The Budget Impact of Monoclonal Antibodies Used to Treat Metastatic Colorectal Cancer in Minas Gerais, Brazil

INTRODUCTION

Biological medicines have increased the cost of cancer treatments, which also raises concerns about sustainability. In Brazil, three monoclonal antibodies (mAbs)-bevacizumab, cetuximab, and panitumumab-are indicated for the treatment of metastatic colorectal cancer (mCRC) but not currently funded by the Unified Health System (SUS). However, successful litigation has led to funding in some cases.

OBJECTIVE

Our objective was to evaluate the budgetary impact of including the mAbs bevacizumab, cetuximab, and panitumumab in standard chemotherapy for the treatment of mCRC within the SUS of Minas Gerais (MG), Brazil.

METHOD

A budget impact analysis of incorporating mAbs as first-line treatment of mCRC in MG was explored. The perspective taken was that of the Brazilian SUS, and a 5-year time horizon was applied. Data were collected from lawsuits undertaken between January 2009 and December 2016, and the model was populated with data from national databases and published sources. Costs are expressed in $US.

RESULTS

In total, 351 lawsuits resulted in funding for first-line treatment with mAbs for mCRC. The three alternative scenarios analyzed resulted in cost increases of 348-395% compared with the reference scenario. The use of panitumumab had a budgetary impact of $US103,360,980 compared with the reference scenario over a 5-year time horizon, and bevacizumab and cetuximab had budgetary impacts of $US111,334,890 and 113,772,870, respectively. The use of the anti-epidermal growth factor receptor (EGFR) mAbs (cetuximab and panitumumab) is restricted to the approximately 41% of patients with KRAS mutations, so the best cost alternative for incorporation would be the combination of panitumumab and bevacizumab, with a cost of approximately $US106 million.

CONCLUSION

These results highlight the appreciable costs for incorporating bevacizumab, cetuximab, and panitumumab into the SUS. Appreciable discounts are likely to be necessary before incorporation of these mAbs is approved.

IS THERE A DIFFERENCE BETWEEN RIGHT- VERSUS LEFT-SIDED COLON CANCERS? DOES SIDE MAKE ANY DIFFERENCE IN LONG-TERM FOLLOW-UP?

BACKGROUND

Since 1990 it was proposed that distal and proximal location of colon cancer might follow different biological, epidemiology, pathology and prognosis, probably due to embryologic different development of the two segments of the colon, which may represent two separate disease entities. These differences might have consequences for the treatment of patients with colorectal cancer.

AIM

To compare the characteristics between patients with right and left colon cancer, with severity and tumor characteristic that influence in the survival of these patients.

METHOD

Were evaluated the outcomes of surgical treatment of patients with colon cancer with data collected retrospectively from prospectively collected database.

RESULTS

The tumor's side did not influence survival time of patients with colon cancer (p=0.112) in the regression model. Only the diseases stage leads to influence on survival time; patients with right colon cancer have more advanced staging (III or IV) and present a risk of death greater in 3.23 times.

CONCLUSION

This analysis provides evidence that the prognosis of localized left-sided colon cancer is better compared to right-sided colon cancer. Also, the patients with right colon cancer have more advanced stage, mucinous tumor and are older.

Analysis of Response Evaluation Criteria in Solid Tumors reduction ratio of primary chemotherapy in unresectable advanced or recurrent colorectal cancer

Response Evaluation Criteria in Solid Tumors (RECIST) is used to assess the objective response of solid tumors to treatment. However, it remains unclear to what extent the response rate assessed by RECIST reflects a reduction of tumor size in multiple organs in patients with unresectable advanced or recurrent colorectal cancer (CRC) with multiple organ metastases. It is also unclear whether the management of liver metastases with systemic chemotherapy in CRC patients with multiple organ metastases improves their prognosis, although surgical resection has been shown to be the most effective treatment approach to CRC cases with liver metastases. A total of 38 CRC patients who underwent systemic chemotherapy in Kyushu Medical Center Hospital between January 2013 and April 2016 were examined. The patients had measurable lesions in multiple organs, including the liver, and did not undergo curative surgery for metastatic lesions after initiation of chemotherapy. The association between the total reduction ratio (TRR) of all lesions and liver lesion reduction ratio (LRR) was retrospectively analyzed. A total of 18 patients (47%) had H3 liver metastases, and the median liver lesion occupancy rate in the sum of the measured lesions with RECIST was 76%. TRR and LRR were strongly correlated, regardless of the volume of the liver metastases. Although a TRR of >30% was significantly associated with improved overall survival (OS), this improvement was not observed in patients with H3 liver metastases. TRR was correlated with LRR and was associated with a better OS. CRC patients with both multiple organ and H3 liver metastases exhibited poor survival, even with a high reduction ratio by chemotherapy.

