Metastatic colorectal cancer: therapeutic options for treating refractory disease

Development of lactate-related gene signature and prediction of overall survival and chemosensitivity in patients with colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a malignant tumor of the digestive system that contains high levels of immune cells. Lactic acid, a major metabolite, plays a crucial role in tumor development, maintenance, and therapeutic response. However, the prognostic potential and therapeutic biomarker potential of lactate-related genes (LRGs) in CRC patients remain to be elucidated.

METHODS

We collected the mRNA expression profile and clinical data of CRC patients from the Cancer Genome Atlas (TCGA) database and the GSE59382 cohort. Univariate Cox regression, Lasso regression and multivariate Cox regression analysis were used to construct the prognosis model. Combined with the risk score and important clinicopathological features, the nomogram was established. In addition, the relationship between risk score and immune infiltration, immune checkpoint gene expression, and drug sensitivity was investigated.

RESULTS

We constructed lactate-related gene signatures (LRGS) based on four LRGs, which independently predicted the prognosis of CRC. Patients with different risk scores are found to have distinct immune status, tumor mutation load, immune response, and drug sensitivity. In addition, nomogram results determined by risk scores and clinical factors have higher predictive performance.

CONCLUSION

We found that LRGS is a reliable biomarker for predicting clinical outcomes, evaluating immune infiltration and efficacy, and predicting the sensitivity to drugs in patients with CRC.

Microwave ablation induces abscopal effect via enhanced systemic antitumor immunity in colorectal cancer

Background

Thermal ablation is the primary procedure for the local treatment of lung metastases. It is known that radiotherapy and cryoablation can stimulate an abscopal effect, while the occurrence of abscopal effect induced by microwave ablation is less; the cellular and molecular mechanisms involved in the abscopal effect after microwave ablation should be further elucidated.

Methods

CT26 tumor-bearing Balb/c mice were treated with microwave ablation with several combinations of ablation power and time duration. The growth of primary or abscopal tumors and the survival of mice were both monitored; moreover, immune profiles in abscopal tumors, spleens, and lymph nodes were examined by flow cytometry.

Results

Microwave ablation suppressed tumor growth in both primary and abscopal tumors. Both local and systemic T-cell responses were induced by microwave ablation. Furthermore, the mice exhibiting significant abscopal effect after microwave ablation markedly elevated Th1 cell proportion both in the abscopal tumors and spleens.

Conclusions

Microwave ablation at 3 w-3 min not only suppressed tumor growth in the primary tumors but also stimulated an abscopal effect in the CT26-bearing mice via the improvement of systemic and intratumoral antitumor immunity.

Hepatic arterial infusion chemotherapy plus regorafenib in advanced colorectal cancer: a real-world retrospective study

Background

Hepatic arterial infusion chemotherapy delivers the drug directly to the liver. We aim to explore the benefits and tolerability of Hepatic arterial infusion chemotherapy plus regorafenib in advanced colorectal liver metastasis refractory to standard systemic chemotherapy.

Methods

This study analyzed 47 patients treated with hepatic arterial infusion chemotherapy plus regorafenib after standard systemic oxaliplatin and/or irinotecan in combination with bevacizumab or cetuximab between Jan 2017 and Jun 2020. Regorafenib was given for only 3 weeks in a 4-week cycle.

Results

Among 47 patients, 32 (68%) were males. The median age was 61 (29–75). With a median follow-up of 22.2 months (3.7–50.7 months). Before Hepatic arterial infusion chemotherapy administration in combination with regorafenib, 34 (72.3%) patients previously received ≥ 2 prior lines of systemic therapy and 37 (78.7%)patients previously received targeted biological treatment (anti-VEGF or anti-EGFR, or both). The initial doses of regorafenib were 40 mg/d (n = 1, 2.13%), 80 mg/d (n = 11, 23.43%), 120 mg/d (n = 2, 4.26%), and 160 mg/d (n = 23, 48.94%), while for 24.6% (n = 14) dose was unknown. Median Overall Survival was 22.2 months. Median Progression-Free Survival was 10.8 (95% CI: 9.0–13.7) months. Common Adverse Events were hand-foot skin reaction (12.77%), fatigue (6.38%), vomiting (6.38%), and decreased appetite (6.38%). Only 2 patients discontinued regorafenib due to Adverse Events.

