Unraveling the role of tumor sidedness in prognosis of stage II colon cancer.

Background: Stage II colon cancer has varying risks for metastasis, and treatment strategies depend on molecular and clinicopathological features. While tumor-sidedness is a well-accepted prognostic factor for stage III/IV colon cancer, its role in stage II is controversial. Understanding its effect in stage II is crucial for improving treatment strategies. Methods: We analyzed clinical and follow-up data of colon cancer from the Surveillance, Epidemiology, and End Results database (2004-2017). Patients were divided into a primary study cohort (2010-2017) and a validation cohort (2004-2009). The baseline characteristics between right-sided colon cancer (RCC) and left-sided colon cancer (LCC) groups were compared. Moreover, the effect of tumor size on cancer-specific survival (CSS) was evaluated using Kaplan-Meier analysis. Results: The study involved 87,355 patients in the study cohort and 65,858 in the validation cohort. Of the study cohort, 52.3% were diagnosed with RCC. The median age was 64 years old, with 48.5% females and 76.8% of white people. In addition, stage II RCC showed better CSS compared with LCC (5-year CSS 88.0% vs 85.5%, P < 0.001), while stage III/IV RCC demonstrated poorer outcomes. Multivariate Cox regression analysis identified that the right-sidedness was a positive prognostic factor in stages I/II but negative in stages III (HR 1.10, P < 0.001) and IV (HR 1.26, P < 0.001). Chemotherapy rates decreased in RCC, particularly in stage II (RCC vs LCC: 16.2% vs 28.5%, P < 0.001). Subgroup analysis, stratified by T3/T4 stages and chemotherapy status, further highlighted better survival outcomes in RCC. Conclusions: RCC is associated with a significantly better prognosis in stage II. The importance of considering tumor-sidedness in clinical decision-making and the design of future clinical trials should be emphasized.

Case report: Successful treatment of advanced colon cancer in an eighty-year-old man with long-term and multi-stage endoscopic minimally invasive therapy.

Background: No previous studies have reported on the use of minimally invasive endoscopic therapy for colon cancer in older patients. Case presentation: An 80-year-old man was admitted to our hospital with haematochezia and diagnosed with advanced colon cancer in 2018. Traditional surgical care was rejected by his family. We successfully treated the patient with multiple minimally invasive endoscopic therapies, such as argon plasma coagulation, from 2018 to 2021. Conclusion: Invasive endoscopic therapy is a feasible way to treat colon cancer in older patients.

Colon stenting as a bridge to surgery in obstructive colorectal cancer management.

Colonic stent placement is a commonly used bridging strategy for surgery in patients with obstructive colorectal cancer. The procedure involves the placement of a self-expandable metallic stent (SEMS) across the obstructive lesion to restore intestinal patency and alleviate the symptoms of obstruction. By allowing patients to receive surgery in a planned and staged manner with time for preoperative optimization and bowel preparation, stent placement may reduce the need for emergency surgery, which is associated with higher complication rates and poorer outcomes. This review focuses on the role of colon stenting as a bridge to surgery in the management of obstructive colorectal cancer. SEMS as a bridge to surgery for left-sided colon cancer has been demonstrated to be particularly useful; however, further research is needed for its application in cases of right-sided colon cancer. Colon stent placement also has limitations and potential complications including stent migration, re-obstruction, and perforation. However, the timing of curative surgery after SEMS placement remains inconclusive. Considering the literature to date, performing surgery at an interval of approximately 2 weeks is considered appropriate. Therefore, colonic stent placement may be an effective strategy as a bridge to surgery in patients with obstructive colorectal cancer.

Laparoscopic right hemicolectomy with complete mesocolic excision and D3 lymphadenectomy using the open book approach: a video vignette.

