Predictors of long-term survival in patients with stage IV colorectal cancer with multi-organ metastases: a single-center retrospective analysis

Exploration of novel isoxazole-fused quinone derivatives as anti-colorectal cancer agents through inhibiting STAT3 and elevating ROS level

Colorectal cancer (CRC) is trending to be a major health problem throughout the world. Therapeutics with dual modes of action have shown latent capacity to create ideal anti-tumor activity. Signal transducer and activator of transcription 3 (STAT3) has been proved to be a potential target for the development of anti-colon cancer drug. In addition, modulation of tumor redox homeostasis through deploying exogenous reactive oxygen species (ROS)-enhancing agents has been widely applied as anti-tumor strategy. Thus, simultaneously targeting STAT3 and modulation ROS balance would offer a fresh avenue to combat CRC. In this work, we designed and synthesized a novel series of isoxazole-fused quinones, which were evaluated for their preliminary anti-proliferative activity against HCT116 cells. Among these quinones, compound 41 exerted excellent in vitro anti-tumor effect against HCT116 cell line with an IC50 value of 10.18 ± 0.4 nM. Compound 41 was proved to bind to STAT3 by using Bio-Layer Interferometry (BLI) assay, and can significantly inhibit phosphorylation of STAT3. It also elevated ROS of HCT116 cells by acting as a substrate of NQO1. Mitochondrial dysfunction, apoptosis, and cell cycle arrest, which was caused by compound 41, might be partially due to the inhibition of STAT3 phosphorylation and ROS production induced by 41. Moreover, it exhibited ideal anti-tumor activity in human colorectal cancer xenograft model and good safety profiles in vivo. Overall, this study provided a novel quinone derivative 41 with excellent anti-tumor activity by inhibiting STAT3 and elevating ROS level, and gave insights into designing novel anti-tumor therapeutics by simultaneously modulation of STAT3 and ROS.

Prognostic Indicators for Intracranial Metastases from Pancreatic Cancer: A Population-Based Retrospective Surveillance, Epidemiology, and End Results Database Analysis

OBJECTIVE

The natural history, treatment options, and clinical outcomes of pancreatic metastases to the brain remain largely unknown. Here, we seek to investigate characteristics that influence OS in pancreatic metastases to the brain.

METHODS

This is a population-based retrospective study of OS in 508 patients with pancreatic metastases to the brain using the SEER database. Univariate and multivariate Cox regression analyses were utilized, and a predictive nomogram was developed.

RESULTS

There were 508 patients identified for this study, with a median OS of 2 months. In the univariate analysis, patients older than 65 years had significantly reduced OS (P < 0.001). Patients with liver metastases (P < 0.001) and liver and lung metastases (P < 0.001) exhibited significantly reduced OS. Treatment of the primary tumor with chemotherapy only (P < 0.001), radiation only (P = 0.01), radiation and chemotherapy (P < 0.001), and surgery only (P = 0.01) were associated with increased OS. Resection of a distant metastasis site (P = 0.009) and of a brain metastasis (P = 0.03) were associated with increased OS. In the multivariable analysis, factors that remained significant included patient age (P = 0.01), liver metastases (P < 0.001), liver and lung metastases (P < 0.001), treatment with chemotherapy (P < 0.001), treatment with radiation and chemotherapy (P < 0.001), and treatment with surgery and chemotherapy (P < 0.001). The nomogram had a C-index of 0.766, suggesting congruence between the findings on the nomogram and the results in the internal verification.

CONCLUSIONS

Median OS is influenced by age, multiorgan metastases, and treatment of the primary tumor. These data highlight the marginal benefit of treatment, yet improved quality of life (QOL) remains to be elucidated.

