[Prediction of EGFR blockade responses in metastatic colorectal carcinoma]. / Predikce odpovedi metastatického kolorektálního karcinomu na cílenou anti-EGFR lécbu.

The combination of modern systemic chemotherapy and anti-EGFR monoclonal antibodies improves overall survival and the quality of life for patients with metastatic colorectal cancer. By contrast, the addition of anti-EGFR therapy to the treatment regime of resistant patients may lead to worse progression-free and overall survival. Therofore, identifying sensitive and resistant patients is key during initial decision-making. A number of clinical trials show that primary resistance to EGFR blockade is in most cases caused by constitutive activation of signalling pathways downstream of EGFR. Of the many biomarkers studied, only the KRAS and NRAS mutation status has reached clinical relevance in routine practice. The other markers (BRAF and PIK3CA mutations, PTEN and TP53 inactivation, EGFR and HER-2 amplification, epiregulin and amphiregulin overexpression, microRNA miR-31-3p and miR-31-5p etc.) still need to be validated. The accuracy of predictive diagnostic tools could also be increased by a combination of predictive markers on the next generation sequencing platform.

MABp1 as a novel antibody treatment for advanced colorectal cancer: a randomised, double-blind, placebo-controlled, phase 3 study.

BACKGROUND: MABp1, an antibody that targets interleukin 1α, has been associated with antitumour activity and relief of debilitating symptoms in patients with advanced colorectal cancer. We sought to establish the effect of MABp1 with a new primary endpoint in patients with advanced colorectal cancer. METHODS: Eligible patients for the double-blind phase of this ongoing, placebo-controlled, randomised, phase 3 trial, had metastatic or unresectable disease, Eastern Cooperative Oncology Group performance status score 1 or 2, systemic inflammation, weight loss, and other disease-related morbidities associated with poor prognosis, and were refractory to oxaliplatin and irinotecan. Patients were randomly assigned 2:1 to receive either MABp1 or placebo. Randomisation codes were obtained from a centrally held list via an interactive web response system. Patients received an intravenous infusion of 7·5 mg/kg MABp1 or placebo given every 2 weeks for 8 weeks. The primary endpoint was assessed in patients who received at least one dose of MABp1 or placebo (modified intention-to-treat population), and was a composite of stable or increased lean body mass and stability or improvement in two of three symptoms (pain, fatigue, or anorexia) at week 8 compared with baseline measurements. This study is registered with ClinicalTrials.gov, number NCT02138422. FINDINGS: Patients were enrolled between May 20, 2014, and Sept 2, 2015. The double-blind phase of the study was completed on Nov 3, 2015. Of 333 patients randomly assigned treatment, 207 received at least one dose of MABp1 and 102 at least one dose of placebo. 68 (33%) and 19 (19%) patients, respectively, achieved the primary endpoint (relative risk 1·76, 95% CI 1·12-2·77, p=0·0045). The most common grade 3-4 adverse events in the MABp1 group compared with in the placebo group were anaemia (eight [4%] of 207 vs five [5%] of 102 patients), increased concentration of alkaline phosphatase (nine [4%] vs two [2%]), fatigue (six [3%] vs seven [7%]), and increased concentration of aspartate aminotransferase (six [3%] vs two [2%]). After 8 weeks, 17 (8%) patients in the MABp1 group and 11 (11%) in the placebo group had died, but no death was judged to be related to treatment. The incidence of serious adverse events was not significantly different in the MABp1 group and placebo groups (47 [23%] vs 33 [32%], p=0·07). INTERPRETATION: The primary endpoint was a useful means of measuring clinical performance in patients. MABp1 might represent a new standard in the management of advanced colorectal cancer. FUNDING: XBiotech.

Prediction of response to anti-EGFR antibody-based therapies by multigene sequencing in colorectal cancer patients.