According to the concept of total mesorectal excision for rectal cancer, Hohenberger translated this concept to colonic cancer by introducing complete mesocolic excision (CME). The concept of this surgical technique was further elucidated by Benz et al. in the form of an open book approach. This article presents and demonstrates in a video a case of laparoscopic right hemicolectomy with CME and D3 lymphadenectomy using open book approach in the treatment of a T3N1M0 distal ascending colonic adenocarcinoma. The final pathology report confirmed moderately differentiated adenocarcinoma with a maximum tumor size of 55 mm and 0/60 lymph nodes. The mesocolic fascia was intact and R0 was achieved. The final staging was pT3pN0pM0. However, D3 lymphadenectomy is not universally adopted due to concerns of higher morbidity we believe that with adequate training and supervision CME with D3 LDN is feasible and safe to be offered to all right-sided colorectal cancers with curative intent treatment.

The diagnostic accuracy of local staging in colon cancer based on computed tomography (CT): evaluating the role of extramural venous invasion and tumour deposits.

PURPOSE: The shift from adjuvant to neoadjuvant treatment in colon cancer demands the radiological selection of patients for systemic therapy. The aim of this study was to evaluate the accuracy of the CT-based TNM stage and high-risk features, including extramural venous invasion (EMVI) and tumour deposits, in the identification of patients with histopathological advanced disease, currently considered for neoadjuvant treatment (T3-4 disease). METHODS: All consecutive patients surgically treated for non-metastatic colon cancer between January 2018 and January 2020 in a referral centre for colorectal cancer were identified retrospectively. All tumours were staged on CT according to the TNM classification system. Additionally, the presence of EMVI and tumour deposits on CT was evaluated. The histopathological TNM classification was used as reference standard. RESULTS: A total of 176 patients were included. Histopathological T3-4 colon cancer was present in 85.0% of the patients with CT-detected T3-4 disease. Histopathological T3-4 colon cancer was present in 96.4% of the patients with CT-detected T3-4 colon cancer in the presence of both CT-detected EMVI and CT-detected tumour deposits. Histopathological T0-2 colon cancer was present in 50.8% of the patients with CT-detected T0-2 disease, and in 32.4% of the patients without CT-detected EMVI and tumour deposits. CONCLUSION: The diagnostic accuracy of CT-based staging was comparable with previous studies. The presence of high-risk features on CT increased the probability of histopathological T3-4 colon cancer. However, a substantial part of the patients without CT-detected EMVI and tumour deposits was diagnosed with histopathological T3-4 disease. Hence, more accurate selection criteria are required to correctly identify patients with locally advanced disease.

Small arteriole sign: an imaging feature for staging T4a colon cancer.

OBJECTIVES: By analyzing the distribution of existing and newly proposed staging imaging features in pT1-3 and pT4a tumors, we searched for a salient feature and validated its diagnostic performance. METHODS: Preoperative multiphase contrast-enhanced CT images of the training cohort were retrospectively collected at three centers from January 2016 to December 2017. We used the chi-square test to analyze the distribution of several stage-related imaging features in pT1-3 and pT4a tumors, including small arteriole sign (SAS), outer edge of the intestine, tumor invasion range, and peritumoral adipose tissue. Preoperative multiphase contrast-enhanced CT images of the validation cohort were retrospectively collected at Beijing Cancer Hospital from January 2018 to December 2018. The diagnostic performance of the selected imaging feature, including accuracy, sensitivity, and specificity, was validated and compared with the conventional clinical tumor stage (cT) by the McNemar test. RESULTS: In the training cohort, a total of 268 patients were enrolled, and only SAS was significantly different between pT1-3 and pT4a tumors. The accuracy, sensitivity, and specificity of the SAS and conventional cT in differentiating T1-3 and T4a tumors were 94.4%, 81.6%, and 97.3% and 53.7%, 32.7%, and 58.4%, respectively (all p < 0.001). In the validation cohort, a total of 135 patients were collected. The accuracy, sensitivity, and specificity of the SAS and the conventional cT were 93.3%, 76.2%, and 96.5% and 62.2%, 38.1%, and 66.7%, respectively (p < 0.001, p = 0.021, p < 0.001). CONCLUSION: Small arteriole sign positivity, an indirect imaging feature of serosa invasion, may improve the accuracy of identifying T4a colon cancer. CLINICAL RELEVANCE STATEMENT: Small arteriole sign helps to distinguish T1-3 and T4a colon cancer and further improves the accuracy of preoperative CT staging of colon cancer. KEY POINTS: • The accuracy of preoperative CT staging of colon cancer is not ideal, especially for T4a tumors. • Small arteriole sign (SAS) is a newly defined imaging feature that shows the appearance of tumor-supplying arterioles at the site where they penetrate the intestine wall. • SAS is an indirect imaging marker of tumor invasion into the serosa with a great value in distinguishing between T1-3 and T4a colon cancer.

