The survival outcome differs between left-sided colon and middle/low rectal cancer after colorectal hepatic metastasectomy

INTRODUCTION

The clinical outcomes between left-sided colon cancer and middle/low rectal cancer appear to be different. We aimed to examine the impact of primary tumor location regarding the left-sided colon and middle/low rectum on the overall survival (OS) of colorectal hepatic metastasectomy.

PATIENTS AND METHODS

Patients who underwent colorectal hepatic metastasectomy were retrospectively enrolled. Patients were classified into two groups according to primary tumor location (left-sided colon and middle/low rectum). Categorical variables were compared using the chi-square test or Fisher's exact test, and continuous variables were analyzed using Student'st-test. Survival was analyzed by the KaplanMeier method and log-rank test. The prognostic factors were analyzed by univariate and multivariate analyses using Cox proportional hazards regression models.

RESULTS

Totally, 365 patients were enrolled. Patients with left-sided colon cancer had significantly better OS than those with middle/low rectal cancer (hazard ratio (HR) 0.725, P=0.018), with a median OS of 48 months and 38 months, respectively. In the subgroup analysis of RAS mutations, those with left-sided colon cancer had significantly prolonged OS compared to those with middle/low rectum cancer (HR 0.608, P=0.034), with a median OS of 49 months and 26 months, respectively. This observation was limited to patients with RAS mutations.

CONCLUSION

According to our findings, middle/low rectal cancer had poorer survival outcome, and should not be categorized together with left-sided colon cancer in terms of OS following colorectal hepatic metastasectomy.

Anti-VEGF Therapy Possibly Extends Survival in Patients With Colorectal Brain Metastasis by Protecting Patients From Neurologic Disability

BACKGROUND

Colorectal brain metastases (CBMs) are rare with poor prognosis. There is still no standard systemic treatment for multiple or unresectable CBM. our study aimed to explore the impact of anti-VEGF therapy on overall survival, brain-specific disease control, and neurologic symptom burden in patients with CBM.

METHODS

A total of 65 patients with CBM under treatment were retrospectively enrolled and divided into anti-VEGF based systemic therapy or non-anti-VEGF based therapy. A total of 25 patients who received at least 3 cycles of anti-VEGF agent and 40 patients without anti-VEGF therapy were analyzed by endpoints of overall survival (OS), progression-free survival (PFS), intracranial PFS (iPFS) and neurogenic event-free survival (nEFS). Gene expression in paired primary metastatic colorectal cancer (mCRC), liver, lung and brain metastasis from NCBI data was analyzed using top Gene Ontology (GO) and cBioPortal.

RESULTS

Patients who treated with anti-VEGF therapy had significantly longer OS (19.5 vs. 5.5 months, P = .009), iPFS (14.6 vs. 4.1 months, P < .001) and nEFS (17.6 vs. 4.4 months, P < .001). Patients who received anti-VEGF therapy beyond any disease progression presented with superior OS (19.7 vs. 9.4 months, P = .039). Top GO and cBioPortal analysis revealed a stronger molecular function of angiogenesis in intracranial metastasis.

CONCLUSIONS

Anti-VEGF based systemic therapy showed favorable efficacy that was reflected in longer overall survival, iPFS and NEFS in patients with CBM.

Surgical strategy for colorectal cancer with synchronous liver and extrahepatic metastases: A scoring system and decision tree model

BACKGROUND

The role of hepatectomy in a specific group of patients with synchronous colorectal cancer with liver metastases (SCRLM) and synchronous extrahepatic disease (SEHD) is still unclear. The aim of this study was to evaluate the efficacy of liver surgery and define the selection criteria for surgical candidates in patients with SCRLM + SEHD.

METHODS

Between July 2007 and October 2018, 475 patients with colorectal cancer with liver metastases (CRLM) who underwent liver resection were retrospectively reviewed. Sixty-five patients with SCRLM + SEHD were identified and included in the study. Clinical pathological data of these patients were analyzed to evaluate the influence on survival. Important prognostic factors were identified by univariate and multivariate analyses. The risk score system and decision tree analysis were generated according to the important prognostic factors for better patient selection.

RESULTS

The 5-year survival rate of patients with SCRLM + SEHD was 21.9%. The most important prognostic factors were SCRLM number of more than five, site of SEHD other than the lung only, inability to achieve SCRLM + SEHD R0 resection, and BRAF mutation of cancer cells. The proposed risk score system and decision tree model easily discriminated between patients with different survival rates and identified the profile of suitable surgical patients.

CONCLUSION

Liver surgery should not be a contraindication for patients with SCRLM + SEHD. Patients with complete SCRLM + SEHD R0 resection, SCRLM number less than or equal to five, SEHD confined to the lung only, and wild-type BRAF could have favorable survival outcomes. The proposed scoring system and decision tree model may be beneficial to patient selection in clinical use.

A Long-Term and Large-Scale Real-World Study in Taiwan: Efficacy of Target Therapy in Stage IV Colorectal Cancer

This study expands the understanding of the role of target therapy in improving survival of patients with mCRC based on real-world study results. These data represent potential survival outcomes of Taiwanese patients with mCRC in clinical practice. CRC is the most commonly diagnosed cancer and the third leading cause of cancer-related death in Taiwan. The aim of this study was to evaluate the efficacy of target therapy in combination with chemotherapy for mCRC in Taiwan. This was a real-world, retrospective, observational study in patients diagnosed with mCRC (N=1583). A total of 792 patients received chemotherapy plus target therapy (anti-EGFR therapy, n=180; anti-VEGF therapy, n=612) and 791 patients who received chemotherapy alone. Overall survival (OS) and progression-free survival (PFS) were examined. For RAS wild-type patients, the median OS (mOS) was 34.3 months in the EGFR L (left-sided colon) group, 27.3 months in the VEGF L group, 18.4 months in VEGF R (right-sided colon) group, and 13.8 months in EGFR R group (P<0.001). Median PFS (mPFS) was 9.8 months in the EGFR L group, 8.9 months in the VEGF L group, 6.8 months in VEGF R group, and 5.8 months in EGFR R group. In patients with a RAS mutation, mOS was 25.4 months in the VEGF L group and 19.4 months in the VEGF R group (P=0.167). Judicious treatment allocation in Taiwanese patients with mCRC can result in an mOS of 34.3 months using cetuximab plus chemotherapy for left-sided tumors. An mOS of 48.5 months can be achieved using cetuximab plus chemotherapy in the neoadjuvant setting in mCRC patients with left-sided tumors. This study expands our understanding of the role of target therapy in improving survival of mCRC patients based on real-world study results.

Taiwan Society of Colon and Rectal Surgeons Consensus on mCRC Treatment

Therapeutic options for metastatic CRC (mCRC) have changed significantly in recent years, greatly increasing the complexity of therapeutic decision-making. Although oncology guidelines have helped improve the care process, guidelines may also limit the flexibility to individualize in-clinic decision-making. This consensus paper addresses specific gaps in the current international guidelines to assist Taiwanese colon and rectal experts make specific therapeutic choices. Over 3 years and three meetings with selected experts on "real-world" Taiwanese practice patterns for mCRC, consensus was achieved. The experts also discussed specific questions during in-depth one-on-one consultation. Outcomes of the discussion were then correlated with published evidence by an independent medical writer. The final consensus includes clinically implementable recommendations to provide guidance in treating Taiwanese mCRC patients. The consensus includes criteria for defining fit and unfit intensive treatment patients, treatment goals, treatment considerations of molecular profiles, treatment consideration, and optimal treatment choices between different patient archetypes, including optimal treatment options based on RAS, BRAF, and microsatellite instability (MSI) status. This consensus paper is the second in the Taiwan Society of Colon and Rectal Surgeons (TSCRS) Consensus series to address unmet gaps in guideline recommendations in lieu of Taiwanese mCRC management. Meticulous discussions with experts, the multidisciplinary nature of the working group, and the final drafting of the consensus by independent medical professionals have contributed to the strong scientific value of this consensus.