Prognostic Value of BRAF, PI3K, PTEN, EGFR Copy Number, Amphiregulin and Epiregulin Status in Patients with KRAS Codon 12 Wild-Type Metastatic Colorectal Cancer Receiving First-Line Chemotherapy with Anti-EGFR Therapy

INTRODUCTION

Mutational analysis of RAS is required for anti-epidermal growth factor receptor (EGFR) treatment for patients with metastatic colorectal cancer (mCRC). However, most patients with KRAS wild-type tumors still do not respond. Other molecules downstream of the EGFR may also play a role in resistance to EGFR therapies.

OBJECTIVE

Our objective was to investigate the clinical importance of biomarkers in relation to response, progression-free survival, and overall survival in patients with mCRC receiving first-line treatment with anti-EGFR therapy plus chemotherapy.

METHODS

We studied the EGFR pathway [EGFR, NRAS, BRAF, PIK3CA, phosphatase and tensin homolog (PTEN), amphiregulin (AREG), and epiregulin (EREG)] in 105 patients with mCRC KRAS codon 12 wild type. We analysed objective response, progression-free survival, and overall survival in molecularly defined subgroups of the patients receiving anti-EGFR therapy plus chemotherapy as first-line treatment.

RESULTS

We found a significant association between RAS wild-type, BRAF wild-type, EREG, and AREG overexpression and response to anti-EGFR therapy (p = 0.003, p = 0.015, p = 0.05, and p = 0.009, respectively). Progression-free survival and overall survival were lower in patients with RAS (p = 0.36 and p ≤ 0.001, respectively) or BRAF (p = 0.003 and p = 0.002, respectively) mutant tumors. Patients with EREG and AREG messenger RNA (mRNA) expression had longer survival than those with low-expression tumors; progression-free survival and overall survival were significant for AREG (p = 0.001 and p = 0.05, respectively). Patients with EGFR amplification tumors responded better to treatment and had better survival rates, although this was not significant. PIK3CA and PTEN were not associated with either response or survival. The multivariate logistic regression model for response showed only BRAF as a significant predictor after adjustment for the other covariates (p = 0.04, odds ratio 8.3, 95 % confidence interval 0.81-86.0).

CONCLUSIONS

RAS, BRAF, AREG, and EREG predict for efficacy of first-line anti-EGFR therapy in patients with mCRC.

Characterization of cancer stem cells from different grades of human colorectal cancer

Colorectal cancer (CRC) is one of the most common solid tumors worldwide. Recent evidence suggests that a population of cancer cells, called cancer stem cells (CSCs), is responsible for tumor heterogeneity, invasion, metastasis, therapeutic resistance, and recurrence of CRC. The isolation and characterization of CSCs using cell surface markers have been reported previously with varying results. In this study, we investigated a panel of four putative CSC markers, CD44, CD24, CD166, and EpCAM, to define CRC-CSC. Paraffin embedded tissue samples from different grades of primary, untreated CRC were analyzed for the expression of four CSC markers CD44, CD326, CD24, and CD166, using immunohistochemistry. Flow cytometric analysis of CRC-CSC from HT29 (low grade) and HCT116 (high grade) human colorectal cancer cell lines was done. Marker-based isolation of CSC and non-CSC-bulk-tumor cells from HT29 was done using FACS, and tumor sphere assay was performed. There was a statistically significant difference (p < 0.05) in the expression of CD44, CD326, and CD166 between cases and controls. A novel cutoff distribution of CD44 and CD166 was suggested to help for better immunohistochemical analysis of CRC. Higher prevalence of CSC was seen in high-grade CRC as compared to low-grade CRC. Sorted and cultured CD44 + CD166+ cells formed tumor spheres, suggesting that these cells, having properties of self renewal and anchorage independent proliferation, were in fact CSC. Hence, CD44 and CD166 may serve as good CRC-CSC markers when used together with novel cutoff immunohistochemistry (IHC) expression levels.

