Nivolumab in the treatment of microsatellite instability high metastatic colorectal cancer

Signaling pathways involved in colorectal cancer: pathogenesis and targeted therapy

Colorectal cancer (CRC) remains one of the leading causes of cancer-related mortality worldwide. Its complexity is influenced by various signal transduction networks that govern cellular proliferation, survival, differentiation, and apoptosis. The pathogenesis of CRC is a testament to the dysregulation of these signaling cascades, which culminates in the malignant transformation of colonic epithelium. This review aims to dissect the foundational signaling mechanisms implicated in CRC, to elucidate the generalized principles underpinning neoplastic evolution and progression. We discuss the molecular hallmarks of CRC, including the genomic, epigenomic and microbial features of CRC to highlight the role of signal transduction in the orchestration of the tumorigenic process. Concurrently, we review the advent of targeted and immune therapies in CRC, assessing their impact on the current clinical landscape. The development of these therapies has been informed by a deepening understanding of oncogenic signaling, leading to the identification of key nodes within these networks that can be exploited pharmacologically. Furthermore, we explore the potential of integrating AI to enhance the precision of therapeutic targeting and patient stratification, emphasizing their role in personalized medicine. In summary, our review captures the dynamic interplay between aberrant signaling in CRC pathogenesis and the concerted efforts to counteract these changes through targeted therapeutic strategies, ultimately aiming to pave the way for improved prognosis and personalized treatment modalities in colorectal cancer.

Deficient mismatch repair and BRAF-V600E-mutated metastatic colorectal cancer responds to nivolumab therapy after progression under bevacizumab plus FOLFIRI

Nivolumab, a PD-1 immune checkpoint inhibitor, has been demonstrated to be clinically effective in patients with deficient mismatch repair (dMMR) and BRAF-V600E-mutated metastatic colorectal cancer (mCRC). We present the case of an 81-year-old Taiwanese woman with mCRC who responded favorably to nivolumab for 20 months after the failure of bevacizumab plus FOLFIRI (5-fluorouracil, folinic acid, and irinotecan) treatment. The woman visited our institute and received a diagnosis of ascending colon cancer in December 2019. She underwent right hemicolectomy; the pathologic stage was T3N1bM0, stage IIIb. After 7 months, multiple liver metastases had developed and bevacizumab plus FOLFIRI were administered. However, the disease progressed even after targeted therapy plus chemotherapy. Since February 2021, she has received 3 mg/kg nivolumab biweekly and the best objective response has been found to be partial response as per the response evaluation criteria in solid tumors criteria. No severe adverse events have occurred. The patient has received 33 cycles of nivolumab over 20 months without exhibiting eventual tumor progression. Nivolumab could be considered for dMMR and BRAF-V600E-mutated mCRC that has progressed despite treatment with bevacizumab plus FOLFIRI.

Redefining the battle against colorectal cancer: a comprehensive review of emerging immunotherapies and their clinical efficacy

Colorectal cancer (CRC) is the third most common cancer globally and presents a significant challenge owing to its high mortality rate and the limitations of traditional treatment options such as surgery, radiotherapy, and chemotherapy. While these treatments are foundational, they are often poorly effective owing to tumor resistance. Immunotherapy is a groundbreaking alternative that has recently emerged and offers new hope for success by exploiting the body's own immune system. This article aims to provide an extensive review of clinical trials evaluating the efficacy of various immunotherapies, including CRC vaccines, chimeric antigen receptor T-cell therapies, and immune checkpoint inhibitors. We also discuss combining CRC vaccines with monoclonal antibodies, delve into preclinical studies of novel cancer vaccines, and assess the impact of these treatment methods on patient outcomes. This review seeks to provide a deeper understanding of the current state of CRC treatment by evaluating innovative treatments and their potential to redefine the prognosis of patients with CRC.

The potential of monoclonal antibodies for colorectal cancer therapy

Conventional chemotherapy has significant limitations for colorectal cancer (CRC) treatment, especially those who have developed metastatic recurrence CRC. A growing number of studies have investigated the potential use of monoclonal antibodies (mAbs) for CRC therapy. mAbs showing clinical benefits for CRC, making the treatment more selective with lower side effects without significant immunogenicity. In addition, recent advancements in antibody engineering strategies and the development of bifunctional or even trifunctional drugs have helped to overcome heterogeneity as the main challenge in cancer treatment. The current review discusses advances in applying mAbs for CRC therapy alone, combined, or with small molecules.