Analysis of the Prognostic Potential of Schlafen 11, Programmed Death Ligand 1, and Redox Status in Colorectal Cancer Patients

The Schlafen 11 (SLFN11) protein has recently emerged as pivotal in DNA damage conditions, with predictive potential for tumor response to cytotoxic chemotherapies. Recent discoveries also showed that the programmed death ligand 1 (PD-L1) protein can be found on malignant cells, providing an immune evasion mechanism exploited by different tumors. Additionally, excessive generation of free radicals, redox imbalance, and consequential DNA damage can affect intestinal cell homeostasis and lead to neoplastic transformation. Therefore, our study aimed to investigate the significance of SLFN11 and PD-L1 proteins and redox status parameters as prognostic biomarkers in CRC patients. This study included a total of 155 CRC patients. SLFN11 and PD-L1 serum levels were measured with ELISA and evaluated based on redox status parameters, sociodemographic and clinical characteristics, and survival. The following redox status parameters were investigated: spectrophotometrically measured superoxide dismutase (SOD), sulfhydryl (SH) groups, advanced oxidation protein products (AOPP), malondialdehyde (MDA), pro-oxidant-antioxidant balance (PAB), and superoxide anion (O2•-). The prooxidative score, antioxidative score, and OXY-SCORE were also calculated. The results showed significantly shorter survival in patients with higher OXY-SCOREs and higher levels of serum SLFN11, while only histopathology-analysis-related factors showed significant prognostic value. OXY-SCORE and SLFN11 levels may harbor prognostic potential in CRC patients.

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.

Identification of cuproptosis-related subtypes and development of a prognostic signature in colorectal cancer

Cuproptosis, a novel form of copper-mediated regulated cell death, participates in tumor progression. However, the role of cuproptosis-related genes (CRGs) in colorectal cancer (CRC) remains unclear. We aimed to investigate the cuproptosis subtypes and build a predictive model to improve the prognosis of patients with CRC. Gene expression data were downloaded from the TCGA database to identify distinct molecular subtypes using a non-negative matrix factorization algorithm. A robust and efficient prognostic signature was constructed by performing multivariate Cox regression analysis and further validated using the Gene Expression Omnibus cohort. Based on the gene expression matrix of CRC, the abundance of infiltrating immune cells and tumour microenvironment scores were calculated using the CIBERSORT and ESTIMATE algorithms, respectively. The pRRophetic algorithm was used to predict the sensitivity of the patients to different chemotherapy drugs. Two distinct molecular subtypes were identified based on 41 CRGs, with subtype C1 being characterized by an advanced clinical stage and worse overall survival. A prognostic signature was constructed based on the DEGs between the two cuproptosis subtypes, and its predictive ability was validated in an external database. Patients with CRC who belonged to the low-risk group had significantly higher survival rates than those who belonged to the high-risk group. Additionally, it remained a valid prognostic indicator in strata of age, sex, tumor location, and TNM stage, and its significance persisted after the multivariate Cox regression analysis. By further analyzing the prognostic signature, a higher immune score was observed in the low-risk group, which presented a better prognosis. AKT.inhibitor.VIII, doxorubicin, lenalidomide, and tipiparnib were more sensitive in the high-risk score group. A highly accurate nomogram was constructed to improve clinical application of the risk score. Compared with an ideal nomogram, our model, consisting of clinicopathological features, performed well in predicting patient survival. In conclusion, our study provides new ways and perspectives for the prediction of the prognosis of patients with CRC and guide more effective treatment regimens.

2D-DIGE-MS Proteomics Approaches for Identification of Gelsolin and Peroxiredoxin 4 with Lymph Node Metastasis in Colorectal Cancer

