRC and has been consolidated as a therapeutic option for all scenarios of unresectable disease. Patient selection by analysis of KRAS mutations has been a fundamental event to increase efficiency, being a dynamic process that continues in assessment. There are few comparative data with other biological agents in combination with chemotherapy, although data from a recent study are promising.

Genetic and epigenetic biomarkers for diagnosis, prognosis and treatment of colorectal cancer

Colorectal cancer (CRC) is one of the most common cancer worldwide and results from the accumulation of mutations and epimutations in colonic mucosa cells ultimately leading to cell proliferation and metastasis. Unfortunately, CRC prognosis is still poor and the search of novel diagnostic and prognostic biomarkers is highly desired to prevent CRC-related deaths. The present article aims to summarize the most recent findings concerning the use of either genetic or epigenetic (mainly related to DNA methylation) biomarkers for CRC diagnosis, prognosis, and response to treatment. Recent large-scale DNA methylation studies suggest that CRC can be divided into several subtypes according to the frequency of DNA methylation and those of mutations in key CRC genes, and that this is reflected by different prognostic outcomes. Increasing evidence suggests that the analysis of DNA methylation in blood or fecal specimens could represent a valuable non-invasive diagnostic tool for CRC. Moreover, a broad spectrum of studies indicates that the inter-individual response to chemotherapeutic treatments depends on both epigenetic modifications and genetic mutations occurring in colorectal cancer cells, thereby opening the way for a personalized medicine. Overall, combining genetic and epigenetic data might represent the most promising tool for a proper diagnostic, prognostic and therapeutic approach.

How to select the optimal treatment for first line metastatic colorectal cancer

Choice of first line treatment for patients with metastatic colorectal cancer (mCRC) is based on tumour and patient related factors and molecular information for determination of individual treatment aim and thus treatment intensity. Recent advances (e.g., extended RAS testing) enable tailored patient assignment to the most beneficial treatment approach. Besides fluoropyrimidines, irinotecan and oxaliplatin, a broad variety of molecular targeting agents are currently available, e.g., anti-angiogenic agents (bevacizumab) and epidermal growth factor receptor (EGFR) antibodies (cetuximab, panitumumab) for first line treatment of mCRC. Although some combinations should be avoided (e.g., oral or bolus fluoropyrimidines, oxaliplatin and EGFR antibodies), treatment options range from single agent to highly effective four-drug regimen. Preliminary data comparing EGFR antibodies and bevacizumab, both with chemotherapy, seem to favour EGFR antibodies in RAS wildtype disease. However, choosing the most appropriate treatment approach for mCRC patients remains a complex issue, with numerous open questions.

Seeing the forest through the trees: a systematic review of the safety and efficacy of combination chemotherapies used in the treatment of metastatic colorectal cancer

Combinations of fluoropyrimidines with oxaliplatin or irinotecan plus a biologic agent are standard treatments for metastatic colorectal cancer (mCRC). Recent approvals of first-line cetuximab, second-line ziv-aflibercept, and regorafenib as salvage therapy have increased the complexity of the treatment armamentarium. To define optimal regimens, we systematically reviewed combination chemotherapy trials (N=83). Descriptive analyses focusing on fluoropyrimidine formulation, oxaliplatin vs irinotecan combinations, and compatibility with biologics indicated the following: infusional 5-fluorouracil (5-FU) yielded better efficacy and safety than bolus 5-FU. Capecitabine had similar outcomes and better safety than 5-FU with oxaliplatin but not irinotecan. First-line oxaliplatin and irinotecan appeared equivalent. Antiangiogenics, such as bevacizumab and ziv-aflibercept, and epidermal growth factor receptor-targeted monoclonal antibodies cetuximab and panitumumab further improved efficacy. The treatment landscape for mCRC has become complex, and we are approaching individualized therapy based on predictive factors, including KRAS mutational status. Appropriate administration of chemotherapy/biologic combinations is critical.

Sorafenib and irinotecan (NEXIRI) as second- or later-line treatment for patients with metastatic colorectal cancer and KRAS-mutated tumours: a multicentre Phase I/II trial

Background:

This trial evaluated the feasibility and efficacy of combined sorafenib and irinotecan (NEXIRI) as second- or later-line treatment of patients with KRAS-mutated metastatic colorectal cancer (mCRC), who had progressed after irinotecan-based chemotherapy.