Conclusions

Regorafenib combined with Hepatic arterial infusion was effective and tolerable in patients with liver predominant metastasis of colorectal cancer. Hence, this therapy can be considered as an alternative for second- or subsequent lines of therapy in patients refractory to standard systemic chemotherapy.

Pertuzumab Plus Trastuzumab for Treatment-Refractory HER2-Amplified Metastatic Colorectal Cancer: Comparison of the MyPathway Trial With a Real-World External Control Arm

We compared overall survival (OS) in patients with human epidermal growth factor receptor 2 (HER2)–amplified, treatment-refractory metastatic colorectal cancer (mCRC) receiving pertuzumab plus trastuzumab (PER-HER) in the phase IIa MyPathway multibasket study (ClinicalTrials.gov identifier: NCT02091141) with OS in those receiving routine clinical care in an electronic health record–derived external control arm.

A dual-targeted molecular therapy of PP242 and cetuximab plays an anti-tumor effect through EGFR downstream signaling pathways in colorectal cancer

Background

Epidermal growth factor receptor (EGFR) and its downstream Ras-mitogen-activated protein kinase kinase (MAPKK, MEK)-extracellular regulated protein kinase (ERK) signaling pathway and phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling pathway play important roles in the pathogenesis of colorectal cancer (CRC). The combination therapy of anti-EGFR and anti-mTOR needs to be explored.

Methods

Here we combined the anti-EGFR monoclonal antibody cetuximab (CTX) with the mTOR inhibitor PP242 in CRC cell lines and mouse xenograft models and discussed the changes of EGFR downstream signaling pathways of CRC cell lines.

Results

In HT-29 cells and Caco-2 cells, combined application of CTX and PP242 significantly inhibited the proliferation of CRC cells in vivo and in vitro. In BRAF wild-type Caco-2 cells, combined application of CTX and PP242 inhibited the activation of the EGFR and its downstream signaling pathways.

Conclusions

Our research further demonstrates the effectiveness of the combined application of CTX and PP242 in inhibiting CRC cell lines from the perspective of cell proliferation, cell cycle, apoptosis, and mouse xenografts. We revealed that the combined application of CTX and PP242 can inhibit tumor growth and proliferation by inhibiting the phosphorylation of key molecules in EGFR downstream MEK-ERK and MEK 4/7 (MKK)-c-Jun N-terminal kinase (JNK) signaling pathways in BRAF wild-type CRC cells. In addition, we found that in BRAF mutant CRC cells, the monotherapy of PP242 resulted in negative feedback increased EGFR phosphorylation rates, accompanied by significant up-regulation of downstream MEK and ERK phosphorylation.

MALAT1: A Promising Therapeutic Target for the Treatment of Metastatic Colorectal Cancer

Cancer metastasis research has emerged in recent years as one of the most important topics of debate in the discovery and development of novel anticancer therapies. Colorectal cancer (CRC), the third most common cancer worldwide, has a high mortality rate due to recurrence and distant metastasis to the liver. Several non-coding RNAs (ncRNAs) have been linked to metastatic CRC (mCRC), including the long non-coding RNA (lncRNA) Metastasis-Associated Lung-Adenocarcinoma Transcript 1 (MALAT1). MALAT1 is an RNA that has been linked to tumor cell proliferation, progression, epithelial-mesenchymal transition (EMT), cell migration and invasion, metastasis, and survival in mammalian species. Previously, there was no convincing evidence linking MALAT1 to mCRC. Studies have shown that MALAT1 functions as a competitive endogenous RNA (ceRNA) with microRNAs (miRNAs) and interacts directly with oncogenes and proteins. This RNA also activates several signaling pathways, including Wnt/β-catenin, PI3K/Akt/mTOR, and EMT. Meanwhile, standard chemotherapy and immunotherapy are the current treatment options for mCRC patients. However, evidence-based studies have recently demonstrated that inhibiting the MALAT1 RNA transcript can be considered as a treatment option for mCRC, highlighting the need to investigate its roles as a therapeutic target in mCRC. Thus, in this review, we looked at studies that linked MALAT1 to multiple signaling pathways implicated in mCRC, as well as its potential as a therapeutic target for the treatment of mCRC.