Clinical outcomes for patients with liver-limited metastatic colorectal cancer: Arguing the case for specialist hepatobiliary multidisciplinary assessment

In patients with liver-limited metastatic colorectal cancer, hepatic resection can offer a significant survival benefit over systemic therapy alone. Specialist hepatobiliary multidisciplinary meetings are currently believed to provide the best forum to discuss the management for these patients. A retrospective analysis was undertaken of patients diagnosed with liver-limited metastatic colorectal cancer over 6 months within a cancer network in the United Kingdom. In addition, patients who were diagnosed but not referred to the hepatobiliary meeting were discussed within a virtual multi-disciplinary setting. Contributors were blinded and proposed management recorded. 159 newly diagnosed patients with liver-limited metastatic colorectal cancer were identified. 68 (43%) were referred at initial diagnosis and 38 (24%) referred following systemic treatment. 35 (51%) who were discussed at baseline underwent a subsequent hepatectomy or radiofrequency ablation, as did 18 (47%) patients referred after chemotherapy. Of the remaining 53 (33%) patients not referred, imaging was available for 31 (58%). Decisions regarding potential liver-directed therapy were discussed within a multi-disciplinary setting. 13 (42%) were identified as resectable or potentially resectable and 11 (36%) may have been suitable for a clinical trial. In reality, none of these 31 patients (100%) underwent surgery or ablation. Whilst the majority of patients with liver-limited metastatic colorectal cancer were referred appropriately, this study demonstrates that a significant number with potentially resectable disease are not being discussed at specialist meetings. A review of all diagnosed cases would ensure that an increased number of patients are offered hepatic resection or ablation.

Personalized treatment is better than one treatment fits all in the management of patients with mCRC: a consensus statement

The VEGF- (bevacizumab) and EGFR- (cetuximab and panitumumab) targeting monoclonal antibodies have become integral components of the first-line treatment strategies for patients with metastatic colorectal cancer (mCRC). Increasingly combination chemotherapy, with or without a targeted agent, is being used to facilitate curative liver resection and improve survival rates in patients with initially unresectable but potentially resectable mCRC. Currently, the only selective marker for the treatment of patients with mCRC is tumor RAS mutational status. BRAF status is a strong prognostic indicator. Medical and clinical oncologists from Central Asia, Russia, the Middle East, Africa and Turkey reviewed data for the use of targeted agents in the treatment of patients with mCRC and have formed recommendations for the biological of choice first-line for patients with mCRC.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Elucidating the prognostic significance of KRAS, NRAS, BRAF and PIK3CA mutations in Chinese patients with metastatic colorectal cancer

AIM

The prognostic significance of KRAS, NRAS, PIK3CA and BRAF mutations was evaluated in Chinese patients with metastatic colorectal cancer (CRC).

METHOD

Tumor samples from 183 patients were retrospectively tested for KRAS, NRAS, PIK3CA and BRAF mutations. Multivariate analysis was performed to determine the relationship between mutational status, drug response and survival.

RESULT

Over 70% of patients received two or more lines of chemotherapy, 50% had cetuximab and 18% had bevacizumab. The prevalence of KRAS, NRAS, BRAF and PIK3CA mutations was 45, 3.2, 5 and 20%, respectively. For the entire cohort, the median overall survival was 24 months (95% confidence interval [CI] = 20.4-26.4 months). Of the genes tested, only KRAS mutation was an independent prognostic factor with a multivariate hazard ratio of 1.5 (95% CI = 1.05-2.16, P = 0.03). In the subgroup of patients who received cetuximab-based therapy in the first-line setting, KRAS mutation was associated with a lack of response to chemotherapy (28% vs 66%, chi-square, P = 0.01). Patients with KRAS mutant tumors (or KRAS wild-type tumors that harbored BRAF and/or PIK3CA mutations) tended to have lower response rates to chemotherapy and/or cetuximab (P = not significant). The number of NRAS mutant cases was too small to allow any statistical analysis.

CONCLUSION

The prevalence of KRAS, NRAS, BRAF and PIK3CA mutations in this cohort is consistent with reports from non-Asian populations, and KRAS mutation has both prognostic and predictive significance in Chinese patients with metastatic CRC.

Personalized medicine approaches for colon cancer driven by genomics and systems biology: OncoTrack

The post-genomic era promises to pave the way to a personalized understanding of disease processes, with technological and analytical advances helping to solve some of the world's health challenges. Despite extraordinary progress in our understanding of cancer pathogenesis, the disease remains one of the world's major medical problems. New therapies and diagnostic procedures to guide their clinical application are urgently required. OncoTrack, a consortium between industry and academia, supported by the Innovative Medicines Initiative, signifies a new era in personalized medicine, which synthesizes current technological advances in omics techniques, systems biology approaches, and mathematical modeling. A truly personalized molecular imprint of the tumor micro-environment and subsequent diagnostic and therapeutic insight is gained, with the ultimate goal of matching the "right" patient to the "right" drug and identifying predictive biomarkers for clinical application. This comprehensive mapping of the colon cancer molecular landscape in tandem with crucial, clinical functional annotation for systems biology analysis provides unprecedented insight and predictive power for colon cancer management. Overall, we show that major biotechnological developments in tandem with changes in clinical thinking have laid the foundations for the OncoTrack approach and the future clinical application of a truly personalized approach to colon cancer theranostics.

