Colorectal cancer. Mayo Clin Proc. 2007;82:114-129. [PMID: 17285793 DOI: 10.1016/S0025-6196(11)60974-9]

Nineteen-year, real-world experience of first-line combination chemotherapy in patients with metastatic colorectal cancer: a propensity score analysis from southern Thailand

OBJECTIVE

Combination fluoropyrimidine-based chemotherapy is the standard first-line treatment for metastatic colorectal cancer (CRC). We performed a propensity score (PS)-based analysis to report our real-world experience with long-term follow-up of this regimen for metastatic CRC.

METHODS

In this retrospective study, 170 patients with newly diagnosed metastatic CRC treated with first-line combination chemotherapy between January 2003 and March 2021 were identified. Cox proportional hazards regression analysis and PS-based approaches with the logistic regression model were adopted, and the results were compared.

RESULTS

The hazard ratio for overall survival (OS) in the oxaliplatin- and irinotecan-based groups was 0.79 (95% confidence interval = 0.56-1.11), and the median OS times in these groups were 16.8 and 13.0 months, respectively. The median time to progression (TTP) for these regimens were 9.0 and 8.9 months, respectively. The objective response rates for the oxaliplatin- and irinotecan-based groups were 42.7% and 34.6%, respectively. OS and TTP did not differ between these regimens in all PS matching models.

CONCLUSIONS

First-line treatment using fluoropyrimidine-based chemotherapy regimens in combination with oxaliplatin or irinotecan in patients with metastatic CRC provided comparable efficacy and tolerable toxicity profiles in a real-world setting with long-term follow-up.

Smad4-deficient T cells promote colitis-associated colon cancer via an IFN-γ-dependent suppression of 15-hydroxyprostaglandin dehydrogenase

Immune cells and the cytokines they produce are important mediators of the transition from colitis to colon cancer, but the mechanisms mediating this disease progression are poorly understood. Interferon gamma (IFN-γ) is known to contribute to the pathogenesis of colitis through immune modulatory mechanisms, and through direct effects on endothelial and epithelial homeostasis. Here we explore whether IFN-γ influences tumor progression by expanding the effector memory T cells (T_EM) population and restricting the expression of tumor suppressors in a preclinical model of spontaneous colitis-associated colorectal cancer (CAC). We show that IFN-γ expression is significantly increased both in the T cells and the colonic mucosal epithelia of mice with a T cell-restricted deletion of the TGF-β intermediate, SMAD4 (Smad4^TKO). The increase of IFN-γ expression correlates with the onset of spontaneous CAC in Smad4^TKO mice by 6 months of age. This phenotype is greatly ameliorated by the introduction of a germline deletion of IFN-γ in Smad4^TKO mice (Smad4^TKO/IFN-γ^KO, DKO). DKO mice had a significantly reduced incidence and progression of CAC, and a decrease in the number of mucosal CD4⁺ T_EM cells, when compared to those of Smad4^TKO mice. Similarly, the colon epithelia of DKO mice exhibited a non-oncogenic signature with a decrease in the expression of iNOS and p-STAT1, and a restoration of the tumor suppressor gene, 15-hydroxyprostaglandin dehydrogenase (15-PGDH). In vitro, treatment of human colon cancer cells with IFN-γ decreased the expression of 15-PGDH. Our data suggest that Smad4-deficient T cells promote CAC through mechanisms that include an IFN-γ-dependent suppression of the tumor suppressor 15-PGDH.

SK1 inhibitor RB005 Induces Apoptosis in Colorectal Cancer Cells through SK1 Inhibition Dependent and Independent Pathway

BACKGROUND AND OBJECTIVE

Colorectal cancer (CRC) is the fourth leading cause of cancer-related death globally, with a high incidence rate in economically fast-growing countries. Sphingosine-1-phosphate (S1P) is a bioactive lipid mediator that plays critical roles in cancer cell proliferation, migration, and angiogenesis converted by the isoforms of sphingosine kinase (SK1 and SK2). SK1 is highly expressed in colorectal cancer, its inhibitors suppress the formation of S1P and increase ceramide levels having a pro-apoptotic function. RB005 is a selective SK1 inhibitor and a structural analog of PP2A activator FTY720. The purpose of this study is to test whether RB005, an SK1 inhibitor, can be used as an anticancer agent by inhibiting the growth of colon cancer cells. <P> Methods: We performed MTT and colony-forming assay using colon cancer cell lines HT29 and HCT116 cells to examine the cell toxicity effect of RB005. To determine whether apoptosis of RB005 in colon cancer cell line is due to SK1 inhibition or other mechanisms due to its structural similarity with FTY720, we conducted LC/MS, siRNA knockdown, and PP2A activity experiments. <P> Results: RB005 notably inhibited CRC cell growth and proliferation compared to PF543 and ABC294640 by inducing the mitochondria-mediated intrinsic apoptotic pathway. Apoptotic cell death is caused by increased mitochondrial permeability necessitated by the activation of pro-apoptotic protein BAX, increased ceramides, and activation of PP2A. Also, RB005 treatment in HT29 cells did not change the expression level of SK1, but strikingly decreased SK1 activity and S1P levels. All these events of cell death and apoptosis were less effective when SK1 was knocked down by siRNA. <P> Conclusion: This result indicates that RB005 shows the in-vitro anti-CRC effect by inhibiting SK1 activity and PP2A activation, increasing proapoptotic ceramide levels following the activation of the intrinsic apoptotic pathway.

