C-Reactive Protein/Albumin Ratio Is an Independent Risk Factor for Recurrence and Survival Following Curative Resection of Stage I-III Colorectal Cancer in Older Patients.

BACKGROUND: The number of older patients with cancer has increased, and colorectal cancer is expected to be affected by this trend. This study aimed to compare prognostic factors, including nutritional and inflammation-based indices, between patients aged ≥ 70 and < 70 years following curative resection of stage I-III colorectal cancer. PATIENTS AND METHODS: This study included 560 patients with stage I-III colorectal cancer who underwent curative resection between May 2010 and June 2018. A retrospective analysis was performed to identify prognosis-associated variables in patients aged ≥ 70 and < 70 years. RESULTS: Preoperative low body mass index, high C-reactive protein/albumin ratio, and comorbidities were mainly associated with poor prognosis in patients aged ≥ 70 years. Tumor factors were associated with a poor prognosis in patients aged < 70 years. The C-reactive protein/albumin ratio was independently associated with poor overall survival and recurrence-free survival in those aged ≥ 70 years. The time-dependent area under the curve for the C-reactive protein/albumin ratio was superior to those of other nutritional and inflammation-based indices in most postoperative observation periods in patients aged ≥ 70 years. CONCLUSIONS: Tumor factors were associated with a poor prognosis in patients aged < 70 years. In addition to lymph node metastasis, preoperative statuses were associated with poor prognosis in patients aged ≥ 70 years. Specifically, the preoperative C-reactive protein/albumin ratio was independently associated with long-term prognosis in patients aged ≥ 70 years with stage I-III colorectal cancer after curative resection.

Survival outcomes of patients with stage III colorectal cancer aged ≥ 80 years who underwent curative resection: the HiSCO-04 prospective cohort study.

BACKGROUND: The efficacy of adjuvant chemotherapy in elderly patients aged ≥ 80 years with stage III colorectal cancer remains unclear. In parallel with a multicenter prospective phase II trial evaluating the efficacy of uracil-tegafur and leucovorin as adjuvant chemotherapy (HiSCO-03), we conducted a prospective observational study of these patients to assess survival outcomes, including those ineligible for chemotherapy. METHODS: This multi-institutional prospective cohort study included 17 institutions in Hiroshima, Japan. Patients aged ≥ 80 years with stage III colorectal cancer who underwent curative resection were enrolled. The primary endpoint was 3-year disease-free survival, and the secondary endpoints were 3-year overall and relapse-free survival. Propensity score matching was used to assess the effects of adjuvant chemotherapy on survival outcomes. RESULTS: A total of 214 patients were analyzed between 2013 and 2018, including 99 males and 115 females with a median age of 84 years (range 80-101 years). Recurrence occurred in 58 patients and secondary cancers were observed in 17. The 3-year disease-free, overall, and relapse-free survival rates were 63.3%, 76.9%, and 62.9%, respectively. Adjuvant chemotherapy was administered to 65 patients with a completion rate of 52%. In a study of 80 patients that adjusted for background factors using propensity score matching, patients who completed the planned treatment showed improved disease-free survival (3-year disease-free survival: completed, 80.0%; not received, 65.5%; and discontinued, 56.3%; p = 0.029). CONCLUSIONS: Completion of adjuvant chemotherapy may improve the prognosis of patients with colorectal cancer aged ≥ 80 years, although the number of patients who would benefit from it is limited.

Long-Term Follow-up Data of a Multi-Institutional Phase-2 Study of S-1/oxaliplatin and Bevacizumab Therapy in Patients with Advanced Colorectal Cancer: The HiSCO-02 Study.

Oral fluoropyrimidines (FUs) have certain advantages over intravenous FUs, such as longer intervals between outpatient visits, no requirement for central venous port (CVP) implantation, and lower incidence of neutropenia. We previously reported the efficacy of S-1/oxaliplatin (SOX) with bevacizumab therapy as a first-line treatment for advanced colorectal cancer (CRC) in a prospective phase-II multi-institutional clinical trial (HiSCO-02 study). However, our prognostic data at the time lacked a sufficient observation period. Herein, we analyze the longer-term follow-up data, focusing on the status of eventual CVP implantation via an open-label, non-randomized, multicenter study. This study enrolled 55 patients (mean age, 64 years), of whom 43 died (41 of primary cancer). The median overall survival was 22.7 months (95% CI: 20.1-34.7 months). Post-treatment regimens after failure of first-line treatment were initiated in 43 patients; CPT11-based regimens were selected in most cases, and other oral FU combinations in nine. CVP was implanted in 35 patients prior to first-line treatment; eleven of the remaining 20 patients did not require CVP implantation. In conclusion, we report here the final prognostic update of the Phase II clinical trial examining the efficacy of SOX plus bevacizumab therapy, the results of which confirm the clinical efficacy of this regimen.

