Madiha Naseem

Colorectal cancer: epigenetic alterations and their clinical implications.

Colorectal cancer (CRC) is a heterogeneous disease with distinct molecular and clinical features, which reflects the wide range of prognostic outcomes and treatment responses observed among CRC patients worldwide. Our understanding of the CRC epigenome has been largely developed over the last decade and it is now believed that among thousands of epigenetic alterations present in each tumor, a small subgroup of these may be considered as a CRC driver event. DNA methylation profiles have been the most widely studied in CRC, which includes a subset of patients with distinct molecular and clinical features now categorized as CpG island methylator phenotype (CIMP). Major advances have been made in our capacity to detect epigenetic alterations, providing us with new potential biomarkers for diagnostic, prognostic and therapeutic purposes. This review aims to summarize our current knowledge about epigenetic alterations occurring in CRC, underlying their potential future clinical implications in terms of diagnosis, prognosis and therapeutic strategies for CRC patients.

Outlooks on Epstein-Barr virus associated gastric cancer

Epstein-Barr virus associated gastric cancer (EBVaGC) comprises approximately 10% of gastric carcinomas. Multiple factors contribute to tumorigenesis, including EBV driven hypermethylation of tumor suppressor genes, inflammatory changes in gastric mucosa, host immune evasion by EBV and changes in cell cycle pathways. The unique molecular characteristics of EBVaGC, such as programmed death ligand 1 (PD-L1) overexpression, highlight the potential for using EBV as a biomarker for response to immunotherapy. Few studies have reported benefit from immunotherapy in EBV positive cancers, and clinical trials investigating the impact of checkpoint inhibitors in EBVaGC are currently underway. This review provides the most recent updates on molecular pathophysiology, epidemiology, clinical features and treatment advances pertaining to EBVaGC.

CXCL9, CXCL10, CXCL11/CXCR3 axis for immune activation - A target for novel cancer therapy.

Chemokines are proteins which induce chemotaxis, promote differentiation of immune cells, and cause tissue extravasation. Given these properties, their role in anti-tumor immune response in the cancer environment is of great interest. Although immunotherapy has shown clinical benefit for some cancer patients, other patients do not respond. One of the mechanisms of resistance to checkpoint inhibitors may be chemokine signaling. The CXCL9, -10, -11/CXCR3 axis regulates immune cell migration, differentiation, and activation, leading to tumor suppression (paracrine axis). However, there are some reports that show involvements of this axis in tumor growth and metastasis (autocrine axis). Thus, a better understanding of CXCL9, -10, -11/CXCR3 axis is necessary to develop effective cancer control. In this article, we summarize recent evidence regarding CXCL9, CXCL10, CXCL11/CXCR3 axis in the immune system and discuss their potential role in cancer treatment.

Association Between Height and Clinical Outcome in Metastatic Colorectal Cancer Patients Enrolled Onto a Randomized Phase 3 Clinical Trial: Data From the FIRE-3 Study

Micro‐Abstract: The objective of this study was to explore the relationship between height and outcomes in metastatic colorectal cancer (mCRC) patients. Data from 695 patients enrolled onto the FIRE‐3 clinical trial were studied. Patients with a height between 165 and 179 cm had better overall survival compared to other patients. Clinicians should consider height as an important prognostic factor when treating mCRC patients. Background: Previous studies have found significant relationships between height and colorectal cancer (CRC) risk. Increased growth has been associated with activated pathways such as insulin‐like growth factor 1. This study examined the impact of height on outcomes in metastatic CRC patients enrolled onto the FIRE‐3 study, a randomized phase 3 clinical trial. Patients and Methods: A total of 695 patients with metastatic CRC were studied and height was measured in centimeters. Male patients were grouped as ≤ 165, 166–175, 176–185, and ≥ 186 cm in height; female patients were grouped as ≤ 154, 155–164, 165–174, and ≥ 175 cm in height. Primary end point was overall survival (OS); secondary end point was progression‐free survival. Results: When patients heights were categorized into 4 groups, the tallest group showed a worse OS compared to the shortest group; however, there was no linear relationship between height and OS. To investigate this, we showed the association between height as a continuous variable and OS. Patients shorter than 172 cm had a worse OS as their height decreased. Patients taller than 172 cm had a worse OS as their height increased. Moreover, patients with heights between 165 and 179 cm had a better OS compared to other patients (P = .05). This effect was independent of treatment arm and gender. Conclusion: Patients shorter than 165 cm and taller than 179 cm have a worse OS, while those between 165 and 179 cm have a better OS. Hence, clinicians should consider height as an important prognostic factor when treating metastatic CRC patients. Future prospective studies are warranted to shed light on the mechanisms underlying the worse OS in taller patients.