Hsa-miR-31-3p expression is linked to progression-free survival in patients with KRAS wild-type metastatic colorectal cancer treated with anti-EGFR therapy

PURPOSE

To identify microRNAs (miRNA) that predict response to anti-EGFR antibodies in patients with wild-type KRAS metastatic colorectal cancer (mCRC).

EXPERIMENTAL DESIGN

miRNA profiling was performed in a training set of 87 patients with mCRC refractory to chemotherapy treated with anti-EGFR antibodies. This included 33 fresh-frozen (FF) and 35 formalin-fixed paraffin-embedded (FFPE) samples retrospectively collected and 19 prospectively collected FF samples. An independent validation cohort consisting of 19 FF and 26 FFPE prospectively collected samples from patients with mCRC treated with anti-EGFR antibodies was used to confirm our findings.

RESULTS

After screening the expression of 1,145 miRNAs in FF samples from the training set, we identified that hsa-miR-31-3p expression level was significantly associated with progression-free survival (PFS). Statistical models based on miRNA expression discriminated between high and low risk of progression for both FF and FFPE samples. These models were confirmed in the validation cohort for both FF [HR, 4.1; 95% confidence interval (CI), 1.1-15.3; P < 0.04] and FFPE samples (HR, 2.44; 95% CI, 1.1-5.4; P = 0.028). The percentage of variation of RECIST criteria in the validation series was significantly associated with the expression level of hsa-miR-31-3p (r(2) = 0.49; P = 0.0035) and risk status determined by hsa-miR-31-3p expression level (P = 0.02, Kruskal-Wallis rank test). Nomograms were built and validated to predict PFS-depending on hsa-miR-31-3p expression level. Following in vitro studies, we identified 47 genes regulated by hsa-miR-31-3p.

CONCLUSION

Hsa-miR-31-3p seems to be a new mCRC biomarker whose expression level allows for the identification of patients with wild-type KRAS mCRC who are more likely to respond to anti-EGFR therapy.

Personalizing therapy for colorectal cancer

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. Several important scientific discoveries in the molecular biology of CRC have changed clinical practice in oncology. These included the comprehensive genome-wide profiling of CRC by the Cancer Genome Atlas Network, the discovery of mutations along the RAS-RAF signaling pathway as major determinants of response to antibodies against the epidermal growth factor receptor, the elucidation of new molecular subsets of CRC or gene signatures that may predict clinical outcome after adjuvant chemotherapy, and the innovative targeting of the family of vascular endothelial growth factor and receptors. These new data have allowed oncologists to individualize drug therapy on the basis of a patient's tumor's unique molecular profile, especially in the management of metastatic CRC. This review article will discuss the progress of personalized medicine in the contemporary management of CRC.

Dual inhibition of EGFR and c-Met kinase activation by MJ-56 reduces metastasis of HT29 human colorectal cancer cells

Quinazolinone derivatives are known to possess anticancer activities on cell metastasis and cell death in different human cancer cell lines. Here, we studied the anti-metastasis activity and the underlying mechanisms of the novel quinazoline derivative MJ-56 (6-pyrrolidinyl-2-(3-bromostyryl)quinazolin-4-one). MJ-56 inhibited cell migration and invasion of HT29 human colorectal cancer cells by wound-healing and Matrigel-coated transwell assays in a concentration-dependent manner. MJ-56-treated cells resulted in the reduced expression of matrix metalloproteinase (MMP)-2, -7, -9 and -10 and the reduced enzymatic activities of MMP-2 and MMP-9. In contrast, MJ-56-treated cells enhanced the expression of the tissue inhibitors of metalloproteinases (TIMPs) TIMP-1 and TIMP-2. Further analyses showed that MJ-56 attenuated the activities of epidermal growth factor receptor (EGFR), c-Met and the downstream ERK-mediated MAPK and PI3K/AKT/mTOR signaling pathways, which led to decreased protein synthesis by dephosphorylating the translation initiation factors eIF-4B, eIF-4E, eIF-4G and S6 ribosomal protein. In addition, MJ-56 interfered with the NF-κB signaling via impairing PI3K/AKT activation and subsequently reduced the NF-κB-mediated transcription of MMPs. Taken together, the reduced expression of phosphor-EGFR and c-MET is chiefly responsible for all events of blocking metastasis. Our results suggest a potential role of MJ-56 on therapy of colorectal cancer metastasis.