Loss of p27Kip1 leads to expansion of CD4+ effector memory T cells and accelerates colitis-associated colon cancer in mice with a T cell lineage restricted deletion of Smad4

The cyclin-dependent kinase inhibitor p27^Kip1 is a tumor suppressor whose intrinsic activity in cancer cells correlates with tumor aggressiveness, invasiveness, and impaired tumor cell differentiation. Here we explore whether p27^Kip1 indirectly influences tumor progression by restricting expansion and survival of effector memory T cell (T_EM) populations in a preclinical model of spontaneous colitis-associated colorectal cancer (CAC). We show mRNA and protein expression of p27^Kip1 to be significantly decreased in the colons of mice with a T cell-restricted deletion of the TGF-β intermediate, SMAD4 (Smad4^TKO). Loss of p27^Kip1 expression in T cells correlates with the onset of spontaneous CAC in Smad4^TKO mice by 8 months of age. This phenotype is greatly accelerated by the introduction of a germline deletion of CDKN1b (the gene encoding p27^Kip1) in Smad4^TKO mice (Smad4^TKO/p27^Kip1-/-, DKO). DKO mice display colon carcinoma by 3 months of age and increased mortality compared to Smad4^TKO. Importantly, the phenotype in DKO mice is associated with a significant increase in the frequency of effector CD4 T cells expressing abundant IFN-γ and with a concomitant decrease in Foxp3⁺ regulatory T cells, both in the intestinal mucosa and in the periphery. In addition, induction of inflammatory mediators (IFN-γ, TNF-γ, IL-6, IL-1β, iNOS) and activation of Stat1, Stat3, and IκB is also observed in the colon as early as 1–2 months of age. Our data suggest that genomic alterations known to influence p27^Kip1 abundance in gastrointestinal cancers may indirectly promote epithelial malignancy by augmenting the production of inflammatory mediators from a spontaneously expanding pool of T_EM cells.

Integration of genetic variants and gene network for drug repurposing in colorectal cancer

Even though many genetic risk loci for human diseases have been identified and comprehensively cataloged, strategies to guide clinical research by integrating the extensive results of genetic studies and biological resources are still limited. Moreover, integrative analyses that provide novel insights into disease biology are expected to be especially useful for drug discovery. Herein, we used text mining of genetic studies on colorectal cancer (CRC) and assigned biological annotations to identified risk genes in order to discover novel drug targets and potential drugs for repurposing. Risk genes for CRC were obtained from PubMed text mining, and for each gene, six functional and bioinformatic annotations were analyzed. The annotations include missense mutations, cis-expression quantitative trait loci (cis-eQTL), molecular pathway analyses, protein-protein interactions (PPIs), a genetic overlap with knockout mouse phenotypes, and primary immunodeficiency (PID). We then prioritized the biological risk candidate genes according to a scoring system of the six functional annotations. Each functional annotation was assigned one point, and those genes with a score ≥2 were designated "biological CRC risk genes". Using this method, we revealed 82 biological CRC risk genes, which were mapped to 128 genes in an expanded PPI network. Further utilizing DrugBank and the Therapeutic Target Database, we found 21 genes in our list that are targeted by 166 candidate drugs. Based on data from ClinicalTrials.gov and literature review, we found four known target genes with six drugs for clinical treatment in CRC, and three target genes with nine drugs supported by previous preclinical results in CRC. Additionally, 12 genes are targeted by 32 drugs approved for other indications, which can possibly be repurposed for CRC treatment. Finally, analysis from Connectivity Map (CMap) showed that 18 drugs have a high potential for CRC.

MicroRNA-199b Deregulation Shows a Strong SET-Independent Prognostic Value in Early-Stage Colorectal Cancer

The endogenous PP2A inhibitor SET Nuclear Proto-Oncogene (SET) has been reported to play oncogenic roles and determines poor outcomes in colorectal cancer (CRC). Our group previously showed that miR-199b is deregulated in metastatic CRC, and reduced the cell viability and enhanced the sensitivity of CRC cells to standard induction chemotherapy drugs, mainly through direct negative SET regulation. Clinically, miR-199b downregulation was identified as the molecular mechanism responsible for SET overexpression in around half of metastatic CRC patients. However, the potential clinical value of miR-199b in early-stage CRC remains totally unknown. Thus, here we explored the expression levels of this microRNA in a cohort of 171 early-stage CRC patients using real-time polymerase chain reactions. MiR-199b downregulation was found in 21.6% of cases (37 out of 171) and was significantly associated with those patients with a worse Eastern Cooperative Oncology Group (ECOG) status (p = 0.045). Moreover, miR-199b downregulation predicted shorter overall (p < 0.001) and progression-free survival (p = 0.015). As expected, we next immunohistochemically analyzed SET, observing that it was significantly associated with miR-199b in our cohort. However, multivariate analyses showed that miR-199b was an independent biomarker of poor outcomes in early-stage CRC with a predictive value stronger than SET. In conclusion, our results highlight the potential clinical usefulness of miR-199b and suggest that it could represent a novel molecular target in this disease.