Methods:

In Phase I, in a 3+3 dose escalation schedule, patients received irinotecan (125, 150 or 180 mg m⁻² every 2 weeks), in combination with 400 mg sorafenib b.d. The primary end point was the maximum-tolerated dose of irinotecan. In Phase II, the primary end point was disease control rate (DCR). Secondary end points were progression-free survival (PFS), overall survival (OS) and toxicity.

Results:

Phase I included 10 patients (median age 63 (49–73)); no dose-limiting toxicity was seen. In Phase II, 54 patients (median age 60 (43–80) years) received irinotecan 180 mg m⁻² every 2 weeks with sorafenib 400 mg b.d. Nine patients (17%) remained on full-dose sorafenib. The DCR was 64.9% (95% CI, 51–77). Median PFS and OS were 3.7 (95% CI, 3.2–4.7) and 8.0 (95% CI, 4.8–9.7) months, respectively. Toxicities included Grade 3 diarrhoea (37%), neutropenia (18%), hand-foot syndrome (13%) and Grade 4 neutropenia (17%).

Conclusion:

The NEXIRI regimen showed promising activity as second- or later-line treatment in this heavily pretreated mCRC population (ClinicalTrials.gov NCT00989469).

New developments in the second-line treatment of metastatic colorectal cancer: potential place in therapy

In this review article we discuss the evolution of second-line treatment options for patients with metastatic colorectal cancer (mCRC). The benefits of second-line chemotherapy have been established for some time, but in the last decade a number of trials have evaluated combinations of irinotecan- and oxaliplatin-based chemotherapy with molecular-targeted agents; e.g., vascular endothelial growth factor (VEGF)-targeting agents (bevacizumab, aflibercept), epidermal growth factor receptor antibodies (cetuximab, panitumumab), and tyrosine kinase inhibitors (vatalanib). Recent developments include the availability of the new VEGF-targeted agent aflibercept and the new concept of continuing bevacizumab after failure of first-line bevacizumab, which is likely to become a new treatment option in the second-line setting. Choosing the most appropriate second-line treatment regimen for mCRC patients remains a complex issue. All of the currently available molecular-targeted agents seem to be active even after patients have received a bevacizumab-based first-line regimen. Overall, the selection of second-line treatment for mCRC depends on several variables and should be determined taking into account the patient's performance and disease status.

Future directions for monitoring treatment response in colorectal cancer

Treatment of advanced colon and rectal cancer has significantly evolved with the introduction of neoadjuvant chemoradiation therapy so much that, along with more effective chemotherapy regimens, surgery has been considered unnecessary among some institutions for select patients. The tumor response to these treatments has also improved and ultimately has been shown to have a direct effect on prognosis. Yet, the best way to monitor that response, whether clinically, radiologically, or with laboratory findings, remains controversial. The authors' aim is to briefly review the options available and, more importantly, examine emerging and future options to assist in monitoring treatment response in cases of locally advanced rectal cancer and metastatic colon cancer.

Effect of BRAF V600E mutation on tumor response of anti-EGFR monoclonal antibodies for first-line metastatic colorectal cancer treatment: a meta-analysis of randomized studies

Anti-EGFR monoclonal antibodies (anti-EGFR MoAbs) in metastatic colorectal cancer (mCRC) treatment are still not effective in all patients. This study aimed to evaluate the relationship between BRAF V600E mutation and the tumor response of anti-EGFR MoAbs for first-line treatment in mCRC patients. We searched the MEDLINE and EMBASE databases, using the key words that included colorectal cancer, cetuximab, panitumumab, and BRAF mutation and retrieved 445 articles. Among them four were included in the systematic review. Relative risks (RRs) with 95% confidence intervals (CI) for response rate were calculated. BRAF mutation carriers had worse ORR than non-carriers in mCRC patients with KRAS wild-type in first-line treatment whether adding anti-EGFR MoAb to chemotherapy or not (RR = 0.43, [95% CI 0.16-0.75]; RR = 0.38, [95% CI 0.20-0.73]). But in the unselected patients whose KRAS mutation were unknown, BRAF mutation carriers had similar ORR whether adding cetuximab to chemotherapy or not (RR = 0.45, [95% CI 0.18-1.09]; RR = 0.57, [95% CI 0.15-2.23]). In BRAF mutation carriers adding anti-EGFR MoAb to chemotherapy was similar to chemotherapy alone whether in patients with wild-type KRAS or unselected patients (RR = 1.61, [95% CI 0.57-4.47]; RR = 0.71, [95% CI 0.18-2.77]). But in the BRAF mutation non-carriers, adding anti-EGFR MoAb produced a clear benefit in response rate than chemotherapy alone and this advantage was restricted to KRAS wild-type patients (RR = 1.48, [95% CI 1.28-1.71]). BRAF mutation decreases tumor response in first-line treatment whether cetuximab was given or not in patients with KRAS wild-type, and anti-EGFR MoAb produces a clear benefit in response rate in patients with BRAF and KRAS wild-type.

