HER2-Positive Gastric Cancer: The Role of Immunotherapy and Novel Therapeutic Strategies.

Gastric cancer is an aggressive disease with increasing global incidence in recent years. Human epidermal growth receptor 2 (HER2) is overexpressed in approximately 10-20% of gastric cancers. The implementation of targeted therapy against HER2 as part of the standard of care treatment in metastatic disease has improved the prognosis of this subset of patients. However, gastric cancer still has high mortality rates and urgently requires new treatment strategies. The combination of immunotherapy with HER2-targeted therapies has shown synergistic effects in preclinical models, this being the rationale behind exploring this combination in clinical trials in locally advanced and metastatic settings. Additionally, the irruption of antibody-drug conjugates and other novel HER2-targeted agents has led to the development of numerous clinical trials showing promising results. This review presents the molecular mechanisms supporting the use of HER2-targeted drugs in combination with immunotherapy and provides an overview of the therapeutic scenario of HER2-positive disease. We focus on the role of immunotherapy but also summarize emerging therapies and combinations under clinical research that may change the standard treatment in HER-2 positive disease in the future.

Treatment of Advanced BRAF-Mutated Colorectal Cancer: Where We Are and Where We Are Going.

In recent years, studies on the molecular typing of colorectal cancer have matured, and the V-raf murine sarcoma viral oncogene homolog B (BRAF) of the mitogen-activated protein kinase pathway has been shown to be an important effector molecule of this pathway and regulates the occurrence and development of colorectal cancer. Clinical observations indicate that colorectal cancer patients harboring the BRAF V600E mutation have a worse prognosis than BRAF wild type patients. Several resistance mechanisms have been identified that have led to the development of different treatment strategies, which have shown encouraging activity in early clinical trials. Therefore, a reasonable combination of targeted therapies is expected to further enhance the efficacy of selective BRAF inhibitors. Moreover, some CRC patients with high microsatellite instability or a mismatch repair deficiency seem to be susceptible to checkpoint inhibitors with objective and sustained clinical responses, providing new opportunities for patients with advanced disease. This article primarily explores 3 aspects of the treatment strategies for advanced BRAF-mutated colorectal cancer; chemotherapy, targeted therapy, and immunotherapy.

Quality of life of patients with metastatic pancreatic adenocarcinoma initiating first-line chemotherapy in routine practice.

BACKGROUND: Despite advances in surgery, radiotherapy, and chemotherapy, pancreatic adenocarcinoma often progresses rapidly and causes death. The physical decline of these patients is expected to impact their quality of life (QoL). Therefore, in addition to objective measures of effectiveness, the evaluation of health-related QoL should be considered a matter of major concern when assessing therapy outcomes. METHODS: Observational, prospective, multicenter study including patients with metastatic pancreatic adenocarcinoma who started first-line chemotherapy in 12 Spanish centers. Treatment and clinical characteristics were recorded at baseline. Patients' health-related quality of life, ECOG, and Karnofsky index were measured at baseline, at Days 15 and 30, and every four weeks up to 6 months of chemotherapy. Health-related quality of life was measured using the EORTC-QLQ-C30 and EQ-5D questionnaires. Other endpoints included overall survival and progression-free survival. RESULTS: The study sample included 116 patients (median age of 65 years). Mean (SD) scores for the QLQ-C30 global health status scale showed a significant increasing trend throughout the treatment (p = 0.005). Patients with either a Karnofsky index of 70-80 or ECOG 2 showed greater improvement in the QLQ-C30 global health status score than the corresponding groups with better performance status (p ≤ 0.010). Pain, appetite, sleep disturbance, nausea, and constipation significantly improved throughout the treatment (p < 0.005). Patients with QLQ-C30 global health status scores ≥50 at baseline had significantly greater overall survival and progression-free survival (p = 0.005 and p = 0.021, respectively). No significant associations were observed regarding the EQ-5D score. CONCLUSIONS: Most metastatic pancreatic adenocarcinoma patients receiving first-line chemotherapy showed an increase in health-related quality of life scores throughout the treatment. Patients with lower performance status and health-related quality of life at baseline tended to greater improvement. The EORTC QLQ-C30 scale allowed us to measure the health-related quality of life of metastatic pancreatic adenocarcinoma patients receiving first-line chemotherapy.

Rectal neuroendocrine carcinoma: case report of a rare entity and perspective review of promising agents.

Neuroendocrine neoplasms (NENs) comprise a heterogeneous group of tumours, which can be classified into neuroendocrine tumours (NETs), neuroendocrine carcinomas (NECs) and mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs). To date, there is no consensus regarding the optimal therapy, which usually depends on the primary location and classification, according to morphological features of differentiation and proliferation rates. Nevertheless, multidisciplinary strategies combining medical treatments and locoregional strategies have yielded better efficacy results. Here, we report the case of a patient diagnosed with a nonfunctional rectal NECs with metastatic widespread to pelvic lymph nodes and bilateral lung metastases. The patient received three cycles of platinum-etoposide, concomitantly with palliative radiotherapy. Although CT scan after three cycles showed a significant partial response, there was an early fatal progression only 3 months after having stopped systemic therapy. As formerly described in the literature, this case highlights the aggressive behaviour of NECs, rare tumours that often present in advanced stages at diagnosis. Lately, new insights into the molecular biology of NECs have unveiled the possibility of using novel drugs, such as targeted agents or immunotherapy, in molecularly selected subgroups of patients. In this review, we discuss the current management of this rare entity and provide an overview of the most relevant molecular findings, whilst illustrating the potential value that prescreening panels can offer, searching for actionable targets (MSI/dMMR, PD-L1, BRAFv600E) to guide therapy with promising agents that could fill a void in this disease.