Role of tumor microenvironment in cancer progression and therapeutic strategy

Cancer is now considered a tumor microenvironment (TME) disease, although it was originally thought to be a cell and gene expression disorder. Over the past 20 years, significant advances have been made in understanding the complexity of the TME and its impact on responses to various anticancer therapies, including immunotherapies. Cancer immunotherapy can recognize and kill cancer cells by regulating the body's immune system. It has achieved good therapeutic effects in various solid tumors and hematological malignancies. Recently, blocking of programmed death-1 (PD-1), programmed death-1 ligand-1 (PD-L1), and programmed death Ligand-2 (PD-L2), the construction of antigen chimeric T cells (CAR-T) and tumor vaccines have become popular immunotherapies Tumorigenesis, progression, and metastasis are closely related to TME. Therefore, we review the characteristics of various cells and molecules in the TME, the interaction between PD-1 and TME, and promising cancer immunotherapy therapeutics.

Combining MEK and SRC inhibitors for treatment of colorectal cancer demonstrate increased efficacy in vitro but not in vivo

Metastatic colorectal cancer (mCRC) is the second leading cause of cancer deaths in the United States. More than 50% of patients with mCRC harbor mutations of the oncogenic driver RAS (KRAS or NRAS). Because directly targeting most mutations of RAS is technically challenging, researchers have concentrated on targeting MEK, a downstream mediator of RAS. However, targeting MEK as single-agent therapy is ineffective in patients with mCRC. We hypothesize that combining a MEK inhibitor with other agents can enhance the efficacy of MEK targeting in mCRC. Unbiased high-throughput screening (HTS) was performed to identify drugs that enhance the efficacy of MEK inhibitors. HTS was performed with KRAS-mutated CRC cells using the MEK inhibitor trametinib as a "backbone" and two "clinically ready" compound libraries approved by the U.S. Food and Drug Administration or in clinical trials. HTS demonstrated that the combination of the SRC inhibitor dasatinib and trametinib was synergistic in CRC cells in vitro (MTT and colony formation assays). Analysis of markers for cell proliferation and apoptosis using fluorescence-activated cell sorting, reverse-phase protein array, or Western blotting demonstrated decreased cell proliferation and increased cell death when targeting both SRC and MEK as compared to single agents in multiple CRC cell lines. However, combining dasatinib and trametinib in vivo at doses in mice equivalent to doses used in humans failed to significantly enhance the antitumor activity of trametinib when compared to that of trametinib alone. These results underscore the importance of performing careful preclinical in vivo validation studies using clinically relevant doses as a prerequisite for translating in vitro findings to the clinic.

Autologous humanized mouse models to study combination and single-agent immunotherapy for colorectal cancer patient-derived xenografts

Designing studies of immunotherapy is limited due to a lack of pre-clinical models that reliably predict effective immunotherapy responses. To address this gap, we developed humanized mouse models of colorectal cancer (CRC) incorporating patient-derived xenografts (PDX) with human peripheral blood mononuclear cells (PBMC). Humanized mice with CRC PDXs were generated via engraftment of autologous (isolated from the same patients as the PDXs) or allogeneic (isolated from healthy donors) PBMCs. Human T cells were detected in mouse blood, tissues, and infiltrated the implanted PDXs. The inclusion of anti-PD-1 therapy revealed that tumor responses in autologous but not allogeneic models were more comparable to that of patients. An overall non-specific graft-vs-tumor effect occurred in allogeneic models and negatively correlated with that seen in patients. In contrast, autologous humanized mice more accurately correlated with treatment outcomes by engaging pre-existing tumor specific T-cell populations. As autologous T cells appear to be the major drivers of tumor response thus, autologous humanized mice may serve as models at predicting treatment outcomes in pre-clinical settings for therapies reliant on pre-existing tumor specific T-cell populations.

Deciphering colorectal cancer immune microenvironment transcriptional landscape on single cell resolution - A role for immunotherapy