Anti-inflammatory mechanisms in cancer research: Characterization of a distinct M2-like macrophage model derived from the THP-1 cell line.

AIMS: Macrophages play an essential role in cancer development. Tumor-associated macrophages (TAMs) have predominantly M2-like attributes that are associated with tumor progression and poor patient survival. Numerous methods have been reported for differentiating and polarizing macrophages in vitro, but there is no standardized and validated model for creating TAMs. Primary cells show varying cytokine responses depending on their origin and functional studies utilizing these cells may lack generalization and validity. A distinct cell line-derived TAM-like M2 subtype is required to investigate the mechanisms mediated by anti-inflammatory TAMs in vitro. Our previous work demonstrated a standardized protocol for creating an M2 subtype derived from a human THP-1 cell line. The cell expression profile, however, has not been validated. The aim of this study was to characterize and validate the TAM-like M2 subtype macrophage created based on our protocol to introduce them as a standardized model for cancer research. METHODS AND RESULTS: Using qRT-PCR and ELISA, we demonstrated that proinflammatory, anti-inflammatory, and tumor-associated marker expression changed during THP-1-derived marcrophage development in vitro, mimicking a TAM-related profile (e.g., TNFα, IL-1ß). The anti-inflammatory marker IL-8/CXCL8, however, is most highly expressed in young M0 macrophages. Flow cytometry showed increased expression of CD206 in the final TAM-like M2 macrophage. Single-cell RNA-sequencing analysis of primary human monocytes and colon cancer tissue macrophages demonstrated that cell line-derived M2 macrophages resembled a TAM-related gene profile. CONCLUSIONS: The THP-1-derived M2 macrophage based on a standardized cell line model represents a distinct anti-inflammatory TAM-like phenotype with an M2a subtype profile. This model may provide a basis for in vitro investigation of functional mechanisms in a variety of anti-inflammatory settings, particularly colon cancer development.

Clinical utility of the carcinoembryonic antigen level in patients with stage III colon cancer after surgery and adjuvant chemotherapy.

PURPOSE: The association between perioperative and post-adjuvant carcinoembryonic antigen (CEA) levels and recurrence and prognosis remains unclear. We aimed to evaluate whether perioperative CEA levels are an integral component of the assessment of recurrence and prognosis of patients with stage III colon cancer (CC). METHODS: This retrospective study was conducted at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research from 2005 to 2013. We enrolled patients with stage III CC who underwent complete resection of a primary tumor and received adjuvant chemotherapy. We analyzed the association between perioperative and post-adjuvant CEA levels and recurrence-free survival (RFS) and overall survival (OS). RESULTS: A total of 564 consecutive patients were included in the analysis. The RFS and OS of patients with high postoperative CEA levels were significantly worse than those of patients with normal postoperative CEA levels. In the multivariate analysis, high postoperative CEA levels were associated with shorter RFS and OS. The number of risk factors, postoperative CEA levels, and T/N-stage all had a cumulative effect on RFS and OS. CONCLUSIONS: High postoperative CEA levels and the number of risk factors are associated with recurrence and worse prognosis for patients with stage III CC.

Survival After Wait-and-See Approach in Older Patients With Unexplained Iron Deficiency Anemia in Primary Care: A Practice Evaluation.