Protocadherin B9 Is Associated with Human Esophageal Squamous Cell Carcinoma Progression.

INTRODUCTION: Esophageal cancer is the sixth leading cause of cancer-related death worldwide. However, molecular targeted therapy and novel therapeutic targets are needed for esophageal squamous cell cancer (ESCC). In a previous study, we reported that protocadherin (PCDH) B9 plays an important role in several cancers. Therefore, in this study, we examined the clinical significance of PCDHB9 expression in ESCC. METHODS: PCDHB9 expression was examined using immunohistochemistry in 128 cases and using quantitative reverse transcription-polymerase chain reaction in 16 cases of ESCC. PCDHB9 function in ESCC cells was examined using RNA interference. RESULTS: High PCDHB9 expression was identified in 5 of 16 (31.3%). In total, 51 (40%) ESCC cases showed strong PCDHB9 expression, whereas nonneoplastic mucosa rarely showed its expression. High PCDHB9 expression was significantly associated with T classification, N grade, and stage in ESCC. In ESCC cell lines, PCDHB9 knockdown affected cell growth, migration, and adhesion. Further, the expression of integrin (ITG) A3, ITGA4, ITGA5, ITGB1, ITGB6, vimentin, snail family transcriptional repressor 1, and cadherin 2 (NCAD) was significantly reduced and cadherin 1 was significantly increased in PCDHB9 knockdown ESCC cells. CONCLUSION: These results suggest that PCDHB9 plays a tumor-promoting role and is a potential biomarker and therapeutic target in ESCC.

Essential Roles of TDO2 in Gastric Cancer: TDO2 Is Associated with Cancer Progression, Patient Survival, PD-L1 Expression, and Cancer Stem Cells.

INTRODUCTION: Tryptophan metabolism has been shown to be involved in tumor development. Two main tryptophan-degrading enzymes, tryptophan 2,3-dioxygenase (TDO2) and indoleamine 2,3-dioxygenase 1 (IDO1), may potently promote cancer cell survival and distant metastasis in diverse types of cancer, such as lung and breast cancer. IDO1 overexpression is an independent prognosticator in gastric cancer (GC). This work aimed to uncover the expression of TDO2 and its clinicopathologic significance in GC. METHODS: TDO2 expression was evaluated in public data of The Cancer Genome Atlas cohort STAD and in two different GC cohorts. Correlation between TDO2 and immune cell infiltrates as well as PD-L1 tumor staining was investigated. The biofunction of TDO2 was examined with MTT, colony formation, and spheroid formation assays by RNA interference. RESULTS: TDO2 expression was correlated with both progressive disease and clinical outcome, and its expression was an independent predictor of prognosis in GC. TDO2 expression was correlated with infiltration of immune cells and tumor expression of PD-L1. Inhibition of TDO2 expression suppressed cell proliferation, colony formation, and cell invasion of GC cells. Additionally, suppression of TDO2 expression inhibited spheroid body-formation and viability of GC organoids. CONCLUSION: Our data show that TDO2 might be a crucial marker for predicting prognosis and targeted therapy in GC.

Effect of abdominal aortic calcification on the prognosis and recurrence of colorectal cancer stages II-III: A retrospective cohort study.

PURPOSE: Abdominal aortic calcification (AAC) is a well-known risk marker for cardiovascular disease. However, its clinical effect on patients who underwent radical surgery for colorectal cancer (CRC) stages II-III is unclear. This study aimed to analyze the associations between AAC and prognosis of patients with stage II-III CRC. METHODS: To evaluate the effect of AAC on clinical outcomes, prognosis, and metastatic patterns of CRC, we analyzed 362 patients who underwent radical surgery for stage II-III CRC between 2010 and 2018. RESULTS: The high AAC group had significantly worse overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS) after propensity score matching to adjust for differences in baseline characteristics of patients and tumors. In the multivariate Cox regression analyses, a high AAC was an independent risk factor for poor OS (hazard ratio [HR], 2.38; 95% confidence interval [CI], 1.23-4.59; p = 0.01), poor CSS (HR, 5.22; 95% CI, 1.74-15.6; p < 0.01), and poor RFS (HR, 1.83; 95% CI, 1.19-2.83; p < 0.01). A high AAC was not associated with a risk of lung metastasis or local or peritoneal recurrence, but a risk for liver metastasis of CRC. CONCLUSION: A high AAC showed a strong relationship with poor OS, CSS, and RFS after curative resection for stage II-III CRC. A high AAC was also associated with a risk for liver metastasis, which may worsen the prognosis in stage II-III CRC. AAC could be a new clinical tool for predicting the prognosis for patients in stage II-III CRC.