Single cell RNA sequencing (scRNA-seq) is a novel high-throughput technique that enables the investigation of a single cell's entire transcriptome. It elucidates intricate cellular networks and generates indices that will eventually enable the development of more targeted and personalized medications. The importance of scRNA-seq has been highlighted in complex biological systems such as cancer and the immune system, which exhibit significant cellular heterogeneity. Colorectal cancer (CRC) is the third most common type of cancer and the second leading cause of cancer-related death globally. Chemotherapy continues to be used to treat these patients. However, 5-FU has been utilized in chemotherapy regimens with oxaliplatin and irinotecan since the 1960s and is still used today. Additionally, chemotherapy-resistant metastatic CRCs with poor prognoses have been treated with immunotherapy employing monoclonal antibodies, immune checkpoint inhibitors, adoptive cell therapy and cancer vaccines. Personalized immunotherapy employing tumor-specific neoantigens allows for treating each patient as a distinct group. Sequencing and multi-omics approaches have helped us identify patients more precisely in the last decade. The introduction of modern methods and neoantigen-based immunotherapy may usher in a new era in treating CRC. The unmet goal is to better understand the cellular and molecular mechanisms that contribute to CRC pathogenesis and resistance to treatment, identify novel therapeutic targets, and make more stratified and informed treatment decisions using single cell approaches. This review summarizes current scRNA-seq utilization in CRC research, examining its potential utility in the development of precision immunotherapy for CRC.

STR Profiling Reveals Tumor Genome Instability in Primary Mediastinal B-Cell Lymphoma

Primary mediastinal B-cell lymphoma (PMBCL) is the only non-Hodgkin’s lymphoma variant responding to immune checkpoint inhibitor (ICI) therapy, approximately in half of the cases; however, no molecular markers predicting a response to ICI therapy in PMBCL have been described so far. In this study, we assessed the incidence of the loss of heterozygosity (LOH), elevated microsatellite alteration at selected tetranucleotides (EMAST), and microsatellite instability (MSI) in the tumor genomes of 72 patients with PMBCL undergoing high-dose chemotherapy treatment at the National Research Center for Hematology (Moscow, Russia). Tumor DNA was isolated from biopsy samples taken at diagnosis. Control DNA was isolated from the blood of patients in complete remission or from buccal epithelium. STR-profiles for LOH and EMAST were assessed by PCR with COrDIS Plus multiplex kit (Gordiz Ltd., Moscow, Russia). LOH was detected in 37 of 72 patients (51.4%). EMAST was found in 40 patients (55.5%); 24 had a combination of EMAST with LOH. MSI-high was not found, while MSI-low was detected only in one patient. The association of certain genetic lesions with the clinical outcome in patients receiving treatment according to the standard clinical protocol R-Da-EPOCH-21 has been estimated (58 patients out of 72) and no associations with the worst overall or event-free survival were found.

YPD-30, a prodrug of YPD-29B, is an oral small-molecule inhibitor targeting PD-L1 for the treatment of human cancer

PD-1 and PD-L1 antibodies have brought about extraordinary clinical benefits for cancer patients, and their indications are expanding incessantly. Currently, most PD-1/PD-L1 agents are administered intravenously, which may be uncomfortable for some cancer patients. Herein, we develop a novel oral-delivered small molecular, YPD-29B, which specifically targets human PD-L1. Our data suggested that YPD-29B could potently and selectively block the interaction between PD-L1 and PD-1, but did not inhibit any other immune checkpoints. Mechanistically, YPD-29B induced human PD-L1 dimerization and internalization, which subsequently activated T lymphocytes and therefore overcomes immunity tolerance in vitro. YDP-29B was modified as the YPD-30 prodrug to improve druggability. Using humanized mice with human PD-1 xenografts of human PD-L1 knock-in mouse MC38 cancer cells, we demonstrated that YPD-30 exhibited significant antitumor activity and was well tolerated in vivo. Taken together, our results indicate that YPD-30 serves as a promising therapeutic candidate for anti-human PD-L1 cancer immunotherapy.

Clinicopathological and Molecular Characteristics of Early-Onset Stage III Colon Adenocarcinoma: An Analysis of the ACCENT Database

BACKGROUND

Colon cancer (CC) incidence in young adults (age 20-49 years), termed early-onset CC (EO-CC), is increasing.

METHODS

Individual patient data on 35 713 subjects with stage III colon cancer from 25 randomized studies in the Adjuvant Colon Cancer ENdpoint database were pooled. The distributions of demographics, clinicopathological features, biomarker status, and outcome data were summarized by age group. Overall survival, disease-free survival, time to recurrence, and survival after recurrence were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for sex, race, body mass index, performance status, disease stage, grade, risk group, number of lymph nodes examined, disease sidedness, and molecular markers. All statistical tests were 2-sided.