Preference criteria for regorafenib in treating refractory metastatic colorectal cancer are the small tumor burden, slow growth and poor/scanty spread

Given the unclear preference criteria for regorafenib in treating refractory metastatic colorectal cancer (mCRC), this study aimed to construct an algorithm in selecting right patients for regorafenib. This was a multicenter retrospective cohort study. Patients with pathology confirmed mCRC and administered with regorafenib for > 3 weeks were enrolled. Patients with good response were defined to have progression-free survival (PFS) of ≥ 4 months. The Kaplan–Meier plot was used to analyze survival. A Cox proportional hazards model was used to analyze univariate and multivariate prognostic factors and was visualized using forest plot. A clustering heatmap was used to classify patients according to responses. The decision tree and nomogram were used to construct the approaching algorithm. A total of 613 patients was analyzed. The median PFS and overall survival (OS) were 2.7 and 10.6 months, respectively. The partial response and stable disease rate are 2.4% and 36.4%. The interval between metastasis (M1) and regorafenib, metastatic status (number, liver, and brain), and CEA level were independent prognostics factors of PFS that classifies patients into three groups: good, bad and modest-1/modest-2 group with PFS >  = 4 months rates of 51%, 20%, 39% and 30%, respectively. Results were used to develop the decision tree and nomogram for approaching patients indicated with regorafenib. The preference criteria for regorafenib in treating patients with refractory mCRC are small tumor burden (CEA), slow growth (interval between metastasis and regorafenib) and poor/scanty spread (metastatic status: number and sites of metastasis): The 3S rules.

TRIAL registration ClinicalTrials.gov Identifier: NCT03829852; Date of first registration (February 11, 2019).

Significance of Kynurenine 3-Monooxygenase Expression in Colorectal Cancer

Colorectal cancer (CRC) is a leading cause of cancer-related deaths. Because of the lack of reliable prognostic and predictive biomarkers for CRC, most patients are often diagnosed at a late stage. The tryptophan–kynurenine pathway plays a crucial role in promoting cancer progression. Kynurenine is considered an oncometabolite in colon cancer, and its downstream metabolites are also associated with CRC. Kynurenine 3-monooxygenase (KMO), a pivotal enzyme that catalyzes kynurenine metabolism, is essential for several cellular processes. In the current study, we explored the role of KMO in CRC. Immunohistochemical results showed that KMO was upregulated in CRC tissues relative to paired healthy tissue and polyps. Moreover, CRC patients with higher KMO expression were associated with higher metastasis and poorer survival rates. Knockdown of KMO decreased the expression of cancer stem cell markers, as well as the sphere-forming, migration, and invasion abilities of CRC cells. Additionally, blockade of the enzymatic activity of KMO using an inhibitor suppressed sphere formation and cell motility in CRC cells. These findings suggest the clinical relevance of KMO in CRC tumorigenesis and aggressiveness.

Effect of Primary Tumor Location on Postmetastasectomy Survival in Patients with Colorectal Cancer Liver Metastasis

BACKGROUND

The effects of primary tumor location on colorectal liver metastasis (CRLM) and post-hepatic-metastasectomy overall survival (OS) are controversial. This study evaluated the difference in post-hepatic-metastasectomy OS among right-sided colon, left-sided colon, and rectal cancer groups.

METHODS

In total, 381 patients who underwent curative-intent CRLM resection were enrolled. Patients were grouped based on the primary tumor location (right-sided, left-sided, and rectum). The Kaplan-Meier analysis and log-rank test were performed for survival analysis. The univariate and multivariate analyses of clinical and pathological factors were performed using the Cox proportional hazards model.

RESULTS

Significant OS difference was noted among the three groups (log-rank, p = 0.014). The multivariate analysis revealed a 32% lower death risk in left-sided colon cancer compared with right-sided colon cancer (hazard ratio [HR] 0.68, p = 0.042), whereas no OS difference was noted between the rectal cancer and right-sided colon cancer groups. The left- versus right-sided OS advantage was noted only in the KRAS wild-type subgroup (HR 0.46, p = 0.002), and a rectal versus right-sided OS disadvantage was noted in the KRAS mutant subgroup (HR 1.78, p = 0.03).

CONCLUSIONS

The CRLM post-hepatic-metastasectomy OS was superior in left-sided colon cancer than in right-sided colon cancer and was similar in rectal and right-sided colon cancer. The OS difference in different primary tumor locations is dependent on KRAS mutation status, with a decreased left- versus right-sided death risk noted only in KRAS wild-type colon cancer and an increased rectal versus right-sided death risk noted only in KRAS mutant colon cancer.

Real-world evidence of the safety and effectiveness of regorafenib in Taiwanese patients with metastatic colorectal cancer: CORRELATE Taiwan

BACKGROUND/PURPOSE

This analysis reports safety and effectiveness data from the Taiwanese cohort of the CORRELATE study.

METHODS

CORRELATE was a prospective, observational study to assess the safety and effectiveness of regorafenib for the treatment of metastatic colorectal cancer (CRC) in real-world clinical practice that was conducted in 13 different countries in Asia, Europe and Latin America. The primary endpoint of the study was incidence of all treatment-emergent AEs (TEAEs), and secondary endpoints included overall survival (OS), progression-free survival (PFS), and disease control rate (DCR).

RESULTS

The global study population (N = 1037) included 128 Taiwanese patients with a median age of 64 years, median weight of 62.02 kg and 66.41% were male. Reduced initiating doses of regorafenib and dose interruptions were common in Taiwanese patients (71.87% and 50.00%, respectively). The safety profile of regorafenib was consistent with that seen in Asian patients in the clinical development trials, including the CORRECT and CONCUR studies, with hand-foot-skin reactions (HFSR) of any grade occurring in 33.59% of patients. Median OS was 11.64 months in the Taiwanese patients (95% confidence interval [CI], 8.36-13.82) and median PFS was 2.17 months (95% CI, 1.97-2.89).

CONCLUSIONS

The safety and effectiveness of regorafenib in this real-world study was generally consistent with the known efficacy and safety profile in Asian patients in clinical trials.

TRIAL REGISTRATION

NCT02042144.

Harnessing stemness and PD-L1 expression by AT-rich interaction domain-containing protein 3B in colorectal cancer

Background and Aims: Cancer stem cells (CSCs) have been shown to be responsible for the tumor initiation, metastasis, and therapeutic resistance of colorectal cancer (CRC). Recent studies have also indicated the importance of CSCs in escaping immune surveillance. However, the coordinated epigenetic control of the stem cell signature and the key molecule(s) involved in immunosurveillance of colorectal CSCs (CRCSCs) are unclear. Here, we investigated the role of a histone modifier, AT-rich interaction domain-containing protein 3B (ARID3B), in CRC.

Methods: CRC patient-derived xenografts (PDXs) with knockout of ARID3B induced by CRISPR/Cas9 in vivo were used. Molecular/cellular biology assays were performed. Clinical data obtained from The Cancer Genome Atlas, as well as from our cohort (Taipei Veterans General Hospital), were analyzed.

Results: ARID3B was crucial for the growth of CRC, and ARID3B promoted the stem-like features of CRC. Mechanistically, ARID3B activated Notch target genes, intestinal stem cell (ISC) genes, and programmed death-ligand 1 (PD-L1) through the recruitment of lysine-specific demethylase 4C (KDM4C) to modulate the chromatin configuration for transcriptional activation. Clinical sample analyses showed that the coexpression of ARID3B and the Notch target HES1 correlated with a worse outcome and that ARID3B and PD-L1 were highly expressed in the consensus molecular subtype 4 of CRC. Pharmacological inhibition of KDM4 activity reversed the ARID3B-induced signature.

Conclusion: We reveal a noncanonical Notch pathway for activating Notch target genes, ISC genes, and PD-L1 in CRC. This finding explains the immune escape of CRCSCs and indicates a potential group that may benefit from immune checkpoint inhibitors. Epigenetic drugs for reversing stem-like features of CRC should also be investigated.