Hyaluronic acid-doxorubicin nanoparticles for targeted treatment of colorectal cancer

Colorectal cancer, common in both men and women, occurs when tumors form in the linings of the colon. Common treatments of colorectal cancer include surgery, chemotherapy, and radiation therapy; however, many colorectal cancer treatments often damage healthy tissues and cells, inducing severe side effects. Conventional chemotherapeutic agents such as doxorubicin (Dox) can be potentially used for the treatment of colorectal cancer; however, they suffer from limited targeting and lack of selectivity. Here, we report that doxorubicin complexed to hyaluronic acid (HA) (HA-Dox) exhibits an unusual behavior of high accumulation in the intestines for at least 24 hr when injected intravenously. Intravenous administrations of HA-Dox effectively preserved the mucosal epithelial intestinal integrity in a chemical induced colon cancer model in mice. Moreover, treatment with HA-Dox decreased the expression of intestinal apoptotic and inflammatory markers. The results suggest that HA-Dox could effectively inhibit the development of colorectal cancer in a safe manner, which potentially be used a promising therapeutic option.

The mutational pattern of homologous recombination-related (HRR) genes in Chinese colon cancer and its relevance to immunotherapy responses

BACKGROUND

Microsatellite-stable (MSS) colon adenocarcinoma (COAD) patients are not sensitive to immune checkpoint inhibitors. Here, we focused on analyzing the relationship between homologous recombination repair (HRR)-related gene mutations and clinical immunotherapy responses in MSS COAD.

METHODS

The mutational landscape was profiled in a cohort of 406 Chinese COAD patients via next-generation sequencing (NGS). Correlations between HRR gene mutations and tumor immunity or clinical outcomes in two COAD genomic datasets were analyzed via bioinformatics.

RESULTS

In the Chinese cohort, seventy (17%) patients exhibited genomic alterations in HRR genes; ATM (9%), BRCA2 (4%), ATR (3%), RAD50 (3%) and BRIP1 (3%) were the most frequently mutated. In the MSK-IMPACT COAD cohort (immune checkpoint inhibitor-treated), HRR-mut patients (n=34) survived longer than HRR-wt patients (n=50) (log-rank P < 0.01). Based on the TCGA MSS COAD cohort, HRR gene mutations increased immune activities, such as infiltration of cytotoxic cells (P < 0.05) and exhausted CD8+ T cells (P < 0.01), and increased the IFN-γ scores (P < 0.05). The results differed in MSI-H COAD patients (all P > 0.05).

CONCLUSION

HRR gene mutations significantly increased immune activities in MSS COAD patients, implying the feasibility of the HRR-mut status as an immunotherapy response predictor in MSS COAD.

Real-world Safety and Efficacy of Raltitrexed in Patients With Metastatic Colorectal Cancer

BACKGROUND

Use of fluoropyrimidine-based therapy in patients with metastatic colorectal cancer is associated with significant toxicities. This study aimed to assess the safety and efficacy of raltitrexed use in patients with metastatic colorectal cancer who developed significant toxicities after fluoropyrimidine-based treatment.

PATIENTS AND METHODS

We identified patients with metastatic colorectal cancer who were treated with raltitrexed-based systemic therapy after developing serious adverse events with fluoropyrimidine-based treatment in a large Canadian province from 2004 to 2018. Demographic, tumor, and treatment characteristics were retrieved from the electronic medical records. Progression-free and overall survival were assessed from the start of raltitrexed-based therapy.

RESULTS

A total of 86 patients were identified for the study. The median age was 66.5 years, and 58.1% of patients were men. The primary cancer site was right, left, and transverse colon in 38.4%, 27.9%, and 9.3%, respectively. The remaining 24.4% had rectal cancer. Among all patients, 43.0% had received more than 2 prior systemic therapies, and 37.6% had developed previous cardiotoxicity to fluoropyrimidine-based treatment. The median progression-free and overall survival were 8.5 and 10.2 months, respectively. On multivariable Cox regression model, patients with left-sided colon cancer (hazard ratio [HR], 0.33; 95% confidence interval [CI], 0.12-0.97; P = .044) and the Eastern Cooperative Oncology Group performance status of 0/1 (HR, 0.10; 95% CI, 0.01-0.82; P = .032) had a longer progression-free survival, whereas left-sidedness of colon cancer was the only factor that predicted overall survival (HR, 0.30; 95% CI, 0.10-0.88; P = .029). Raltitrexed was well-tolerated with common adverse events that included anemia in 41.7% of patients and chemotherapy-induced nausea and vomiting in 27.4%. Most toxicities were grade 1/2, but 16.7% of patients experienced grade 3. There were no cardiac events and treatment-related deaths.