OBJECTIVES: Guidelines recommend upper and lower gastrointestinal endoscopic evaluation for patients without a clear physiological explanation for iron deficiency anemia (IDA). However, the consequences of watchful waiting in older patients with unexplained IDA in general practice are unknown. The aim of this study was to investigate characteristics and survival of patients with an unexplained IDA in general practice who refrain from medical specialist evaluation. DESIGN: Historical prospective study. SETTING AND PARTICIPANTS: Patients aged ≥70 years with IDA coded in their medical records were selected from the Dutch Academic General Practitioner Development Network (AHON) database. METHODS: Based on their medical records, patients with an unexplained IDA were classified as (1) referred for medical specialist evaluation, or (2) no or noninvasive evaluation in general practice. RESULTS: Compared to patients who were referred for medical specialist evaluation (n = 235, 47.8%), patients who had no or noninvasive evaluation (n = 257; 52.5%) were older (median respectively 79 vs 82 years old, P < .01) and more likely to have congestive heart failure (respectively 17.4% and 26.1%, P = .02) and dementia (respectively 2.6% and 8.9%, P < .01). Two-year survival was significantly higher in patients who were referred for medical specialist evaluation compared to patients who had no or noninvasive evaluation (respectively, 83.9% and 75.5%, P = .02). CONCLUSIONS AND IMPLICATIONS: Although mortality was significantly higher in the older and more comorbid patients who had no or noninvasive evaluation in general practice, survival was still high in this patient group. Therefore, non-guideline adherence and a wait-and-see approach could be discussed in a shared-decision-making consultation.

Sigmoid-rectal intussusception in an elderly patient: A case report of an unusual presentation of intestinal obstruction.

INTRODUCTION: Sigmoid-rectal intussusception or invagination is an infrequently documented condition in the adult population, with only a handful of cases reported in the medical literature. The underlying pathological mechanism involves impaired peristalsis, often attributed to a malignant tumor. CASE PRESENTATION: A 78-year-old patient, with a history of abdominal pain and lower gastrointestinal bleeding, sought care at our emergency department with evident symptoms indicative of large bowel obstruction. Abdominal examination revealed distension and rectal examination found a mass mimicking an internal rectal prolapse. Subsequently, imaging studies confirmed the diagnosis of sigmoid-rectal intussusception. The patient underwent an emergency open sigmoid resection with Hartman's procedure. The postoperative course was uneventful. Anatomopathological analysis revealed the presence of stage I adenocarcinoma. A restoration of digestive continuity was scheduled six months later. One-year follow-up assessments showed no indications of local recurrence or distant metastasis. DISCUSSION: Sigmoid rectal intussusception stands as a unique and infrequently reported medical entity. The absence of distinct clinical symptoms often renders diagnosis a challenging task, with confirmation typically relying on radiological findings. In contrast to the non-surgical approaches employed in pediatric cases, intussusception in adults necessitates surgical intervention due to its predominantly malignant underpinnings. CONCLUSION: While sigmoid-rectal intussusception is an exceedingly rare occurrence, its manifestation with a multitude of non-specific symptoms can complicate clinical recognition. Nevertheless, it should be duly considered as a potential etiological factor in cases of large bowel obstruction, particularly when suggestive signs are found on rectal examination.

The apelin­apelin receptor signaling pathway in fibroblasts is involved in tumor growth via p53 expression of cancer cells.

Cancer­associated fibroblasts (CAFs) are pivotal in tumor progression. TP53­deficiency in cancer cells is associated with robust stromal activation. The apelin­apelin receptor (APJ) system has been implicated in suppressing fibroblast­to­myofibroblast transition in non­neoplastic organ fibrosis. The present study aimed to elucidate the oncogenic role of the apelin­APJ system in tumor fibroblasts. APJ expression and the effect of APJ suppression in fibroblasts were investigated for p53 status in cancer cells using human cell lines (TP53­wild colon cancer, HCT116, and Caco­2; TP53­mutant colon cancer, SW480, and DLD­1; and colon fibroblasts, CCD­18Co), resected human tissue samples of colorectal cancers, and immune­deficient nude mouse xenograft models. The role of exosomes collected by ultracentrifugation were also analyzed as mediators of p53 expression in cancer cells and APJ expression in fibroblasts. APJ expression in fibroblasts co­cultured with p53­suppressed colon cancer cells (HCT116sh p53 cells) was significantly lower than in control colon cancer cells (HCT116sh control cells). APJ­suppressed fibroblasts treated with an antagonist or small interfering RNA showed myofibroblast­like properties, including increased proliferation and migratory abilities, via accelerated phosphorylation of Sma­ and Mad­related protein 2/3 (Smad2/3). In addition, xenografts of HCT116 cells with APJ­suppressed fibroblasts showed accelerated tumor growth. By contrast, apelin suppressed the upregulation of phosphorylated Smad2/3 in fibroblasts. MicroRNA 5703 enriched in exosomes derived from HCT116sh p53 cells inhibited APJ expression, and inhibition of miR­5703 diminished APJ suppression in fibroblasts caused by cancer cells. APJ suppression from a specific microRNA in cancer cell­derived exosomes induced CAF­like properties in fibroblasts. Thus, the APJ system in fibroblasts in the tumor microenvironment may be a promising therapeutic target.