RAB27B-activated secretion of stem-like tumor exosomes delivers the biomarker microRNA-146a-5p, which promotes tumorigenesis and associates with an immunosuppressive tumor microenvironment in colorectal cancer

The dynamic cell-cell communication is essential for tissue homeostasis in normal physiological circumstances and contributes to a diversified tumor microenvironment. Although exosomes are extracellular vesicles that actively participate in cell-cell interaction by shutting cellular components, impacts of tumor exosomes in the context of cancer stemness remain elusive. Here, we expand colorectal cancer stem cells (CRCSCs) as cancer spheroids and demonstrate that the β-catenin/Tcf-4-activated RAB27B expression is required for the secretion of CRCSC exosomes. In an exosomal RNA sequencing analysis, a switch of exosomal RNA species from retrotransposons to microRNAs (miRNAs) is identified upon expanding CRCSCs. miRNA-146a-5p (miR-146a) is the major miRNA in CRCSC exosomes and exosomal miR-146a promotes stem-like properties and tumorigenicity by targeting Numb in recipient CRC cells. Among 53 CRC patients, those with abundant exosomal miR-146a expression in serum exhibits higher miR-146aHigh /NumbLow CRCSC traits, an increased number of tumor-filtrating CD66(+) neutrophils and a decreased number of tumor-infiltrating CD8(+) T cells. Our study elucidates a unique mechanism of tumor exosome-mediated stemness expansion.

PD-L1 is a double-edged sword in colorectal cancer: the prognostic value of PD-L1 depends on the cell type expressing PD-L1

PURPOSE

To investigate the associations between programmed cell death ligand-1 (PD-L1) on tumor cells (TCs) or PD-L1 on tumor-infiltrating immune cells (TIICs) and the microsatellite instability (MSI) status in colorectal cancer (CRC).

METHODS

In total, 238 CRC patients were enrolled. PD-L1 expression and MSI status were studied by immunohistochemical staining and polymerase chain reaction. The χ² test was used to compare characteristics. The Kaplan-Meier method was used for survival analysis. Cox proportional hazards models were used to determine the prognostic influence of clinicopathological factors.

RESULTS

Eighteen patients (7.6%) were had MSI-high (MSI-H) CRC. The number of patients with PD-L1 expression on TCs, stromal TIICs and intraepithelial TIICs was 13 (5.5%), 64 (26.9%) and 45 (18.9%), respectively. The MSI-H phenotype was significantly associated with younger age, right sidedness, mucinous component, high grade, stromal TIICs expressing PD-L1 (P = 0.042) and intraepithelial TIICs expressing PD-L1 (P < 0.001), but not TCs expressing PD-L1. PD-L1-expressing TCs were an independent marker of poor prognosis [hazard ratio (HR) = 3.387, P = 0.003], and PD-L1-expressing stromal TIICs were an independent marker of good prognosis (HR = 0.551, P < 0.001).

CONCLUSIONS

PD-L1-expressing TCs were a marker of poor prognosis; in contrast, PD-L1-expressing TIICs were a marker of good prognosis. The MSI-H phenotype was associated with the presence of PD-L1-expressing TIICs, but not of PD-L1-expressing TCs.

Author Correction: MicroRNA-146a directs the symmetric division of Snail-dominant colorectal cancer stem cells

In the version of Supplementary Fig. 6c originally published with this Article, the immunoprecipitation (IP) and immunoblotting (IB) tags in the top panel were mislabelled. In addition, in Supplementary Fig. 6e, the blot of the IP: Numb; IB: β-Trcp panel for HCT15 was mistakenly duplicated for HCT116. The correct versions of these figures are shown below. An independent repeat of the experiments presented in Supplementary Fig. 6c and e, showing results that are consistent with those reported in the unprocessed blots, have been deposited in figshare ( 10.6084/m9.figshare.7570685 ).

ER stress-related ATF6 upregulates CIP2A and contributes to poor prognosis of colon cancer

Endoplasmic reticulum (ER) stress is an adaptive response to various stress conditions and plays emerging roles in cancer. Activating transcription factor 6 (ATF6), one of the three major ER stress transducers, has been shown to contribute to chemoresistance by altering cancer cell survival. Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncogene, and its expression has been correlated with the prognosis of patients with cancer. In this study, we aimed to explore the relationship between ER stress‐related ATF signaling and CIP2A. We found that CIP2A expression was positively correlated with ATF6 expression by analyzing publicly available RNA sequence data of patients with colorectal cancer (The Cancer Genome Atlas, TCGA). In addition, we demonstrated that tunicamycin‐induced ER stress in vitro upregulated ATF6 and CIP2A. Mechanistically, we found that ATF6 directly bound to the CIP2A promoter and induced CIP2A gene expression, which contributed to colon cancer cell survival. Furthermore, knockdown of CIP2A reduced the viability of cells under ER stress. Most importantly, immunohistochemical analysis of a tissue microarray from a colon cancer patient cohort showed that higher expression levels of ATF6 and CIP2A were associated with a trend toward poor prognosis. Taken together, our results show that ER stress‐related ATF6 upregulates CIP2A and contributes to the prognosis of colon cancer. Targeting CIP2A may disrupt ER stress‐mediated colon cancer cell survival and thus improve the prognosis of patients with colon cancer.

Regorafenib (Stivarga) pharmacologically targets epithelial-mesenchymal transition in colorectal cancer

Epithelial-to-mesenchymal transition (EMT) is well-known to evoke cancer invasion/metastasis, leading to a high frequency of mortality in patients with metastatic colorectal cancer (mCRC). Protein tyrosine phosphatase (PTPase)-targeted therapy has been identified as a novel cancer therapeutic. Previously, we proved that sorafenib with anti-EMT potency prevents TGF-β1-induced EMT/invasion by directly activating SH2-domain-containing phosphatase 1 (SHP-1)-dependent p-STAT3Tyr705 suppression in hepatocellular carcinoma. Regorafenib has a closely related chemical structure as sorafenib and is approved for the pharmacotherapy of mCRC. Herein, we evaluate whether regorafenib activates PTPase SHP-1 in the same way as sorafenib to abolish EMT-related invasion/metastasis in CRC. Notably, regorafenib exerted potent anti-EMT activity to curb TGF-β1-induced EMT/invasion in vitro as well inhibited lung metastatic outgrowth of SW480 mesenchymal cells in vivo. Mechanistically, regorafenib-enhanced SHP-1 activity significantly impeded TGF-β1-induced EMT/invasion via low p-STAT3Tyr705 level as proved by a SHP-1 inhibitor or siRNA-mediated SHP-1 depletion. Conversely, overexpression of SHP-1 further enhanced the inhibitory effects of regorafenib on TGF-β1-induced p-STAT3Tyr705 and EMT/invasion. Regorafenib directly activates SHP-1 by potently relieving the autoinhibited N-SH2 domain of SHP-1 to inhibit TGF-β1-induced p-STAT3Tyr705 and EMT/invasion. Importantly, the clinical evidence indicated that SHP-1 was positively correlated with E-cadherin and that significantly determined the overall survival of CRC patients. This result further confirms our in vitro data that SHP-1 is a negative regulatory PTPase in EMT regulation and serves as a pharmacological target for mCRC therapy. Collectively, activating PTPase SHP-1 by regorafenib focusing on its anti-EMT activity might be a useful pharmacotherapy for mCRC.

Intraperitoneal ziv-aflibercept effectively manages refractory ascites in colorectal cancer patients

Ascites related to metastatic colorectal cancer (mCRC) reduces patient survival and quality of life, and systemic chemotherapy is largely ineffective for managing ascites. Here, we examined the clinical efficacy of intraperitoneal (IP) ziv-aflibercept for managing refractory ascites in 15 mCRC patients who did not respond to standard chemotherapy. Fifty or 100 mg of ziv-aflibercept in 100 mL of saline solution were infused through a pigtail catheter and retained for 24 h. When the ascites drainage volumes were subsequently monitored, 73.3% of patients showed an objective response (OR) to IP ziv-aflibercept treatment. Patients with low Eastern Cooperative Oncology Group (ECOG) performance status or with serum ascites albumin gradients (SAAG) less than 1.1 g/dL had better responses to treatment, and 4 patients with SAAG less than 1.1 g/dL showed rapid objective responses (rOR). These findings indicate that intraperitoneal ziv-aflibercept therapy may be a highly effective means of treating refractory ascites in mCRC patients, and that SAAG may be predictive of a rapid response to this treatment.