Systemic treatment of liver metastases from colorectal cancer

Patients presenting with synchronous or metachronous colorectal cancer liver metastases (CLM) should be evaluated for multimodal management with curative intent. Preoperative systemic chemotherapy shows beneficial impact on adjuvant progression-free survival and also borderline on overall survival, without significantly increasing initially R0 resectable patients postoperative complication rates. Postoperative chemotherapy recommended based on the perioperative trial experience for those patients achieving at least stable disease during preoperative chemotherapy, or based on the adjuvant trials for patients receiving upfront resection. 'Borderline' resectable CLM, preoperative chemotherapy plays an important role in both in achievement of a resectable status and improvement of prognosis. Recent 4 drug combinations demonstrated response rates up to 80% even for advanced disease and are thus promising regimens for further evaluation in patients with resectable or unresectable liver-limited (+/- lung) disease.

The KRAS mutation detection within the initial management of patients with metastatic colorectal cancer: a status report in France in 2011

BACKGROUND

The detection of KRAS mutations is mandatory to initiate an anti-epidermal growth factor receptor (EGFR) antibody in the treatment of metastatic colorectal carcinoma (mCRC).

PATIENTS AND METHODS

This observational retrospective study was performed in 160 French centres during a 2-week period in 2011. Its main objective was to evaluate the rate of KRAS testing in patients with mCRC having initiated their first-line therapy. Secondary objectives included time of process, techniques used and reasons for non-prescription.

RESULTS

Five hundred and thirty eight mCRC patients (67.1 ± 11.3 years, synchronous metastases: 69.9%) were enrolled in the study. KRAS testing was prescribed in 81.1% of patients, in a median of 15 days after the diagnosis of metastases, and of 15 days prior to the initiation of the first-line metastatic chemotherapy. KRAS status was available for 87% of patients, after 23.6 ± 28.2 days, but after the choice of the first-line therapy in 56.6% of patients. Heterogeneity of reception time was noteworthy within regions (8.3 ± 7 days to 38.8 ± 101 days). KRAS testing was not prescribed mainly due to the planned non-prescription of an anti-EGFR antibody.

CONCLUSION

This study confirmed that KRAS testing is definitely part of the management of most of mCRC patients, despite discrepancies observed in the rate of prescription and the time of results.

Treatment with bevacizumab and FOLFOXIRI in patients with advanced colorectal cancer: presentation of two novel trials (CHARTA and PERIMAX) and review of the literature

BACKGROUND

More than half of patients with colorectal cancer will develop metastatic disease either evident at the time of initial diagnosis or during their course of disease. Besides multidisciplinary management further treatment intensification is warranted to improve the still limited prognosis.

METHODS/DESIGN

In these two multi-centre, randomized phase II trials, conducted in Germany, 380 patients with R0-resectable colorectal liver metastases (PERIMAX) and with unresectable, metastatic colorectal cancer (CHARTA) will be recruited. Patients previously untreated for metastatic disease with either synchronous or metachronous metastases are randomly assigned in a 1:1 ratio to resection of colorectal liver metastases followed by postoperative FOLFOX for 6 months or perioperative FOLFOXIRI and bevacizumab for 3 months pre- and postoperative and resection (PERIMAX), or to induction chemotherapy with FOLFOX and bevacizumab +/- irinotecan for a maximum of 6 months followed by maintenance treatment with fluoropyrimidine and bevacizumab. The primary objective of these trials is to evaluate the feasibility and efficacy of FOLFOXIRI and bevacizumab in metastatic colorectal cancer. Primary endpoint is failure free survival rate at 18 months in the PERIMAX trial and progression free survival rate at 9 months in CHARTA. Secondary objectives include efficacy, safety and tolerability.

DISCUSSION

The CHARTA and PERIMAX trials are designed to evaluate the benefits and limitations of a highly active four-drug regimen in distinct treatment situations of metastatic CRC. Eligible patients are classified into resectable liver metastases to be randomized to perioperative treatment with FOLFOXIRI and bevacizumab or postoperative FOLFOX in the PERIMAX, or unresectable metastatic CRC to be randomized between FOLFOX and bevacizumab with or without irinotecan, stratified for clinical groups according to disease and patients' characteristics in the CHARTA trial.