Association between social background and implementation of postoperative adjuvant chemotherapy for older patients undergoing curative resection of colorectal cancers, sub-analysis of the HiSCO-04 study.

PURPOSE: Adjuvant chemotherapy is recommended following colorectal cancer resection based on risk of recurrence. In older patients, treatment decisions should consider recurrence rates and tolerability, as well as functional prognosis, residual disease, and social factors. This study aims to investigate factors, including social background, influencing implementation of postoperative adjuvant chemotherapy in older patients undergoing curative resection for colorectal cancer. METHODS: This multi-institutional prospective cohort study included 15 institutions belonging to the Hiroshima Surgical study group for Clinical Oncology. We analyzed 159 older patients aged ≥ 80 years, who underwent curative resection for stage III colorectal cancer between December 2013 and June 2018, as sub-analysis of the HiSCO-04 study. RESULTS: In total, 62 (39.0%) patients underwent postoperative adjuvant chemotherapy. Four factors were significantly associated with its implementation: performance status < 2, Charlson Comorbidity Index < 2, prognostic nutritional index ≥ 40, and presence of a spouse or siblings as lifestyle supporters. No significant difference was found in the backgrounds between complete and incomplete postoperative adjuvant chemotherapy patients. CONCLUSION: Performance status, Charlson Comorbidity Index, nutritional status, and presence of a spouse or siblings as lifestyle supporters are possible factors influencing the implementation of postoperative adjuvant chemotherapy in older patients. To select appropriate treatment options, including postoperative adjuvant chemotherapy, it is essential to consider physical condition and comorbidities of older patients, thoroughly explain the situation to their families, and establish a support system to enhance understanding of the available treatment options.

Protocadherin B9 Is Associated with Tumorigenesis and Cancer Progression in Colorectal Cancer.

BACKGROUND: Genes encoding transmembrane proteins expressed specifically in cancer cells may be ideal therapeutic targets or biomarkers for diagnosis. METHODS: In the present study, we investigated the expression and function of PCDHB9, which encodes transmembrane protein protocadherin B9 in colorectal cancer (CRC). RESULTS: Immunohistochemical analysis showed that 39 (26%) of 148 CRC cases were positive for protocadherin B9. Expression of protocadherin B9 correlated with lymphatic invasion, venous invasion, and T classification and was weakly detected in adenomas by immunohistochemistry. Although PCDHB9 knockdown did not change cell growth and invasion activity in CRC cell lines, cell adhesion to fibronectin was significantly reduced by PCDHB9 knockdown. Expressions of ITGA3, ITGA4, ITGA5, ITGB1, and ITGB6 were significantly reduced by PCDHB9 knockdown. In addition, the number of spheres was significantly decreased by PCDHB9 knockdown. CONCLUSION: These results suggest that protocadherin B9 might be associated with colorectal tumorigenesis and cancer progression in CRC.

Overexpression of aldolase, fructose-bisphosphate C and its association with spheroid formation in colorectal cancer.

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide. The spheroid colony formation assay is a useful method to identify cancer stem cells (CSCs). Using the DLD-1 and WiDr CRC cell lines, we performed microarray analyses of spheroid body-forming and parental cells and demonstrated that aldolase, fructose-bisphosphate C (ALDOC) was overexpressed in the spheroid body-forming cells of both lines. Cells transfected with small interfering RNA against ALDOC demonstrated lower proliferation, migration, and invasion compared with negative control cells. Both the number and size of spheres produced by the CRC cells were significantly reduced by ALDOC knockdown. Additionally, inhibition of ALDOC reduced lactate production. Immunohistochemistry was used to analyze ALDOC protein expression in tissues from 135 CRC patients and revealed that 66 (49%) cases were positive for ALDOC. The ALDOC-positive cases were associated with higher T and M grades and, as determined by Kaplan-Meier analysis, a poorer prognosis. Univariate and multivariate analyses indicated that ALDOC expression was an independent prognostic factor for CRC patients. Furthermore, ALDOC expression was associated with CD44 expression. These results suggest that ALDOC contributes to CRC progression and plays an important role in CSCs derived from CRC.