Methionine synthase 2756AA polymorphism is associated with the risk of cognitive impairment in patients with late-life depression

BACKGROUNDS

Apolipoprotein E epsilon-4 (APOE ε4) allele, methylenetetrahydrofolate reductase (MTHFR C677T), and methionine synthase (MTR A2756G) were tested their associations with cognitive impairment in people with late-life depression (LLD).

METHODS

People with LLD were assessed by mini-mental state examination and were examined the distribution of APOE ε4 allele, MTHFR, and MTR polymorphisms.

RESULTS

Odds ratio of MTR 2756 AA to MTR 2756 AG and GG genotypes for the risk of cognitive impairment was 5.80 (95% confidence interval = 1.18-28.50; P = 0.03).

CONCLUSION

People with LLD carrying MTR2756 AA genotype have higher risk of cognitive impairment than those carrying G allele.

Protein tyrosine phosphatase 1B targets PITX1/p120RasGAP thus showing therapeutic potential in colorectal carcinoma

Protein tyrosine phosphatase 1B (PTP1B) is known to promote the pathogenesis of diabetes and obesity by negatively regulating insulin and leptin pathways, but its role associated with colon carcinogenesis is still under debate. In this study, we demonstrated the oncogenic role of PTP1B in promoting colon carcinogenesis and predicting worse clinical outcomes in CRC patients. By co-immunoprecipitation, we showed that PITX1 was a novel substrate of PTP1B. Through direct dephosphorylation at Y160, Y175 and Y179, PTP1B destabilized PITX1, which resulted in downregulation of the PITX1/p120RasGAP axis. Interestingly, we found that regorafenib, the approved target agent for advanced CRC patients, exerted a novel property against PTP1B. By inhibiting PTP1B activity, regorafenib treatment augmented the stability of PITX1 protein and upregulated the expression of p120RasGAP in CRC. Importantly, we found that this PTP1B-dependant PITX1/p120RasGAP axis determines the in vitro anti-CRC effects of regorafenib. The above-mentioned effects of regorafenib were confirmed by the HT-29 xenograft tumor model. In conclusion, we demonstrated a novel oncogenic mechanism of PTP1B on affecting PITX1/p120RasGAP in CRC. Regorafenib inhibited CRC survival through reserving PTP1B-dependant PITX1/p120RasGAP downregulation. PTP1B may be a potential biomarker predicting regorafenib effectiveness, and a potential solution for CRC.

Adjuvant FOLFOX treatment for stage III colon cancer: how many cycles are enough?

Purpose

Adjuvant FOLFOX (5-fluorouracil and oxaliplatin) chemotherapy benefits stage III colon cancer patients. However, it still results in side effects and increased cost. Reducing cycles had been thought to decrease these problems. This retrospective study aimed to find the appropriate number of treatment cycles that are sufficient for treating these patients.

Patients and methods

A total of 213 stage III colon cancer patients receiving adjuvant FOLFOX therapy were retrospectively recruited. Demographic data were collected for analysis. Survival analyses were performed between all cases of patients receiving above and below a certain cycle number. If a significant difference was reached at that cycle number, multivariate Cox Regression was performed with those factors resulting in p < 0.2 to assess the independent prognostic factors.

Results

The 5-year overall survival rate of patients was 77.9 %, and the 3-year disease-free survival was 76.7 %. For overall survival, a significant benefit was noted for treatment of at least 8 cycles, for disease-free survival, significant differences were apparent from patient data of those who underwent from 7 to 12 treatment cycles. Multivariate survival analysis of that patient data at cycle 8 for overall survival and cycle 7 for disease free survival revealed cycle number as the only independent prognostic factor (p = 0.04, 0.048).

Conclusion

Cycle number of adjuvant FOLFOX is a significant prognostic factor for stage III colon cancer patients. At least 8 cycles are needed to have an overall survival benefit, and 7 to disease-free survival.

Pharmacological Targeting SHP-1-STAT3 Signaling Is a Promising Therapeutic Approach for the Treatment of Colorectal Cancer

STAT3 activation is associated with poor prognosis in human colorectal cancer (CRC). Our previous data demonstrated that regorafenib (Stivarga) is a pharmacological agonist of SH2 domain-containing phosphatase 1 (SHP-1) that enhances SHP-1 activity and induces apoptosis by targeting STAT3 signals in CRC. This study aimed to find a therapeutic drug that is more effective than regorafenib for CRC treatment. Here, we showed that SC-43 was more effective than regorafenib at inducing apoptosis in vitro and suppressing tumorigenesis in vivo. SC-43 significantly increased SHP-1 activity, downregulated p-STAT3^Tyr705 level, and induced apoptosis in CRC cells. An SHP-1 inhibitor or knockdown of SHP-1 by siRNA both significantly rescued the SC-43–induced apoptosis and decreased p-STAT3^Tyr705 level. Conversely, SHP-1 overexpression increased the effects of SC-43 on apoptosis and p-STAT3^Tyr705 level. These data suggest that SC-43–induced apoptosis mediated through the loss of p-STAT3^Tyr705 was dependent on SHP-1 function. Importantly, SC-43–enhanced SHP-1 activity was because of the docking potential of SC-43, which relieved the autoinhibited N-SH2 domain of SHP-1 and inhibited p-STAT3^Tyr705 signals. Importantly, we observed that a significant negative correlation existed between SHP-1 and p-STAT3^Tyr705expression in CRC patients (P = .038). Patients with strong SHP-1 and weak p-STAT3^Tyr705 expression had significantly higher overall survival compared with patients with weak SHP-1 and strong p-STAT3^Tyr705 expression (P = .029). In conclusion, SHP-1 is suitable to be a useful prognostic marker and a pharmacological target for CRC treatment. Targeting SHP-1-STAT3 signaling by SC-43 may serve as a promising pharmacotherapy for CRC.

Shift from darbepoetin-α to continuous erythropoietin receptor activator decreases serum aluminium concentration in patients on hemodialysis

OBJECTIVE

The response of erythropoietic stimulating agents (ESA) in uremic patients may be associated with the changes of biochemical parameters, metal elements and inflammation status during the shift from one ESA to another.

METHOD

We compared changes in above mentioned factors after switching from darbepoetin-α (DPO) 20μg weekly for 10 weeks to continuous erythropoietin receptor activator (CERA) 100μg monthly for 10 weeks in uremic patients on hemodialysis. The haematocrit (Hct), metal elements and inflammation status are the primary outcome. Subjects included 54 patients without transfusion or bleeding or additional ESAs. Responders (IR, n=36) were defined as patients with an increase in Hct after the swtich.

RESULT

Although there was no significant difference in overall mean Hct after the switch (p=0.135), there are significantly greater mean number of red blood cells (RBC) (p=0.006), higher platelet numbers (p=0.001), larger RBCs (p=0.017) and higher creatinine (p=0.04) and total cholesterol (T-CHOL) (p=0.003) levels. Mean overall aluminium (Al) level decreased significantly (p=0.001). C-reactive protein (CRP) also decreased (p=0.016). The overall LDH increased (p=0.049) and potassium decreased significantly (p=0.036), which indicating active erythropoiesis. The calcium (Ca) level was significantly higher (p=0.034) and phosphate was significantly lower (p=0.028) after the shift. Although there was no significant increase in overall levels of parathyroid hormone (PTH) after the shift (p=0.061), but the pre-shift and post-shift PTH level was significantly higher in IRs than in non-IRs (p=0.003 and p=0.027, respectively). IRs had a significantly lower initial T-CHOL (p=0.03) and initial CRP (p=0.012) than non-responders, which may be related to lower inflammation.

CONCLUSION

We found the shift from DPO to CERA results in lower Al levels, a reduced inflammatory response, and an increase in RBC number and PTH level in uremic patients on hemodialysis.