Background/Aims: A combination of fluorescence two-dimensional difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization time of flight mass spectrometry approach was used to search for potential markers for prognosis and intervention of colorectal cancer (CRC) at different stages of lymph node metastasis (LMN). This quantitative proteomic survey aimed to investigate the LNM-associated proteins and evaluate the clinicopathological characteristics of these target proteins in CRC from stage I to stage IV. Methods: Sixteen CRC cases were categorized into paired non-LNM and LNM groups, and two-dimensional difference gel electrophoresis and MS proteome analysis were performed. Differential protein expression between non-LNM and LNM CRC was further validated in a tissue microarray, including 40 paraffin-embedded samples by immunohistochemistry staining. Moreover, a Boyden chamber assay, flow cytometry, and shRNA were used to examine the epithelial–mesenchymal transition and mechanism invasiveness of the differentially expressed proteins in DLD-1 cells and in vivo xenograft mouse model. Results: Eighteen differentially expressed proteins were found between non-LNM and LNM CRC tissues. Among them, protein levels of Gelsolin (GSN) and peroxiredoxin 4 (PRDX4) were abundant in node-positive CRC. Downregulation of GSN and PRDX4 markedly suppressed migration and invasiveness and also induced cell cycle G1/S arrest in DLD-1. Mechanistically, the EGFR/RhoA/PKCα/ERK pathways are critical for transcriptional activation of histone modification of H3 lysine 4 trimethylation (H3K4me3) of GSN and PRDX4 promoters, resulting in upregulation of GSN, PRDX4, Twist-1/2, cyclinD1, proliferating cell-nuclear antigen, β-catenin, N-cadherin, and matrix metalloprotein-9. Conclusions: GSN and PRDX4 are novel regulators in CRC lymph node metastasis to potentially provide new insights into the mechanism of CRC progression and serve as a biomarker for CRC diagnosis at the metastatic stage.

The Significance of Neutrophil Extracellular Traps in Colorectal Cancer and Beyond: From Bench to Bedside

Neutrophil extracellular traps (NETs), products of neutrophil death when exposed to certain stimuli, were first proposed as a type of response to bacterial infection in infectious diseases. Since then, extensive studies have discovered its involvement in other non-infectious inflammatory diseases including thromboembolism, autoimmune diseases, and cancer. Colorectal cancer (CRC) is one of the most common malignancies in the world. NET formation is closely associated with tumorigenesis, progression, and metastasis in CRC. Therefore, the application of NETs in clinical practice as diagnostic biomarkers, therapeutic targets, and prognostic predictors has a promising prospect. In addition, therapeutics targeting NETs are significantly efficient in halting tumor progression in preclinical cancer models, which further indicates its potential clinical utility in cancer treatment. This review focuses on the stimuli of NETosis, its pro-tumorigenic activity, and prospective clinical utility primarily in but not limited to CRC.

The biological activity of Ocimum minimum L. flowers on redox status parameters in HCT-116 colorectal carcinoma cells

Medicinal plants have widely been used as a natural source of remedies for treating several diseases, including colorectal cancer. Ocimum minimum L. is a very important dietary plant used in traditional and modern medicine, due to its health beneficial effect realized by cytotoxic, proapoptotic, antioxidant/prooxidant, antiviral and antimicrobial activity. The biological activity of O. minimum flowers has been evaluated in HCT116 colorectal carcinoma cells through antiproliferative activity by MTT assay, pro-apoptotic activity by AO/EB and concentrations of redox status parameters (O2∙ and lipid peroxidation) by colorimetric methods. The protein expression of iNOS was analyzed by immunocytochemistry, while the antimigratory effect was measured by xCELLigence system. The treatment with O. minimum shows the antiproliferative, proapoptotic, impact on redox status parameters and antimigratory effect on HCT-116 cells. Based on obtained results, the pharmacological effect of O. minimum is evident against HCT-116 colorectal carcinoma cells, suggesting that this plant may be good start material for future anticancer therapy investigation.

Solitary adrenal metastasis from salivary duct carcinoma of the parotid gland successfully treated by surgery: A case report

RATIONALE

Salivary duct carcinoma (SDC) is a rare and highly aggressive cancer with a poor prognosis. SDC demonstrates a potential for invasive growth with early regional and distant metastasis to organs, such as bone, lung, liver, and brain. Because, adrenal gland metastasis from SDC is rare, its treatment options are not well established. Herein, we report a case of SDC metastasis from the parotid gland to the adrenal gland, which was successfully treated by surgery.

