The emergence of RAS mutations in patients with RAS wild-type mCRC receiving cetuximab as first-line treatment: a noninterventional, uncontrolled multicenter study.

ABSRTACT: BACKGROUND: Patients treated with anti-epidermal growth factor receptor (anti-EGFR) will ultimately develop acquired resistance promoted by clonal selection, mainly the emergence of mutations in the MAPK pathway (mostly RAS mutations). Baseline assessment of RAS mutations in the blood of patients correlates well with RAS tumour tissue testing and is currently an alternative option in routine clinical practice to guide first-line therapy. The aim of this study was the prevalence of acquired genomic alterations detected in the auxiliary tool of ctDNA testing and investigated the role of RAS ctDNA status for detecting tumour response and predicting benefit to anti-EGFR therapy. METHODS: Only patients with concordant wild-type formalin-fixed, paraffin-embedded (FFPE) tumour tissue and baseline ctDNA RAS wild-type were included. RAS mutations in plasma were evaluated using MassARRAY platform. Blood samples were collected at baseline, every 3 months during first-line treatment, and at disease progression. The primary endpoint was the detection rate of RAS mutations during cetuximab treatment. The correlation between response and survival outcomes and the emergence of circulating RAS mutations was also analysed. RESULTS: The detection rate of RAS mutations during treatment was 9.3% (10/108). RAS mutations detection occurred a median of 3 months prior to radiologic documentation. The subgroup of patients with RAS mutations exhibited significantly inferior progression-free survival and overall survival (P = 0.002 and 0.027, respectively) but the baseline characteristics, response rates, disease control rates, and metastatectomy were not significant (all P > 0.05). CONCLUSIONS: We demonstrated that RAS ctDNA status might be a valuable biomarker for detecting early tumour response and predicting benefit to anti-EGFR therapy. CLINICAL TRIAL REGISTRATION: NCT03401957 (January 17, 2018).

The Negative Prognostic Impact of Lymph Node Skip Metastasis in Stage III Colon Cancer With pN1 Disease: A Single-Center and Retrospective Cohort Study.