TRIAL REGISTRATION

Clinical trial identifier CHARTA: NCT01321957, PERIMAX: NCT01540435.

Overview of biomarkers in metastatic colorectal cancer: tumour, blood and patient-related factors

During the last 20 years there have been major therapeutic developments in colorectal cancer (CRC) with the introduction of multiple novel therapeutic agents into routine clinical practice. This has improved survival in both the adjuvant and advanced disease settings. However, improvements have come with substantial increases in expense to the community and potential toxicity to the patient. There has been substantial research to identify tumour factors in CRC that predict treatment response and survival outcomes. This research has identified clinically useful predictive biomarkers to aid clinical decision making, such as the presence or absence of KRAS gene mutations which can determine the benefit of using epidermal growth factor receptor (EGFR) inhibiting antibodies. However, less attention has been paid to the identification and impact of predictive patient-derived factors such as age, gender and the presence of comorbid conditions or evidence of a systemic inflammatory response. In this article, the current concepts of tumour and patient-related predictive factors in CRC management are reviewed.

Tumor and non-tumor liver angiogenesis is traced and evaluated by hepatic arterial ultrasound in murine models

We studied the relationships between hepatic and mesenteric mean blood-flow velocities (mBFVs) measured by ultrasound imaging and (1) downstream tumor angiogenesis during liver metastasis induced by spleen injection of LS174 human colon cells overexpressing the antiangiogenic Netrin4 (LS174-NT4) or not (LS174-WT) and (2) downstream normal angiogenesis during hepatic regeneration after 50% hepatectomy. Liver volume and mBFVs were measured before and after surgery, at day 30 in the first model and at days 2, 7 and 16 in the second model. LS174-NT-4 vs. LS174-WT mice presented fewer metastases (25% vs. 90%, p < 0.001) and decreased hepatic mBFVs (16.5 ± 0.8 vs. 21.8 ± 1.4 cm s(-1), p < 0.01), without difference in mesenteric mBFVs. After partial hepatectomy, hepatic and mesenteric mBFVs increased at day 7, from 12.4 ± 1.7 and 11.8 ± 2.6 to 19.1 ± 1.8 and 17.5 ± 2.4 cm s(-1), respectively, (p < 0.01) then returned to baseline as liver volume. Duplex Doppler ultrasonography reliably assesses normal or tumor angiogenesis and may provide follow-up functional evaluation.

An EZH2 polymorphism is associated with clinical outcome in metastatic colorectal cancer patients

BACKGROUND

Despite therapeutic innovations, metastatic colorectal cancer (mCRC) is still characterized by poor prognosis and few molecular markers predict the risk of progression. Polycomb group genes (PcGs) are epigenetic modifiers involved in tumor suppressor gene silencing. PcG member EZH2 mediates gene silencing through histone-H3 lysine-27 methylation. In colorectal cancer (CRC), EZH2 overexpression predicts shorter survival. Recently, four EZH2 single-nucleotide polymorphisms (SNPs) have been described. The present study was aimed at evaluating the correlation between EZH2 SNPs and outcome parameters in mCRC patients.

PATIENTS AND METHODS

DNA was extracted from blood samples of 110 mCRC patients treated with first-line 5-fluorouracil, folinic acid, irinotecan (FOLFIRI) and bevacizumab. Genotyping was carried out by real-time PCR. Genotype was used to predict objective response, progression-free survival (PFS) and overall survival (OS). EZH2 messenger RNA levels were evaluated on lymphocytes of a parallel cohort of 50 CRC patients.

RESULTS

One allelic variant (rs3757441 C/C versus C/T or T/T) was significantly associated with shorter PFS and OS (P < 0.01 and P < 0.05, respectively). At multivariate analysis, the same variant resulted an independent predictor of PFS and OS (P < 0.05). The C/C variant was associated with significantly higher EZH2 expression (P < 0.05).

CONCLUSION

An EZH2 SNP may be useful to predict clinical outcome in mCRC patients.

Role of oncogenic pathways and KRAS/BRAF mutations in the behavior of colon adenocarcinoma in renal transplant patients

BACKGROUND

The behavior and mechanisms of colorectal carcinoma in solid organ transplantation have not been well characterized. Our aim was to determine the clinical and molecular phenotypes of colorectal carcinoma in kidney transplant recipients and compare with those in the nonimmunosuppressed population. For the first time, we analyzed the impact of KRAS and BRAF mutations in kidney transplantation.