Prediction of anastomotic leakage after left-sided colorectal cancer surgery: a pilot study utilizing quantitative near-infrared spectroscopy.

BACKGROUND: Anastomotic leakage (AL) occurs with some frequency in all types of colorectal cancer surgery and is associated with increased morbidity, mortality and recurrence rates. Complications might be prevented by monitoring intra-operative bowel perfusion at the anastomotic site. A pilot study concerning the objective and quantitative measurement of tissue perfusion by monitoring regional tissue saturation of oxygen (rSO2) was conducted, using the In Vivo Optical Spectroscopy (INVOS™) system (Medtronic, Minneapolis, MN, USA). METHODS: This study evaluated the ability of the INVOS™ system to predict AL after left-sided colorectal cancer surgery. rSO2 measurements of the oral side of the site of bowel anastomosis were taken before anastomosis in 73 patients. Clinical factors, including rSO2, were analyzed to identify risk factors for AL. RESULTS: Among 73 patients, 6 (8.2%) experienced AL. The rSO2 values of the oral anastomotic site were significantly lower in AL patients than in non-AL patients. In the multivariate analysis, the rSO2 value of the oral anastomotic site was an independent risk factor for AL. CONCLUSION: Monitoring the rSO2 at the anastomotic site enabled the prediction of AL. A prospective study to evaluate the efficacy of the INVOS™ system for monitoring intestinal rSO2 is in progress.

Clinicopathologic features of TDO2 overexpression in renal cell carcinoma.

BACKGROUND: Tryptophan 2,3-dioxygenase (TDO2) is the primary enzyme catabolizing tryptophan. Several lines of evidence revealed that overexpression of TDO2 is involved in anoikis resistance, spheroid formation, proliferation, and invasion and correlates with poor prognosis in some cancers. The aim of this research was to uncover the expression and biofunction of TDO2 in renal cell carcinoma (RCC). METHODS: To show the expression of TDO2 in RCC, we performed qRT-PCR and immunohistochemistry in integration with TCGA data analysis. The interaction of TDO2 with PD-L1, CD44, PTEN, and TDO2 expression was evaluated. We explored proliferation, colony formation, and invasion in RCC cells line affected by knockdown of TDO2. RESULTS: RNA-Seq and immunohistochemical analysis showed that TDO2 expression was upregulated in RCC tissues and was associated with advanced disease and poor survival of RCC patients. Furthermore, TDO2 was co-expressed with PD-L1 and CD44. In silico analysis and in vitro knockout of PTEN in RCC cell lines revealed the ability of PTEN to regulate the expression of TDO2. Knockdown of TDO2 suppressed the proliferation and invasion of RCC cells. CONCLUSION: Our results suggest that TDO2 might have an important role in disease progression and could be a promising marker for targeted therapy in RCC. (199 words).

KIFC1 regulates ZWINT to promote tumor progression and spheroid formation in colorectal cancer.

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality worldwide. Kinesin Family Member C1 (KIFC1) has been proposed as a promising therapeutic target due to its pivotal role in centrosome clustering to mediate cancer cell progression. This study aimed to analyze the expression and biological function of KIFC1 in CRC. Immunohistochemically, 67 (52%) of 129 CRC cases were positive for KIFC1 and statistically associated with poorer overall survival. KIFC1 small interfering RNA (siRNA)-transfected cells demonstrated lower cell proliferation as compared to the negative control cells. A specific KIFC1 inhibitor, kolavenic acid analog (KAA) drastically inhibited CRC cell proliferation. Microarray analysis revealed that KAA-treated CRC cells presented reduced ZW10 interacting kinetochore protein (ZWINT) expression as compared to control cells. Immunohistochemical analysis demonstrated that 61 (47%) of 129 CRC cases were positive for ZWINT and ZWINT expression was significantly correlated with KIFC1 expression. ZWINT-positive cases exhibited significantly worse overall survival. KIFC1 siRNA-transfected cells showed reduced ZWINT expression while ZWINT siRNA-transfected cells decreased cell proliferation. Both KIFC1 and ZWINT knockdown cells attenuated spheroid formation ability. This study provides new insights into KIFC1 regulating ZWINT in CRC progression and its potential as a therapeutic target.