Tumor Expression of Cyclin-Dependent Kinase 5 (Cdk5) Is a Prognostic Biomarker and Predicts Outcome of Oxaliplatin-Treated Metastatic Colorectal Cancer Patients.

In recent years, an increasing number of studies have shown that elevated expression of cyclin dependent kinase (Cdk5) contributes to the oncogenic initiation and progression of many types of cancers. In this study, we investigated the expression pattern of Cdk5 in colorectal cancer (CRC) cell lines and in a large number of tumor samples in order to evaluate its relevance in this pathogenesis and possible use as a prognostic marker. We found that Cdk5 is highly expressed and activated in CRC cell lines and that silencing of the kinase decreases their migration ability. In tumor tissues, Cdk5 is overexpressed compared to normal tissues due to a copy number gain. In patients with localized disease, we found that high Cdk5 levels correlate with poor prognosis, while in the metastatic setting, this was only the case for patients receiving an oxaliplatin-based treatment. When exploring the Cdk5 levels in the consensus molecular subtypes (CMS), we found the lowest levels in subtype 1, where high Cdk5 again was associated with a poorer prognosis. In conclusion, we confirm that Cdk5 is involved in CRC and disease progression and that it could serve as a prognostic and predictive biomarker in this disease.

Resistant mechanisms to BRAF inhibitors in melanoma.

Patients with advanced melanoma have traditionally had very poor prognosis. However, since 2011 better understanding of the biology and epidemiology of this disease has revolutionized its treatment, with newer therapies becoming available. These newer therapies can be classified into immunotherapy and targeted therapy. The immunotherapy arsenal includes inhibitors of CTLA4, PD-1 and PDL-1, while targeted therapy focuses on BRAF and MEK. BRAF inhibitors (vemurafenib, dabrafenib) have shown benefit in terms of overall survival (OS) compared to chemotherapy, and their combination with MEK inhibitors has recently been shown to improve progression-free survival (PFS), compared with monotherapy with BRAF inhibitors. However, almost 20% of patients initially do not respond, due to intrinsic resistance to therapy and, of those who do, most eventually develop mechanisms of acquired resistance, including reactivation of the MAP kinase pathway, persistent activation of receptor tyrosine kinase (RTKS) receptor, activation of phosphatidyinositol-3OH kinase, overexpression of epidermal growth factor receptor (EGFR), and interactions with the tumor microenvironment. Herein we comment in detail on mechanisms of resistance to targeted therapy and discuss the strategies to overcome them.

Curcumin mediates oxaliplatin-acquired resistance reversion in colorectal cancer cell lines through modulation of CXC-Chemokine/NF-κB signalling pathway.

Resistance to oxaliplatin (OXA) is a complex process affecting the outcomes of metastatic colorectal cancer (CRC) patients treated with this drug. De-regulation of the NF-κB signalling pathway has been proposed as an important mechanism involved in this phenomenon. Here, we show that NF-κB was hyperactivated in in vitro models of OXA-acquired resistance but was attenuated by the addition of Curcumin, a non-toxic NF-κB inhibitor. The concomitant combination of Curcumin + OXA was more effective and synergistic in cell lines with acquired resistance to OXA, leading to the reversion of their resistant phenotype, through the inhibition of the NF-κB signalling cascade. Transcriptomic profiling revealed the up-regulation of three NF-κB-regulated CXC-chemokines, CXCL8, CXCL1 and CXCL2, in the resistant cells that were more efficiently down-regulated after OXA + Curcumin treatment as compared to the sensitive cells. Moreover, CXCL8 and CXCL1 gene silencing made resistant cells more sensitive to OXA through the inhibition of the Akt/NF-κB pathway. High expression of CXCL1 in FFPE samples from explant cultures of CRC patients-derived liver metastases was associated with response to OXA + Curcumin. In conclusion, we suggest that combination of OXA + Curcumin could be an effective treatment, for which CXCL1 could be used as a predictive marker, in CRC patients.

Tumor-Related Molecular Mechanisms of Oxaliplatin Resistance.

Oxaliplatin was the first platinum drug with proven activity against colorectal tumors, becoming a standard in the management of this malignancy. It is also considered for the treatment of pancreatic and gastric cancers. However, a major reason for treatment failure still is the existence of tumor intrinsic or acquired resistance. Consequently, it is important to understand the molecular mechanisms underlying the appearance of this phenomenon to find ways of circumventing it and to improve and optimize treatments. This review will be focused on recent discoveries about oxaliplatin tumor-related resistance mechanisms, including alterations in transport, detoxification, DNA damage response and repair, cell death (apoptotic and nonapoptotic), and epigenetic mechanisms.