BACKGROUND: Lymph node skip metastasis is a subgroup of lymph node metastatic patterns with low incidence in node-positive colon cancer. Its clinical significance is still unclear. OBJECTIVE: This study aimed to investigate the prognostic impact of lymph node skip metastasis in stage III colon cancer. DESIGN: This is a retrospective observational analysis. SETTINGS: The study was conducted at the Taipei Veterans General Hospital. PATIENTS: This study included patients with stage III colon cancer who underwent D3 lymphadenectomy between 2006 and 2015. MAIN OUTCOME MEASURES: The patients were divided into a lymph node skip metastasis-positive group and a negative group. Recurrence-free survival and overall survival were compared using Kaplan-Meier curves and log-rank test. Cox regression was applied to identify related risk factors influencing survival. RESULTS: A total of 461 patients were reviewed, and lymph node skip metastasis-positive patients represented 13.2% of our sample. Patients with lymph node skip metastasis tended to present with a higher proportion of right-sided cancer, lower positive lymph nodes, lower lymph node ratio, and higher mean BMI. Liver recurrence was more prevalent in the lymph node skip metastasis group ( p = 0.028) than in the negative group. The presence of lymph node skip metastasis was a negative prognostic factor for 5-year recurrence-free survival (51.4% vs 68.7%; p = 0.002) and 5-year overall survival (66.4% vs 80.4%; p = 0.024) in Kaplan-Meier curves and multivariate Cox regression. Subgroup analysis revealed the survival significance of recurrence-free survival ( p = 0.001) and overall survival ( p = 0.011) in lymph node skip metastasis with pN1 disease. LIMITATIONS: This study was limited by its retrospective design, single-center nature, and sampling error. CONCLUSIONS: Lymph node skip metastasis is an independent negative prognostic factor in stage III colon cancer with pN1 disease. More intensive surveillance may be necessary for patients of this subgroup. See Video Abstract at https://links.lww.com/DCR/C60 . IMPACTO PRONSTICO NEGATIVO DE LAS METSTASIS DISCONTNUAS GANGLIONARES LINFTICAS EN CASOS DE CNCER DE COLON ESTADIO III CON ENFERMEDAD PN ESTUDIO DE COHORTES RETROSPECTIVO MONOCENTRICO: ANTECEDENTES:Las metástasis discontínuas ganglionares linfáticas, son un subgrupo de patrones metastásicos en los ganglios linfáticos con baja incidencia en el cáncer de colon con nódulos positivos. Su significado clínico aún no está claro.OBJETIVO:Estudio que tiene por objetivo el investigar el impacto pronóstico de las metástasis discontínuas de los ganglios linfáticos en el cáncer de colon de estadio III.DISEÑO:Análisis observacional retrospectivo.AJUSTES:El estudio se realizó en el Hospital General de Veteranos de Taipei.PACIENTES:Pacientes con cáncer de colon en estadio III que se sometieron a linfadenectomía D3 entre 2006 y 2015.PRINCIPALES MEDIDAS DE RESULTADO:Los pacientes se dividieron en un grupo positivo de metástasis discontínuas en los ganglios linfáticos y un otro grupo negativo. La sobrevida libre de recidiva y la sobrevida global, fueron comparadas mediante las curvas de Kaplan-Meier y la prueba de rango logarítmico. Se aplicó la regresión de Cox para identificar los factores de riesgo relacionados que influyeron en la sobrevida.RESULTADOS:Se revisaron un total de 461 casos, donde los pacientes positivos con metástasis en los ganglios linfáticos representaron el 13,2% de nuestra muestra. Los pacientes con metástasis discontínuas ganglionares linfáticas tendían a presentar una mayor proporción de cáncer localizado en el lado derecho del colon, presentar un menor numéro de ganglios linfáticos positivos y una proporción menor de ganglios linfáticos con un IMC promedio más alto. Las recidivas hepáticas fueron más prevalentes en el grupo de metástasis discontínuas ganglionares linfáticas ( p = 0,028) que en el grupo negativo. La presencia de metástasis discontínuas ganglionares linfáticas fué un factor de pronóstico negativo en la sobrevida libre de recidiva a 5 años (51,4% frente a 68,7%, p = 0,002) y la sobrevida general a 5 años (66,4% frente a 80,4%, p = 0,024) evaluada por las curvas de Kaplan-Meier y la regresión multivariada de Cox. El análisis de subgrupos reveló la importancia de la sobrevida libre de recidiva ( p = 0,001) y la sobrevida general ( p = 0,011) en los casos con metástasis discontínuas ganglionares linfáticas con enfermedad pN1.LIMITACIONES:Diseño retrospectivo, naturaleza de centro único y error de muestreo.CONCLUSIONES:Las metástasis discontínuas ganglionares linfáticas son un factor pronóstico negativo independiente en los casos de cáncer de colon estadio III con enfermedad pN1. Tal vez sea necesaria una mayor vigilancia de los pacientes en este subgrupo.Consulte Video Resumen en https://links.lww.com/DCR/C60 . (Traducción-Dr. Xavier Delgadillo ).

Clinical outcome of local treatment and radical resection for pT1 rectal cancer.

BACKGROUND: Rectal cancer is mainly cured by radical resection with neoadjuvant chemoradiation or adjuvant chemotherapy. Pathological T1 lesions can be managed by local treatment and radiotherapy thereafter. Lower morbidity is the key benefit of these local treatments. Since nodal metastasis is important for staging, radical resection (RR) is suggested. Rectal cancer has higher surgical morbidity than colon cancer; local treatment has been the preferred choice by patients. METHODS: We retrospectively enrolled data of 244 patients with pT1 rectal adenocarcinoma. A total of 202 patients (82.8%) underwent RR, including low anterior resection (LAR) and abdomino-perineal resection (APR), and 42 patients (17.2%) underwent LT, including transanal excision and colonoscopic polypectomy. RESULTS: In our study, seven patients (16.7%) had loco-regional recurrence and distant metastasis from the LT group while eight patients (4.0%) had distant metastasis without loco-regional recurrence from the RR group. The lymph node metastasis rate in RR group was 8.4%. Forty-seven patients (24.2%) underwent LAR with temporary stoma, and its reversal rate was 100%. In the RR group, postoperative complication rate was 10.4% with a mortality rate of 0.5%. Recurrence-free survival (RFS) was 95.7% for RR and 80.2% for LT (P = 0.001), and overall survival (OS) was 93.7% for RR and 70.0% for LT (P = 0.001). CONCLUSION: This study found that RFS and OS in patients of pT1 rectal adenocarcinoma that had received RR were better than receiving LT. Further adjuvant chemotherapy was possible for some RR patients. A higher recurrence rate after LT must be balanced against the morbidity and mortality associated with RR.