Multivariate Prognostic Models for Patients with Stages I and Ii Colon Carcinoma: a Strobe-Compliant Retrospective Cohort Study.

Background: Colorectal cancer is the most frequent gastrointestinal malignancy worldwide. The value of adjuvant treatment is controversial in Stages I and II. Objective: The aim of this study was to construct post-operative prognostic models applicable to patients with stages I-II colon carcinoma (CC). Methods: This is a retrospective cohort study of patients with Stage I-II CC treated over a 25-year period. Exposure was defined as clinical, histopathological, and immunohistochemical factors (including CDX2 and MUC2 expression). Patients were randomly allocated to either a "modeling set" or a "validation set". Factors associated with recurrence, disease-free survival (DFS), and overall survival (OS) were defined in the "modeling set". Their performances were tested in the "validation set". Results: From a total of 556 recruited patients, 339 (61%) were allocated to the "modeling set" and 217 (39%) to the "validation set". Three models explaining recurrence, DFS, and OS were described. Tumor location in the left colon (Hazards ratio [HR] = 1.57; 95% Confidence interval [CI] 0.99-2.48), lymphocyte (HR = 0.46; 96% CI 0.27-0.88) and monocyte (HR = 0.99; 95% CI 0.99-1) counts, neutrophil/platelet ratio (HR = 1.3; 95% CI 0.74-2.3, and HR = 2.3; 95% CI 1.3-4.1; for second and third category, respectively), albumin/monocyte ratio (HR = 0.43; 95% CI 0.21-0.87), and microscopic residual disease after surgery (HR = 8.7; 95% CI 3.1-24) were independently associated with OS. T classification and expression of CDX2 and/or MUC2 were not independently associated with recurrence or prognosis. Conclusion: These models are simple and readily available, and distinguish the risk and prognosis in patients with CC stages I and II; these models require cheaper processes than the use of more sophisticated molecular biology techniques. They may guide either the need for adjuvant therapy versus post-operative surveillance only, as well as aid in the design of clinical trials.

Cystic lymphangioma causing intussusception of the right colon: a case report and review of current literature.

Among intraabdominal lymphangiomas, colonic lymphangiomas are rare. These cystic tumors are generally asymptomatic and incidentally found but may present with bleeding or obstructive symptoms. Intussusception by such tumors is scarcely reported, with only nine previously reported cases listed in Pubmed. We report a case of a 41-year-old female Asian patient who presented with acute abdomen and was diagnosed with colonic intussusception caused by lymphangioma. She received emergent right hemicolectomy, recovered well without complications, and was discharged on the 5th postoperative day.

Intestinal obstruction, obturator hernia, and/or colonic neoplasms: a case study.

Occlusive hernias are rare and difficult to diagnose. We present an extraordinary case of simultaneous occurrence of an obturator hernia with colon cancer. An 86-year-old woman arrived at the hospital after ˃2 weeks of abdominal pain, nausea, vomiting, and constipation. The computed tomography axis map showed that part of the right lower abdominal small intestine had intruded into the femoral triangle through the obturator, which was diagnosed as an obturator hernia. When the abdominal cavity was opened for herniorrhaphy, a 4 × 4 cm colon mass was observed. Only herniorrhaphy was performed, without any complications. At present, there has been no report of the coexistence of occlusive hernia and colon cancer; the main symptoms are intestinal obstruction, nausea, vomiting, and constipation. The decision whether the tumor should be removed simultaneously with herniorrhaphy and/or a mesh patch.