BACKGROUND: The anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (moAbs) cetuximab or panitumumab are administered to colorectal cancer (CRC) patients who harbor wild-type RAS proto-oncogenes. However, a percentage of patients do not respond to this treatment. In addition to mutations in the RAS genes, mutations in other genes, such as BRAF, PI3KCA, or PTEN, could be involved in the resistance to anti-EGFR moAb therapy. METHODS: In order to develop a comprehensive approach for the detection of mutations and to eventually identify other genes responsible for resistance to anti-EGFR moAbs, we investigated a panel of 21 genes by parallel sequencing on the Ion Torrent Personal Genome Machine platform. We sequenced 65 CRCs that were treated with cetuximab or panitumumab. Among these, 37 samples were responsive and 28 were resistant. RESULTS: We confirmed that mutations in EGFR-pathway genes (KRAS, NRAS, BRAF, PI3KCA) were relevant for conferring resistance to therapy and could predict response (p = 0.001). After exclusion of KRAS, NRAS, BRAF and PI3KCA combined mutations could still significantly associate to resistant phenotype (p = 0.045, by Fisher exact test). In addition, mutations in FBXW7 and SMAD4 were prevalent in cases that were non-responsive to anti-EGFR moAb. After we combined the mutations of all genes (excluding KRAS), the ability to predict response to therapy improved significantly (p = 0.002, by Fisher exact test). CONCLUSIONS: The combination of mutations at KRAS and at the five gene panel demonstrates the usefulness and feasibility of multigene sequencing to assess response to anti-EGFR moAbs. The application of parallel sequencing technology in clinical practice, in addition to its innate ability to simultaneously examine the genetic status of several cancer genes, proved to be more accurate and sensitive than the presently in use traditional approaches.

First-Line Nivolumab and Relatlimab Plus Chemotherapy for Gastric or Gastroesophageal Junction Adenocarcinoma: The Phase II RELATIVITY-060 Study.

PURPOSE: Open-label phase II study (RELATIVITY-060) to investigate the efficacy and safety of first-line nivolumab, a PD-1-blocking antibody, plus relatlimab, a lymphocyte-activation gene 3 (LAG-3)-blocking antibody, plus chemotherapy in patients with previously untreated advanced gastric cancer (GC) or gastroesophageal junction cancer (GEJC). METHODS: Patients with unresectable, locally advanced or metastatic GC/GEJC were randomly assigned 1:1 to nivolumab + relatlimab (fixed-dose combination) + chemotherapy or nivolumab + chemotherapy. The primary end point was objective response rate (ORR; per RECIST v1.1 by blinded independent central review [BICR]) in patients whose tumors had LAG-3 expression ≥1%. RESULTS: Of 274 patients, 138 were randomly assigned to nivolumab + relatlimab + chemotherapy and 136 to nivolumab + chemotherapy. Median follow-up was 11.9 months. In patients with LAG-3 expression ≥1%, BICR-assessed ORR (95% CI) was 48% (38 to 59) in the nivolumab + relatlimab + chemotherapy arm and 61% (51 to 71) in the nivolumab + chemotherapy arm; median progression-free survival (95% CI) by BICR was 7.0 months (5.8 to 8.4) versus 8.3 months (6.9 to 12.1; hazard ratio [HR], 1.41 [95% CI, 0.97 to 2.05]), and median overall survival (95% CI) was 13.5 months (11.9 to 19.1) versus 16.0 months (10.9 to not estimable; HR, 1.04 [95% CI, 0.70 to 1.54]), respectively. Grade 3 or 4 treatment-related adverse events (TRAEs) occurred in 69% and 61% of all treated patients, and 42% and 36% of patients discontinued because of any-grade TRAEs in the nivolumab + relatlimab + chemotherapy and nivolumab + chemotherapy arms, respectively. CONCLUSION: RELATIVITY-060 did not meet its primary end point of improved ORR in patients with LAG-3 expression ≥1% when relatlimab was added to nivolumab + chemotherapy compared with nivolumab + chemotherapy. Further studies are needed to address whether adding anti-LAG-3 to anti-PD-1 plus chemotherapy can benefit specific GC/GEJC patient subgroups.

Management of pheochromocytomas and paragangliomas: Review of current diagnosis and treatment options.