A novel machine learning-based algorithm to identify and classify lesions and anatomical landmarks in colonoscopy images.

OBJECTIVES: Computer-aided diagnosis (CAD)-based artificial intelligence (AI) has been shown to be highly accurate for detecting and characterizing colon polyps. However, the application of AI to identify normal colon landmarks and differentiate multiple colon diseases has not yet been established. We aimed to develop a convolutional neural network (CNN)-based algorithm (GUTAID) to recognize different colon lesions and anatomical landmarks. METHODS: Colonoscopic images were obtained to train and validate the AI classifiers. An independent dataset was collected for verification. The architecture of GUTAID contains two major sub-models: the Normal, Polyp, Diverticulum, Cecum and CAncer (NPDCCA) and Narrow-Band Imaging for Adenomatous/Hyperplastic polyps (NBI-AH) models. The development of GUTAID was based on the 16-layer Visual Geometry Group (VGG16) architecture and implemented on Google Cloud Platform. RESULTS: In total, 7838 colonoscopy images were used for developing and validating the AI model. An additional 1273 images were independently applied to verify the GUTAID. The accuracy for GUTAID in detecting various colon lesions/landmarks is 93.3% for polyps, 93.9% for diverticula, 91.7% for cecum, 97.5% for cancer, and 83.5% for adenomatous/hyperplastic polyps. CONCLUSIONS: A CNN-based algorithm (GUTAID) to identify colonic abnormalities and landmarks was successfully established with high accuracy. This GUTAID system can further characterize polyps for optical diagnosis. We demonstrated that AI classification methodology is feasible to identify multiple and different colon diseases.

Three-dimensional versus conventional two-dimensional laparoscopic colectomy for colon cancer: A 3-year follow-up study.

Background: Three-dimensional (3D) laparoscopy was developed to overcome the drawbacks of two-dimensional (2D) laparoscopy, namely lack of depth perception. However, the benefit of 3D laparoscopy in colorectal surgery is inconclusive. Here, we compare the 3-year follow-up outcomes of 3D and 2D laparoscopic colectomy. Patients and Methods: A total of 91 consecutive patients who underwent either 3D or 2D laparoscopy colectomy from October 2015 to November 2017 by a single surgical team for colon cancer were enrolled. Data were collected from a prospectively constructed database, including clinico-pathological features and operative parameters. The pathological results, recurrence, survival and systemic treatment were collected from the Taiwan Cancer Database. Results: There were 47 patients in the 3D group and 44 in the 2D group. There were no significant differences in characteristics of patients, operation data, pathological results, complications, operative time, blood loss or the number of lymph node harvested between the two groups. In addition, disease-free survival and overall survival were equal between the two groups. Conclusions: This is the first long-term result of a 3D laparoscopic colectomy. In our 3-year follow-up, there was no difference in long-term outcomes between 2D and 3D laparoscopy for colorectal surgery in an experienced centre.

The efficacy of anti-EGFR therapy in treating metastatic colorectal cancer differs between the middle/low rectum and the left-sided colon.

BACKGROUND: Clinically, metastatic rectal cancer has been considered a subset of left-sided colon cancer. However, heterogeneity has been proposed to exist between high and middle/low rectal cancers. We aimed to examine the efficacy of anti-epidermal growth factor receptor (EGFR) treatment for middle/low rectal and left-sided colon cancers. METHODS: This study enrolled 609 patients with metastatic colorectal cancer who were treated with anti-EGFR therapy. They were divided into groups based on primary tumour locations: the right-sided colon, the left-sided colon or the middle/low rectum. The efficacy of first-line and non-first-line anti-EGFR treatment was analysed. Genomic differences in colorectal cancer data from The Cancer Genome Atlas (TCGA) were investigated and visualised with OncoPrint and a clustered heatmap. RESULTS: On first-line anti-EGFR treatment, patients with middle/low rectal tumours had significantly lower progression-free survival, overall survival, and overall response rates (6.8 months, 27.8 months and 43%, respectively) than those with left-sided colon cancer (10.1 months, 38.3 months and 66%, respectively). Similar outcomes were also identified on non-first-line anti-EGFR treatment. In TCGA analysis, rectal tumours displayed genetic heterogeneity and shared features with both left- and right-sided colon cancer. CONCLUSIONS: Anti-EGFR treatment has lower efficacy in metastatic middle/low rectal cancer than in left-sided colon cancer.