Stratified phase II trial to establish the usefulness of the collagen gel droplet embedded culture-drug sensitivity test (CD-DST) for advanced gastric cancer

BACKGROUND

We conducted a multicenter phase II trial to assess the suitability of three types of chemotherapy (docetaxel plus S-1, irinotecan plus S-1, or S-1 alone) for patients with advanced gastric cancer by means of the collagen gel droplet embedded culture-drug sensitivity test (CD-DST). To our knowledge, this is the first multicenter clinical trial that has employed CD-DST to choose anticancer agents for the treatment of advanced gastric cancer.

METHODS

Subjects (n = 64) were patients with advanced or recurrent gastric cancer. Patients were allocated to one of the treatment regimens on the basis of CD-DST results. Outcome of the patients was compared between the groups deemed chemosensitive or chemoresistant by the CD-DST.

RESULTS

Thirty-three patients showed high sensitivity (T/C ratio <60 %) to at least one type of anticancer agent (sensitive group), and 31 showed low sensitivity (T/C ratio ≥60 %) to all agents (resistant group). Specifically, the 1-year survival rate was significantly higher in the sensitive group (78.5 %; 95 % CI, 67.2-94.7 %) than in the resistant group (54.7 %; 95 % CI, 38.7-74.3 %; P = 0.019), whereas time to progression (TTP) was significantly longer in the sensitive group (59.8 %; 95 % CI, 48.2-81.7 %) than in the resistant group (30.0 %; 95 % CI 13.6-46.4 %; P = 0.023). Median survival time was also significantly longer in the sensitive group (15.5 months; 95 % CI, 12.8-18.2) than in the resistant group (12.5 months; 95 % CI, 10.2-14.9; P = 0.038).

CONCLUSIONS

CD-DST predicts the outcome of patients undergoing chemotherapy for advanced gastric cancer, presumably through evaluating chemosensitivity.

Panitumumab in the management of patients with KRAS wild-type metastatic colorectal cancer

The past 15 years has seen a marked increase in available therapeutic options for patients with metastatic colorectal cancer resulting in improvements in median survival from 12 to 24 months. One of these new options is panitumumab, which is a fully humanized monoclonal antibody that binds to the epidermal growth factor receptor of tumor cells and inhibits downstream cell signaling with antitumor effects of inhibition of tumor growth, induction of apoptosis and inhibition of angiogenesis. Large randomized clinical trials have demonstrated significant improvements in tumor response rates and progression-free survival when panitumumab is combined with chemotherapy and as monotherapy in chemorefractory metastatic colorectal cancer. Clinical benefit with panitumumab is limited to patients with nonmutated KRAS tumors. Rash is a common toxicity of panitumumab treatment but can potentially be ameliorated with the use of prophylactic strategies. The role of panitumumab in the overall treatment of metastatic colorectal cancer is evolving and future clinical trials will focus on improved patient selection through use of novel predictive biomarkers, and the optimal timing of treatment.

Modeling RAS phenotype in colorectal cancer uncovers novel molecular traits of RAS dependency and improves prediction of response to targeted agents in patients

PURPOSE

KRAS wild-type status is an imperfect predictor of sensitivity to anti-EGF receptor (EGFR) monoclonal antibodies in colorectal cancer, motivating efforts to identify novel molecular aberrations driving RAS. This study aimed to build a quantitative readout of RAS pathway activity to (i) uncover molecular surrogates of RAS activity specific to colorectal cancer, (ii) improve the prediction of cetuximab response in patients, and (iii) suggest new treatment strategies.