Pheochromocytomas (PCCs) are rare neuroendocrine tumors derived from the chromaffin cells of the adrenal medulla. When these tumors have an extra-adrenal location, they are called paragangliomas (PGLs) and arise from sympathetic and parasympathetic ganglia, particularly of the para-aortic location. Up to 25% of PCCs/PGLs are associated with inherited genetic disorders. The majority of PCCs/PGLs exhibit indolent behavior. However, according to their affiliation to molecular clusters based on underlying genetic aberrations, their tumorigenesis, location, clinical symptomatology, and potential to metastasize are heterogenous. Thus, PCCs/PGLs are often associated with diagnostic difficulties. In recent years, extensive research revealed a broad genetic background and multiple signaling pathways leading to tumor development. Along with this, the diagnostic and therapeutic options were also expanded. In this review, we focus on the current knowledge and recent advancements in the diagnosis and treatment of PCCs/PGLs with respect to the underlying gene alterations while also discussing future perspectives in this field.

Stereotactic Body Radiotherapy (SBRT) of Pancreatic Cancer-A Critical Review and Practical Consideration.

Pancreatic cancer is the third leading cause of cancer death in the developed world and is predicted to become the second by 2030. A cure may be achieved only with surgical resection of an early diagnosed disease. Surgery for more advanced disease is challenging and can be contraindicated for many reasons. Neoadjuvant therapy may improve the probability of achieving R0 resection. It consists of systemic treatment followed by radiation therapy applied concurrently or sequentially with cytostatics. A novel approach to irradiation, stereotactic body radiotherapy (SBRT), has the potential to improve treatment results. SBRT can deliver higher doses of radiation to the tumor in only a few treatment fractions. It has attracted significant interest for pancreatic cancer patients, as it is completed quickly, requires less time away from full-dose chemotherapy, and is well-tolerated than conventional radiotherapy. In this review, we aim to provide the reader with a basic overview of current evidence for SBRT indications in the treatment of pancreatic tumors. In the second part of the review, we focus on practical information with respect to SBRT treatment plan preparation the performance of such therapy. Finally, we discuss future directions related to the use of magnetic resonance linear accelerators.

[Cetuximab and irinotecan for the treatment of metastatic colorectal cancer--pilot results from Masaryk Memorial Cancer Institute]. / Cetuximab a irinotekan v lécbe metastatického kolorektálního karcinomu--pilotní výsledky z Masarykova onkologického ustavu.

BACKGROUND: Combination of cetuximab and irinotecan is an efficacious second- (and further-)-line treatment-alternative in patients with EGFR-positive metastatic colorectal cancer refractory to irinotecan. In this retrospective study we present treatment results of patients treated combination of cetuximab and irinotecan in Masaryk Memorial Cancer Institute. PATIENTS AND METHODS: Results were collected on forty-seven patients who started the therapy from July 2005 to February 2008. Primary outcomes were: response rate, time to progression and overall survival. Secondary outcomes were: treatment-related toxicity and identification of any predictive and prognostic markers. P-value was based on Gehan-Wilcoxon test or chi-square test and P-values < or = 0.05 were considered significant. The Kaplan-Meier method was used to estimate overall (OS) and progression-free survival (PFS). RESULTS: Forty-two patients were valuable for the treatment response. Objective response rate (complete and partial remission) was 35.7% (15 patients) and disease control (response and disease stabilization) was achieved in 30 patients (71.4%). The median time to progression was 6, 4 months (range 1, 5-25 months). On the date of statistical processing (median follow-up: 9, 2 months, range 2, 5-27 months) there were 26 patients alive and the median overall survival was 17, 1 months. We have confirmed correlation between the grade of the skin rush and the treatment response (p = 0.05) and time to progression ( p = 0.01), on the other hand there was no association between EGFR expression and these parameters. The therapy was also effective in 8 of 14 patients (57%), who had documented resistance to irinotecan. CONCLUSIONS: We have confirmed the efficacy of cetuximab and irinotecan combination for the therapy of patients with pretreated metastatic colorectal cancer. Our results are optimistic, but have to be validated in the course of time. The existence of nonresponding patients and by reason of pharmacoeconomy, we should give attention to the new molecular predictive and prognostic markers such as: K-ras-mutation and EGFR gene copy number.

The Pharmacoeconomic Analysis of Cetuximab and Panitumumab in the 1st Line Treatment of mCRC in Real Clinical Practice in the Czech Republic.