Taiwan Society of Colon and Rectal Surgeons (TSCRS) Consensus for Cytoreduction Selection in Metastatic Colorectal Cancer.

BACKGROUND: Taiwan has witnessed a surge in the incidence of colorectal cancer (CRC), of which 40-60% metastasize. Continuous updating of cytoreductive strategies in metastatic CRC (mCRC) has contributed to median overall survival reaching 40 months. In this changing scenario, to standardize the approaches across Taiwan, a group of experts from the Taiwan Society of Colon and Rectal Surgeons (TSCRS) convened to establish evidence- and opinion-based recommendations for defining the criteria of "resectability" in mCRC. METHODS: Over the course of one-on-one consultations, lasting 30-40 min each, with 30 medical specialists (19 colorectal surgeons, 4 general surgeons, and 7 medical oncologists) from 16 hospitals in Taiwan followed by a 2-h meeting with 8 physician experts (3 general surgeons, 4 colorectal surgeons, and 1 thoracic surgeon), 12 key questions on cytoreduction were addressed. This was further contextualized based on published literature. RESULTS: The final consensus includes eight recommendations regarding the criteria for metastasis resection, role of local control treatment in liver potentially resectable patients, management of synchronous liver metastases, approach for peritoneal metastasis, place for resection in multiple-organ metastasis, and general criteria for resectability. CONCLUSIONS: mCRC patients undergoing R0 resection have the greatest survival advantage following surgery. Our role as a multidisciplinary team (MDT) should be to treat potentially resectable mCRC patients as rapidly and safely as possible, and achieve R0 resection as far as possible and for as long as possible (continuum of care). This TSCRS consensus statement aims to help build clinical capacity within the MDTs, while making better use of existing healthcare resources.

Identification of a noncanonical function for ribose-5-phosphate isomerase A promotes colorectal cancer formation by stabilizing and activating ß-catenin via a novel C-terminal domain.

Altered metabolism is one of the hallmarks of cancers. Deregulation of ribose-5-phosphate isomerase A (RPIA) in the pentose phosphate pathway (PPP) is known to promote tumorigenesis in liver, lung, and breast tissues. Yet, the molecular mechanism of RPIA-mediated colorectal cancer (CRC) is unknown. Our study demonstrates a noncanonical function of RPIA in CRC. Data from the mRNAs of 80 patients' CRC tissues and paired nontumor tissues and protein levels, as well as a CRC tissue array, indicate RPIA is significantly elevated in CRC. RPIA modulates cell proliferation and oncogenicity via activation of ß-catenin in colon cancer cell lines. Unlike its role in PPP in which RPIA functions within the cytosol, RPIA enters the nucleus to form a complex with the adenomatous polyposis coli (APC) and ß-catenin. This association protects ß-catenin by preventing its phosphorylation, ubiquitination, and subsequent degradation. The C-terminus of RPIA (amino acids 290 to 311), a region distinct from its enzymatic domain, is necessary for RPIA-mediated tumorigenesis. Consistent with results in vitro, RPIA increases the expression of ß-catenin and its target genes, and induces tumorigenesis in gut-specific promotor-carrying RPIA transgenic zebrafish. Together, we demonstrate a novel function of RPIA in CRC formation in which RPIA enters the nucleus and stabilizes ß-catenin activity and suggests that RPIA might be a biomarker for targeted therapy and prognosis.

Insulin-Like Growth Factor 2 mRNA-Binding Protein 1 (IGF2BP1) Is a Prognostic Biomarker and Associated with Chemotherapy Responsiveness in Colorectal Cancer.

Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) is an RNA-binding protein and serves as a post-transcriptional fine-tuner regulating the expression of mRNA targets. However, the clinicopathological roles of IGF2BP1 in colorectal cancer (CRC) remains limited. Thus, we aimed to elucidate the clinical significance and biomarker potentials of IGF2BP1 in CRC. A total of 266 specimens from two sets of CRC patients were collected. IGF2BP1 expression was studied by immunohistochemical (IHC) staining. The Kaplan-Meier survival plot and a log-rank test were used for survival analysis. The Cox proportional hazards model was applied to determine the survival impact of IGF2BP1. Public datasets sets from The Cancer Genome Atlas (TCGA) and Human Cancer Metastasis Database (HCMDB), receiver operating characteristic (ROC) plotter, and two CRC cell lines, HCT-116 and DLD-1, were used for validating our findings. We showed that IGF2BP1 was overexpressed in tumor specimens compared to 13 paired normal parts by examining the immunoreactivity of IGF2BP1 (p = 0.045). The increased expression of IGF2BP1 in primary tumor parts was observed regardless of metastatic status (p < 0.001) in HCMDB analysis. IGF2BP1 expression was significantly associated with young age (59.6% vs. 46.7%, p-value = 0.043) and advanced stage (61.3% vs. 40.0%, p-value = 0.001). After controlling for confounding factors, IGF2BP1 remained an independent prognostic factor (HR = 1.705, p-value = 0.005). TCGA datasets analysis indicated that high IGF2BP1 expression showed a lower 5-year survival rate (58% vs. 65%) in CRC patients. The increased expression of IGF2BP1 in chemotherapy non-responder rectal cancer patients was observed using a ROC plotter. Overexpression of IGF2BP1 promoted the colony-forming capacity and 5-fluorouracil and etoposide resistance in CRC cells. Here, IGF2BP1 was an independent poor prognostic marker in CRC patients and contributed to aggressive phenotypes in CRC cell lines.

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 ß-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.

Emergence of RAS mutations in patients with metastatic colorectal cancer receiving cetuximab-based treatment: a study protocol.

BACKGROUND: In the management of patients with RAS wild-type metastatic colorectal cancer (mCRC), anti-epidermal growth factor receptor (EGFR) therapies have demonstrated a clinical benefit, with longer survival. However, the correlation between the emergence of circulating RAS mutations and secondary resistance to anti-EGFR therapies requires further elucidation. In this study, we aim to examine evolutionary changes in RAS mutations through liquid biopsy in patients with mCRC during and after anti-EGFR therapy. METHODS: A total of 120 patients diagnosed with RAS wild-type mCRC will be enrolled in this study. Patients will receive a cetuximab-based infusional 5-fluorouracil regimen as first-line treatment. Cetuximab-based treatment is expected to continue until disease progression, intolerable toxic effects, or withdrawal of consent. Blood samples from enrolled patients will be collected before and then every 3 months during cetuximab-based treatment and also at disease progression. These blood samples will be evaluated for RAS resistance mutations by using the MassARRAY platform. The primary endpoint is the percentage of RAS mutations detected in circulating DNA from patients during cetuximab treatment. The correlation between the tumor response and survival outcomes of these patients and the emergence of circulating RAS mutations will be further analyzed. DISCUSSION: Liquid biopsy is a powerful technology that can represent tumor heterogeneity in a relatively noninvasive manner. Because RAS mutations play a major role in resistance to anti-EGFR therapy for mCRC, examining evolutionary changes in these mutations during such treatment through liquid biopsy would be useful. After comprehensively analyzing the emergence of circulating RAS mutations and its clinical relevance in this study, our results should provide practical guidance on anti-EGFR therapy for mCRC. TRIAL REGISTRATION: The date of trial registration ( NCT03401957 ) in this study was January 17, 2018.

Risk factors for delayed perineal wound healing and its impact on prolonged hospital stay after abdominoperineal resection.

BACKGROUND: Perineal wound complications are a long-lasting issue for abdominoperineal resection (APR) patients. Complication rates as high as 60% have been reported, with the most common complication being delayed perineal wound healing. The aim of this study was to identify risk factors for delayed perineal wound healing and its impact on prolonged hospital stay. METHODS: We included low rectal tumor patients who underwent APR at a referral medical center from April 2002 to December 2017; a total of 229 patients were included. The basic characteristics and surgical outcomes of the patients were analyzed to identify risk factors for delayed perineal wound healing (> 30 days after APR) and prolonged hospital stay (post-APR hospital stay > 14 days). RESULTS: All patients received primary closure for their perineal wound. The majority of patients were diagnosed with adenocarcinoma (N = 213, 93.1%). In the univariate analysis, patients with hypoalbuminemia (albumin < 3.5 g/dL) had an increased risk of delayed wound healing (39.5% vs. 60.5%, P = 0.001), which was an independent risk factor in the multivariable analysis (OR 2.962, 95% CI 1.437-6.102, P = 0.003). Patients with delayed wound healing also had a significantly increased risk of prolonged hospital stay (OR 6.404, 95% CI 3.508-11.694, P < 0.001). CONCLUSIONS: Hypoalbuminemia was an independent risk factor for delayed wound healing, which consequently led to a prolonged hospital stay. Further clinical trials are needed to reduce the incidence of delayed perineal wound healing by correcting albumin levels or nutritional status before APR.