Clinical Effectiveness of Fluorescence Lymph Node Mapping Using ICG for Laparoscopic Right Hemicolectomy: A Prospective Case-Control Study.

BACKGROUND: The distinction between D3 lymph nodes and actual lymphatic pathways in primary tumors can be difficult during surgery, making it challenging to confirm the completeness of D3 lymph node dissection. Fluorescence lymph node mapping (FLNM) is a promising method for lymph node visualization. PURPOSE: This study aimed to assess whether FLNM enhances the effectiveness of D3 lymph node dissection in patients with right-sided colon cancer. METHODS: Endoscopic submucosal indocyanine green injection were performed on the distal margin of the colon cancer. In an FLNM group, the lymphatic drainage pathway and distribution of D3 lymph nodes were explored. Pathological evaluations were conducted for the fluorescent D3 and non-fluorescent D3 lymph nodes. RESULTS: The FLNM group showed a significantly higher number of harvested lymph nodes in the D3 area. In stage III patients, the proportion of D3 lymph node metastasis was significantly higher in the FLNM group. The harvested D3 lymph node count showed a proportional correlation with a metastatic lymph node count of up to 15. CONCLUSION: FLNM could be considered a promising new strategy to potentially increase harvested D3 lymph node counts in colon cancer surgery.

Synergistic Antigenotoxic and Antioxidant Action of Gum Arabic and Eugenol in Rat Liver Following Induction of Colorectal Carcinogenesis.

OBJECTIVE: Much research has been conducted to identify natural antioxidant and antimutagenic compounds capable of preventing, reverting or treating conditions caused by oxidative stress and genotoxicity. In this study we evaluated the effects of 10% gum arabic (GA) and eugenol (EUG) on hepatic oxidative stress and genotoxicity induced by dimethylhydrazine (DMH) in rats. METHODS: The prevention arm of the study included 4 control groups and 4 experimental groups. Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the same period and for an additional 9 weeks, the animals received either water, 10% GA , EUG or 10% GA + EUG  by gavage. The treatment arm of the study included 4 control groups and 4 experimental groups. Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the subsequent 9 weeks, the animals received either water, 10% GA, EUG or 10% GA + EUG  by gavage. Finally, the livers were harvested for histopathological study with HE, measurement of genotoxicity and oxidative stress. RESULT: Genotoxicity and oxidative stress were found to be significantly lower in Group XII (animals treated concomitantly with GA and EUG). This is the first study to observe the synergistic action of GA and EUG administered concomitantly in this scenario. CONCLUSION: Indicating a synergistic antigenotoxic and antioxidant effect on liver cells in rats with DMH-induced colorectal carcinogenesis.

The predictive value of liver tests for the presence of liver metastases.

Aim: To analyze the predictive value of biochemical liver tests in patients with malignant melanoma, breast, colorectal or lung cancers at the time of diagnosis of liver metastases. Methods: A retrospective review of patients with the above-mentioned solid tumors at MedStar Georgetown University Hospital from 2016-2020. Results: The highest optimal cutoff according to sensitivity and specificity for the presence of liver metastases was for AST ≥1.5 × ULN for melanoma, lung, and breast cancers and ≥2 × ULN for colorectal cancer, ALT ≥1.25 × ULN for melanoma, breast and colorectal cancers and ≥1.5 × ULN for lung cancer, and ALP ≥1.5 × ULN for melanoma, breast and colorectal cancers. Conclusion: Using thresholds of liver enzymes above the ULN may improve the diagnostic accuracy for the presence of liver metastases.

α-SMA+ cancer-associated fibroblasts increased tumor enhancement ratio on contrast-enhanced multidetector-row computed tomography in stages I-III colon cancer.