RESULTS

Using a 5% difference between age groups as the clinically meaningful cutoff, patients with stage III EO-CC had similar sex, race, performance status, risk group, tumor sidedness, and T stage compared with patients with late-onset CC (age 50 years and older). EO-CC patients were less likely to be overweight (30.2% vs 36.2%) and more commonly had 12 or more lymph nodes resected (69.5% vs 58.7%). EO-CC tumors were more frequently mismatch repair deficient (16.4% vs 11.5%) and less likely to have BRAFV600E (5.6% vs 14.0%), suggesting a higher rate of Lynch syndrome in EO-CC. Patients with EO-CC had statistically significantly better overall survival (hazard ratio [HR] = 0.81, 95% confidence interval [CI] = 0.74 to 0.89; P < .001), disease-free survival (HR = 0.91, 95% CI = 0.84 to 0.98; P = .01), and survival after recurrence (HR = 0.88, 95% CI = 0.80 to 0.97; P = .008) in the analysis without molecular markers; however, age at onset of CC lost its prognostic value when outcome was adjusted for molecular markers.

CONCLUSION

Tumor biology was found to be a more important prognostic factor than age of onset among stage III colon cancer patients in the Adjuvant Colon Cancer ENdpoint database.

The Role of Oncogenes and Redox Signaling in the Regulation of PD-L1 in Cancer

Tumor cells can evade the immune system via multiple mechanisms, including the dysregulation of the immune checkpoint signaling. These signaling molecules are important factors that can either stimulate or inhibit tumor immune response. Under normal physiological conditions, the interaction between programmed cell death ligand 1 (PD-L1) and its receptor, programmed cell death 1 (PD-1), negatively regulates T cell function. In cancer cells, high expression of PD-L1 plays a key role in cancer evasion of the immune surveillance and seems to be correlated with clinical response to immunotherapy. As such, it is important to understand various mechanisms by which PD-L1 is regulated. In this review article, we provide an up-to-date review of the different mechanisms that regulate PD-L1 expression in cancer. We will focus on the roles of oncogenic signals (c-Myc, EML4-ALK, K-ras and p53 mutants), growth factor receptors (EGFR and FGFR), and redox signaling in the regulation of PD-L1 expression and discuss their clinical relevance and therapeutic implications. These oncogenic signalings have common and distinct regulatory mechanisms and can also cooperatively control tumor PD-L1 expression. Finally, strategies to target PD-L1 expression in tumor microenvironment including combination therapies will be also discussed.

Recent Advances in Anti-Metastatic Approaches of Herbal Medicines in 5 Major Cancers: From Traditional Medicine to Modern Drug Discovery

Metastasis is the main cause of cancer-related death. Despite its high fatality, a comprehensive study that covers anti-metastasis of herbal medicines has not yet been conducted. The aim of this study is to investigate and assess the anti-metastatic efficacies of herbal medicines in the five major cancers, including lung, colorectal, gastric, liver, and breast cancers. We collected articles published within five years using PubMed, Google Scholar, and Web of Science with "cancer metastasis" and "herbal medicine" as keywords. Correspondingly, 16 lung cancer, 23 colorectal cancer, 10 gastric cancer, 10 liver cancer, and 18 breast cancer studies were systematically reviewed. The herbal medicines attenuated metastatic potential targeting various mechanisms such as epithelial mesenchymal transition (EMT), reactive oxygen species (ROS), and angiogenesis. Specifically, the drugs regulated metastasis related factors such as matrix metalloproteinase (MMP), serine-threonine protein kinase/extracellular regulated protein kinase (AKT/ERK), angiogenic factors, and chemokines. Overall, the present study is the first review, comprehensively investigating the anti-metastasis effect of herbal medicines on five major cancers, providing the experimental models, doses and durations, and mechanisms. Herbal medicines could be a potent candidate for anti-metastatic drugs.

Druggable targets meet oncogenic drivers: opportunities and limitations of target-based classification of tumors and the role of Molecular Tumor Boards

The therapeutic landscape of cancer is changing rapidly due to the growing number of approved drugs capable of targeting specific genetic alterations. This aspect, together with the development of noninvasive methods for the assessment of somatic mutations in the peripheral blood of patients, generated a growing interest toward a new tumor-agnostic classification system based on ‘predictive’ biomarkers. The current review article discusses this emerging alternative approach to the classification of cancer and its implications for the selection of treatments. It is suggested that different types of cancers sharing the same molecular profiles could benefit from the same targeted drugs. Although recent clinical trials have demonstrated that this approach cannot be generalized, there are also specific examples that demonstrate the clinical utility of this alternative vision. In this rapidly evolving scenario, a multidisciplinary approach managed by institutional Molecular Tumor Boards is fundamental to interpret the biological and clinical relevance of genetic alterations and the complexity of their relationship with treatment response.

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The identification of oncogenic drivers offers the opportunity to develop target-specific drugs.