PATIENT CONCERNS

The patient had an abnormal but painless lump on the right parotid gland. The size of the mass had increased over a period of 3 years. The patient underwent complete removal of the right parotid gland and radical neck dissection followed by adjuvant radiotherapy and chemotherapy. Two years later, a mass was identified in the left adrenal gland by computed tomography. As no local recurrence or metastasis to other organs was observed, the patient underwent adrenalectomy.

DIAGNOSES

Metastasis of SDC in the adrenal gland was confirmed by histopathological examination of the adrenalectomized specimen.

INTERVENTIONS

After adrenalectomy, the patient was followed-up without adjuvant therapy.

OUTCOMES

The patient was well and alive during the 13-month postoperative follow-up period without any complications.

LESSONS

Surgical resection of solitary metastatic lesion may show a survival benefit with metastatic SDC.

The Role of Oxidative Stress and Its Counteractive Utility in Colorectal Cancer (CRC)

An altered redox status accompanied by an elevated generation of reactive oxygen/nitrogen species (ROS/RNS) has been implicated in a number of diseases including colorectal cancer (CRC). CRC, being one of the most common cancers worldwide, has been reported to be associated with multiple environmental and lifestyle factors (e.g., dietary habits, obesity, and physical inactivity) and harboring heightened oxidative stress that results in genomic instability. Although under normal condition ROS regulate many signal transduction pathways including cell proliferation and survival, overwhelming of the antioxidant capacity due to metabolic abnormalities and oncogenic signaling leads to a redox adaptation response that imparts drug resistance. Nevertheless, excessive reliance on elevated production of ROS makes the tumor cells increasingly vulnerable to further ROS insults, and the abolition of such drug resistance through redox perturbation could be instrumental to preferentially eliminate them. The goal of this review is to demonstrate the evidence that links redox stress to the development of CRC and assimilate the most up-to-date information that would facilitate future investigation on CRC-associated redox biology. Concomitantly, we argue that the exploitation of this distinct biochemical property of CRC cells might offer a fresh avenue to effectively eradicate these cells.

Postoperative chemotherapy is associated with prognosis of stage IV colorectal cancer treated with preoperative chemotherapy/chemoradiotherapy and curative resection

PURPOSE

Advances in systemic chemotherapy have increased the resectability in colorectal cancer (CRC) associated with metastases even if it was initially unresectable. However, what determines the prognosis of stage IV CRC patients treated by preoperative therapy and surgery remains unclear. We attempted to identify prognostic factors in such CRC patients.

METHODS

We reviewed stage IV CRC patients who underwent curative resection between December 2007 and May 2019. The patients who underwent conversion chemotherapy for initially unresectable disease and those who received neoadjuvant chemotherapy (NAC) for resectable synchronous metastases or neoadjuvant chemoradiotherapy (NACRT) for advanced lower rectal cancer with resectable metastases were included. Recurrence-free survival (RFS) and overall survival (OS) were examined by multivariate analyses using Cox proportional hazard models. The RFS and OS curves were analyzed according to postoperative adjuvant chemotherapy (AC).

RESULTS

Among 70 patients who underwent curative surgery (34 men, mean age: 60 years old), 33 had initially unresectable disease, 23 received NAC, and 14 NACRT. By multivariate analyses, AC was an independent predictor for improved RFS and OS (hazard ratio = 0.29, p = 0.0002, and hazard ratio = 0.37, p = 0.025). Patients treated with AC showed improved RFS and OS than those without AC (2-year RFS rate = 30% vs 19%, p = 0.031, and 3-year OS rate = 87% vs 67%, p = 0.045).

CONCLUSION

Because of its association with improved prognosis, AC should be considered for stage IV CRC patients after curative resection regardless of initial resectability status and preoperative therapy.

Prognostic significance of primary tumor sidedness in patients undergoing liver resection for metastatic colorectal cancer

BACKGROUND

Approximately 38% of patients with colorectal cancer will develop isolated liver metastases. Sidedness of colon tumor is identified in non-metastatic and unresected metastatic cancers as predictive of survival, yet its dedicated analysis in resected liver metastases is minimal. Our primary aim was to assess whether left-sided primary tumors improve prognosis in stage IV cancer patients undergoing curative-intent liver metastasectomy; it was hypothesized that it would.