Clinical significance of the BRAFV600E mutation in Asian patients with colorectal cancer.

BACKGROUND: To investigate the clinicopathological features and prognostic significance of the BRAFV600E mutation in Asian patients with colorectal cancer. METHODS: We retrospectively reviewed the medical records of 1969 patients with colorectal cancer admitted to Taipei Veterans General Hospital for surgical treatment between 2000 and 2013. The measured endpoint was overall survival after surgery. The prognostic value of the BRAFV600E mutation was analyzed using the log-rank test and Cox regression analysis. RESULTS: The BRAFV600E mutation was detected in 106 (5.4%) patients and associated with female gender, abnormal cancer antigen (CA)19-9 at diagnosis, microsatellite status, right-sided primary tumors, mucinous histology, poor differentiation, and lymphovascular invasion. Metastatic patterns were more common in non-regional lymph node metastasis (20.8 vs. 7.4%, p = 0.06) and peritoneal seeding (41. vs. 21.2%, p = 0.04). Mutations were not prognostic in the overall survival of the entire study group but only in specific patients: age < 65, normal carcinoembryonic antigen at diagnosis, and stage IV disease. CONCLUSION: The BRAFV600E mutation was associated with distinct clinicopathological features and metastatic patterns. The overall survival rate was lower in selected colorectal patients with the BRAFV600E mutation.

Metastatic Malignancy to the Colon and Rectum: A Report of 14 Cases from One Single Institute.

BACKGROUND: Metastatic malignancy occurs rarely in the colon or rectum. We presented 14 patients with colorectal metastasis (CRM). METHODS: A retrospective review was conducted on a computerized colorectal tumor database at the Taipei Veterans General Hospital from January 2000 to June 2013. RESULTS: The incidence of CRM was 0.19% (14 in 7,524 patients). There were 6 males and 8 females with a mean age of 66.9 ± 13.6 years. Origins of the CRM included lung cancers (n = 3), prostate cancers (n = 2), and others (n = 1, respectively). Clinical presentations were not specific and colonoscopic pictures were indistinguishable from primary colorectal cancers; 5 of the 9 biopsies identified metastasis. Eight patients had extracolonic metastasis and 6 patients had CRM only. Significantly better survival was observed in the CRM-only group (p = 0.037). The mean interval from the treatment of primary tumor to the diagnosis of CRM was 30.2 ± 49.0 months. The mean survival time after CRM was 24.9 ± 30.8 months. CONCLUSION: Clinical features and colonoscopic findings of CRM were indistinguishable from primary colorectal cancer. Histopathological review of the biopsy could be helpful in identifying the primary lesion. Surgical resection with curative intent provided longer survival in CRM-only patients.

Differences in gene mutations according to gender among patients with colorectal cancer.

BACKGROUND: The incidence, site distribution, and mortality rates of patients with colorectal cancer differ according to gender. We investigated gene mutations in colorectal patients and wanted to examine gender-specific differences. METHODS: A total of 1505 patients who underwent surgical intervention for colorectal cancer were recruited from March 2000 to January 2010 at Taipei Veterans' General Hospital and investigated for gene mutations in K-ras, N-ras, H-ras, BRAF, loss of 18q, APC, p53, SMAD4, TGF-ß, PIK3CA, PTEN, FBXW7, AKT1, and MSI. RESULTS: There were significant differences between male and female patients in terms of tumor location (p < 0.0001) and pathological stage (p = 0.011). The female patients had significantly more gene mutations in BRAF (6.4 vs. 3.3%, OR 1.985, p = 0.006), TGF-ß (4.7 vs. 2.5%, OR 1.887, p = 0.027), and revealed a MSI-high status (14.0 vs. 8.3%, OR 1.800, p = 0.001) than male patients. Male patients had significantly more gene mutations in N-ras (5.1 vs. 2.3%, OR 2.227, p = 0.012); however, the significance was maintained only for mutations in BRAF (OR 2.104, p = 0.038), MSI-high status (OR 2.003 p = 0.001), and N-ras (OR 3.000, p = 0.010) after the groups were divided by tumor site. CONCLUSION: Gene mutations in BRAF, MSI-high status, and N-ras differ according to gender among patients with colorectal cancer.

