Tackling Refractory Metastatic Colorectal Cancer: Future Perspectives

Colorectal Cancer: Genetic Underpinning and Molecular Therapeutics for Precision Medicine

Colorectal cancer (CRC) accounts for about 10% of all cancer cases and 9% of cancer-related deaths globally. In the United States alone, CRC represents approximately 12.6% of all cancer cases, with a mortality rate of about 8%. CRC is now the first leading cause of cancer death in men younger than age 50 and second in women younger than age 50. This review delves into the genetic landscape of CRC, highlighting key mutations and their implications in disease progression and treatment. We provide an overview of the current and emerging therapeutic strategies tailored to individual genomic profiles.

The Role of Beclin 1 and HER2 in Colorectal Carcinoma; An Immunohistochemical Study

OBJECTIVE

This study aimed to evaluate the expression of Beclin 1 and HER2 proteins using immunohistochemistry in CRC tissues compared to colonic adenoma, and to investigate the correlation of their expression with clinicopathological parameters and survival outcomes in CRC patients.

METHODS

The study utilized paraffin-embedded blocks from 17 colonic adenoma and 81 CRC cases. Immunohistochemical analysis was performed to assess the expression of Beclin 1 and HER2 proteins.

RESULTS

The cytoplasmic expression of Beclin 1 was significantly higher in CRC tissues compared to adenoma specimens (P=0.051). High Beclin 1 expression was significantly associated with distal colon location (P=0.028). High HER2 cytoplasmic expression was significantly associated with vascular invasion (P=0.05), perineural invasion (P=0.03), and shorter overall survival (P=0.035).

CONCLUSIONS

The findings suggest that Beclin 1 plays a role in colorectal carcinogenesis, with higher expression observed in CRC cases compared to adenoma cases.  Furthermore, HER2 carries poor prognostic impact in CRC cases.

Cardiac Interventions in Patients With Active, Advanced Solid and Hematologic Malignancies: JACC: CardioOncology State-of-the-Art Review

Invasive cardiac interventions are recommended to treat ST-segment elevation myocardial infarction, non-ST-segment elevation acute coronary syndromes, multivessel coronary disease, severe symptomatic aortic stenosis, and cardiomyopathy. These recommendations are based on randomized controlled trials that historically included few individuals with active, advanced malignancies. Advanced malignancies represent a significant competing risk for mortality, and there is limited evidence to inform the risks and benefits of invasive cardiac interventions in affected patients. We review the benefit conferred by invasive cardiac interventions; the periprocedural considerations; the contemporary survival expectations of patients across several types of active, advanced malignancy; and the literature on cardiovascular interventions in these populations. Our objective is to develop a rational framework to guide clinical recommendations on the use of invasive cardiac interventions in patients with active, advanced cancer.

Amentoflavone induces caspase-dependent/-independent apoptosis and dysregulates cyclin-dependent kinase-mediated cell cycle in colorectal cancer in vitro and in vivo

Colorectal cancer (CRC) is recognized as the third most common malignancy and the second most deadly in highly developed countries. Although the treatment of CRC has improved in the past decade, the mortality rate of CRC is still increasing. Amentoflavone, one of the flavonoids detected in medical plants, is reported to possess potential anticancer properties in various cancers. However, its role in CRC has not been studied. This study aimed to investigate the role and underlying mechanism of amentoflavone on CRC in vitro and in vivo. We identified the cytotoxicity, apoptosis effect, cell cycle alteration, DNA damage induction and tumor progression inhibition of amentoflavone in HT-29 model by using MTT assay, flow cytometry, immunofluorescence (IF) staining, Western blotting and animal experiments. Amentoflavone induced cytotoxicity is caused by triggering G1 arrest, DNA damage and apoptosis in HT-29 cells. The expression of cyclin D1, CDK4 and CDK6 was decreased by amentoflavone; in contrast, the phosphorylation of ATM and CHK2 and the expression of p21 and p27 were increased. The apoptosis induction of amentoflavone in CRC is not only caspase-dependent but also increases EndoG and AIF nuclear translocation in a caspase-independent manner. Importantly, the apoptosis induction of amentoflavone is not affected by the activity of p53 in CRC. Amentoflavone suppressed the progression of CRC by initiating G1 arrest and ATM/CHK2-mediated DNA damage-responsive, caspase-dependent/independent apoptotic effects. We uncovered a novel tumor-inhibitory role of amentoflavone in CRC that is not associated with p53 activity, which may serve as a potential treatment for CRC.