METHODS

This is a retrospective, observational cohort study from 1996 to 2016 in a single tertiary-care facility. Survival from diagnosis was calculated via Kaplan-Meier method and compared between the right and left sides via log-rank analysis.

RESULTS

Median survival differs significantly between colorectal tumors of the right and left origins after hepatic metastasectomy in 612 patients. In patients with right-sided tumors, median survival from diagnosis was 4.5 years (IQR 4.1-5.3), and 6.3 years (IQR 5.6-6.9) in those with left tumors (HR 1.5, 95% CI 1.38-1.60, p < 0.001).

CONCLUSION

As in studies on earlier-stage or unresected metastatic disease, tumor sidedness is an important prognostic factor in patient survival with liver metastasectomy. Clinical risk scores should include side of primary tumor. Further work is needed to determine the molecular basis for this difference.

Impact of primary tumor location in patients with RAS wild-type metastatic colon cancer treated with first-line chemotherapy plus anti-EGFR or anti-VEGF monoclonal antibodies: a retrospective multicenter study

Emerging evidence supports a prognostic role of primary tumor location in metastatic colon cancer (mCC). We conducted a retrospective analysis to evaluate the effect of tumor location on prognosis and efficacy of biological agents (anti-EGFR, Cetuximab and Panitumumab, or anti-VEGF, Bevacizumab) added to first-line chemotherapy in patients with RAS wild-type (wt) mCC. Patients with newly diagnosed RAS wt mCC candidates to first-line chemotherapy with anti-EGFRs or Bevacizumab were selected. Clinical outcomes were assessed and stratified by tumor location and type of treatment. Overall, 351 patients met the inclusion criteria. Primary colon cancer was right-sided (RCC) in 105 (29.9%) patients and left-sided (LCC) in 246 (70.1%). Patients with LCC had a better OS compared to those with RCC (33.6 vs 23.5 months, HR 0.74; 95% CI, 0.55 to 0.99; p=0.049). In the overall study population, OS was not significantly different for patients treated with Cetuximab or Panitumumab as compared to those receiving Bevacizumab. However, when comparing treatment outcome according to tumor sidedness, patients with LCC treated with Cetuximab or Panitumumab had a significantly longer PFS (12.4 vs 10.7 months; HR: 0.69; 95% CI, 0.51 to 0.93; p= 0.015) and OS (40.7 vs 28.6 months; HR: 0.67; 95% CI 0.47 to 0.95; p= 0.026). No relevant differences were observed in patients with RCC.

We found evidence in support of the impact of tumor location in RAS wt mCC treated with first-line chemotherapy in association with targeted therapy. More favorable outcomes were observed in LCC patients, but not in RCC patients, treated with anti-EGFR agents compared with those who received Bevacizumab. Further, prospective and adequately sized studies are warranted to confirm our findings.

Surgical resectability of multisite metastatic colorectal cancer: Pushing the limits while appropriately selecting patients

Management of multisite colorectal metastases is expanding to make curative resection possible for more patients who present with advanced disease. Patient selection, tumor biology, meticulous surgical technique, and thoughtful perioperative care are essential to extending the benefit to patients previously treated with palliative goals of care.

DNA methylation-regulated and tumor-suppressive roles of miR-487b in colorectal cancer via targeting MYC, SUZ12, and KRAS