EXPERIMENTAL DESIGN

A model of RAS pathway activity was trained in a large colorectal cancer dataset and validated in three independent colorectal cancer patient datasets. Novel molecular traits were inferred from The Cancer Genome Atlas colorectal cancer data. The ability of the RAS model to predict resistance to cetuximab was tested in mouse xenografts and three independent patient cohorts. Drug sensitivity correlations between our model and large cell line compendiums were performed.

RESULTS

The performance of the RAS model was remarkably robust across three validation datasets. (i) Our model confirmed the heterogeneity of the RAS phenotype in KRAS wild-type patients, and suggests novel molecular traits driving its phenotype (e.g., MED12 loss, FBXW7 mutation, MAP2K4 mutation). (ii) It improved the prediction of response and progression-free survival (HR, 2.0; P < 0.01) to cetuximab compared with KRAS mutation (xenograft and patient cohorts). (iii) Our model consistently predicted sensitivity to MAP-ERK kinase (MEK) inhibitors (P < 0.01) in two cell panel screens.

CONCLUSIONS

Modeling the RAS phenotype in colorectal cancer allows for the robust interrogation of RAS pathway activity across cell lines, xenografts, and patient cohorts. It demonstrates clinical utility in predicting response to anti-EGFR agents and MEK inhibitors.

Management of colorectal cancer

Colorectal cancer is one of the most frequent solid tumors in the Western world. Treatment options are dependent on the stage of the disease, the performance status of the patient, and increasingly the molecular makeup of the tumor. In countries with surveillance programs, the incidence rate as well as the mortality rate has gone down because of the earlier stages at which the tumors are detected. For rectal cancer, standard of care differs from that of colon cancer with regard to perioperative treatment. In the metastatic setting, treatment options are uniform for colorectal cancer. Over the years, treatment options have emerged from single-agent 5-fluorouracil (5-FU) treatment to combination regimens using 5-FU and oxaliplatin or irinotecan or both. Treatment efficacy in the metastatic setting has been increased with the introduction of targeted substances. These include (a) the anti-vascular endothelial growth factor-A (anti-VEGF-A) antibody bevacizumab, (b) the anti-epidermal growth factor receptor (anti-EGFR) antibodies cetuximab and panitumumab, (c) the anti-angiogenic multi-kinase inhibitor regorafenib, and (d) the anti-angiogenic compound aflibercept. Anti-EGFR antibodies have shown efficacy only in the subpopulations of tumors that do not have any mutation in KRAS and NRAS exon 2, 3, 4. Physicians have the choice in the first line to use anti-EGFR or anti-VEGF inhibitors in combination with chemotherapy based on treatment goals and patient performance. In recent years, tumor location has been shown to be prognostic and predictive for clinical outcome. Right-sided sporadic colon cancers differ significantly in molecular characteristics and, with the exception of microsatellite instability (MSI-H) tumors, are associated with poor prognosis. Tumors based on hereditary non-polyposis colorectal cancer, on the other hand, have excellent prognosis in stage II and III disease. Recent efforts have focused on the molecular classification of colorectal cancer with the purpose of establishing molecularly defined subgroups.

Comparison of FOLFIRI with or without cetuximab in patients with resected stage III colon cancer; NCCTG (Alliance) intergroup trial N0147

BACKGROUND

Two arms with FOLFIRI, with or without cetuximab, were initially included in the randomized phase III intergroup clinical trial NCCTG (North Central Cancer Treatment Group) N0147. When other contemporary trials demonstrated no benefit to using irinotecan as adjuvant therapy, the FOLFIRI-containing arms were discontinued. We report the clinical outcomes for patients randomized to FOLFIRI with or without cetuximab.

PATIENTS AND METHODS

After resection, patients were randomized to 12 biweekly cycles of FOLFIRI, with or without cetuximab. KRAS (Kirsten rat sarcoma viral oncogene homolog) mutation status was retrospectively determined in a central lab. The primary end point was disease-free survival (DFS). Secondary end points included overall survival (OS) and toxicity.