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The inhibition of crucial pathways realizes the principle of druggable target to exploit cancer vulnerability.

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The approval of new anticancer agents based on target-based concept represents a paradigm shift in cancer therapy.

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However, only few drugs have been approved so far on an agnostic basis and the concept of biomarker cannot be generalized.

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Tumor Molecular Boards will have an increasing role in the identification of new therapeutic options in selected patients.

Gutting it Out: Developing Effective Immunotherapies for Patients With Colorectal Cancer

Risk factors for colorectal cancer (CRC) include proinflammatory diets, sedentary habits, and obesity, in addition to genetic syndromes that predispose individuals to this disease. Current treatment relies on surgical excision and cytotoxic chemotherapies. There has been a renewed interest in immunotherapy as a treatment option for CRC given the success in melanoma and microsatellite instable (MSI) CRC. Immunotherapy with checkpoint inhibitors only plays a role in the 4%-6% of patients with MSIhigh tumors and even within this subpopulation, response rates can vary from 30% to 50%. Most patients with CRC do not respond to this modality of treatment, even though colorectal tumors are frequently infiltrated with T cells. Tumor cells limit apoptosis and survive following intensive chemotherapy leading to drug resistance and induction of autophagy. Pharmacological or molecular inhibition of autophagy improves the efficacy of cytotoxic chemotherapy in murine models. The microbiome clearly plays an etiologic role, in some or most colon tumors, realized by elegant findings in murine models and now investigated in human clinical trials. Recent results have suggested that cancer vaccines may be beneficial, perhaps best as preventive strategies. The search for therapies that can be combined with current approaches to increase their efficacy, and new knowledge of the biology of CRC are pivotal to improve the care of patients suffering from this disease. Here, we review the basic immunobiology of CRC, current "state-of-the-art" immunotherapies and define those areas with greatest therapeutic promise for the future.

Application of Next Generation Sequencing in Laboratory Medicine

The rapid development of next-generation sequencing (NGS) technology, including advances in sequencing chemistry, sequencing technologies, bioinformatics, and data interpretation, has facilitated its wide clinical application in precision medicine. This review describes current sequencing technologies, including short- and long-read sequencing technologies, and highlights the clinical application of NGS in inherited diseases, oncology, and infectious diseases. We review NGS approaches and clinical diagnosis for constitutional disorders; summarize the application of U.S. Food and Drug Administration-approved NGS panels, cancer biomarkers, minimal residual disease, and liquid biopsy in clinical oncology; and consider epidemiological surveillance, identification of pathogens, and the importance of host microbiome in infectious diseases. Finally, we discuss the challenges and future perspectives of clinical NGS tests.

Immunotherapy with Checkpoint Inhibitors for Hepatocellular Carcinoma: Where Are We Now?

Immune checkpoint inhibitors (ICIs) are beginning to show promise in the clinical management of hepatocellular carcinoma (HCC). Most recently, the anti-programmed death protein-1 (PD-1) agent atezolizumab combined with bevacizumab demonstrated superiority to sorafenib in a Phase 3 randomised clinical trial in the frontline setting. Other ongoing trials of immunotherapy for HCC are exploring different drug combinations, such as a double checkpoint blockade with PD-1 and anti-Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) agents or with tyrosine kinase inhibitors. Moreover, ICIs are being tested in the adjuvant and neoadjuvant settings trying to resolve long-time unmet needs in HCC. The results of the ongoing trials will be critical to understanding the extent of the therapeutic role of ICIs in the complex and multifaceted clinical scenario of HCC. Still, there are some critical points which need further attention to clarify the best use of ICIs in HCC patients. For instance, the actual eligibility rate of patients in the real-life scenario, the prompt identification and correct management of immune-mediated adverse events, the identification of biomarkers predicting response or resistance, and strategies to prevent the tumour escape from ICI effect.

Pathology-based Biomarkers Useful for Clinical Decisions in Melanoma

The dramatic recent advances in therapy of melanoma require a more personalized and precise diagnostic approach to aid in clinical decisions. Tissue-based biomarkers in pathology have diagnostic, prognostic and predictive relevance. Herein we review the most commonly used pathology-based biomarkers in melanoma. Most of these biomarkers are evaluated through immunohistochemistry (IHC) or fluorescent in situ hybridization (FISH) performed on formalin fixed paraffin embedded tissue (FFPE), and are widely available in clinical pathology laboratories. We describe the utility of MART1/Ki67, p16, PRAME, markers of lymphovascular invasion (D2-40, CD31, D2-40/MITF, CD31/SOX-10), BRAF V600E, NRAS, KIT, BAP1, ALK, NTRK, PD-L1, TERT, PTEN, iNOS, and MMR proteins (MLH1, MSH2, MSH6, PMS2) in the evaluation of melanoma specimens. Correct interpretation and awareness of the significance of these biomarkers is crucial for pathologists, dermatologists, and oncologists who take care of melanoma patients.

