Prognostic significance of p16, p21, and Ki67 expression at the invasive front of colorectal cancers.

Cancer cells at the invasive front are believed to be responsible for invasion/metastasis. This has led to examining various morphological features and protein expressions at the invasive front. However, accurate assessment of the pathological section requires long-time training, and inter-observer disagreement is problematic. Immunohistochemistry and digital imaging analysis may mitigate these problems; however, the choice of which proteins to stain and the best analysis method remains controversial. We used the "go-or-grow" hypothesis to select markers with the greatest prognostic relevance. Importantly, nonproliferating cells can migrate. We used Ki67 as a proliferation marker, with p16 and p21 designating nonproliferating cells. We established a semi-automated quantification workflow to study protein expression in serial pathological sections. A total of 51 patients with completely resected colorectal cancer (stages I-IV) were analyzed, and 44 patients were followed up. Patients with cancer cells with p16-high/p21-low or p21-low/Ki67-low at the deepest invasive front demonstrated a significantly worse prognosis than those who did not display these characteristics. These results suggest that the nonproliferating cancer cells at the invasion front possess invasion/metastatic property with heterogeneity of senescence.

Analysis of factors associated with operative difficulty in thoracoscopic esophageal cancer surgery in the left-decubitus position: a single-center retrospective study.

BACKGROUND: The degree of difficulty in the overall procedure and forceps handling encountered by surgeons is greatly influenced by the positional relationship of intrathoracic organs in minimally invasive esophagectomy. This study aimed to identify the anatomical factors associated with the difficulty of minimally invasive esophagectomy assessed by intraoperative injuries and postoperative outcomes. METHODS: Minimally invasive esophagectomy in the left-decubitus position was performed in 258 patients. We defined α (mm) as the anteroposterior distance between the front of the vertebral body and aorta, ß (mm) as the distance between the center of the vertebral body and center of the aorta, and γ (degree) as the angle formed at surgeon's right-hand port site by insertion of lines from the front of aorta and from the front of vertebrae in the computed tomography slice at the operator's right-hand forceps hole level. We retrospectively analyzed the correlations among clinico-anatomical factors, surgeon- or assistant-caused intraoperative organ injuries, and postoperative complications. RESULTS: Intraoperative injuries significantly correlated with shorter α (0.2 vs. 3.9), longer ß (33.0 vs. 30.5), smaller γ (3.0 vs. 4.3), R1 resection (18.5% vs. 8.3%), and the presence of intrathoracic adhesion (46% vs. 26%) compared with the non-injured group. Division of the median values into two groups showed that shorter α and smaller γ were significantly associated with organ injury. Longer ß was significantly associated with postoperative tachycardia onset, respiratory complications, and mediastinal recurrence. Furthermore, the occurrence of intraoperative injuries was significantly associated with the onset of postoperative pulmonary complications. CONCLUSIONS: Intrathoracic anatomical features greatly affected the procedural difficulty of minimally invasive esophagectomy, suggesting that preoperative computed tomography simulation and appropriate port settings may improve surgical outcomes.

[A case of acalculous gangrenous cholecystitis due to artery dissection].

A 62-year-old male presented with right intercostal muscle pain. Clinical examination revealed muscular defense in the same area. Abdominal ultrasonography revealed a distended gallbladder and ascites effusion, but no gallstones or polyps were present. Contrast-enhanced computerized tomography was performed, which revealed luminal obstruction due to arterial dissection of the celiac artery and intrinsic hepatic artery. This finding suggested gangrenous cholecystitis; thus, urgent cholecystectomy was performed. Only a few cases of celiac artery dissection and only one case of gangrenous cholecystitis without stones have been reported. We report here an extremely rare case of celiac artery dissection.

Dynamic switch of immunity and antitumor effects of metformin in rat spontaneous esophageal carcinogenesis.

Chronic inflammation contributes to tumor development by creating a local microenvironment that facilitates neoplastic transformation and potentiates the progression of cancer. Esophageal cancer (EC) is an inflammation-associated malignancy with a poor prognosis. The nature of the switch between chronic inflammation of the esophagus and EC-related immunological changes remains unclear. Here, we examined the dynamic alterations of immune cells at different stages of chronic esophagitis, Barrett's esophagus (BE) and EC using an esophageal spontaneous carcinogenesis rat model. We also investigated the anticancer effects of metformin. To stimulate EC carcinogenesis, chronic gastroduodenal reflux esophagitis via esophagojejunostomy was induced in 120 rats in metformin-treated and non-treated (control) groups. After 40 weeks, BE and EC developed in 96.7% and 63.3% of the control group, and in 66.7% and 23.3% of the metformin-treated group, respectively. Flow cytometric analysis demonstrated that the balance of M1/M2-polarized or phospho-Stat3-positive macrophages, regulatory T, cytotoxic T, natural killer (NK), NK T cells, and Th17 T cells was dynamically changed at each stage of the disease and were resolved by metformin treatment. These findings clarify the immunity in esophageal carcinogenesis and suggest that metformin could suppress this disease by improving the immunosuppressive tumor microenvironment and immune evasion.