Human colorectal cancer (CRC), characterized by its high morbidity and lethality, seriously threatens human health and lives. MicroRNA‐487b (miR‐487b) is currently reported to be aberrantly expressed in several tumors, but the detailed functions and underlying mechanisms of miR‐487b in CRC remain unclear. Here, we found that miR‐487b is downregulated in CRC cell lines and is markedly decreased in tumor specimens derived from CRC patients. MiR‐487b inhibits cell proliferation, migration and invasion and promotes the apoptosis of CRC cells in vitro. Statistical analysis of clinical samples indicates that miR‐487b may serve as a biomarker for early CRC diagnosis. Inverse correlations between the expression levels of MYC, SUZ12, and KRAS and that of miR‐487b exist in vitro and in CRC patient tissue specimens. Further experiments demonstrated the regulatory effects of miR‐487b on MYC, SUZ12, and KRAS, and the disruption of these genes partially restores the miR‐487b inhibitor‐induced phenotype. Additionally, miR‐487b promoter region is in a DNA hypermethylated condition and the DNA methyltransferase inhibitor 5‐aza‐2’‐deoxycytidine (5‐Aza) increases the levels of miR‐487b but suppresses the expression of MYC, SUZ12, and KRAS in a time‐ and concentration‐dependent manner in CRC cells. Collectively, miR‐487b is regulated by DNA methylation and it functions as a tumor suppressor in CRC mainly through targeting MYC, SUZ12, and KRAS. Our study provides insight into the regulatory network in CRC cells, offering a new target for treating CRC patients.

Efficacy and safety of nivolumab for metastatic biliary tract cancer

Objective

PD-1 inhibitors have improved efficacy in many cancers. There are currently no reports of the use of PD-1 inhibitors, such as nivolumab, for metastatic biliary tract cancer (mBTC). This study reviewed the efficacy and safety of nivolumab for mBTC with the aim of exploring ways to improve efficacy and survival.

Methods

Thirty patients with mBTC were voluntarily treated with nivolumab at the PLA General Hospital. Nivolumab 3 mg/kg was administered. Progression-free survival (PFS) and overall survival were evaluated by Kaplan-Meier and univariate and multivariate analyses were carried out for clinical characteristics. Objective response rate (ORR), disease control rate (DCR), and treatment-related adverse events (AEs) were also evaluated.

Results

The median treatment cycle is four cycles. One case was complete response, 5 cases partial response, 12 cases stable, and 12 cases progression. ORR was 20%, DCR was 60%, and PFS was 3.1 months (95% CI: 2.13-4.06). The AEs of nivolumab monotherapy were fatigue (three cases), fever (two cases), hypothyroidism (one case), skin reaction (one case), and liver injury (one case). Nivolumab combined with chemotherapy related grade 1-2 hematologic toxicity were leukopenia (five cases) and thrombocytopenia (two cases), and grade 3-4 were leukopenia (three cases). Non-hematologic toxicity grade 1-2 were nausea and vomiting (four cases), fatigue (four cases), fever (three cases), peripheral neurotoxicity (three cases), and hypothyroidism (one case). Univariate analysis showed that PFS of nivolumab combined with chemotherapy was statistically significant compared with that of nivolumab monotherapy (4.1 vs 2.3 months, P=0.031). Programmed death-ligand 1 (PD-L1) expression positively has no relationship with better PFS in contrast with PD-L1 negatively (3.6 vs 3.0 months P>0.05). Multivariate analysis show nivolumab combined with chemotherapy was only the independent factor for longer PFS (HR: 0.432, P<0.05).

Conclusion

The safety of nivolumab in mBTC is controllable. Further selection of superior populations is needed to improve the efficacy of nivolumab in mBTC.

Colorectal Cancer Biomarkers in the Era of Personalized Medicine

The 5-year survival probability for patients with metastatic colorectal cancer has not drastically changed over the last several years, nor has the backbone chemotherapy in first-line disease. Nevertheless, newer targeted therapies and immunotherapies have been approved primarily in the refractory setting, which appears to benefit a small proportion of patients. Until recently, rat sarcoma (RAS) mutations remained the only genomic biomarker to assist with therapy selection in metastatic colorectal cancer. Next generation sequencing has unveiled many more potentially powerful predictive genomic markers of therapy response. Importantly, there are also clinical and physiologic predictive or prognostic biomarkers, such as tumor sidedness. Variations in germline pharmacogenomic biomarkers have demonstrated usefulness in determining response or risk of toxicity, which can be critical in defining dose intensity. This review outlines such biomarkers and summarizes their clinical implications on the treatment of colorectal cancer. It is critical that clinicians understand which biomarkers are clinically validated for use in practice and how to act on such test results.