Primary tumor location is an important predictive factor for wild-type KRAS metastatic colon cancer treated with cetuximab as front-line bio-therapy

INTRODUCTION

Left- and right-sided colon cancers were significantly different in epidemiologic, clinical and histological parameters. However, the impact of primary tumor location in metastatic colon cancer treated with front-line targeted triplet regimens is unclear, particularly in Asian populations.

METHODS

A total of 121 patients with KRAS exon 2 codon 12/13 wild-type metastatic colon cancer were enrolled between January 2007 and December 2013. All patients received one target agent, such as cetuximab or bevacizumab, as a front-line targeted triplet regimen. The impact of primary tumor location for cetuximab and bevacizumab groups was analyzed, respectively.

RESULTS

In cetuximab group, left-sided metastatic colon cancer was superior to right-sided metastatic colon cancer in objective response rate (70.1% vs 33.3%, P = 0.024), progression-free survival (15.0 vs 5.3 months, P < 0.001) and overall survival (35.8 vs 14.4 months, P = 0.031). Primary tumor location was an independent prognostic factor for progression-free survival (hazard ratio 0.240, 95% confidence interval 0.114-0.508, P < 0.001). However, in the bevacizumab group, there were no differences in outcomes for either side. Primary tumor location was insignificant for progression-free survival and overall survival in univariate analysis.

CONCLUSION

Left-sided primary tumors were favored in cetuximab-based front-line targeted triplet regimen for metastatic colon cancer.

SHP-1 is a target of regorafenib in colorectal cancer

Regorafenib is an inhibitor of multiple protein kinases which exerts antitumor and antimetastatic activities in metastatic colorectal cancer (CRC). SH2 domain-containing phosphatase 1 (SHP-1) is reported to have tumor suppressive potential because it acts as a negative regulator of p-STAT3^Tyr705 signaling. However, little is known about the mechanism regarding regorafenib affects SHP-1 tyrosine phosphatase activity and leads to apoptosis and tumor suppression in CRC. Here, we found that regorafenib triggered apoptotic cell death and significantly enhanced SHP-1 activity, which dramatically decreased the phosphorylated form of STAT3 at Tyr705 (p-STAT3^Tyr705). Importantly, regorafenib augmented SHP-1 activity by direct disruption of the association between N-SH2 and catalytic PTP domain of SHP-1. Deletion of the N-SH2 domain (dN1) or point mutation (D61A) of SHP-1 blocked the effect of regorafenib-induced SHP-1 activity, growth inhibition and a decrease of p-STAT3^Tyr705 expression, suggesting that regorafenib triggers a conformational change in SHP-1 by relieving its autoinhibition. In vivo assay showed that regorafenib significantly inhibited xenograft growth and decreased p-STAT3^Tyr705 expression but induced higher SHP-1 activity. Collectively, regorafenib is a novel SHP-1 agonist exerts superior anti-tumor effects by enhancing SHP-1 activity that directly targets p-STAT3^Tyr705. Small molecule-enhancement of SHP-1 activity may be a promising therapeutic approach for CRC treatment.

Statins Reduces the Risk of Dementia in Patients with Late-Onset Depression: A Retrospective Cohort Study

Objective

Patients with late-onset depression (LOD) have been reported to run a higher risk of subsequent dementia. The present study was conducted to assess whether statins can reduce the risk of dementia in these patients.

Methods

We used the data from National Health Insurance of Taiwan during 1996–2009. Standardized Incidence Ratios (SIRs) were calculated for LOD and subsequent dementia. The criteria for LOD diagnoses included age ≥65 years, diagnosis of depression after 65 years of age, at least three service claims, and treatment with antidepressants. The time-dependent Cox proportional hazards model was applied for multivariate analyses. Propensity scores with the one-to-one nearest-neighbor matching model were used to select matching patients for validation studies. Kaplan-Meier curve estimate was used to measure the group of patients with dementia living after diagnosis of LOD.

Results

Totally 45,973 patients aged ≥65 years were enrolled. The prevalence of LOD was 12.9% (5,952/45,973). Patients with LOD showed to have a higher incidence of subsequent dementia compared with those without LOD (Odds Ratio: 2.785; 95% CI 2.619–2.958). Among patients with LOD, lipid lowering agent (LLA) users (for at least 3 months) had lower incidence of subsequent dementia than non-users (Hazard Ratio = 0.781, 95% CI 0.685–0.891). Nevertheless, only statins users showed to have reduced risk of dementia (Hazard Ratio = 0.674, 95% CI 0.547–0.832) while other LLAs did not, which was further validated by Kaplan-Meier estimates after we used the propensity scores with the one-to-one nearest-neighbor matching model to control the confounding factors.

Conclusions

Statins may reduce the risk of subsequent dementia in patients with LOD.

Incidence of Second Primary Malignancies Following Colorectal Cancer: A Distinct Pattern of Occurrence Between Colon and Rectal Cancers and Association of Co-Morbidity with Second Primary Malignancies in a Population-Based Cohort of 98,876 Patients in Taiwan

The purpose of this study is to determine the features of second primary malignancies (SPMs) among patients with prior colorectal cancer (CRC) using a nationwide population-based dataset.Patients with CRC newly diagnosed between 1996 and 2011, and >1 year of follow-up were recruited from the Taiwan National Health Insurance database. Standardized incidence ratios (SIRs) of SPMs in patients with CRC were calculated.During the 16-year study period, 4259 SPMs developed among 98,876 CRC patients. The median duration of follow-up was 4.03 years. The SIR for all SPMs was 1.13 (95% confidence interval = 1.10-1.17). Compared with the general population, a higher incidence of thyroid, prostate, ovarian, and hematologic malignancies developed among patients with colon cancer, whereas the risk for bone and soft tissue cancers increased among patients with rectal cancer. The risk for breast, bladder, kidney, lung, and uterine cancers was significantly higher in patients with colon and rectal cancers than the general population. The risk for liver and biliary tract cancers declined in patients with rectal cancer. Based on multivariate analysis among patients with CRC, age ≥70 years, men, chronic obstructive pulmonary disease (COPD), cirrhosis, and dyslipidemia were independent predictors of an SPM.In conclusion, patients with CRC were at increased risk for a second cancer. The pattern of SPMs was distinct between patients with colon and rectal cancer. Age, men, COPD, cirrhosis, and dyslipidemia were independent risk factors for SPMs. Surveillance and education should be provided for survivors with respect to risk for SPMs.

The Prognostic Role of Para-Aortic Lymph Nodes in Patients with Colorectal Cancer: Is It Regional or Distant Disease?

Introduction

Visible para-aortic lymph nodes of ≥2 mm in size are common metastatic patterns of colorectal cancer (CRC) seen on imaging. Their prognostic value, however, remains inconclusive. We aimed to assess the prognostic role of visible para-aortic lymph nodes (PALNs).

Methods

Patients with confirmed pathologic diagnosis of CRC were enrolled. Correlations among clinicopathologic variables were analyzed using the χ² test. The Cox proportional hazards model was applied for univariate and multivariate analyses. Survival was estimated using the Kaplan-Meier method and log-rank test. A prognostic model for visible PALNs in CRC patients was established.

Results

In total, 4527 newly diagnosed CRC patients were enrolled. Patients with visible PALNs had inferior overall survival compared to those without visible PALNs (5-year overall survival, 67% vs. 76%, P = 0.015). Lymphovascular invasion (LVI) (hazard ratio = 1.865, P = 0.015); nodal disease (pN+) status (hazard ratio = 2.099, P = 0.006); elevated preoperative serum carcinoembryonic antigen (CEA) levels (hazard ratio = 2.263, P < 0.001); and visible PALNs ≥10 mm (hazard ratio = 1.638, P = 0.031) were independent prognostic factors for patients with visible PALNs. If each prognostic factor scored one point, 5-year overall survival of lower- (prognostic score 0–1), intermediate- (prognostic score 2), and high- (prognostic score 3–4) risk groups were, 78%. 54%, and 25% respectively (P < 0.001).