Novel chemotherapeutic agent, FND-4b, activates AMPK and inhibits colorectal cancer cell proliferation

Colorectal cancer (CRC) is the second leading cause of cancer deaths in the US with the majority of deaths due to metastatic disease. Current chemotherapeutic regimens involve highly toxic agents, which limits their utility; therefore, more effective and less toxic agents are required to see a reduction in CRC mortality. Novel fluorinated N,N’-diarylureas (FND) were developed and characterized by our group as potent activators of adenosine monophosphate-activated kinase (AMPK) that inhibit cell cycle progression. The purpose of this study was to determine the effect of a lead FND compound, FND-4b, either alone or combined with PI-103 (a dual PI3K/mTOR inhibitor) or SN-38 (active metabolite of irinotecan) on cell cycle arrest and apoptosis of CRC cell lines (both commercially-available and novel lines established from our patient population). Treatment with FND-4b for 24h resulted in a marked induction of phosphorylated AMPK expression and a concomitant reduction in markers of cell proliferation, such as cyclin D1, in all CRC cell lines. Apoptosis was also notably increased in CRC cells treated with FND-4b. Regardless of the genetic profile of the CRC cells, FND-4b treatment alone resulted in decreased cell proliferation. Moreover, the combination of FND-4b with PI-103 resulted in increased cell death in all cell lines, while the combination of FND-4b with SN-38 resulted in increased cell death in select cell lines. Our findings identify FND-4b, which activates AMPK at micromolar concentrations, as a novel and effective inhibitor of CRC growth either alone or in combination with PI-103 and SN-38.

Maintenance Versus Intermittent Strategies in the Treatment of Metastatic Colorectal Cancer: A Meta-Analysis from Another Angle

INTRODUCTION

Considering the differences in overall survival (OS) and progression-free survival (PFS), treatment options for metastatic colorectal cancer (mCRC) are still inconclusive. We carried out a meta-analysis of maintenance and intermittent strategies for the treatment of mCRC aiming at providing an accurate estimation of different treatments in increasing the chance and duration of survival.

METHODS

PubMed, Embase and CNKI were systematically searched. The pooled hazard ratio (HR) and 95% confidence interval (CI) were counted. We used STATA 12.0 and RevMan 5.2 for statistical analyses.

RESULTS

A total of six publications with a population of 1975 mCRC patients were included in our meta-analysis. Analysis of OS revealed a statistically significant benefit associated with maintenance therapy (HR: 0.86, 95% CI 0.75-0.98, P = 0.02). Comparing maintenance therapy with an intermittent strategy, the first progression-free survival (PFS1) showed no significant difference (HR, 0.77; 95% CI 0.48-1.24, P = 0.29), but maintenance therapy improved the second progression-free survival (PFS2) significantly (HR, 0.66; 95% CI 0.54-0.81, P < 0.001). Sensitivity analysis was carried out to assess the stability of results. No publication bias was detected during analysis.

CONCLUSION

Compared with the maintenance strategy, first-line chemotherapy that was completely stopped until disease progression did not benefit mCRC patients in terms of OS and PFS2. Therefore, a maintenance strategy is a good option for individualized mCRC patients.

Efficacy and safety of trifluridine/tipiracil in third-line and beyond for the treatment of patients with metastatic colorectal cancer in routine clinical practice: patterns of use and prognostic nomogram

INTRODUCTION

Trifluridine/tipiracil combination has shown a benefit over placebo in the treatment of patients with chemorefractory metastatic colorectal cancer (mCRC). We evaluated the efficacy and safety of this combination in the real-life setting at eight Galician centers in Spain.

PATIENTS AND METHODS

This is a retrospective study of a cohort of patients with mCRC in treatment with trifluridine/tipiracil within usual clinical practice who have been previously treated or are not considered candidates for treatment with available therapies.

RESULTS

A total of 160 mCRC patients were included. Our data showed that 11.9% of patients achieved disease control. Median progression-free survival was 2.75 months; at 5.66 months follow-up, median overall survival was 7.94 months. Asthenia and neutropenia (48.1% both) were the most frequent adverse events. Overall survival was lower in patients with ECOG 2, multiple metastatic sites, platelets count 350,000/µl, alkaline phosphatase > 500 IU/l, and carcinoembryonic antigen > 10 ng/ml.

CONCLUSION

The results of this study confirm the efficacy and safety of trifluridine/tipiracil in chemorefractory mCRC patients. However, patients in clinical practice differ from patients in clinical trials. Due to this, prognostic factors have special importance to offer the best therapeutic approach.