CONCLUSIONS

Raltitrexed in patients with colorectal cancer who were previously treated with fluoropyrimidine-based systemic therapy is effective and well-tolerated.

Trial watch: TLR3 agonists in cancer therapy

Toll-like receptor 3 (TLR3) is a pattern recognition receptor that senses exogenous (viral) as well as endogenous (mammalian) double-stranded RNA in endosomes. On activation, TLR3 initiates a signal transduction pathway that culminates with the secretion of pro-inflammatory cytokines including type I interferon (IFN). The latter is essential not only for innate immune responses to infection but also for the initiation of antigen-specific immunity against viruses and malignant cells. These aspects of TLR3 biology have supported the development of various agonists for use as stand-alone agents or combined with other therapeutic modalities in cancer patients. Here, we review recent preclinical and clinical advances in the development of TLR3 agonists for oncological disorders.

Abbreviations

cDC, conventional dendritic cell; CMT, cytokine modulating treatment; CRC, colorectal carcinoma; CTL, cytotoxic T lymphocyte; DC, dendritic cell; dsRNA, double-stranded RNA; FLT3LG, fms-related receptor tyrosine kinase 3 ligand; HNSCC, head and neck squamous cell carcinoma; IFN, interferon; IL, interleukin; ISV, in situ vaccine; MUC1, mucin 1, cell surface associated; PD-1, programmed cell death 1; PD-L1, programmed death-ligand 1; polyA:U, polyadenylic:polyuridylic acid; polyI:C, polyriboinosinic:polyribocytidylic acid; TLR, Toll-like receptor.

EGFR targeting enhances the efficiency of chemotherapy through inhibiting IRE1α-XBP1s pathway in colorectal cancer cells

Targeting EGFR combined with chemotherapy is one of the most valuable therapeutic strategies in colorectal cancer. However, resistance remains a major obstacle to improve efficacy. IRE1α-XBP1s signaling pathway is activated in many malignant tumors, and plays important roles in chemoresistance. Therefore, IRE1α-XBP1s might be a potential target to overcome the chemoresistance in colorectal cancer. In this study, we detected the activation of IRE1α-XBP1s signaling in patient cancer tissues and colorectal cancer cell lines. The phosphorylation level of IRE1α and the spliced XBP1s were aberrantly elevated in colorectal cancer, and IRE1α-XBP1s signaling activation was correlated with high EGFR expression. By overexpression of EGFR protein or activation by EGF treatment, we found that EGFR activation could enhance the phosphorylation of IRE1α and spliced XBP1s expression. On the contrary, inhibition of EGFR decreased the IRE1α-XBP1s signaling. Further, we examined the downstream signaling pathways regulated by EGFR. Inhibition of ERK activity could reverse the EGFR induced IRE1α-XBP1s activation. Co-IP confirmed the physical interaction of ERK and IRE1α. Cell growth and colony formation assay showed that the inhibition of IRE1α activity could suppress EGFR driven colorectal cancer cell proliferation. Furthermore, we found that oxaliplatin could activate IRE1α-XBP1s signaling, and combination with cetuximab partially reversed the activation. Inhibition of EGFR signaling could enhance the efficacy of oxaliplatin in vitro and in vivo. Our results showed that IRE1α RNase activity is aberrantly elevated in colorectal cancer, and EGFR signaling could activate IRE1α/XBP1s possibly through EGFR-MEK-ERK pathway. IRE1α-XBP1s pathway might involve in EGFR driven tumor cell proliferation. Cetuximab could partially recover oxaliplatin-induced IRE1α-XBP1s activation, and therefore enhance the anti-tumor efficacy of oxaliplatin. Our findings declare a new mechanism that targeting EGFR could inhibit chemotherapy-induced IRE1α-XBP1s activation and therefore enhance the efficacy.