Pharmacogenomics in colorectal cancer: current role in clinical practice and future perspectives

The treatment scenario of colorectal cancer (CRC) has been evolving in recent years with the introduction of novel targeted agents and new therapeutic strategies for the metastatic disease. An extensive effort has been directed to the identification of predictive biomarkers to aid patients selection and guide therapeutic choices. Pharmacogenomics represents an irreplaceable tool to individualize patients treatment based on germline and tumor acquired somatic genetic variations able to predict drugs response and risk of toxicities. The growing knowledge of CRC molecular characteristics and complex genomic makeup has played a crucial role in identifying predictive pharmacogenomic biomarkers, while supporting the rationale for the development of new drugs and treatment combinations. Clinical validation of promising biomarkers, however, is often an issue. More recently, a deeper understanding of resistance mechanisms and tumor escape dynamics under treatment pressure and the availability of novel technologies are opening new perspectives in this field. This review aims to present an overview of current pharmacogenomic biomarkers and future perspectives of pharmacogenomics in CRC, in an evolving scenario moving from a single drug-gene interactions approach to a more comprehensive genome-wide approach, comprising genomics and epigenetics.

Prognostic Effect of Adenosine-related Genetic Variants in Metastatic Colorectal Cancer Treated With Bevacizumab-based Chemotherapy

Background: Adenosine has an immunosuppressive and angiogenic modulation of the tumor microenvironment. The present study explored the efficacy of single nucleotide polymorphisms (SNPs) in adenosine‐related molecules for patients with metastatic colorectal cancer treated with bevacizumab‐based chemotherapy. Patients and Methods: We analyzed genomic DNA extracted from 451 samples from 3 independent cohorts: a discovery cohort of 107 patients treated with FOLFIRI (5‐fluorouracil, leucovorin, oxaliplatin, irinotecan) plus bevacizumab in FIRE‐3 (ClinicalTrials.gov identifier, NCT00433927); a validation cohort of 215 patients with FOLFIRI plus bevacizumab in TRIBE (ClinicalTrials.gov identifier, NCT00719797); and a control cohort of 129 patients treated with FOLFIRI plus cetuximab in FIRE‐3. The relationship between the selected SNPs and clinical outcomes was analyzed. Results: In the discovery cohort, patients with any C allele in CD39 rs11188513 had significantly shorter median progression‐free survival compared with those with the T/T variant (11.3 vs. 13.1 months; hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.04‐2.77; P = .022) on univariate analysis. Also, their overall survival (OS) was shorter (27.4 vs. 49.9 months; HR, 2.10; 95% CI, 1.07‐4.10; P = .031) on univariate and multivariable analyses. The significant association between CD39 rs11188513 and OS was confirmed in the validation cohort (25.8 vs. 31.6 months; HR, 1.53; 95% CI, 1.09‐2.15; P = .013). CD73 rs2229523 and A2BR rs2015353 in the discovery cohort and CD39 rs2226163 in the validation cohort showed significant correlations with OS on univariate and multivariable analyses. None of SNPs were significant in the cetuximab control cohort. Conclusion: Selected SNPs in the adenosine pathway could affect the clinical outcomes of patients with metastatic colorectal cancer treated with FOLFIRI plus bevacizumab. Micro‐Abstract Adenosine has an immunosuppressive and angiogenic modulatory role in the tumor microenvironment. The present study revealed that CD39 rs11188513, a single nucleotide polymorphism in the adenosine pathway, affected the clinical outcomes of 451 patients with metastatic colorectal cancer from 2 phase III clinical trials treated with FOLFIRI (5‐fluorouracil, leucovorin, oxaliplatin, irinotecan) plus bevacizumab.

Molecular biomarkers in gastro-esophageal cancer: recent developments, current trends and future directions

Gastro-esophageal adenocarcinomas (GEA) represent a severe global health burden and despite improvements in the multimodality treatment of these malignancies the prognosis of patients remains poor. HER2 overexpression/amplification has been the first predictive biomarker approved in clinical practice to guide patient selection for targeted treatment with trastuzumab in advanced gastric and gastro-esophageal junction cancers. More recently, immunotherapy has been approved for the treatment of GEA and PD-L1 expression is now a biomarker required for the administration of pembrolizumab in these diseases. Significant progress has been made in recent years in dissecting the genomic makeup of GEA in order to identify distinct molecular subtypes linked to distinct patterns of molecular alterations. GEA have been found to be highly heterogeneous malignances, representing a challenge for biomarkers discovery and targeted treatment development. The current review focuses on an overview of established and novel promising biomarkers in GEA, covering recent molecular classifications from TCGA and ACRG. Main elements of molecular heterogeneity are discussed, as well as emerging mechanisms of primary and secondary resistance to HER2 targeted treatment and recent biomarker-driven trials. Future perspectives on the role of epigenetics, miRNA/lncRNA and liquid biopsy, and patient-derived xenograft models as a new platform for molecular-targeted drug discovery in GEA are presented. Our knowledge on the genomic landscape of GEA continues to evolve, uncovering the high heterogeneity and deep complexity of these tumors. The availability of new technologies and the identification of promising novel biomarker will be critical to optimize targeted treatment development in a setting where therapeutic options are currently lacking. Nevertheless, clinical validation of novel biomarkers and treatment strategies still represents an issue.