Adjuvant Effect of Toll-Like Receptor 9 Activation on Cancer Immunotherapy Using Checkpoint Blockade

Immunotherapy using checkpoint blockade has revolutionized cancer treatment, improving patient survival and quality of life. Nevertheless, the clinical outcomes of such immunotherapy are highly heterogeneous between patients. Depending on the cancer type, the patient response rates to this immunotherapy are limited to 20–30%. Based on the mechanism underlying the antitumor immune response, new therapeutic strategies have been designed with the aim of increasing the effectiveness and specificity of the antitumor immune response elicited by checkpoint blockade agents. The activation of toll-like receptor 9 (TLR9) by its synthetic agonists induces the antitumor response within the innate immunity arm, generating adjuvant effects and priming the adaptive immune response elicited by checkpoint blockade during the effector phase of tumor-cell killing. This review first describes the underlying mechanisms of action and current status of monotherapy using TLR9 agonists and immune checkpoint inhibitors for cancer immunotherapy. The rationale for combining these two agents is discussed, and evidence indicating the current status of such combination therapy as a novel cancer treatment strategy is presented.

Improvements in Clinical Outcomes for BRAFV600E -Mutant Metastatic Colorectal Cancer

Although the last two decades have seen a broad improvement in overall survival, colorectal cancer is still the second leading cause of cancer deaths worldwide. Patient populations continue to face poor disease prognoses due to the challenges of early detection and the molecular subtypes driving their colorectal cancer. Consequently, many patients present with metastatic colorectal cancer, which often limits options and shifts treatment focus away from curative interventions. BRAF^V600E mutations are present in approximately 10% of colorectal cancer tumors and are associated with uninhibited cell proliferation, reduced apoptosis, and resistance to standard therapeutic options. In colorectal cancer, BRAF^V600E mutations are associated with decreased overall survival, poor treatment responses, and different patterns of metastatic spread compared with tumors with wild-type BRAF Success in treating other BRAF^V600E -mutant cancers with BRAF inhibitors as monotherapy has not translated into efficacious treatment of metastatic colorectal cancer. Consequently, combination therapy with inhibitors of BRAF, MEK, and EGFR, which overcomes the innate treatment-resistant characteristics of BRAF ^V600E-mutant colorectal cancer, is now recommended by treatment guidelines.

Endocrine-Related Adverse Events Related to Immune Checkpoint Inhibitors: Proposed Algorithms for Management

Immune checkpoint inhibitors have proven to be effective for various advanced neoplasia. Immune-related adverse events (irAEs) as a result of increased T cell activation are unique and potentially life-threating toxicities associated with the use of immune checkpoint inhibitors. Multiple endocrine irAEs, including primary hyperthyroidism and hypothyroidism, thyroiditis, primary adrenal insufficiency, type 1 diabetes mellitus, and hypophysitis, have been reported with the use of various immune checkpoint inhibitors. In some cases, these irAEs can lead to discontinuation of treatment. Here we propose for the general oncologist algorithms for managing endocrine irAEs to aid in the clinical care of patients receiving immunotherapy. KEY POINTS: There is a relative high risk of endocrine immune-related adverse events (irAEs) during therapy with checkpoint inhibitors, particularly when combination therapy is implemented. Patients treated with anti-CTLA-4 antibodies have an increased risk of hypophysitis, whereas patients treated with anti-PD-1/PD-L1 antibodies have a higher risk of primary thyroid dysfunction. Rarely, patients develop T1DM and central diabetes insipidus, and hypoparathyroidism is a rare occurrence. A growing clinical understanding of endocrine irAEs has led to effective treatment strategies with hormone replacement.