Deregulation of SET is Associated with Tumor Progression and Predicts Adverse Outcome in Patients with Early-Stage Colorectal Cancer

SET nuclear proto-oncogene (SET) deregulation is a novel molecular target in metastatic colorectal cancer (CRC). However, its role in CRC progression and its potential clinical impact in early-stage CRC patients remain unknown. Here, we studied the biological effects of SET on migration using wound-healing and transwell assays, and anchorage-independent cell growth using soft agar colony formation assays after ectopic SET modulation. SET was analyzed by immuno-staining in 231 early-stage CRC patients, and miR-199b expression was quantified by real-time PCR in a set of CRC patients. Interestingly, SET enhances cell migration, markedly affects the colony-forming ability, promotes epithelial to mesenchymal transition, and induces the expression of the MYC proto-oncogene (c-MYC) in CRC cells. SET overexpression was detected in 15.4% of cases and was associated with worse Eastern Cooperative Oncology Group (ECOG) status (p = 0.021) and relapse in stage-II CRC patients (p = 0.008). Moreover, SET overexpression predicted shorter overall survival (p < 0.001) and time to metastasis (p < 0.001), and its prognostic value was particularly evident in elderly patients. MiR-199b downregulation was identified as a molecular mechanism to deregulate SET in patients with localized disease. In conclusion, SET overexpression is a common alteration in early-stage CRC, playing an oncogenic role associated with progression and aggressiveness, and portends a poor outcome. Thus, SET emerges as a novel potential molecular target with clinical impact in early-stage in CRC.

How and when adjuvant treatment should be intensified in stage III colorectal cancers?

The adjuvant chemotherapy (FOLFOX) represents the standard of care in stage III colon cancer with some exceptions in old patients. Adjuvant treatment must also be discussed in high-risk stage II colon cancer. However, 40-50% of patients develop disease recurrence after curative R0 surgical resection. The liver was the most common site of recurrence followed by peritoneum. Although adjuvant chemotherapy improved disease-free survival and overall survival, 5-year overall survival remains less than 55% in stage III colon cancer. Different strategies could be adopted to escalate the standard adjuvant chemotherapy in these patients going from aggressive intravenous chemotherapy, hepatic arterial infusion chemotherapy, hyperthermic intraperitoneal chemotherapy to adding targeted therapies or immunotherapies. We reported in this review the published and ongoing trials evaluating these treatment modalities in colon cancer.

Tumor-suppressive miR-26a and miR-26b inhibit cell aggressiveness by regulating FUT4 in colorectal cancer

Metastasis is a multistep molecular network process, which is the major cause of death in patients with colorectal cancer (CRC). MicroRNAs (miRNAs) play pivotal roles in tumorigenesis as either tumor suppressors or oncogenes. Increased expression of fucosyltransferase4 (FUT4) has been reported to be associated with the invasive and metastatic properties of CRC. Here to identify potential key miRNAs and their target genes for colorectal cancer (CRC), we compared miRNA expression profiles between metastatic CRC cell SW620 and primary CRC cell SW480. Microarray analysis revealed that there were 85 differentially expressed miRNAs in SW620 cells with highly metastatic potential compared to SW480 cells with lowly metastatic potential. The expression of miR-26a and miR-26b were lower in SW620 cells than in SW480 cells, as well as downregulated in tumor tissues than in adjacent normal tissues of CRC patients. By applying bioinformatic approaches for the prediction of miRNA targeting 3'-UTR of FUT4, we identified FUT4 as one of the miR-26a/26b-targeted genes, while the expression of the target gene exhibited patterns opposite to that of miR-26a/26b in CRC cell lines, tumor tissues and corresponding adjacent tissues. Forced miR-26a/26b expression affected migratory behavior of CRC cells and FUT4 expression, while altered expression of FUT4 in CRC cell lines modulated progression upon transfection with miR-26a/26b mimic or inhibiter. FUT4 also regulated directly aggressiveness of SW620 and SW480 cells. Moreover, statistical analyses revealed that low miR-26a/26b levels and high expression of FUT4 were positively correlated with poor overall survival. The identified CRC-restricted miR-26a and miR-26b might be implicated in cancer progression via their target gene FUT4, suggesting their potential usage in CRC treatment.

Current and future biomarkers in the treatment of colorectal cancer

Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. CRC develops as a consequence of genomic instability, characterized by various genetic and epigenetic alterations. Its molecular heterogeneity explains the large variability in patient prognosis and treatment response, emphasizing the need for development of accurate prognostic and predictive biomarkers. This article delineates the different pathways of colorectal carcinogenesis and its molecular subtype classification. With this review, we aim to provide a comprehensive overview of the current and future biomarkers guiding clinical decision-making and CRC treatment.