Molecular and Clinicopathological Differences by Age at the Diagnosis of Colorectal Cancer.

We compared the clinicopathological and molecular profiles between different age groups of sporadic colorectal cancer (CRC) patients (age <50, 56-60, 60-70, 70-80, and >80); 1475 CRC patients were enrolled after excluding 30 individuals with Lynch syndrome. The mutation spectra for APC, TP53, KRAS, PIK3CA, FBXW7, BRAF, NRAS, HRAS, TGFbR, Akt1, and PTEN were analyzed using polymerase chain reaction (PCR), followed by MassArray and microsatellite (MSI-high) analysis by performing genotyping. Male patients (74.1%) were significantly predominant to females (25.9%) in the older age group (70-80, >80). There was an insignificantly linear trend between TNM staging and age-onset of CRC diagnosis. Patients aged < 50 had 58.7% diseases in the advanced stages (Stage III: 36.5% and IV: 22.2% respectively), while this decreased to 40.2% (Stage III: 26.2% and IV; 14.0% respectively) in patients >80. The distributions of mutation frequency were similar in majority of the genes studied among different age groups. Additionally, patients aged <50 had significantly higher frequency of MSI-high, PTEN, and HRAS mutations than those of other groups. Age-onset at diagnosis significantly affected overall survival (HR = 1.46; 95% CI: 1.35-1.58), but not cancer-specific survival (HR = 1.08; 95% CI: 0.99-1.18) in multivariate analysis. In conclusion, molecular and clinicopathological differences were not as significant among different age groups of CRC patients as previously suspected.

Interleukin-1 Receptor Type 2 Acts with c-Fos to Enhance the Expression of Interleukin-6 and Vascular Endothelial Growth Factor A in Colon Cancer Cells and Induce Angiogenesis.

Interleukin-1 receptor type 2 (IL1R2) acts as a decoy receptor of exogenous IL-1; however, its intracellular activity is poorly understood. We previously demonstrated that IL1R2 intracellularly activates the expression of several proinflammatory cytokines and affects cell migration. In this study, we found that intracellular IL1R2 expression was increased in human colorectal cancer cells (CRCs) compared with normal colon cells. We also observed that the mRNA levels of IL1R2 were highly correlated with IL-6 in tumor tissues of CRC patients. By modulating its expression in CRC cells, we verified that enhanced IL1R2 expression transcriptionally activated the expression of IL-6 and VEGF-A. Conditioned medium harvested from IL1R2-overexpressing CRC cells contained higher levels of IL-6 and VEGF-A than that from vector control cells and significantly enhanced the proliferation, migration, and tube formation of cultured endothelial cells. We further demonstrated a positive association of intracellular IL1R2 levels with tumor growth and microvessel density in xenograft mouse models. These results revealed that IL1R2 activates the expression of angiogenic factors. Mechanistically, we revealed that IL1R2 complexes with c-Fos and binds to the AP-1 site at the IL-6 and VEGF-A promoters. Together, these results reveal a novel function of intracellular IL1R2 that acts with c-Fos to enhance the transcription of IL-6 and VEGF-A, which promotes angiogenesis in CRC.

Serological and viraemic status of human cytomegalovirus infection in patients with colorectal cancer is not correlated with viral replication and transcription in tumours.

Colorectal cancer (CRC) is amongst the leading causes of cancer-related mortality worldwide. Emerging evidence suggests that human cytomegalovirus (HCMV) exists in the tumour tissue of CRC and is associated with disease outcome. To study whether tumoral HCMV is related to viral reactivation in blood, tumour specimens and pre- and post-operative blood samples from CRC patients were collected prospectively. PCR and quantitative PCR were performed to detect HCMV DNA. HCMV IgG and IgM antibodies were measured using a microparticle enzyme immunoassay. Transcription of a spliced HCMV UL73 gene transcript was analysed by quantitative reverse transcription PCR. HCMV was detected in 42.2% (35/83) of the tumour samples, with a low median viral load (30.08, range 2.33-5704 copies per 500  ng genomic DNA). The vast majority (80/81, 98.8%) of the CRC patients were seropositive for HCMV IgG. HCMV DNA was positive in 11.3% (22/194) of the pre-operative and 8.9% (15/168) of the post-operative blood samples. However, presence of HCMV and its viral load in tumours were not associated with the detection or viral loads in blood samples. About 26.67% (8/30) of the HCMV-positive tumours with available RNA had detectable viral UL73 transcripts, whilst none of the blood samples were positive for viral RNA (P < 0.0001). Therefore, presence of HCMV in tumours does not correlate with the serological or viraemic status of CRC patients. Active viral gene transcription occurred in the tumour but not in the blood of CRC patients. HCMV reactivation in CRC patients is possibly due to virus-cancer interactions in the CRC tumour microenvironment.