A Belgian Population-Based Study Reveals Subgroups of Right-Sided Colorectal Cancer with a Better Prognosis Compared to Left-sided Cancer

BACKGROUND

Patients with left-sided colorectal cancer (L-CRC) are known to have a significantly better prognosis than those with right-sided CRC (R-CRC). It has been hypothesized that RAS, BRAF mutations, or deficient mismatch repair status (MMR) might be responsible for the prognostic effect of primary tumor location (PTL). This study aims to evaluate the prognostic effect of PTL in the Belgian population and to determine the role of biomarkers (MMR, BRAF, and RAS status) in this effect.

PATIENTS AND METHODS

We performed a retrospective analysis of Belgian Cancer Registry data. First, we studied the prognostic effect of PTL on 5-year relative survival of 91 946 patients diagnosed with CRC (all stages) from 2004-2015. Second, we investigated the interaction between biomarkers and the prognostic effect of PTL in 1818 patients diagnosed with stage IV CRC in 2014-2015.

RESULTS

L-CRC was associated with a significantly better 5-year relative survival compared to R-CRC in all stages and ages combined (68.4%, 95% CI, 67.7-69.1% vs 65.6%, 95% CI, 64.7-66.4%). Also, when stratified by age, sex, and stage, the prognosis of L-CRC was better compared to R-CRC in most subgroups. Only in stage II and certain subgroups of elderly patients, the opposite was observed. Furthermore, our data showed that none of the biomarkers had a significant interaction with the effect of PTL on survival.

CONCLUSION

This population-based study confirms that L-CRC is associated with significantly better relative survival compared to R-CRC, in all stages and ages combined. Furthermore, in stage IV L-CRC is associated with a longer survival than R-CRC, regardless of MMR, RAS, and BRAF status.

Resistance to targeted therapy in metastatic colorectal cancer: Current status and new developments

Colorectal cancer (CRC) is one of the most lethal and common malignancies in the world. Chemotherapy has been the conventional treatment for metastatic CRC (mCRC) patients. However, the effects of chemotherapy have been unsatisfactory. With the advent of targeted therapy, the survival of patients with CRC have been prolonged. Over the past 20 years, targeted therapy for CRC has achieved substantial progress. However, targeted therapy has the same challenge of drug resistance as chemotherapy. Consequently, exploring the resistance mechanism and finding strategies to address the resistance to targeted therapy, along with searching for novel effective regimens, is a constant challenge in the mCRC treatment, and it is also a hot research topic. In this review, we focus on the current status on resistance to existing targeted therapies in mCRC and discuss future developments.

Rechallenge with anti-EGFR therapy to extend the continuum of care in patients with metastatic colorectal cancer

In patients with RAS wild-type metastatic colorectal cancer (mCRC), an anti-epidermal growth factor receptor (EGFR) monoclonal antibody plus chemotherapy is a standard option for treatment in the first-line setting. Patients who progress while on treatment with anti-EGFR-based therapy can be resistant to further anti-EGFR treatment, but evidence suggests that the anti-EGFR-resistant clones decay, thereby opening the potential for rechallenge or reintroduction in later lines of treatment. Results from recent clinical studies have shown that some patients with mCRC who are rechallenged with anti-EGFR monoclonal antibodies exhibit durable responses. While other therapies have demonstrated improved overall survival in chemorefractory mCRC over the past decade, rechallenge with anti-EGFR monoclonal antibodies in later lines of treatment represents a new option that deserves further investigation in clinical trials. In this review, we summarize the molecular rationale for rechallenge or reintroduction in patients with mCRC who have progressed on earlier-line anti-EGFR treatment and examine the current evidence for using liquid biopsy as a method for selecting rechallenge as a therapeutic option. We also provide an overview of published trials and trials in progress in this field, and outline the potential role of rechallenge in the current clinical setting.

Hyperforin Suppresses Oncogenic Kinases and Induces Apoptosis in Colorectal Cancer Cells

BACKGROUND/AIM

Signal transducer and activator of transcription 3 (STAT3), Janus Kinase 1 (JAK1), extracellular signal-regulated kinase (ERK), and protein kinase B (AKT) are essential for malignant transformation and progression in colorectal cancer (CRC) and can be considered as targets for therapeutic interventions. Hyperforin, an active constituent from Hypericum perforatum, has been reported to inhibit inflammation. However, whether hyperforin may suppress CRC progression via inactivation of JAK/STAT3, ERK or AKT signaling remains unclear.

MATERIALS AND METHODS

Human CRC cells were used to identify the treatment efficacy of hyperforin and its underlying mechanisms of action by MTT, flow cytometry, wound healing, and western blotting assays.