Phase II study of the Multikinase inhibitor of angiogenesis, Linifanib, in patients with metastatic and refractory colorectal cancer expressing mutated KRAS

Background Targeting angiogenesis in advanced colorectal cancer (CRC) has been one of the many factors prolonging survival. Bevacizumab was the first agent to demonstrate this, but even after progression on bevacizumab, continued VEGF-inhibition continues to improve survival. Combining epidermal growth factor receptor monoclonal antibodies with standard frontline therapies have also improved clinical outcomes, yet the improved benefit is not observed in patients with mutant KRAS. Thus, an unmet medical need exists to develop additional therapeutic options for patients with KRAS mutant CRC. Methods Patients received the anti-angiogenic agent linifanib at the recommended phase II dose of 17.5 mg. Primary endpoint was objective response rate (ORR), with a goal of 10%. Secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Simon's optimal two-stage design was used to assess futility. Linifanib was considered inactive if two or fewer patients among the first 30 achieved an objective response. Results Thirty patients were enrolled on study. Grade 3 treatment-related toxicities occurring in at least two patients were fatigue, hypertension, proteinuria, diarrhea, nausea, oral pain, vomiting, thrombocytopenia, and arthralgia. Although no responses were observed, 63.5% of patients achieved stable disease. The median PFS and OS were 4.7 months and 9.5 months, respectively. Stopping rules for lack of clinical efficacy led to study closure. Conclusion Despite observing zero responses, a majority of patients had stable disease and eight patients had stable disease lasting longer than 5 months. These results suggest that linifanib has some anti-tumor activity in KRAS mutant metastatic and refractory CRC.

A novel antimetabolite: TAS-102 for metastatic colorectal cancer

TAS-102 is a new oral anti-tumor drug, composed of a thymidine-based nucleoside analog (trifluridine: FTD) and a thymidine phosphorylase inhibitor (tipiracil hydrochloride: TPI). TAS-102 has been shown to significantly improve overall survival and progression-free survival in patients with refractory metastatic colorectal cancer (mCRC) in placebo-controlled randomized phase II and III trials. The current review summarizes mechanisms of action, pharmacokinetics/dynamics and preclinical and clinical data of TAS-102 in colorectal cancer. TAS-102 is a new salvage-line treatment option for patients with mCRC. TAS-102 is well tolerated and has great potential in future clinical drug combination therapies.

Clinical Implication of UGT1A1 Promoter Polymorphism for Irinotecan Dose Escalation in Metastatic Colorectal Cancer Patients Treated with Bevacizumab Combined with FOLFIRI in the First-line Setting

PURPOSE: This study aimed to identify the efficacy and toxicity of the FOLFIRI regimen (fluorouracil, leucovorin, and irinotecan) with irinotecan dose escalation plus bevacizumab as first-line chemotherapy for metastatic colorectal cancer (mCRC) via UGT1A1 genotyping. METHODS: We administered bevacizumab plus FOLFIRI with irinotecan dose escalation to treat 70 mCRC patients. The UGT1A1 *1/*1 and *1/*28 genotypes started with a 180-mg/m² dose of irinotecan, and UGT1A1 *28/*28 genotype started with a dose of 120 mg/m². The dose of irinotecan was escalated at increasing intervals of 20 to 30 mg/m² until grade 3/4 adverse events (AEs) occurred. The clinical response rate, toxicity, and survival were analyzed. RESULTS: The clinical response and disease control rates of mCRC patients treated with FOLFIRI plus bevacizumab were significantly better in patients with UGT1A1 *1/*1 and *1/*28 genotypes than in patients with UGT1A1 *28/*28 (P = .006 and P < .001, respectively). Grade 3/4 AEs were significantly more common in mCRC patients with the UGT1A1 *28/*28 genotype (P < .001). Progression-free survival was significantly higher in UGT1A1 *1/*1 and *1/*28 patients (P = .002). mCRC patients who underwent metastasectomy achieved better overall survival than those who did not undergo metastasectomy (P = .015). CONCLUSIONS: Our study showed that mCRC patients with UGT1A1 *1/*1 and *1/*28 genotypes could receive escalated doses of irinotecan to obtain a more favorable clinical outcome without significant AEs.

Bevacizumab in combination with fluoropyrimidine-irinotecan- or fluoropyrimidine-oxaliplatin-based chemotherapy for first-line and maintenance treatment of metastatic colorectal cancer

Despite a slight decrease in mortality rates, recent advances in screening methods, diagnosis and overall improved therapeutic options, colorectal cancer (CRC) remains among the leading causes of cancer-related death worldwide. The major cause is the mortality related to metastatic status of CRC. Increasing clinical evidence derived from randomized trials strongly suggests that the efficacy of standard cytotoxic agents, including various combinations of 5-fluoouracil (5-FU)/leucovorin (LV), capecitabine, irinotecan and oxaliplatin, may be significantly augmented with concomitant administration of molecular agents targeting the vascular endothelial growth factor (VEGF) signaling pathways, such as bevacizumab. Herein, we critically discuss the current data on the efficacy and safety profile of bevacizumab in combination with fluoropyrimidine-based chemotherapy for first-line and maintenance treatment of metastatic CRC and briefly comment on existing controversies and future perspectives.