nPTD classification: an updated classification of gastric cancer location for function preserving gastrectomy based on physiological lymphatic flow.

BACKGROUND: The correlation between tumor location and lymphatic flow distribution in gastric cancer has been previously reported, and PTD (Proximal - Transitional - Distal) classification was proposed. Our group updated and developed the nPTD classification. METHOD: We retrospectively studied gastric cancer patients who underwent the dye method sentinel node biopsy from 1993 to 2020. The inclusion criteria were a single lesion type 0 cancer of ≤5 cm in the long axis, clinically node-negative, and invasion within the proper muscle layer pathologically. In this study, the distribution of dyed lymphatic flow was evaluated for each occupied area of the tumor. RESULTS: We included 416 patients in this study. The tumors located in the watershed of the right and left gastroepiploic arteries near greater curvature had extensive lymphatic flow; therefore, a newly circular region with a diameter of 5 cm is set on the watershed of the greater curvature between P and T zone as the 'n' zone. In addition, for cancers located in the lesser P curvature, lymphatic flow to the greater curvature was not observed. Therefore, the P zone was divided into two: the lesser curvature side (PL) and the greater curvature side (PG). CONCLUSIONS: The advantage of the nPTD classification is that it provides not only proper nodal dissection but also adequate function-preserving gastrectomy. If the tumor is localized within the PL, the proximal gastrectomy resection area can be further reduced. In contrast, for cancers located in the 'n' zone, near-total gastrectomy is required because of the extensive lymphatic flow.

Analysis of perioperative glucose metabolism using an artificial pancreas.

Hyperglycemia associated with insulin resistance is common in surgical patients with and without diabetes and is associated with poor surgical outcomes. Several studies have recently shown that a closed-loop blood glucose monitoring system in the form of an artificial pancreas is safe and effective for surgical patients. In this study, we analyzed the risk factors for insulin resistance in patients using an artificial pancreas. We investigated 109 patients who underwent surgical management by an artificial pancreas for 24 hours from the start of surgery during either major hepatectomy (MH), defined as resection of more than two liver segments, or pancreaticoduodenectomy (PD). The target glucose range was from 80 to 110 mg/dL using an artificial pancreas. We analyzed the risk factors for and predictors of a high insulin dose, including sarcopenia markers, according to the median 24-hour total insulin infusion. The median total insulin dose and glycemic control rate (GCR), which is the rate of achieving the target blood glucose range, per 24 hours were 78.0 IU and 30.4% in the MH group and 82.6 IU and 23.5% in the PD group, respectively. The muscle volume was the only independent factor in the high-dose subgroup, and the GCR was significantly lower in the high-dose subgroup despite a high insulin dose in both the MH and PD groups. The results of this study suggest that preoperative sarcopenia is closely associated with insulin resistance in the perioperative period. Clinicians must effectively manage sarcopenia, which may result in improved perioperative glycemic control and reduced postoperative complications.

Relationship between fatty liver change and nutritional status after total gastrectomy in gastric cancer patients: a retrospective study.

BACKGROUND: The relationship between chronological nutritional changes and development of fatty liver after total gastrectomy (TG) in gastric cancer (GC) patients is still unclear. This study aimed to evaluate relationship between development of fatty liver and chronological changes of nutritional parameters during 12 months after TG. METHODS: We retrospectively analyzed medical records of 59 patients with GC who underwent TG at the Kanazawa Medical University Hospital between January 2009 and December 2017. We defined fatty liver change as a mean liver-to-spleen attenuation ratio (L/S ratio) of less than 1.2 in the computed tomography images at 12 months after TG and divided the patients into fatty liver (FL) and non-FL groups from the L/S ratio. We analyzed serum levels of total protein and albumin, and psoas muscle index (PMI) before TG and at 6 and 12 months after TG in the non-FL and FL groups. RESULTS: Six patients showed an L/S ratio of less than 1.2 at 12 months after TG and were included into FL group. There was no significant difference between the groups in serum parameters, L/S ratio, and PMI before TG. In the FL group, the mean levels of total protein and albumin decreased after TG and were significant lower at 6 months, compared with the non-FL group. And then, these levels in the FL group recovered at 12 months. In contrast, the mean levels of total protein and albumin in the non-FL group did not decrease below the preoperative levels throughout the year after surgery. As with laboratory parameters, all patients in the FL group showed decrease of PMI at 6 months after TG. This proportion was significantly higher than that in the non-FL group (100% vs. 40.8%, P = 0.006). CONCLUSIONS: We evaluated that the patients with fatty liver occurring after TG had significantly lower levels of serum nutritional parameters and skeletal muscle index at 6 months, not but 12 months, after TG.