RESULTS

Hyperforin not only induced cytotoxicity, extrinsic/intrinsic apoptosis signaling, but also suppressed the invasion/migration ability of CRC. The phosphorylation of STAT3, JAK1, ERK and AKT was found to be decreased by hyperforin.

CONCLUSION

Hyperforin inactivates multiple oncogenic kinases and induces apoptosis signaling in CRC cells.

Current Progress of EMT: A New Direction of Targeted Therapy for Colorectal Cancer with Invasion and Metastasis

Colorectal cancer (CRC) is a common malignant tumor with a high frequency of recurrence and metastasis, which are the major causes of death in patients. The prerequisite for the invasion and metastasis is the strong mobility of CRC cells to transport far away from the original site to the distant organs and tissues, where they settle down and proliferate. It was reported that the epithelial-mesenchymal transition (EMT) is involved in the occurrence and development of various tumors in the entire process of tumor invasion and metastasis. Therefore, as a vital factor for the biological characteristics of tumor cells, EMT markers may serve as prognostic predictors and potential therapeutic targets in CRC. This article mainly reviews the current status of CRC with metastasis, the studies of EMT, the possible relationship of EMT with CRC, as well as the potential targeted therapy.

Prognostic and predictive molecular biomarkers in advanced colorectal cancer

The revolution of precision medicine has produced unprecedented seismic shifts in the treatment paradigm of advanced cancers. Among the major killers, colorectal cancer (CRC) is far behind the others. In fact, the great successes obtained in breast, NSCLC, melanoma, and genitourinary tract tumors have been observed only in fewer than 5 % metastatic colorectal cancer (mCRC): those with the mismatch repair deficiency (dMMR), a well-known predictive factor for to the outstanding efficacy of checkpoint inhibitors (CPI). The treatment of the remaining vast majority mCRC patients is still based upon only two molecular determinants: the RAS and BRAF mutational status. New promising biomarkers include HER2, tumor mutational burden (TMB) for its possible implications on CPI efficacy, and the extremely rare NTRK fusions. The Consensus Molecular Subtypes classification (CMS) is a good example of the efforts to combine different molecular features of this disease, although its relevance in clinical practice is still under investigation. In this Review, we focus on all these prognostic and predictive biomarkers, analyzing data from the most important clinical trials of the last years. We also try to rank them according to their prognostic and predictive power.

Studies of the Efficacy of Low-Dose Apatinib Monotherapy as Third-Line Treatment in Patients with Metastatic Colorectal Cancer and Apatinib’s Novel Anticancer Effect by Inhibiting Tumor-Derived Exosome Secretion

Simple Summary

We assessed the efficacy and safety of low-dose apatinib monotherapy as a third-line treatment in patients with metastatic colorectal cancer. The ORR and DCR were 4.0% (2/50) and 70% (35/50), and the median PFS and OS were 4.7 months and 10.1 months, which demonstrated comparable survival outcomes, significant improvements to the patient’s quality of life, and tolerable adverse reactions. We also disclosed a novel role of apatinib’s anticancer effect, i.e., inhibiting tumor-derived exosome release. Our results indicated that apatinib treatment inhibited exosome secretion through the regulation of MVB biogenesis, transport, and fusion by regulating LAMP2, RAB11, Snap23, and VAMP2. This novel regulatory mechanism provides a new perspective for the antitumor effect of apatinib in CRC treatment.

Abstract

Antiangiogenic therapy is an important treatment strategy for metastatic colorectal cancer (mCRC). We carried out a clinical study of low-dose apatinib (250 mg) monotherapy as a third-line treatment in patients with mCRC and assessed its efficacy and safety. It demonstrated that low-dose apatinib had comparable survival outcomes, significantly improved the patient quality of life, and caused tolerable adverse reactions. To further investigate the underlying mechanism of the effects of apatinib in CRC besides angiogenesis, we performed RNA-seq, and our results suggested that apatinib may have other potential antitumor mechanisms in CRC through multiple pathways, including exosomes secretion. In RKO and HCT116 cells, apatinib significantly reduced exosomes secretion by targeting multivesicular body (MVB) transport. Further studies have indicated that apatinib not only promoted the degradation of MVBs via the regulation of LAMP2 but also interfered with MVB transport by inhibiting Rab11 expression. Moreover, apatinib inhibited MVB membrane fusion by reducing SNAP23 and VAMP2 expression. In vivo, apatinib inhibited orthotopic murine colon cancer growth and metastasis and reduced the serum exosomes amount. This novel regulatory mechanism provides a new perspective for the antitumor effect of apatinib beyond angiogenesis inhibition.