METHODS

Kidney transplant recipients with colorectal carcinoma were diagnosed and followed up from 1992 to 2007. Twelve patients fulfilled inclusion criteria and were matched with the general population with colorectal cancer. To assess the possible mechanisms involved in the clinical behavior of colorectal carcinoma, we compared the tumoral expression by immunohistochemical analysis of molecule markers of mammalian target of rapamycin (mTOR) pathway, angiogenesis and proliferation, and the role of activating mutations in KRAS and BRAF genes.

RESULTS

Colorectal carcinoma was more prevalent and exhibited a trend for worse prognosis in transplant patients. Although the mTOR pathway was activated in both populations, activation was lower in transplant patients because of relatively higher phosphatase and tensin homolog expression in the former. Angiogenesis was activated in colorectal carcinoma in both groups. KRAS mutations were found in transplant recipients treated with calcineurin inhibitors and with high expression of phosphatase and tensin homolog.

CONCLUSION

The activation of oncogenic pathways could be responsible for the clinical behavior of posttransplant colorectal carcinoma. The mutation status of the KRAS gene is likely involved in mTOR pathway and to be a prognosis marker for colorectal cancer in kidney transplantation.

Combination Agents Versus Multi-Targeted Agents – Pros and Cons

Cancer, in all its various forms, is perhaps the archetypical multi-factorial disease and it is therefore not surprising that single-target drugs are rarely useful as anti-cancer agents when used on their own. Traditional cancer therapy has relied on effective drug combinations and the more recent emergence of compounds that simultaneously modulate multiple targets has added to the oncology armoury and raised the question as to which approach, drug combinations or single compound multi-targeted drug, is to be preferred. This chapter reviews the basis for combining existing drugs and how these combinations are selected, and compares these with multi-targeted drugs (MTDs) such as sunitinib, a broad-spectrum kinase inhibitor that inhibits a range of growth factors. Whether using physical combinations or MTDs, or indeed combinations of MTDs, the choice of which targets and which pathways to attack is crucial and the rationale for selecting these is discussed in detail. The NCI Cancer Therapy Evaluation Program, designed to facilitate trials of novel combinations, will aid in the rational selection of targets and pathways to combine in future MTDs. The pros and cons of combinations and MTDs in terms of the relative challenges in clinical development are examined, and the systematic use of biomarkers, better approaches to patient selection, and improved design of trials to take account of the heightened potential for acute and delayed on- and off-target toxicities are highlighted.

Pharmacogenomics and personalized medicine: wicked problems, ragged edges and ethical precipices

In the age of genomic medicine we can often now do the genetic testing that will permit more accurate personal tailoring of medications to obtain the best therapeutic results. This is certainly a medically and morally desirable result. However, in other areas of medicine pharmacogenomics is generating consequences that are much less ethically benign and much less amenable to a satisfactory ethical resolution. More specifically, we will often find ourselves left with 'wicked problems,' 'ragged edges,' and well-disguised ethical precipices. This will be especially true with regard to these extraordinarily expensive cancer drugs that generally yield only extra weeks or extra months of life. Our key ethical question is this: Does every individual faced with cancer have a just claim to receive treatment with one of more of these targeted cancer therapies at social expense? If any of these drugs literally made the difference between an unlimited life expectancy (a cure) and a premature death, that would be a powerful moral consideration in favor of saying that such individuals had a strong just claim to that drug. However, what we are beginning to discover is that different individuals with different genotypes respond more or less positively to these targeted drugs with some in a cohort gaining a couple extra years of life while others gain only extra weeks or months. Should only the strongest responders have a just claim to these drugs at social expense when there is no bright line that separates strong responders from modest responders from marginal responders? This is the key ethical issue we address. We argue that no ethical theory yields a satisfactory answer to this question, that we need instead fair and respectful processes of rational democratic deliberation.

TOP1 gene copy numbers in colorectal cancer samples and cell lines and their association to in vitro drug sensitivity

OBJECTIVE

A positive relationship between topoisomerase-1 (TOP1) protein and sensitivity toward the TOP1 inhibitor irinotecan has been reported in patients with metastatic colorectal cancer (mCRC). In this study, we analyzed TOP1 gene copy number variation in tumor tissue from CRC patients and CRC cell lines with different sensitivities to the TOP1 inhibitor SN-38 and oxaliplatin.