Conclusions

The prognostic model, which included LVI, pN+ status, preoperative serum CEA level, and the size of visible PALNs, could effectively distinguish the outcome of patients with visible PALNs.

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an independent prognostic marker in wild-type KRAS metastatic colorectal cancer after colorectal liver metastasectomy

Background

The impact of KRAS signaling on cancerous inhibitor of protein phosphatase 2A (CIP2A) expression has not yet been explored. We investigated the impact of KRAS on CIP2A expression in colorectal cancer patients after colorectal liver metastasectomy.

Methods

We examined CIP2A expression by immunohistochemistry (IHC) and used direct sequencing to identify the mutational status of KRAS exon 2 (codon 12 and 13). The association between CIP2A expression, KRAS genotype, clinicopathological parameters and survival were examined by the Kaplan–Meier method and the Cox proportional hazards model. A combination of immunoblotting and proliferation assays were employed to elucidate the role of CIP2A in signal transduction pathways in wild-type KRAS Caco-2 cells.

Results

A total of 220 colorectal cancer patients who had undergone colorectal liver metastasectomy were included in the study. The mutant KRAS genotype was associated with CIP2A overexpression. CIP2A expression was an independent prognostic marker in patients with wild-type KRAS metastatic colorectal cancer after colorectal liver metastasectomy (relative risk = 1.873, P = 0.019). Targeted silencing of CIP2A in Caco-2 cells (wild-type KRAS) led to decreased expression of pERK/ERK and decreased cell proliferation. Overexpression of mutant KRAS G12D in Caco-2 cells led to an increase in CIP2A expression and cell proliferation. In Caco-2 cells with the KRAS G12D, KRAS overexpression preserved the regulation effect of CIP2A in KRAS and abrogated the impact of CIP2A regulation on pERK/ERK and cell proliferation. CIP2A inhibition also increased the efficacy of cetuximab in Caco-2 cells.

Conclusions

CIP2A is an independent prognostic marker in patients with wild-type KRAS metastatic colorectal cancer after colorectal liver metastasectomy.

MicroRNA-146a directs the symmetric division of Snail-dominant colorectal cancer stem cells

Asymmetrical cell division (ACD) maintains the proper number of stem cells to ensure self-renewal. In cancer cells, the deregulation of ACD disrupts the homeostasis of the stem cell pool and promotes tumour growth. However, this mechanism is unclear. Here, we show a reduction of ACD in spheroid-derived colorectal cancer stem cells (CRCSCs) compared with differentiated cancer cells. The epithelial-mesenchymal transition (EMT) inducer Snail is responsible for the ACD-to-symmetrical cell division (SCD) switch in CRCSCs. Mechanistically, Snail induces the expression of microRNA-146a (miR-146a) through the β-catenin-TCF4 complex. miR-146a targets Numb to stabilize β-catenin, which forms a feedback circuit to maintain Wnt activity and directs SCD. Interference with the Snail-miR-146a–β-catenin loop by inhibiting the MEK or Wnt activity reduces the symmetrical division of CRCSCs and attenuates tumorigenicity. In colorectal cancer patients, the Snail(High)Numb(Low) profile is correlated with cetuximab resistance and a poorer prognosis. This study elucidates a unique mechanism of EMT-induced CRCSC expansion.

Temsirolimus enhances the efficacy of cetuximab in colon cancer through a CIP2A-dependent mechanism

PURPOSE

A dozen clinical trials examining a combination of temsirolimus and cetuximab in treating metastatic colon cancer are currently underway. We investigated the role of cancerous inhibitor of protein phosphatase 2A (CIP2A) in the synergism between temsirolimus and cetuximab in colon cancer.

METHODS

Five colon cancer cell lines were used for in vitro studies. Signal transduction pathways were assessed by immunoblotting. The synergism between studied drugs was analyzed with combination indexes. Gene silencing was performed using small interfering RNAs. The efficacies of temsirolimus and cetuximab were tested in nude mice with colon cancer xenografts. Transcriptional activity was assessed using a reporter assay. The inhibitors leupeptin, chloroquine, and MG132 were used to assess protein degradation. The association between CIP2A, clinicopathological parameters, and survival was examined by immunohistochemical staining using a tumor tissue microarray.

RESULTS

Temsirolimus decreased the resistance of cells to cetuximab by both inhibiting transcription of CIP2A and increasing degradation of CIP2A through the lysosomal-autophagy pathway. The mammalian target of rapamycin (mTOR) protein immunoprecipitated along with CIP2A. Temsirolimus decreased expression of phosphorylated extracellular regulated protein kinase (pErk) and phosphorylated v-akt murine thymoma viral oncogene (pAKT) and decreased the interaction of CIP2A and mTOR in cell lines without the K-ras codon 12 mutation. CIP2A was a prognostic marker only in colon cancer patients with weak expression of pErk or pAKT.

CONCLUSIONS

Temsirolimus decreases cellular resistance to cetuximab by regulating CIP2A expression in colon cancer cells. Potential biomarkers for CIP2A inhibitors include pErk and pAKT.

Prognostic significance of C-reactive protein polymorphism and KRAS/BRAF in synchronous liver metastasis from colorectal cancer

BACKGROUND

The liver is the most common target organ in the metastasis of colorectal cancer (CRC). Synchronous liver metastases may confer a poorer prognosis than metachronous metastases, and genetic alterations and an inflammatory response have also been associated with a poor prognosis in cases of a liver metastasis arising from CRC. However, few studies have examined the relationship between KRAS mutations and inflammatory status in CRC, especially with respect to liver metastases.

METHODS

The effect of the activated mitogen-activated protein kinase pathway and another protein involved in inflammation, C-reactive protein, in liver metastases were examined. We aimed to determine the impact of the CRP-specific single nucleotide polymorphism (SNP) rs7553007 in liver metastasis on the CRC-specific survival (CSS) of patients after colorectal liver metastasectomy.

RESULTS

We found no significant differences in genotype distributions and allele frequencies at the CRP SNP rs7553007 between CRC patients with liver metastasis and the control group. CSS rates were low in the subgroup of patients with synchronous metastasis with the A-allele (A/A and A/G) at rs7553007 or mutated KRAS/BRAF in liver metastatic specimens. Furthermore, the CRP SNP rs7553007 (hazard ratio [HR] = 1.101; 95% confidence interval [CI] = 1.011-1.200; P = 0.027) and KRAS/BRAF mutations (HR = 2.377; 95% CI = 1.293-4.368; P = 0.005) remained predictive for the CSS of CRC patients with synchronous liver metastasis in multivariate analysis.

CONCLUSIONS

Both the CRP SNP rs7553007 and KRAS/BRAF mutations were independent prognostic factors for CRC patients with synchronous liver metastasis.

Concurrent chemoradiotherapy followed by metastasectomy converts to survival benefit in stage IV rectum cancer

BACKGROUND

To investigate the impact of concurrent chemoradiotherapy (CCRT) on stage IV rectum cancer.

METHODS

Between 2000 and 2011, 297 consecutive patients diagnosed with stage IV rectum cancer (synchronous metastasis) were enrolled. Cox proportional hazard analyses were used for prognostic factors determination, and the Kaplan-Meier method was used for survival analyses. Propensity scores with the one-to-one nearest-neighbor matching model were used to select matched patients for validation studies.

RESULTS

In total, 63 patients received CCRT and 234 did not. The patients in the CCRT group were younger, had more low-lying lesions, and had more T4 lesions, lung metastases, metastasectomies, and oxaliplatin-based upfront chemotherapy. Before propensity-score matching, a younger age (HR = 0.662, P = 0.016), lower carcinoembryonic antigen (CEA) level (≤20 ng/ml) (HR = 0.531, P = 0.001), no metastasectomy (HR = 3.214, P < 0.001), and no CCRT (HR = 1.844, P = 0.019) were independent prognostic factors after controlling for other confounding factors. After matching, only CEA and metastasectomy, but not CCRT, were independent prognostic factors. The survival benefit of CCRT was restricted to patients who undergo subsequent metastasectomy.