FOXQ1 mediates the crosstalk between TGF-β and Wnt signaling pathways in the progression of colorectal cancer

A wide variety of signaling transduction pathways contribute to tumorigenesis. Forkhead box Q1 (FOXQ1) is a member of the forkhead transcription factor family and its upregulation is closely correlated with tumor progression and prognosis of multiple cancer types, including colorectal cancer. However, the molecular mechanisms by which FOXQ1 promotes tumorigenesis, especially cancer cell invasion and metastasis in colorectal cancer, have not been fully elucidated. In the present study, we demonstrate that FOXQ1 is overexpressed in colorectal tumor tissues and its expression level is closely correlated with the stage and lymph node metastasis of colorectal cancer. In in vitro cultured SW480 colorectal cancer cells, knockdown of FOXQ1 expression by small interfering RNA greatly diminished the aggressive tumor behaviors of SW480 cells, including angiogenesis, invasion, epithelial-mesenchymal transition, and resistance to chemotherapy drug-induced apoptosis. Further mechanistic investigation showed that FOXQ1 silencing prevents the nuclear translocation of β-catenin, thus reducing the activity of Wnt signaling. Moreover, TGF-β1 induced the expression of FOXQ1 as well as the migration and invasion of SW480 cells, which was partially prevented following knockdown of FOXQ1. Our results demonstrate that FOXQ1 plays a critical role during the tumorigenesis of colorectal cancer and is a mediator of the crosstalk between Wnt and TGF-β signaling pathways. Our findings provide further insight into the cancer biology of colorectal cancer and suggest that FOXQ1 is a potential therapeutic target for the development of therapies for colorectal cancer.

A review of the evolution of systemic chemotherapy in the management of colorectal cancer

Herein we present a historical review of the development of systemic chemotherapy for colorectal cancer (CRC) in the metastatic and adjuvant treatment settings. We describe the discovery of 5-fluorouracil (5-FU) by Heidelberger and colleagues in 1957, the potentiation of 5-FU cytotoxicity by the reduced folate leucovorin, and the advent of novel cytotoxic agents, including the topoisomerase I inhibitor irinotecan, the platinum-containing agent oxaliplatin, and the 5-FU prodrug capecitabine. The combination therapies, FOLFOX (5-FU/leucovorin and oxaliplatin) and FOLFIRI (5-FU/leucovorin and irinotecan), have become established as efficacious cytotoxic regimens for the treatment of metastatic CRC, resulting in overall survival times of approximately 2 years. When used as adjuvant therapy, FOLFOX also improves survival and is now the gold standard of care in this setting. Biological agents have been discovered that enhance the effect of cytotoxic therapy, including bevacizumab (a humanized monoclonal antibody that targets vascular endothelial growth factor, a central regulator of angiogenesis) and cetuximab/panitumumab (monoclonal antibodies directed against the epidermal growth factor receptor). Despite the ongoing development of novel antitumor agents and therapeutic principles as we enter the era of personalized cancer medicine, systemic chemotherapy involving infusional 5-FU/leucovorin continues to be the cornerstone of treatment for patients with CRC.

Quercetin Liposome Sensitizes Colon Carcinoma to Thermotherapy and Thermochemotherapy in Mice Models

Thermotherapy and thermochemotherapy have been used in clinics to treat patients with malignant diseases, including colon cancer, and their efficacy has been well proved. Heat shock proteins (HSPs), especially Hsp70, play important roles in neutralizing their efficacy. It has been reported that quercetin can suppress cancer by inhibiting the intratumoral expression of Hsp70. This study was designed to investigate whether quercetin could enhance sensitivity to thermotherapy and thermochemotherapy. Soluble quercetin liposome was used in this study. The effects of quercetin were investigated in vitro and in mouse colon cancer models of subcutaneous tumor and peritoneal carcinomatosis. The results showed that quercetin liposome inhibited the upregulation of Hsp70 and enhanced apoptosis induced by hyperthermia and thermochemotherapy. Systemic administration of quercetin liposome can sensitize CT26 cells to thermotherapy and chemothermotherapy. This study suggests that quercetin liposome might be potentially applied for clinical cancer therapy.

Treatment decisions after diagnosis of metastatic colorectal cancer

Treatment of metastatic colorectal cancer (mCRC) involves the use of active cytotoxic drugs (irinotecan, oxaliplatin, 5-fluorouracil [5-FU], and capecitabine) and biological agents (bevacizumab, cetuximab, and panitumumab) either in combination or as single agents. Until recently, the only biological agent with proven first-line efficacy was bevacizumab, but options have expanded from the data generated with anti-endothelial growth factor (EGFR) monoclonal antibodies. Anti-EGFR agents can be added to first-line FOLFIRI (5-fluorouracil, leucovorin [folinic acid], irinotecan) or FOLFOX (5-fluorouracil, leucovorin [folinic acid], oxaliplatin) in patients whose tumors express wild-type KRAS. These agents may improve outcomes when added to chemotherapy, particularly progression-free survival (PFS), and in the case of cetuximab, overall survival (OS) and response rates. The selection of first-line therapy should be based on the individual treatment goals after considering the efficacy and tolerability of each regimen. For patients with metastases confined to the liver, surgical resection offers a potentially curative approach. For initially unresectable lesions, treatment regimens offering high response rates may produce sufficient tumor shrinkage to permit complete resection. Regimens with high response rates are also preferable for patients requiring symptom relief or for those with large tumor burdens. The choice between intensive vs. nonintensive management also depends on other factors, including the patient's functional status, comorbidities, and desires. A sequential single-agent strategy or an intermittent approach (combination therapy followed by maintenance) may minimize toxicity and be appropriate for patients who are not surgical candidates, irrespective of treatment response. Guidelines, such as those of the National Comprehensive Cancer Network (NCCN), recommend that KRAS mutational status should be determined at mCRC diagnosis to identify candidates for anti-EGFR therapy whether they are used in first or subsequent lines of treatment.