Primary tumor sidedness is an independent prognostic marker for survival in metastatic colorectal cancer: Results from a large retrospective cohort with mutational analysis

Recent reports demonstrate inferior outcomes associated with primary right‐sided vs left‐sided colorectal tumors in patients with metastatic colorectal cancer (mCRC). We sought to describe our experience with mCRC patients on whom we have molecular data to determine whether primary tumor sidedness was an independent prognostic marker for overall survival (OS). mCRC patients with documented primary tumor sidedness who received mutational profiling between 2009 and 2014 were identified (n = 367, median follow‐up 30.4 months). Mutational profiling for >150 mutations across commonly mutated cancer genes including RAS, PIK3CA, BRAF, and PTEN as well as treatment data, including receipt of a biologic agent, were collected. Univariable/multivariable models were used to analyze relationships between collected data and OS. Among 367 patients, sidedness breakdown was as follows: 234 left (64%), 133 right (36%). 56% were male, with a median age at diagnosis of 57 (range 24‐89). A total of 143 patients had RAS mutations. Five‐year OS was 41%, median OS was 54 months (range 1‐149). Five‐year OS for left‐ vs right‐sided tumors was 46% vs 24% (P < .0001). On univariable analysis, among both RAS wildtype and mutant tumors, left‐sided tumors continued to have improved OS vs right‐sided tumors (HR: 0.49, 95% CI: 0.34‐0.69 RAS wildtype; HR: 0.61, 95% CI: 0.40‐0.95 RAS mutant). Left‐sidedness was an important prognostic factor for OS among RAS wildtype patients despite treatment with or without a biologic agent (P < .05). Left‐sidedness remained significant for improved OS on multivariable analysis (P < .0001). Left‐sided primary tumor remained most important prognostic factor for OS, even when adjusting for mutational status and receipt of biologic agent.

Reactive oxygen species and colorectal cancer

Colorectal cancer (CRC) has become the fourth leading cause of cancer-related death in the worldwide. It is urgent to find more effective therapeutic strategies for it. Reactive oxygen species (ROS) play multiple roles in normal cellular physiology processes. Thus, a certain level of ROS is essential to keep normal cellular function. However, the accumulation of ROS shows dual roles for cells, which is mainly dependent on the concentration of ROS, the origin of the cancer cell and the activated signaling pathways during tumor progression. In general, moderate level of ROS leads to cell damage, DNA mutation and inflammation, which promotes the initiation and development of cancer. Excessive high level of ROS induces cancer cell death, showing an anti-cancer role. ROS are commonly higher in CRC cells than their normal counterpart cells. Therefore, it is possible that ROS induce cell death in cancer cells while not affecting the normal cells, demonstrating lower side effects. Besides, ROS also play a role in tumor microenvironment and drug resistance. These multiple roles of ROS make them a promising therapeutic target for cancer. To explore potential ROS-target therapies against CRC, it is worth to comprehensively understanding the role of ROS in CRC and therapy. In this review, we mainly discuss the strategies of ROS in CRC therapy, including direct CRC cell target and indirect tumor environment target. In addition, the influences of ROS in drug resistance will also been discussed.

The predictive value of primary tumor location in patients with metastatic colorectal cancer: A systematic review

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers worldwide. It has been reported that left- and right-sided CRC harbor varying disease characteristics, which leads to a difference in prognosis and response to therapy. Recently, there have been retrospective studies about tumor location in metastatic CRC (mCRC) and its potential to predict the effect of anti-vascular endothelial growth factor and anti-epidermal growth factor receptor (anti-EGFR) therapies. In this review, we provide a comprehensive overview of the latest trials studying the predictive value of primary tumor location in mCRC and discuss biomarkers that might be associated with the differences in treatment response. Although data need to be interpreted with caution due to the absence of randomized trials stratified based on tumor location, patients with left-sided CRC seem to benefit more from anti-EGFR therapy than patients with right-sided CRC. Further clinical trials, stratified for tumor location, are warranted.