Tumor budding as a predictive marker for 5-fluorouracil response in adjuvant-treated stage III colorectal cancer.

BACKGROUND: Tumor budding (TB) has been described as an adverse prognostic marker for operable colorectal cancer (CRC); however, a limited number of studies have demonstrated the prognostic significance of TB in patients with drug therapy. This study was conducted to determine the predictive power of TB in stage III CRC patients who received adjuvant chemotherapy. METHODS: We retrospectively collected clinicopathological data including TB of 237 stage III colorectal cancer patients at Hiroshima University Hospital between July 1, 2006 and June 31, 2019. Differential disease-free survival (DFS) was investigated according to TB status. RESULTS: This study included 237 patients with a median age of 67 years, comprising patients who underwent surgery alone (n = 65), 5-fluorouracil (5-FU) monotherapy (n = 129), and oxaliplatin-based chemotherapy (n = 43). Overall, 81 patients developed disease recurrence, and 33 patients died of cancer-related causes. The TB status was categorized into two groups: 99 with low budding (< 5 buds) and 138 with high budding (≥ 5 buds). Overall, the low budding cases demonstrated significantly better DFS. In the 5-FU monotherapy group, low-risk patients (T1, T2, or T3 and N1) with low budding showed a remarkably higher 3-year DFS (91%) compared to high budding (55%). CONCLUSION: Our results indicate that TB could play a subsidiary role in selecting patients who could maintain a favorable prognosis with 5-FU monotherapy in stage III CRC.

A case of Turcot's syndrome type 1 with loss of immunoexpression of MSH6 in colon cancer and liver metastasis due to secondary somatic mutation in coding mononucleotide (C)8 tract: a case report.

BACKGROUND: Lynch syndrome (LS), which is known as a hereditary cancer syndrome, is distinguished by microsatellite instability, represented by the altered number of repetitive sequences in the coding and/or non-coding region. Immunohistochemical staining (IHC) of DNA mismatch repair (MMR) proteins (e.g., MLH1, MSH2, MSH6, and PMS2) has been recognized as an useful technique for screening of LS. Previous study has shown that the assessment of IHC, however, requires specific caution due to variable staining patterns even without germline mutations in MMR genes. CASE PRESENTATION: A 48-year-old man, who had been treated for anaplastic astrocytoma, was referred to our department for the precise examination of progressing anemia. Whole-body examination revealed two advanced carcinomas in descending colon and stomach. A hypo-vascular mass lesion was detected in liver as well. Pathological diagnosis (on surgical specimens) was poorly differentiated adenocarcinoma in descending colon, moderately differentiated tubular adenocarcinoma in stomach, and liver metastasis, which is possibly from colon. It was suspected that this case would be Turcot's syndrome-type-1 due to its specific family history having two cases of colon cancer within the second relatives. Pathogenic frameshift mutations in codon 618 of MLH1 gene was identified. Immunohistochemical analyses (IHC) demonstrated complete loss of MLH1 immuno-expression as well as of PMS2 except for those in brain tumor. Although frameshift mutation was not found in MSH6 gene, histological expression of MSH6 was patchy in primary colon carcinoma and was completely lost in the metastatic site in liver. MSH6 expression in gastric carcinoma, a coincidental cancer in this case, was intact. An abnormal (C)8 region was identified by the cloned PCR of colon and liver tumors but not from gastric cancer. Frameshift mutation in a (C)8 tract in exon 5 of the MSH6 gene was also detected in liver metastasis. CONCLUSION: This case supports a plausible mechanism, proposed by a previous literature, for the reduced expression of MSH6 in a somatic mutation manner, which might preferentially happen in colon cancer rather than in stomach carcinoma in MLH1/PMS2-deficient type of Turcot's syndrome type 1.

The prognostic value of organ/space surgical site infection in stage I colorectal cancer recurrence.