Fruquintinib: a novel antivascular endothelial growth factor receptor tyrosine kinase inhibitor for the treatment of metastatic colorectal cancer

Angiogenesis plays a critical role in the neoplastic growth, progression, and metastasis of colorectal cancer (CRC) in a process regulated by vascular endothelial growth factor (VEGF) family members and their receptors (VEGFR). Several small-molecule anti-VEGFR tyrosine kinase inhibitors (TKIs), such as regorafenib, famitinib, axitinib and apatinib, have been shown to be effective in treating metastatic colorectal cancer (mCRC). Fruquintinib (ELUNATE^®) is a novel oral anti-VEGFR TKI, originated and developed by Hutchison MediPharma. Fruquintinib is a potent and highly selective small-molecule inhibitor of VEGFR-1, -2 and -3. In the Phase 3 FRESCO trial, fruquintinib improved both overall survival (OS) and progression-free survival (PFS) in patients with mCRC, compared with placebo. Fruquintinib also showed an acceptable safety and tolerability profile. Based on the data from this trial, fruquintinib was approved by the China Food and Drug Administration (CFDA) in 2018, for the treatment of patients with mCRC who had undergone at least two prior standard anticancer therapies. The existing clinical trials and future prospects of fruquintinib in mCRC will be discussed in this article. In addition, to better understand the role of fruquintinib in this setting, recent advances in other anti-VEGFR TKIs for mCRC treatment are also reviewed herein.

Pseudo progression in heterogeneity of right-sided metastatic colon carcinoma during nivolumab therapy: A case report

RATIONALE

Pseudo progression is a noted phenomenon of immune checkpoint inhibitors therapy, which has been defined as a response after an initial enlargement of the tumor followed by tumor reduction. In July 2017, the Food and Drug Administration granted accelerated approval of nivolumab for the treatment of metastatic colorectal cancer patients whose tumor harbors deficient mismatch repair.

PATIENT CONCERNS AND DIAGNOSIS

We present a patient who received nivolumab for heterogeneity of right-sided metastatic colon carcinoma.

INTERVENTION

The patient was treated with nivolumab combined with chemotherapy.

OUTCOME

The computed tomography showed mass lesion in the left lobe of liver remained stable while metastasis tumors under envelop of liver were exacerbated after 6 cycles of nivolumab combined with chemotherapy, and later regressed.

LESSONS

The status of mismatch repair in primary tumor and metastatic liver carcinoma is contradictory but using nivolumab demonstrated encouraging efficacy. This is the first case of pseudo progression undergoing immunotherapy for heterogeneity of right-sided metastatic colon carcinoma.

Bone Marrow Findings of Immune-Mediated Pure Red Cell Aplasia Following Anti-Programmed Cell Death Receptor-1 Therapy: A Report of Two Cases and Review of Literature

Immune checkpoint inhibitors have recently emerged as important and effective advanced cancer treatment options. Programmed cell death receptor-1 (PD-1) antagonists such as pembrolizumab and nivolumab have been approved by the US Food and Drug Administration for treatment of many advanced cancers. As anti-PD-1 checkpoint inhibitor use has been increasing, previously unreported rare side effects emerge. These checkpoint inhibitors upregulate humoral and cellular immune responses to tumor antigens. Consequently, they can be associated with immune-related adverse events including hematological-related reactions such as autoimmune hemolytic anemia, immune thrombocytopenia, neutropenia and pancytopenia. However, pure red cell aplasia (PRCA) induced by anti-PD-1 checkpoint inhibitors is rarely reported in the literature. We herein report cases of two patients who developed PRCA during treatment with anti-PD-1 checkpoint inhibitors. In both cases, a peripheral blood smear examination demonstrated reticulocytopenia. Bone marrow biopsies revealed severe erythroid hypoplasia with maturation arrest at the proerythroblast stage, relative granulocytic hyperplasia and lymphocytosis. Flow cytometry and immunohistochemistry revealed that the lymphocytes were predominantly CD8⁺ T cells. T lymphocytosis, especially in one of the two patients, mimicked a T-cell lymphoproliferative disorder; lack of clonality indicated a reactive process. Our findings, in addition to data presented in the literature, suggest that T cells play a critical role in the pathogenesis of immune-related PRCA. PRCA is an under-recognized immune-mediated adverse event that does not manifest during the clinical trial phase. It is a potentially life-threatening complication, which should be considered in the differential diagnosis of anemia in patients treated with anti-PD-1 checkpoint inhibitors.