Topic update: effects of colorectal cancer treatments on female fertility and potential methods for fertility preservation

PURPOSE

Preservation of fertility in young females with a diagnosis of colorectal cancer is gaining increasing importance as survival rates of cancer increase. This review examines the effects of pelvic surgery, chemotherapy, and radiotherapy on fecundity. It also discusses the options available to patients including ovarian transposition, gonadotropin-releasing hormone analogs, embryo and ovarian cryopreservation, and ovarian tissue transplantation.

METHODS

A search of MEDLINE, EMBASE, and the Cochrane library was performed using keywords and exploded Mesh search headings and the subsequent articles were reviewed. Relevant studies were included.

RESULTS

There are no studies that examine the effect of surgery for colorectal cancer on female fertility, in particular, surgery below the peritoneal reflection for rectal cancer. However, patients with familial adenomatous polyposis have a similar fecundity before and after proctocolectomy with ileal pouch-anal anastomosis. These patients did significantly better than patients with ulcerative colitis who underwent the same procedure. There is conflicting evidence regarding the effects of open vs laparoscopic surgery on fertility. Oxaliplatin, an adjuvant therapy, has moderate gonadotoxic effects. Fluorouracil is considered to have almost no effect on human reproductive function. Gonadotropin-releasing hormone agonists are currently used to preserve female fecundity during chemotherapy. A recent update of patients treated for Hodgkin lymphoma showed that significantly fewer women treated with a gonadotropin-releasing hormone agonist during chemotherapy exhibited premature ovarian failure. Ovarian transposition reduces the radiation dose to approximately 5% to 10% of the dose to the ovaries in their normal position. Other options are available to women with cancer who wish to preserve their germ line, including embryo and oocyte cryopreservation and ovarian tissue cryopreservation.

CONCLUSION

Significant advances are now allowing females to preserve their fertility after cancer treatment. It is essential that patients receive adequate fertility counseling before any intervention to give them an opportunity to consider fertility alternatives.

Stem cells in clinical practice: applications and warnings

Stem cells are a relevant source of information about cellular differentiation, molecular processes and tissue homeostasis, but also one of the most putative biological tools to treat degenerative diseases. This review focuses on human stem cells clinical and experimental applications. Our aim is to take a correct view of the available stem cell subtypes and their rational use in the medical area, with a specific focus on their therapeutic benefits and side effects. We have reviewed the main clinical trials dividing them basing on their clinical applications, and taking into account the ethical issue associated with the stem cell therapy.

Fertility preservation for young women with rectal cancer--a combined approach from one referral center

BACKGROUND

Up to 6% of women with colorectal cancer are diagnosed in the reproductive age and are at risk for premature ovarian failure and infertility due to pelvic irradiation and chemotherapy.

STUDY DESIGN

Between 1997 and 2007, six women with rectal carcinoma were referred to the McGill Reproductive Center (Montreal, Canada) for fertility preservation. Following resection of their primary tumor, they were scheduled to undergo pelvic irradiation.

RESULTS

Five patients underwent laparoscopic ovarian lateral transposition before radiotherapy in order to relocate their ovaries outside the radiation field. A concomitant ovarian wedge resection was performed for ovarian cryopreservation. In two of these women, before dissecting the ovarian cortical tissue for cryopreservation, all visible follicles were aspirated. The sixth patient who had had low anterior resection underwent hormonal ovarian stimulation followed by oocyte retrieval and embryo vitrification.

CONCLUSIONS

Fertility preservation in women with rectal cancer is feasible. This includes laparoscopic ovarian transposition and cryopreservation of ovarian tissue, embryo, or oocyte.

Female fertility and colorectal cancer

PURPOSE

It is estimated that the incidence of cancer in women aged 40 years or less is 8%. Females under the age of 40 are in their childbearing years. In the Western world, colorectal cancer (CRC) is the most common malignancy of the gastrointestinal tract. It is the third most commonly diagnosed cancer and the second leading cause of cancer-related death in the USA. The incidence of CRC in patients under 40 is 3-6%. Over the past decades, there has been a significant improvement in survival rates due to progress in cancer treatment, including CRC. This has been achieved with advances in adjuvant chemotherapeutic regimens. In the case of locally advanced rectal cancer, radiation therapy is also used. Treatment for CRC may have adverse effects on female fertility. The purpose of this paper is to discuss the effects of treatment of CRC on female fertility as well as the options for fertility preservation.