Identification of human cytomegalovirus in tumour tissues of colorectal cancer and its association with the outcome of non-elderly patients.

Increasing evidence suggests that human cytomegalovirus (HCMV) plays an oncomodulatory role in human cancers. In colorectal cancer (CRC), presence of HCMV in tumours has been associated with a poor outcome in elderly patients. This study aimed to investigate the association between HCMV and the outcome of non-elderly patients with CRC. In tumour samples, HCMV DNA was detected by PCR. Viral transcript and protein were detected by in situ hybridization (ISH) and immunohistochemical staining (IHC), respectively. Clinical, pathological and survival data were compared between patients with HCMV-positive and -negative tumours. Quantitative reverse transcription PCR (qRT-PCR) was used to analyse the expression levels of cellular signals related to CRC progression and metastasis. Among 89 CRC non-elderly patients aged <65 years, HCMV was detected in 31 (34.8 %) tumour samples by PCR. By ISH and IHC, viral transcript and protein specifically localized to the cytoplasm of neoplastic mucosal epithelium. Outcome analysis revealed a more favourable disease-free survival (DFS) rate in patients with HCMV-positive tumours (P<0.01), specifically in patients with stage III disease. In a multivariate Cox proportional-hazard model, tumoural presence of HCMV independently predicted a higher DFS rate (hazard ratio 0.22; 95 % confidence interval 0.075-0.66, P<0.01). By qRT-PCR, the tumoural levels of interleukin-1 were relatively lower in samples positive for HCMV. The results suggest that HCMV may influence the outcome of CRC in an age-dependent manner and possibly has a dual oncomodulatory effect. How the virus interacts with the tumour microenvironment should be further studied.

Mutation Spectra of Common Cancer-Associated Genes in Different Phenotypes of Colorectal Carcinoma Without Distant Metastasis.

BACKGROUND: Colorectal cancer (CRC) is a heterogeneous disease caused by genetic and epigenetic alterations. This study aimed to describe the mutation frequency of 12 genes in different CRC phenotypes. METHODS: Patients who underwent surgery at the Taipei Veterans General Hospital during 2000-2010 for CRC (n = 1249) were enrolled. The endpoint was overall survival. The prognostic value was determined with the log-rank test and Cox regression analysis. RESULTS: We found 1836 mutations of 12 genes in 997 (79.8%) tumors. Mutations were most frequently in KRAS (485, 38.8%), TP53 (373, 29.9%), APC (363, 29.0%), and PIK3CA (179, 14.3%); 137 (11.0%) cancers had high microsatellite instability (MSI). Women had significantly higher high MSI (14.3%) and BRAF mutation (6.3%) frequencies. The abnormal MSI (21.7%) and KRAS (44.6%), BRAF (8.6%), PIK3CA (19.4%), AKT1 (2.2%), and TGF - ßR (9.6%) mutation frequencies were significantly higher in proximal colon cancer. The high MSI (35.6%) and BRAF (20.3%), TGF - ßR (18.6%), PTEN (5.1%), and AKT1 (3.4%) mutation frequencies were significantly higher in 59 (4.7%) poorly differentiated tumors. The high MSI (21.3%) and KRAS (51.9%), BRAF (8.3%), PIK3CA (25.0%), AKT1 (4.6%), and SMAD4 (8.3%) mutation frequencies were significantly higher in 108 mucinous tumors. TNM stage, lymphovascular invasion, and mucinous histology were significantly associated with patient outcomes in univariate and multivariate analyses. Only NRAS mutation (hazard ratio 1.59, 95% confidence interval 1.06-2.38) affected patient survival. CONCLUSIONS: Mutational spectra differ significantly between CRC subtypes, implying diverse carcinogenetic pathways. The NRAS mutation is important, despite its low frequency.