[Significance of Preoperative Chemoradiotherapy for Resectable Pancreatic Cancer].

We investigated the effect of chemoradiotherapy(CRT)on pancreatic cancer and the significance of preoperative chemoradiotherapy( NACRT)on resectable pancreatic cancer. The subjects were 36 patients who underwent CRT for locally advanced pancreatic cancer experienced in our department in the past 12 years(. 1)Regarding the antitumor effect of CRT, tumor diameter, tumor marker, and FDG for PET examination were reduced in 72%, 81%, and 96% of cases, respectively. In addition, the effect of Grade 1b plus 2 was observed in 10 of 16 patients who were resected after CRT(response rate 63%). In these successful cases, irradiation of 40 Gy or more and oral administration of S-1 1,500 mg or more were performed during this period. In addition, the survival rate of the NACRT plus S group(16 cases)was the same as that of the SF group (20 cases)of cStage ⅡA or lower at the same time, 50% survival was longer, and local recurrence was less. Based on the above, preoperative chemoradiotherapy combined with S-1 for resectable pancreatic cancer may be a promising preoperative treatment in the future.

[Role of Surgical Resection after Chemoradiotherapy in Locally Advanced Pancreatic Cancer].

We investigated 34 cases of preoperative chemoradiotherapy(CRT)for locally advanced pancreatic cancer including resectable pancreatic cancer in our department during the past 11 years. For resectable(R)or borderline resectable(BR)pancreatic cancer, survival curves were generally higher in the CRT plus S-1 group treated after CRT than in the CRT group treated with post-CRT chemotherapy, but there was no statistically significant difference. In non-resected cases, local exacerbation was observed, which was one of the causes of a decline in terminal QOL. From the above, at present, it is desirable to remove R or BR pancreatic cancer after CRT, but the significance of surgery may change in the future due to the improvement of multidisciplinary treatment.

The neutrophil/lymphocyte ratio as a predictor of successful conversion surgery for stage IV gastric cancer: a retrospective study.

BACKGROUND: Conversion surgery (CS) following a response to chemotherapy occasionally leads to prolonged survival in patients with stage IV gastric cancer (GC). This study aimed to evaluate the predictive value of the neutrophil/lymphocyte ratio (NLR) for the success of CS in patients with stage IV GC. METHODS: We retrospectively analyzed data of 50 patients with stage IV GC who received systemic chemotherapy between January 2009 and December 2017 at the Kanazawa Medical University Hospital. The successful CS group included the patients who underwent R0 or R1 resection with CS, and the failed CS group included the patients who did not undergo CS after chemotherapy or those who, despite undergoing CS, had to additionally undergo R2 resection. Clinicopathological characteristics were examined in both groups. Univariate and multivariate analyses were performed to identify pretherapeutic parameters that were independently associated with the achievement of successful CS. RESULTS: The number of patients in the successful and failed CS groups were 12 and 38, respectively. On univariate analysis, gender (P = 0.01), NLR (P = 0.003), albumin levels (P = 0.004), and absence of peritoneal metastasis (P = 0.004) were found to be significantly correlated with a successful CS. On multivariate analysis, NLR < 4 and absence of peritoneal metastasis were independently correlated with a successful CS (P = 0.02 and P = 0.002, respectively). In patients without peritoneal metastasis, successful CS rates in patients with NLR < 4 were significantly higher than those in patients with NLR ≥ 4 (61.1% vs. 10.0%, P = 0.005). CONCLUSIONS: The NLR was a significant independent predictor of the achievement of successful CS in stage IV GC patients, especially among the patients without peritoneal metastasis. Patients with a low NLR could have higher possibility of achieving successful CS.

[A Case of Effective Disease Control of Advanced Gastric Cancer with Distant Lymph Node Metastases Following Nivolumab Treatment].