BACKGROUND AND AIM: Our prior research revealed that the tumor enhancement ratio (TER) on triphasic abdominal contrast-enhanced MDCT (CE-MDCT) scans was a prognostic factor for patients with stages I-III colon cancer. Building upon this finding, the present study aims to investigate the proteomic changes in colon cancer patients with varying TER values. METHODS: TER was analyzed on preoperative triphasic CE-MDCT scans of 160 stages I-III colon cancer patients. The survival outcomes of those in the low-TER and high-TER groups were compared. Proteomic analysis on colon cancer tissues was performed by mass spectrometry (MS) and verified by immune-histological chemistry (IHC) assays. In vivo, mouse xenograft models were employed to test the function of target proteins identified through the MS. CE-MDCT scans were conducted on mice xenografts, and the TER values were compared. RESULTS: Patients in the high-TER group had a significantly worse prognosis than those in the low-TER group. Proteomic analysis of colon cancer tissues revealed 153 differentially expressed proteins between the two groups. A correlation between TER and the abundance of α-SMA protein in tumor tissue was observed. IHC assays further confirmed that α-SMA protein expression was significantly increased in high-TER colon cancer, predominantly in cancer-associated fibroblasts (CAFs) within the cancer stroma. Moreover, CAFs promoted the growth of CRC xenografts in vivo and increased TER. CONCLUSIONS: Our study identified the distinct protein changes in colon cancer with low and high TER for the first time. The presence of CAFs may promote the growth of colon cancer and contribute to an increased TER.

[Clinical and histopathological characteristics of malignant colon tumors by location]. / Características clínicas e histopatológicas de los tumores malignos de colon por localización.

Background: The colon has two different embryological origins, which is why it can be divided into right and left with different characteristics each one; therefore, neoplastic lesions have a different clinical picture and are also associated with different pathologies. Objective: To describe the clinical and histopathological characteristics of malignant colon tumors acording to their location. Material and methods: Descriptive, retrospective study with 94 patients diagnosed with colon cancer. Descriptive statistics were performed with the calculation of frequencies and percentages, and chi-squared tests were calculated. Results: Mean age was 61.3 years, 49 (52.1%) were women; 53 (56.4%) were left-sided and 41 (43.6%) right-sided. The main symptom was hematochezia in 32 (60.4%), in patients with left cancer; and diarrhea in 20 (48.8%), in patients with right-sided colon cancer. The presentation of stage I tumors and polyps, p = 0.044 and p = 0.043, respectively, was more frequent on the right side compared to the left side; in the left, hematochezia (p = 0.001), narrow stools(p = 0.05), and a history of type 2 diabetes mellitus (T2DM) (p= 0.036) were more frequent compared to the opposite site. Conclusions: Stage I and the presence of polyps were more frequent in right-sided cancer compared to left-sided cancer; T2DM, as well as hematochezia and narrow stools were more associated with the left side compared to the right side.

Introducción: el colon tiene dos orígenes embriológicos distintos, con lo que se puede dividir en derecho e izquierdo y cada uno tiene características diferentes; por tanto, las lesiones neoplásicas tienen un cuadro clínico diferente y se asocian también a diferentes patologías. Objetivo: describir las características clínicas e histopatológicas de los tumores malignos de colon según su localización. Material y métodos: estudio descriptivo, retrospectivo con 94 pacientes con diagnóstico de cáncer de colon. La estadística descriptiva se realizó con el cálculo de frecuencias y porcentajes, y se aplicaron pruebas de chi cuadrada. Resultados: la edad media fue 61.3 años, 49 (52.1%) fueron mujeres; 53 (56.4%) casos fueron izquierdos y 41 (43.6%) derechos. El síntoma principal fue hematoquecia en 32 (60.4%), en pacientes con cáncer izquierdo; y diarrea en 20 (48.8%), en pacientes con cáncer derecho. La presentación de tumores en estadio I y pólipos, p = 0.044 y p = 0.043, respectivamente, fue más frecuente en el lado derecho comparado con el lado izquierdo; en el izquierdo fueron más frecuentes la hematoquecia (p = 0.001), la disminución del grosor de las heces (p = 0.05) y el antecedente de diabetes mellitus 2 (p= 0.036) respecto al sitio contrario. Conclusiones: el estadio I y la presencia de pólipos fueron más frecuentes en el cáncer derecho comparado con el izquierdo; la diabetes mellitus 2, así como la hematoquecia y la disminución en el grosor de las heces se asociaron más al lado izquierdo en comparación con el derecho.