PURPOSE: Evidence on risk factors for postoperative recurrence in patients with colorectal cancer (CRC) confined to pathological stage I is limited. Therefore, this study aimed to identify the risk factors for recurrence in patients with stage I CRC. METHODS: Data on clinicopathological factors and blood tests of patients diagnosed with pathological stage I CRC at Hiroshima University Hospital between April 1, 2010, and December 31, 2018, were retrospectively obtained. The statistical significance between the clinical factors and postoperative recurrence was also investigated. RESULTS: A total of 244 patients were included. The median observation period was 45 months. There were 17 patients (6.6%) with a postoperative recurrence (8 local and 9 distant recurrences). In the log-lank test, rectal cancer (p = 0.004), pT2 (p = 0.020) and organ/space surgical site infection (SSI) (p = 0.008) were significantly associated with postoperative recurrence. In a multivariate analysis, rectal cancer (hazard ratio [HR] 3.678, 95% confidence interval [CI] 1.184-11.425, p = 0.024) and organ/space SSI (HR 3.137, 95% CI 1.013-9.713, p = 0.047) were independently associated with a higher recurrence rate. Among 18 patients with organ/space SSI, 4 recurrences occurred, all of which were distant metastases. CONCLUSION: Organ/space SSI significantly affects the postoperative recurrence in patients with stage I CRC.

Preoperative incremental maximum squeeze pressure as a predictor of fecal incontinence after very low anterior resection for low rectal cancer.

PURPOSE: Very low anterior resection (VLAR) is performed widely, but some patients are left with fecal incontinence (FI), which compromises their quality of life (QOL) severely. This study sought to identify the predictive factors of postoperative FI after VLAR, which remain unclear. METHODS: We evaluated the anorectal manometry data of patients who underwent VLAR to identify the risk factors for postoperative FI among the various clinicopathological factors and manometric characteristics. FI and QOL were analyzed using the Wexner score and EORTC QLQ-C30, respectively. RESULTS: The subjects of this study were 40 patients who underwent VLAR for low rectal cancer between April, 2015 and May, 2018. There were 11 (27%) patients in the major-FI group and 29 (73%) in the minor-FI group. Multivariate analysis revealed that low preoperative incremental maximum squeeze pressure (iMSP) was an independent risk factor for postoperative major-FI. Postoperative QOL tended to be worse in the major-FI group. CONCLUSIONS: Preoperative low iMSP increases the risk of major-FI and impaired QOL after VLAR. This highlights the importance of performing preoperative anorectal manometry to evaluate the patient's anal function as well as to select the most appropriate operative procedure and early multifaceted treatment such as medication, rehabilitation, and biofeedback for postoperative FI.

Is laparoscopic colorectal surgery with continuation of antiplatelet therapy safe without increasing bleeding complications?

PURPOSE: The number of patients on antiplatelet therapy (APT) who need surgery is increasing; however, it is unclear whether APT should be continued for abdominal surgery, particularly laparoscopic colorectal surgery. We investigated the safety of continuing APT for patients undergoing laparoscopic colorectal surgery. METHODS: We collected retrospective data from 529 patients who underwent laparoscopic colorectal surgery at Hiroshima University between January, 2013 and December, 2018. We analyzed information related to APT. Thirty-six pairs were matched by the propensity score method between patients on APT (APT+) and those not on APT (APT-). We compared the surgical outcomes of both groups. RESULTS: Among 463 patients eligible for the study, 48 were on APT for cerebrovascular or cardiovascular disease, and 36 continued to take aspirin. In the case-matched comparison, the amount of intraoperative blood loss in the APT+ group was not significantly higher than that in the APT- group, and the incidences of bleeding complications, thromboembolic complications, and other complications were not significantly different between the groups. CONCLUSION: In a case-matched comparison, continuation of aspirin during laparoscopic colorectal surgery did not increase perioperative complications. In laparoscopic colorectal surgery, continuation of aspirin is an acceptable strategy for patients with thromboembolic risk caused by interruption of APT.

[Two Cases of Colorectal Liver Metastasis with Localized Biliary Dilatation].

We encountered 2 cases of colorectal liver metastasis with biliarydilatation mimicking cholangiocarcinoma. Case 1: A 70- year-old male patient, who was diagnosed with colorectal cancer and underwent transverse colectomy3 years prior, was preoperativelydiagnosed with cholangiocarcinoma with biliarydilatation of the medial and lateral segments. He underwent left hemi-hepatectomy. The pathological diagnosis was colorectal liver metastasis with intra-biliarytumor thrombosis. Case 2: A 67-year-old male patient was diagnosed with descending colon cancer and cholangiocarcinoma with biliarydilatation of the medial segment. He underwent left hemi-colectomyand left hemi-hepatectomy. The pathological diagnosis was descending colon cancer and colorectal liver metastasis with biliaryinfiltration. The immunopathological findings showed double positivityfor CK20 and CDX2 antibodies and negativityfor CK7 antibodyin these cancer lesions.