Exploiting DNA repair defects in colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. Therapies that take advantage of defects in DNA repair pathways have been explored in the context of breast, ovarian, and other tumor types, but not yet systematically in CRC. At present, only immune checkpoint blockade therapies have been FDA approved for use in mismatch repair-deficient colorectal tumors. Here, we discuss how systematic identification of alterations in DNA repair genes could provide new therapeutic opportunities for CRCs. Analysis of The Cancer Genome Atlas Colon Adenocarcinoma (TCGA-COAD) and Rectal Adenocarcinoma (TCGA-READ) PanCancer Atlas datasets identified 141 (out of 528) cases with putative driver mutations in 29 genes associated with DNA damage response and repair, including the mismatch repair and homologous recombination pathways. Genetic defects in these pathways might confer repair-deficient characteristics, such as genomic instability in the absence of homologous recombination, which can be exploited. For example, inhibitors of poly(ADP)-ribose polymerase are effectively used to treat cancers that carry mutations in BRCA1 and/or BRCA2 and have shown promising results in CRC preclinical studies. HR deficiency can also occur in cells with no detectable BRCA1/BRCA2 mutations but exhibiting BRCA-like phenotypes. DNA repair-targeting therapies, such as ATR and CHK1 inhibitors (which are most effective against cancers carrying ATM mutations), can be used in combination with current genotoxic chemotherapies in CRCs to further improve therapy response. Finally, therapies that target alternative DNA repair mechanisms, such as thiopurines, also have the potential to confer increased sensitivity to current chemotherapy regimens, thus expanding the spectrum of therapy options and potentially improving clinical outcomes for CRC patients.

Oxaliplatin-Based Intra-arterial Chemotherapy in Colo-Rectal Cancer Liver Metastases: A Review from Pharmacology to Clinical Application

Liver metastases (LM) are often consequences of colo-rectal cancer (CRC)and the majority of patients have unresectable LM. Oxaliplatin-based intravenous chemotherapy represents the gold standard treatment for CRC. Intravenous oxaliplatin has several side effects i.e., nephrologic, hematologic and neurological toxicity. Moreover, hepatic arterial infusion (HAI) of antitumor drugs deeply modifies the treatment of LMCRC due to the knowledge that LM are perfused by the hepatic artery network, whereas healthy tissue is perfused by the portal vein. Therefore, oxaliplatin-based HAI becomes an interesting possibility to treat LMCRC. The aim of this review is to shed light on the important impact of the oxaliplatin-based chemotherapy from a non-conventional clinical point of view, considering that, being universally accepted its antitumor effect if administered intravenously, fragmentary information are known about its clinical applications and benefits deriving from intra-arterial administration in loco-regional chemotherapy.

The capability and potential of new forms of personalized colon cancer treatment: Immunotherapy and Photodynamic Therapy

INTRODUCTION

PDT can interfere with cytokine-mediated responses that play an important role in the processes of cancer progression, tumor angiogenesis and metastasis. Therefore, based on the identification of these cancer biomarkers, the therapy of combining various forms of treatment, including immunotherapy and PDT, may be a justified strategy for colorectal cancer treatment that focuses on individualized comprehensive therapy.

METHOD

We reviewed the major approaches on the use of immunotherapy in colorectal cancer, with the special regard to photodynamic therapy, its immunological effect and new oncological treatment directions, connected with adjuvant immunotherapy including use of nanoparticles. Databases such as PubMed, ScienceDirect and Springer were utilized to search the literature for relevant articles.

PURPOSE

To review studies of the immunotherapy in colon cancer and immune response to PDT.

CONCLUSION

Based on the identification of immunological cancer biomarkers, the therapy of combining various forms of treatment, including immunotherapy and PDT, may be a justified strategy for colorectal cancer treatment that focuses on individualized comprehensive therapy.

Targeting Colon Cancers with Mutated BRAF and Microsatellite Instability

The subgroup of colon cancer (CRC) characterized by mutation in the BRAF gene and high mutation rate in the genomic DNA sequence, known as the microsatellite instability (MSI) phenotype, accounts for roughly 10% of the patients and derives from polyps with a serrated morphology. In this review, both features are discussed with regard to therapeutic opportunities. The most prevalent cancer-associated BRAF mutation is BRAF V600E that causes constitutive activation of the pro-proliferative MAPK pathway. Unfortunately, the available BRAF-specific inhibitors had little clinical benefit for metastatic CRC patients due to adaptive MAPK reactivation. Recent contributions for the development of new combination therapy approaches to pathway inhibition will be highlighted. In addition, we review the promising role of the recently developed immune checkpoint therapy for the treatment of this CRC subtype. The MSI phenotype of this subgroup results from an inactivated DNA mismatch repair system and leads to frameshift mutations with translation of new amino acid stretches and the generation of neo-antigens. This most likely explains the observed high degree of infiltration by tumour-associated lymphocytes. As cytotoxic lymphocytes are already part of the tumour environment, their activation by immune checkpoint therapy approaches is highly promising.