MATERIAL AND METHODS

A TOP1 gene probe with a chromosome 20 centromere (CEN-20) reference probe was applied on normal mucosa and on tumor tissue from 50 stage III CRC patients. Additionally, associations between TOP1/CEN-20 ratio and in vitro sensitivity to SN-38 (irinotecan) and oxaliplatin were tested on 10 CRC cell lines. Results. In the malignant epithelium, 84% of the samples demonstrated an increased TOP1 gene copy number and 64% had an increased TOP1/CEN-20 ratio compared with the non-affected mucosa. Sixteen (32%) of the tumors had a ratio of ≥ 1.5 and 9 (18%) of these had a ratio of ≥ 2.0. A positive association was observed between the TOP1 gene copy number and the TOP1/CEN-20 ratio and in vitro sensitivity toward SN-38, but not toward oxaliplatin.

CONCLUSIONS

A large fraction of the clinical samples demonstrated increased TOP1 gene copy number and increased TOP1/CEN-20 ratio. The cell line study suggested an association between TOP1 gene copy number or TOP1/CEN-20 ratio and sensitivity to irinotecan but not oxaliplatin.

Molecular predictors of response to chemotherapy in colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer mortality worldwide. In the last decade, median overall survival has increased significantly with the introduction of new cytotoxics and biologic therapies. Notably, the definition of molecular markers predicting benefit with epidermal growth factor receptor (EGFR)-targeted agents has led to important advances in the personalized treatment of CRC. Data derived from multiple phase III trials have indicated that KRAS mutations can be considered a highly specific negative biomarker of response to anti-EGFR monoclonal antibodies. The predictive value of additional mutations and deregulations of the signaling pathways downstream of the EGFR such as BRAF, NRAS, PIK3CA, or PTEN is under intensive investigation. In addition, status of microsatellite instability and molecular markers related to the metabolism of chemotherapy agents has shown promising ability to select patients with higher chances of response to cytotoxic agents. Although attempts to identify predictive factors for efficacy to antiangiogenic therapies have been disappointing, further research on this field will maximize their therapeutic index. Determination of molecular predictive factors before selection of chemotherapy is rapidly approaching us to the paradigm of individualized treatment of CRC.

Integrating biomarkers in clinical trials

Biomarkers have a growing role in clinical trials. With the advent of the targeted therapy era, molecular biomarkers in particular are becoming increasingly important within both clinical research and clinical practice. This article focuses on biomarkers that anticipate the prognosis of individual patients ('prognostic' biomarkers) and on biomarkers that predict how individual patients will respond to specific treatments ('predictive' biomarkers, also called 'effect modifiers'). Specific Phase II and III clinical trial designs are discussed in detail for their ability to validate the biomarker and/or to establish the effect of an experimental therapy in patient populations defined by the presence or absence of the biomarker. Contemporary biomarker-based clinical trials in oncology are used as examples.

Biologic modulation of chemotherapy in patients with hepatic colorectal metastases: the role of anti-VEGF and anti-EGFR antibodies

In the treatment of metastatic colorectal cancer, the subset of patients with liver-only metastases shows the greatest promise for prolonged survival and cure. Advances in surgery and medical treatment have encouraged multimodality treatment strategies and therefore require a true multidisciplinary approach. The current standard of care includes peri-operative chemotherapy and surgery. The new era of biologically targeted therapy requires an in-depth look at the possible efficacy and risks of adding these agents to the treatment protocol.

Tumour gene expression predicts response to cetuximab in patients with KRAS wild-type metastatic colorectal cancer

BACKGROUND

Although it is accepted that metastatic colorectal cancers (mCRCs) that carry activating mutations in KRAS are unresponsive to anti-epidermal growth factor receptor (EGFR) monoclonal antibodies, a significant fraction of KRAS wild-type (wt) mCRCs are also unresponsive to anti-EGFR therapy. Genes encoding EGFR ligands amphiregulin (AREG) and epiregulin (EREG) are promising gene expression-based markers but have not been incorporated into a test to dichotomise KRAS wt mCRC patients with respect to sensitivity to anti-EGFR treatment.

METHODS

We used RT-PCR to test 110 candidate gene expression markers in primary tumours from 144 KRAS wt mCRC patients who received monotherapy with the anti-EGFR antibody cetuximab. Results were correlated with multiple clinical endpoints: disease control, objective response, and progression-free survival (PFS).

RESULTS

Expression of many of the tested candidate genes, including EREG and AREG, strongly associate with all clinical endpoints. Using multivariate analysis with two-layer five-fold cross-validation, we constructed a four-gene predictive classifier. Strikingly, patients below the classifier cutpoint had PFS and disease control rates similar to those of patients with KRAS mutant mCRC.

CONCLUSION

Gene expression appears to identify KRAS wt mCRC patients who receive little benefit from cetuximab. It will be important to test this model in an independent validation study.