CONCLUSIONS

Upfront CCRT only provided a survival benefit in patients with stage IV rectum cancer who undergo subsequent metastasectomy.

BRAF mutation is a prognostic biomarker for colorectal liver metastasectomy

BACKGROUND AND OBJECTIVES

In metastatic colorectal cancer, v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) is a predictive biomarker for anti-epidermal growth factor receptor (EGFR) treatment and V-raf murine sarcoma viral oncogene homolog B1 (BRAF) is a prognostic biomarker. We aimed to determine the impact of KRAS and BRAF mutation as determined from liver metastases specimens on overall survival (OS) in patients following colorectal liver metastasectomy.

METHODS

Liver metastases specimens (n = 292) obtained from patients after liver metastasectomy were used to determine the KRAS/BRAF genotype. Associations between clinicopathological parameters and KRAS/BRAF genotype were identified by univariate and multivariate analyses using the Cox proportional hazards model. The impact of KRAS/BRAF genotype on survival was analyzed using the Kaplan-Meier method.

RESULTS

The 5-year survival rate of the cohort was 55.8%. The KRAS and BRAF mutation rates were 38.0 and 2.1%, respectively. BRAF genotype, but not KRAS, was found to be an independent prognostic biomarker (HR = 5.181, P = 0.002) after adjustment for other significant confounding clinicopathological variates: Number of liver metastases (HR = 1.983, P = 0.009), concomitant extrahepatic disease (HR = 1.858, P = 0.014), and surgical margin (HR = 3.241, P < 0.001). BRAF genotype was an independent prognostic biomarker in patients with liver metastases only after metastasectomy (HR = 6.245, P < 0.003).

CONCLUSIONS

BRAF mutation is an independent prognostic biomarker for colorectal liver metastasectomy.

Evaluation of prognostic factors and the role of chemotherapy in unfavorable carcinoma of unknown primary site: a 10-year cohort study

BACKGROUND

Carcinoma of unknown primary site (CUP) has a poor prognosis and the prognostic factors in these patients are not well established. Furthermore, there are no selection criteria for patients who should benefit from chemotherapy.

METHODS

The medical records of 179 CUP patients who were treated at Taipei Veterans General Hospital from 2000 to 2009 were reviewed. Factors associated with survival were determined by Kaplan-Meier analysis. Differences between the groups with and without palliative chemotherapy were analyzed.

RESULTS

Univariate analysis revealed multiple prognostic factors, including performance status, lung metastasis, number of metastatic organs, serum albumin, corrected serum calcium, lactate dehydrogenase (LDH), sodium, and cholesterol levels, palliative chemotherapy, and white blood cell and lymphocyte counts. Multivariate analysis showed that performance status < 2, serum albumin level ≥ 3.5 g/dl, corrected serum calcium level < 10.7 mg/dl, single metastatic organ, and palliative chemotherapy were independent factors of better prognosis. Patients with better performance status, higher serum albumin, and lower serum LDH levels had significantly greater benefit from palliative chemotherapy.

CONCLUSIONS

Certain patients with unfavorable CUP will have better survival. Identification of patients with unfavorable CUP who could benefit from palliative chemotherapy warrants future prospective studies.

A new classification scheme for recurrent or metastatic colon cancer after liver metastasectomy

BACKGROUND

Metastasectomy is the standard treatment for patients with resectable liver metastasis from colon cancer. This study aimed to determine the impact of initial stage on overall survival (OS) after metastasectomy.

METHODS

A retrospective analysis of 2804 patients diagnosed with colon cancer between 1999 and 2008.

RESULTS

Of the cohort, 38.1% of the patients were stage IV or had recurrence after curative surgery, and 131 received liver metastasectomy. The 5-year survival rate for patients after liver metastasectomy was 42.1%. The 5-year survival rates after metastasectomy for initial stage I disease, stage II disease, stage III disease, and stage IV disease were 100%, 82.5%, 31.8%, and 36.9%, respectively (p = 0.014). When patients were grouped as initial stage I/II and stage III/IV, the 5-year survival rate after liver metastasectomy differed significantly (83.9% vs. 35.7%, p = 0.006). Patients with initial stage I/II disease after liver metastasectomy had a significantly better 5-year progression-free period compared to those with stage III/IV disease (60% vs. 28%, p = 0.021), which was due to the lower recurrence rate in the stage I/II group.

CONCLUSION

Our results suggest that patients who receive liver metastasectomy for metastatic colon cancer should be grouped into two groups: those with initial stages I and II disease, and those with stages III and IV disease, since the progression-free survivals (PFS) and OS after metastasectomy in these two groups differ significantly.

Duloxetine improves oxaliplatin-induced neuropathy in patients with colorectal cancer: an open-label pilot study

BACKGROUND

This open-label pilot study is aimed to evaluate the efficacy and tolerability of the antidepressant duloxetine, which is effective for diabetic neuropathic pain, in the treatment of chronic oxaliplatin-induced peripheral neuropathy (OIPN).

METHODS

We enrolled a total of 39 patients with stage III or IV colorectal cancer with chronic OIPN. They were treated with duloxetine by increasing the dose from 30 mg/day to 60 mg/day. Patients' pain intensity was rated at baseline and 12 weeks after duloxetine administration. The severity of neuropathic pain was evaluated using the visual analog scale (VAS) score and the National Cancer Institute Common Toxicity Criteria for Adverse Events, version 3 (NCI-CTCAE v3.0).

RESULTS

Nine patients (23.1%) discontinued duloxetine before the end of treatment because of adverse events. Of the remaining 30 patients, 19 patients (63.3%) had a VAS score improvement. Among them, nine (47.4%) showed a simultaneous grade improvement, and the other 10 patients (52.6%) had a stable grade according to NCI-CTCAE v3.0. Treatment with duloxetine did not impair renal or liver function and did not interfere with chemotherapy.

CONCLUSIONS

Duloxetine is feasible in treating chronic OIPN with tolerable toxicity at a daily dose of 60 mg/day.

The efficacy of chemotherapy in patients with high-grade metastatic colon cancer

BACKGROUND/AIMS

This study was undertaken to assess the prognostic role of histological grade in colon cancer and the efficacy of either oxaliplatin or irinotecan after incorporation into an infusional regimen of 5-fluorouracil and leucovorin in patients with high-grade metastatic colon cancer.

METHODOLOGY

Data from 2409 consecutive and eligible patients with colon cancer from a single institute was used to assess the impact of histological grade on survival and the efficacy of the two doublet regimens on patients with metastatic colon cancer relative to histological grade.

RESULTS

High histological grade has unfavorable outcome for patients with stage III (p=0.021) or stage IV (p=0.003) colon cancer but not for those with stage I (p=0.703) or stage II (p=0.767) colon cancer. Progression free survival and overall survival in patients with high-grade metastatic colon cancer were not improved by the addition of irinotecan or oxaliplatin to the infusional 5-fluorouracil + leucovorin regimen.

CONCLUSIONS

Histological grade is a prognostic factor in stage III/IV colon cancer but not in stage I/II. Oxaliplatin and irinotecan may not enhance the efficacy of infusional 5-fluorouracil + leucovorin in the treatment of high-grade metastatic colon cancer.

SNAIL regulates interleukin-8 expression, stem cell-like activity, and tumorigenicity of human colorectal carcinoma cells

BACKGROUND & AIMS

Some cancer cells have activities that are similar to those of stem cells from normal tissues, and cell dedifferentiation correlates with poor prognosis. Little is known about the mechanisms that regulate the stem cell-like features of cancer cells; we investigated genes associated with stem cell-like features of colorectal cancer (CRC) cells.

METHODS

We isolated colonospheres from primary CRC tissues and cell lines and characterized their gene expression patterns by microarray analysis. We also investigated the biological features of the colonosphere cells.