A 66-year-old man was diagnosed with advanced gastric cancer(L, Less, Type 2, T4a[SE], N2, M1[LYM], H0, P0, cStage Ⅳ)and received treatment with S-1/cisplatin as first-line chemotherapy. This treatment resulted in partial response(PR) after 3 months, with reduction in the sizes of metastatic lymph nodes surrounding the pancreatic head and paraaortic lesion. However, the sizes of metastatic lymph nodes increased after 7 months of chemotherapy. Ramucirumab/nab-paclitaxel was then administered as second-line chemotherapy, and the diameter of the metastatic lymph nodes subsequently decreased after 4 months of the regimen. However, progressive disease was observed at 7 months, and blood transfusion was required because of bleeding from the primary gastric tumor. Therefore, nivolumab was initiated as third-line chemotherapy 14 months after the first treatment. After nivolumab administration, a 28% reduction in metastatic lymph nodes was achieved within 3 months, together with the regression of the primary gastric tumor and improvement in anemia within 6 months. PR was achieved after 12 months of nivolumab administration, and effective disease control was maintained for 16 months without any adverse reaction to nivolumab.

The Embryonic Stem Cell-Specific Transcription Factor ZFP57 Promotes Liver Metastasis of Colorectal Cancer.

BACKGROUND: The embryonic stem cell-specific transcription factor, ZFP57, has been shown to play an important role in tumor formation. In this study, we examined if ZFP57 is involved in colorectal cancer metastasis. MATERIALS AND METHODS: First, we used colorectal cancer cell lines to perform in vivo metastatic experiments with nude mice. Next, we carried out immunohistochemical analysis of clinical specimens of colorectal cancers. RESULTS: In liver metastatic experiments using human colorectal cancer HT29 and HCT116 cells, liver polymetastases occurred at high frequency in ZFP57-overexpressing HT29 and HCT116 cells, whereas both control cells only resulted in oligometastases. Next, we analyzed ZFP57 expression using clinical specimens. Liver metastasis-positive cases were more frequently associated with ZFP57 overexpression than negative cases in primary lesions of colorectal cancer, and the overexpression was particularly remarkable in tumor invasive lesions. Furthermore, ZFP57 overexpression was significantly correlated not only with liver metastasis but also with lymph node metastasis. In addition, the expression level of ZFP57 was significantly correlated with that of the metastasis-related gene NANOG. We also found that ZFP57 overexpression reduced the progression-free survival rate of patients with colorectal cancer. CONCLUSIONS: This study demonstrated that ZFP57 plays an important role in the hematogenous metastasis of colorectal cancer, suggesting that it could be used as a novel treatment target.

[A Case of Stage â £Rectal Cancer with Dyskeratosis Congenita].

A 27-year-old man was diagnosed with dyskeratosis congenita from DKC1 gene mutation at 9 years of age and had been followed-up regularly.An upper gastrointestinal endoscopy performed for vomiting revealed gastric varices.Further examination resulted in a diagnosis of Stage Ⅳrectal cancer with portal hypertension, splenomegaly, liver, and lung metastasis and he was referred to our department.A laparoscopic splenectomy was performed, followed by a laparoscopic low anterior resection for rectal cancer.Subsequently, resection of the pulmonary and liver metastasis was performed, resulting in macroscopic radical resection.However, 3 months after the hepatectomy, unresectable multiple lung metastasis was detected and he received 5 courses of chemotherapy with cetuximab.A grade 3 skin rash was observed and chemotherapy was discontinued. After 5 courses, he had pneumothorax and received drainage.He had sudden respiratory failure 2 days after pleural adhesion therapy of OK-432 was performed.He was diagnosed with interstitial pneumonia induced by OK-432 and steroid pulse therapy, which resulted in his death without improvement 21 days after admission.

[A Case of Thrombotic Microangiopathy Arising from Breast Cancer Treated with Chemotherapy].

The present study reports the case of a 49-year-old woman who was diagnosed with cancer of the left breast at the age of 43 years.Following chemotherapy, the patient had undergone partial mastectomy and axillary lymphadenectomy.Postoperatively, she underwent radiotherapy and hormone therapy.Five years and 4 months after the operation, the patient developed pain in the cervical vertebrae and was diagnosed with spinal metastasis.During the period, she began experiencing fatigue and hematological investigations indicated anemia, as well as thrombocytopenia, jaundice, and schistocytes.The patient was referred to our facility for further examination and treatment.On investigation, she was diagnosed with cancer-related thrombotic microangiopathy(TMA).The patient was advised to undergo chemotherapy due to which symptoms of TMA were relieved.She continued to receive chemotherapy for the following 3 years and 2 months until her death.