BACKGROUND: The anti-epidermal growth factor receptor (EGFR) drugs cetuximab and panitumumab are currently reimbursed when administered during the first and subsequent lines of treatment of patients in the Czech Republic with metastatic colorectal cancer (mCRC). Because cetuximab and panitumumab do not show significant differences in efficacy, their choice may be dependent on cost. This retrospective study analyzed the costs of first-line treatment with cetuximab and panitumumab of patients with mCRC and wild type KRAS, as well as evaluated the correlations between costs and effectiveness, as determined by progression-free survival (PFS) and overall survival (OS). PATIENTS AND METHODS: This analysis included 51 patients with mCRC and confirmed wild type KRAS treated at the comprehensive cancer centre in the Czech Republic between November 2011 and April 2018. Of these 51 patients, 22 were treated with cetuximab and 29 with panitumumab. Direct medical costs (medications, clinical examinations and procedures, and hospitalization) were evaluated from the initiation of treatment with anti-EGFR drug to disease progression and death. Mean follow-up was 21 months in the cetuximab group and 19 months in the panitumumab group. RESULTS: Reimbursement for anti-EGFR drugs until disease progression accounted for 71% (mean, 964,288 CZK per patient) of total costs in the cetuximab group and 77% (mean, 1,003,229 CZK per patient) of total costs in the panitumumab group, with median PFS in these two groups being 10.7 months and 8.1 months, respectively. Reimbursement of expensive center drugs from the start of anti-EGFR treatment to patient death accounted for 55% of total costs in the cetuximab group (mean, 1,752,702 CZK per patient) and 63% of total costs in the panitumumab group (mean, 1,596,919 CZK per patient), with median OS in these two groups being 20.2 months and 19.8 months, respectively. No significant between-group differences in clinical effectiveness and costs of treatment were observed (p > 0.05 each). CONCLUSION: Reimbursement for biological agents is the most expensive item in the first-line treatment of mCRC patients with wild type KRAS, both to disease progression and death. The clinical effectiveness and costs of cetuximab and panitumumab did not differ significantly. Supported by CZECRIN (identification code LM2015090); CZECRIN_4 PACIENTY (No. CZ.02.1.01/0.0/0.0/16_013/0001826). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 30. 4. 2019 Accepted: 17. 6. 2019.

Deficient mismatch repair as a prognostic marker in stage II colon cancer patients.

BACKGROUND: A number of reports have evaluated the relationship between deficient DNA mismatch repair (dMMR) and colorectal cancer prognosis. Unfortunately, the exact prognostic role of dMMR has not been clearly established due to contradictory results. This study aims to determine the prognostic impact of dMRR in stage II colon cancer patients only. The appropriate identification of high-risk stage II colon cancers is of paramount importance in the selection of patients who may benefit from adjuvant treatment after surgery. METHODS: Four hundred and fifty-two patients with curative resection of stage II colon cancer were included. Hospital records were used as data source, providing clinical, surgical, pathology, oncology and follow-up information for statistical analysis focusing on overall survival (OS) and time to progression (TTP). Mismatch repair status was determined by immunohistochemistry. Patient survival was followed-up for a mean of 77·35 months. RESULTS: dMMR was detected in 93 of 452 patients (20·6%). No impact on overall survival (Log-Rank, p = 0·583, 95% CI 0·76-1·67). However, the hazard ratio 0·50 for TTP was highly significant (Log-Rank, p = 0·012, 95% CI 0·28-0·87) in patients with dMMR compared with those with mismatch repair proficient tumours (pMMR). CONCLUSIONS: Patients with dMMR tumours have a lower risk for recurrence compared to those with pMMR tumours, but this finding did not correlate to better overall survival.

Mutational analysis of primary and metastatic colorectal cancer samples underlying the resistance to cetuximab-based therapy.