RESULTS

Expanded CRC colonospheres contained cells that expressed high levels of CD44 and CD166, which are markers of colon cancer stem cells, and had many features of cancer stem cells, including chemoresistance and radioresistance, the ability to initiate tumor formation, and activation of epithelial-mesenchymal transition (EMT). SNAIL, an activator of EMT, was expressed at high levels by CRC colonospheres. Overexpression of Snail in CRC cells induced most properties of colonospheres, including cell dedifferentiation. Two hundred twenty-seven SNAIL-activated genes were up-regulated in colonospheres; gene regulatory networks centered around interleukin (IL)-8 and JUN. Blocking IL-8 expression or activity disrupted SNAIL-induced stem cell-like features of colonospheres. We observed that SNAIL activated the expression of IL8 by direct binding to its E3/E4 E-boxes. In CRC tissues, SNAIL and IL-8 were coexpressed with the stem cell marker CD44 but not with CD133 or CD24.

CONCLUSIONS

In human CRC tissues, SNAIL regulates expression of IL-8 and other genes to induce cancer stem cell activities. Strategies that disrupt this pathway might be developed to block tumor formation by cancer stem cells.

Effective salvage therapy of imatinib-resistant gastrointestinal stromal tumor with combination of imatinib and pegylated liposomal doxorubicin

Here we presented a 60-year-old Taiwanese man with advanced gastrointestinal stromal tumor. Disease progression was noted during imatinib treatment. Surgical resection was done and mutation analysis of KIT gene in all the resected tumors revealed deletion mutations of codons 558-565 in exon 11, whereas a missense mutation was also identified at codon 822 in exon 17 in one resected tumor. Patient's disease was refractory to escalating dose of imatinib and dasatinb. Surprisingly, combination of imatinib with pegylated liposomal doxorubicin produced a substantial response and resulted in a 5-month progression free period for this imatinib-resistant gastrointestinal stromal tumor.

Pneumothorax after bevacizumab-containing chemotherapy: a case report

Bevacizumab added to 5-fluorouracil-based chemotherapy can improve outcomes in patients with metastatic colorectal cancer. Bevacizumab had several notable adverse effects including bowel perforation but pneumothorax had never been reported in the available English literature. We reported a 45-year-old male with lung metastases from colorectal cancer who had spontaneous pneumothorax after the second cycle of bevacizumab-containing chemotherapy. His pneumothorax resolved after tube thoracostomy with a small caliber catheter. The mechanism of pneumothorax developed after bevacizumab therapy was not clear as bowel perforation but tumor necrosis with ruptured parietal pleura might be the cause. In patients who had chest discomfort after bevacizumab-containing therapy, pneumothorax should never be overlooked as one of the differential diagnoses.

High early mortality rate in elderly patients with multiple myeloma receiving a vincristine-doxorubicin-dexamethasone regimen

Treatment-related mortality (TRM) is not uncommon in patients after the first course of vincristine-doxorubicin-dexamethasone (VAD) chemotherapy,but quite rare after melphalan-prednisolone (MP). This motivated us to compare the rates of TRM after the first course of VAD with those after the first course of MP. We retrospectively assessed survival and TRM in 179 patients treated for multiple myeloma with either MP or VAD. Survival was similar in two groups (P 50.463 in log-rank test). However, TRM was significantly higher inpatients after the first course of VAD (11 in 100 patients, 11.0%) than that after the first course of MP (1 in 79, 1.3%; P 5 0.010). Poor performance status (P 5 0.004) and advanced age (P 5 0.009) before treatment were independent significant factors associated with TRM after the first course of induction therapy. Pyogenic infection was the major cause of TRM after VAD (9 in 11, 81.8%). We concluded that VAD should be cautiously used as induction therapy in multiple myeloma patients, especially in elderly and/or those with poor performance status.

Diabetes mellitus negatively impacts survival of patients with colon cancer, particularly in stage II disease

PURPOSE

This retrospective study aimed to determine the effects of diabetes on overall survival (OS) and cancer-specific survival (CSS) in patients with newly diagnosed colon cancers, with particular focus on the impact of diabetes on survival at each stage of colon cancer.

METHODS

From January 1999 to January 2008, 2762 consecutive patients diagnosed with colon cancer in Taipei Veterans General Hospital were enrolled. The general characteristics as well as presence of diabetes prior to colon cancer diagnosis were identified. Cox proportional hazard analyses were used for prognostic factors determination; and survival was analyzed using the Kaplan-Meier method with log-rank test.

RESULTS

A total of 469 patients (17%) had diabetes at diagnosis of colon cancer. Patients with diabetes had baseline characteristics comparable to those without diabetes with the exception that the patients with diabetes were older (>65 years). Diabetes significantly and negatively impacted OS and CSS in multivariate analyses. After adjusting for possible confounding factors, the prognostic impact of diabetes on OS and CSS was particularly significant in patients with stage II colon cancer.

CONCLUSIONS

Diabetes is a poor prognostic factor in patients with newly diagnosed colon cancer, and it may directly impact the tumor behavior of stage II disease. Further study is required to elucidate the underlying pathophysiologic mechanisms.

Adjuvant oxaliplatin- or irinotecan-containing chemotherapy improves overall survival following resection of metachronous colorectal liver metastases

PURPOSE

Adjuvant systemic 5-fluorouracil (5-FU)-based chemotherapy improves survival after resection of synchronous colorectal liver metastases (CLMs), but not metachronous. We retrospectively examined if adjuvant chemotherapy with new regimen containing oxaliplatin or irinotecan improved survivals after resection of metachronous CLMs.

METHODS

Between 2000 and 2007, 52 patients having undertaken resection of metachronous CLMs with curative intent were identified from Taipei Veterans General Hospital hospitalization registry. One patient with perioperative mortality and another being lost to follow-up within 3 months after metastasectomy were excluded. Thirty-one patients experienced six to 12 cycles of FOLFOX or FOLFIRI chemotherapy while 19 patients with 5-FU/leucovorin (LV)-based chemotherapy following CLM resection. The primary end point was disease-free survival (DFS) and secondary end point, overall survival (OS).

RESULTS

By the univariate analysis, median DFS was 34.3 months in the FOLFOX/FOLFIRI group vs 14.2 months in the 5-FU/LV group (P = 0.022). The median OS and 5-year survival rates were longer than 57.7 months (not reached, with median follow-up of 35.5 months) and 54.0%, respectively, in the FOLFOX/FOLFIRI group compared to 49 months and 34.6% in the 5-FU/LV group (P = 0.027). FOLFOX/FOLFIRI chemotherapy was shown by multivariate analyses to be an independent factor predicting a better DFS (hazard ratio [HR] = 0.37; 95% CI: 0.15-0.94; P = 0.036) and a better OS (HR = 0.27; 95% CI: 0.083-0.86, P = 0.026) than 5-FU/LV-based.

CONCLUSIONS

Adjuvant FOLFOX/FOLFIRI chemotherapy following resection of metachronous CLMs is demonstrated to have better DFS and OS than 5-FU/LV chemotherapy.

High Prevalence of SV40 Infection in Patients with Nodal Non-Hodgkin's Lymphoma But Not Acute Leukemia Independent of Contaminated Polio Vaccines in Taiwan

Recent studies have linked simian virus 40 (SV40) to non-Hodgkin's lymphoma (NHL), especially in countries in which people were exposed to contaminated polio vaccines prior to 1963. In Taiwan, nearly all children were not exposed to contaminated polio vaccine during this period; the relationship between SV40 infection and hematological malignancies is unclear and deserves to be studied. Using PCR amplification of SV40 large T antigen DNA, confirmed by Southern blot hybridization and sequence analysis, 91 frozen lymph nodes from NHL patients were examined. Thirteen (14.3 percent) showed positive for SV40. All other test samples, including diagnostic bone marrow from patients with acute leukemia, peripheral blood from 10 relatives of SV40 positive-patients and 91 age-matched normal volunteers, and 5 reactive hyperplastic lymphoid tissues, showed negative. These results may reflect that human-to-human transmission of SV40 is independent of contaminated polio vaccines; and SV40 is possibly associated with the development of NHL in Taiwan (p = 0.0001). Prospective studies are needed to determine the prevalence of SV40 infections in our and other human populations and to explore the means of transmission of the virus.