RESULTS

One hundred and six patients received FOLFIRI and 40 received FOLFIRI plus cetuximab. Median follow-up was 5.95 years (range, 0.1-7.0 years). The addition of cetuximab showed a trend toward improved DFS (hazard ratio [HR], 0.53; 95% CI, 0.26-1.1; P = .09) and OS (HR, 0.45; 95% CI, 0.17-1.16; P = .10) in the overall group, regardless of KRAS status, and in patients with wild type KRAS. Grade ≥ 3 nonhematologic adverse effects were significantly increased in the cetuximab versus FOLFIRI-alone arm (68% vs. 46%; P = .02). Adjuvant FOLFIRI resulted in a 3-year DFS less than that expected for FOLFOX.

CONCLUSION

In this small randomized subset of patients with resected stage III colon cancer, the addition of cetuximab to FOLFIRI was associated with a nonsignificant trend toward improved DFS and OS. Nevertheless, considering the limitations of this analysis, FOLFOX without the addition of a biologic agent remains the standard of care for adjuvant therapy in resected stage III colon cancer.

[Targeted therapies, prognostic and predictive factors in endocrine oncology]

A better understanding of molecular mechanisms responsible for tumorigenesis has allowed the development of targeted drugs designed to improve the outcome of cancer. In endocrine tumors, several molecules have demonstrated efficacy in terms of progression free survival during phase III trials such as vandetanib and cabozantinib in medullary thyroid carcinoma, sorafenib in differentiated thyroid carcinoma and everolimus or sunitinib for pancreatic neuroendocrine tumors. Rare cancer network has allowed ongoing phase III trials in malignant pheochromocytoma and adrenocortical carcinoma. However, to date no specific predictive biomarker has yet been identified for a personalized cancer medicine. We review recent advances in endocrine oncology concerning molecular targets identification, targeted therapies and predictive or prognostic markers.

BRAFV600E mutation analysis in patients with metastatic colorectal cancer (mCRC) in daily clinical practice: correlations with clinical characteristics, and its impact on patients' outcome

Background

To prospectively evaluate the usefulness of the BRAFV600E mutation detection in daily clinical practice in patients with metastatic Colorectal Cancer (mCRC).

Patients and Methods

504 mCRC patients treated with systemic chemotherapy ± biologics were analyzed.

Results

A statistically significant higher incidence of the BRAF mutation was observed in patients with ECOG-PS 2 (p=0.001), multiple metastatic sites (p=0.002),> 65 years old (p=0.004), primary tumors located in the colon (p<0.001), high-grade tumors (p=0.001) and in those with mucinous features (p=0.037). Patients with BRAFV600E mutated tumors had a statistically significantly reduced progression-free survival (PFS) compared to wild-type (wt) ones (4.1 and 11.6 months, respectively; p<0.001) and overall survival (OS) (14.0 vs. 34.6 months, respectively; p<0.001). In the multivariate analysis the BRAFV600E mutation emerged as an independent factor associated with reduced PFS (HR: 4.1, 95% CI 2.7–6.2; p<0.001) and OS (HR: 5.9, 95% CI 3.7–9.5; p<0.001). Among the 273 patients treated with salvage cetuximab or panitumumab, the BRAFV600E mutation was correlated with reduced PFS (2.2 vs. 6.0 months; p<0.0001) and OS (4.3 vs. 17.4 months; p<0.0001).

Conclusions

The presence of BRAFV600E-mutation in mCRC characterizes a subgroup of patients with distinct biologic, clinical and pathological features and is associated with very poor patients’ prognosis.

Evidence-based appraisal of the upfront treatment for unresectable metastatic colorectal cancer patients

Colorectal cancer (CRC) is a significant health problem, with around 1 million new cases and 500000 deaths every year worldwide. Over the last two decades, the use of novel therapies and more complex treatment strategies have contributed to progressively increase the median survival of patients with unresectable advanced CRC up to approximately 30 mo. The availability of additional therapeutic options, however, has created new challenges and generated more complicated treatment algorithms. Moreover, several clinically important points are still in debate in first-line, such as the optimal treatment intensity, the most appropriate maintenance strategy, the preferred biologic to be used upfront in patients with KRAS wild-type CRC, and the need for more detailed information on tumor biology. In this moving landscape, this review analyses why the first-line treatment decision is crucial and how the choice may impact on further treatment lines. In addition, it focuses on results of major phase III randomized trials.