MATERIALS AND METHODS

A review of relevant English language articles was performed on the basis of a MEDLINE search of the keywords: female, fertility, fecundity, colon, rectal cancer, fertility preservation, chemotherapy, and radiation.

RESULTS

Surgical resection for colon cancer possibly has no effect on female fertility. Resection below the peritoneal reflection may adversely affect fertility, based on lower fertility and fecundity rates associated with pelvic surgery for ulcerative colitis and familial adenomatous polyposis. Standard 5-FU-based chemotherapy may not have significant effects. The advent of oxaliplatin in adjuvant chemotherapy may be more harmful. Adjuvant and neoadjuvant radiation therapy may cause premature ovarian failure using current dosing schedules. The effect of pregnancy and female hormones on the incidence, progression, and recurrence of CRC remains unclear. Established methods for fertility preservation include ovarian transposition and embryo cryopreservation. Oocyte cryopreservation has yielded inferior results. An investigational fertility preservation method is ovarian tissue cryopreservation, with promising results. Ovarian suppression and the use of apoptotic inhibitors are also investigational at present.

CONCLUSION

Young female patients need to be informed about the effects of treatment on fertility and options for fertility preservation. A multidisciplinary approach for appropriate consultation of these patients is mandatory.

Update on clinical data combining capecitabine with targeted agents in newly diagnosed colorectal cancer

Colorectal cancer (CRC) is a worldwide public health problem, with nearly 800,000 new cases diagnosed each year, resulting in approximately 500,000 deaths. When advanced metastatic disease is diagnosed, CRC is associated with a poor prognosis, and 5-year survival rates are in the range of 5%-8%. Chemotherapy has been the mainstay approach for patients with advanced CRC. For nearly 40 years, the main drug used for this disease was the fluoropyrimidine 5-fluorouracil (5-FU). Significant advances have been made in chemotherapy treatment options for patients with metastatic disease, such that improvements in 2-year survival are now being reported with median survival rates of 21 months to 24 months. Over the past 10 years, 3 new cytotoxic chemotherapy agents have been approved by the FDA for metastatic CRC. These compounds include the topoisomerase I inhibitor irinotecan, the third-generation platinum analogue oxaliplatin, and the oral fluoropyrimidine capecitabine. Since 2004, 3 novel biologic agents have been approved by the FDA, and they include the anti-epidermal growth factor receptor antibodies cetuximab and panitumumab and the anti-vascular endothelial growth factor bevacizumab. The oral fluoropyrimidine capecitabine has been effectively and safely combined with irinotecan (CAPIRI) and/or oxaliplatin (CAPOX). Three randomized phase III studies have now shown that CAPOX is equivalent to FOLFOX (5-FU/leucovorin/oxaliplatin)-based regimens. Significant interest has centered around combining capecitabine-based cytotoxic regimens with the biologic agents, and specifically, bevacizumab and cetuximab. This review will update the current status of these capecitabine-based combination regimens.

In vivo and in vitro anti-tumor effects of β-elemene liposome

AIM: To investigate the inhibitory effects of β-elemene liposome on digestive tumors in vitro and in vivo.

METHODS: Five digestive tumor cell lines and one human lung embryonic fibroblast cell line were used to test the IC₅₀ values of β-elemene liposome in vitro by cell culture. H22-bearing Kunming mice were treated with injection of β-elemene liposome through the tail vein at 20, 40 or 80 mg/kg to establish solid and ascites tumor models. Mice treated with glucose or elemene emulsion served as negative or positive controls, respectively. The anti-tumor effects, survival and side effects of β-elemene liposome observed and compared between different groups.

RESULTS: IC₅₀ values of β-elemene liposome and elemene emulsion for the five digestive tumor cell lines were from 34.1 ± 4.5 to 51.4 ± 4.2 mg/L and 41.5 ± 4.7 mg/L to 82.3 ± 8.8 mg/L, respectively, and IC₅₀ of the former was half of the later. In solid tumor models, the inhibitory rates of 80-, 40- or 20-mg/kg β-elemene liposome and elemene emulsion were 47.4%-50.8%, 38.2%-45.0%, 23.2%-28.2% and 21.8%-43.0%, respectively, and the average tumor weights were lower than those in the glucose control group (t > 4.09, P < 0.05). In ascites tumor models, the survival time was 51.3%-153.0% longer in β-elemene liposome or emulsion group than that in the glucose control group (t > 7.92, P < 0.05). Furthermore, the survival time in 80- or 40-mg/kg β-elemene liposome group was longer than that in elemene emulsion group (t > 4.64, P < 0.05). The stimulating symptoms and phlebitis of tail vein generated by injection of β-elemene liposome were slighter than those by elemene emulsion.

CONCLUSION: β-elemene liposome has greater ability to inhibit tumor growth and relieve side effects than elemene emulsion.