PURPOSE: Although several molecular markers predicting resistance to cetuximab- or panitumumab-based therapy of metastatic colorectal cancer were described, mutations in RAS proto-oncogenes remain the only predictors being used in daily clinical practice. However, 35%-45% of wild-type RAS patients still do not respond to this anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibody-based therapy, and therefore the definition of other predictors forms an important clinical need. The aim of the present retrospective single-institutional study was to evaluate potential genes responsible for resistance to anti-EGFR therapy in relation to mutational analysis of primary versus metastatic lesions. PATIENTS AND METHODS: Twenty-four paired primary and corresponding metastatic tissue samples from eight nonresponding and four responding metastatic colorectal cancer patients treated with cetuximab-based therapy were sequenced using a next-generation sequencing panel of 26 genes involved in EGFR signaling pathway and colorectal carcinogenesis. RESULTS: Mutational status of primary tumors and metastatic lesions was highly concordant in TP53, APC, CTNNB1, KRAS, PIK3CA, PTEN, and FBXW7 genes. Metastatic samples harbor significantly more mutations than primary tumors. Potentially negative predictive value of FBXW7 mutations in relationship to anti-EGFR treatment outcomes was confirmed. Finally, new occurrences of activating KRAS mutations were identified in a group of patients initially determined as wild-type RAS by routinely used qPCR-based RAS mutational tests. All newly detected activating KRAS mutations most likely led to cetuximab treatment failure. CONCLUSION: The results of the present study suggest a need of careful consideration of previously published results of anti-EGFR-targeted therapy with regard to potentially inaccurate diagnostic tools used in the past. Based on our findings, we recommend more extensive use of next-generation sequencing testing in daily clinical practice, as it brings a significant added value in terms of validity of the diagnostic procedure.

MicroRNA expression profiling identifies miR-31-5p/3p as associated with time to progression in wild-type RAS metastatic colorectal cancer treated with cetuximab.

The aim of our study was to investigate whether microRNAs (miRNAs) could serve as predictive biomarkers to anti-EGFR therapy (cetuximab, panitumumab) in patients with RAS wild-type (wt-RAS) metastatic colorectal cancer (mCRC). Historical cohort of 93 patients with mCRC (2006-2009) was included and further divided into exploratory and validation cohorts. MiRNAs expression profiling was performed on the exploratory cohort of 41 wt-KRAS mCRC patients treated with cetuximab to identify miRNAs associated with time to progression (TTP). The validation was performed on two independent cohorts: 28 patients of wt-RAS mCRC treated with cetuximab and 24 patients of wt-RAS mCRC treated with panitumumab. We identified 9 miRNAs with significantly different expression between responders and non-responders to cetuximab therapy (P ≤ 0.01). These 9 miRNAs were further evaluated in two independent cohorts of patients and miR-31-3p (P < 0.001) and miR-31-5p (P < 0.001) were successfully confirmed as strongly associated with TTP in wt-RAS mCRC patients treated with cetuximab but not panitumumab. When evaluated on the complete cohort of cetuximab patients (N = 69), miR-31-3p (HR, 5.10; 95% CI, 2.52-10.32; P < 0.001) and miR-31-5p (HR, 4.80; 95% CI, 2.50-9.24; P < 0.001) were correlated with TTP on the comparable level of significance. There was no difference in miR-31-5p/3p expression levels in RAS mutated and wild-type tumor samples. MiR-31-5p/3p are promising predictive biomarkers of cetuximab response in wt-RAS mCRC patients.

MicroRNAs targeting EGFR signalling pathway in colorectal cancer.

MicroRNAs (miRNAs) are short, 18-25-nucleotide long, non-coding single-stranded RNAs, which are capable to regulate gene expression on post-transcriptional level through binding to their target protein-encoding mRNAs. miRNAs regulate individual components of multiple oncogenic pathways. One of them is epidermal growth factor receptor (EGFR) signalling pathway that regulates cell proliferation, differentiation, migration, angiogenesis and apoptosis. All these processes are deregulated in colorectal cancer (CRC). Moreover, EGFR has been validated as the therapeutic target in CRC, and monoclonal antibodies cetuximab and panitumumab are used in the therapy of patients with metastatic CRC. Because of the extensive involvement of miRNAs in the regulation of EGFR signalling, it seems they could also serve as promising predictive biomarkers to anti-EGFR therapy. In this review, we summarize current knowledge about miRNAs targeting EGFR signalling pathway, their functioning in CRC pathogenesis and potential usage as biomarkers.