[A Case of Histiocytoid Breast Carcinoma Accompanied by Multiple Axillary Lymph Node Metastases].

According to previous reports in our country, histiocytoid breast carcinoma is a very rare case of its tissue type, accounting for only 0.3% of all breast cancer cases. We have neither established a diagnostic standard nor a general idea for these tumors. Previously, its inherited pathology was assumed to be a sub-form of invasive lobular carcinoma. However, some researchers indicate the presence of components that are assumed to originate from milk ducts or differentiation in the apocrine gland. In this way, origins of pathologies for these tumors seem to be complex. Previous reports suggest cases of relatively long survival times without spreading to distant sites. Recently, we encountered one case of histiocytoid breast carcinoma accompanied by multiple axillary lymph node metastases.

Survival benefit of multimodal local therapy for repeat recurrence of thoracic esophageal squamous cell carcinoma after esophagectomy.

BACKGROUND: This study was performed to clarify the optimal therapeutic strategy for recurrent disease after esophagectomy. METHODS: We investigated the prognosis of 37 patients who developed recurrence among 128 patients who underwent curative thoracoscopic esophagectomy (TE) at Kanazawa University Hospital. The prognostic factors after recurrence were examined by univariate and multivariate analyses. RESULTS: Of these 37 recurrences, 29 patients underwent local therapy (surgery, 10 patients; surgery followed by radiation, 2 patients; radiation, 17 patients). Radiation includes intensity-modulated radiation therapy, chemoradiation, and simple radiation therapy. Seventeen patients (58.6%) were considered to have undergone successful therapy by disappearance or diminishment of the targeted region without regrowth. Eleven of 17 patients (64.7%) showed repeat recurrence at another site. Multiple local therapy was performed for repeat recurrence or uncontrollable first therapy. Finally, 57 local therapies were performed. Using multimodal local therapy, 37 (64.9%) of 57 recurrences were successfully managed. The 12 patients treated by surgery as the initial therapy showed the most favorable survival. Seventeen patients who underwent successful initial therapy showed better survival than others. Multiple or miscellaneous organ metastasis, abdominal lymphatic recurrence and best supportive care at recurrence were statistically significant negative variables for survival after recurrence. Performance of surgery and successful therapy as the initial recurrence were statistically significant positive variables for survival after recurrence. Multivariate analysis showed that successful therapy at the initial recurrence was the only independent variable for survival after recurrence. CONCLUSIONS: Multimodal local therapy for repeat recurrence after TE contributes to the improvement of survival after recurrence.

Oral cryotherapy for prophylaxis of oral mucositis caused by docetaxel, cisplatin, and fluorouracil chemotherapy for esophageal cancer.

BACKGROUND: Chemotherapy, including preoperative chemotherapy, plays an important role in the treatment of esophageal cancer. However, although docetaxel, cisplatin, and fluorouracil (DCF) therapy has a powerful antitumor effect, the associated adverse events make it difficult to maintain the patient's general condition. Oral mucositis is an important adverse effect of chemotherapy, and its severity, frequency, and impact on patient quality of life should not be underestimated. This study evaluated the role of oral cryotherapy for prophylaxis of oral mucositis caused by DCF therapy. METHODS: We retrospectively examined the incidence and severity of adverse events, including mucositis, in 72 patients with esophageal cancer treated with DCF. Fifty-eight patients received cryotherapy during docetaxel administration and 14 received no cryotherapy. RESULTS: The incidence of mucositis of all grades and grade 3 was significantly lower in the cryotherapy group compared with the no-cryotherapy group (24.1% vs. 71.4%, P < 0.001 and 0% vs. 28.6%, P = 0.001, respectively). The incidence of anorexia of all grades and grade 3 was also significantly lower in the cryotherapy group (22.4% vs. 57.1%, P = 0.037 and 0% vs. 28.6%, P = 0.010, respectively). CONCLUSION: Adjunctive oral cryotherapy is effective for the prophylaxis and relief of oral mucositis and anorexia caused by chemotherapy.

Use of esophageal stent for the treatment of postoperative gastrointestinal-airway fistula after esophagectomy.

A gastrointestinal-airway fistula (GAF) after esophagectomy is a very serious postoperative complication that can cause severe respiratory complications due to digestive juice inflow. Generally, GAF is managed by invasive surgical treatment; less-invasive treatment has yet to be established. We performed esophageal stent placement (ESP) in three cases of GAF after esophagectomy. We assessed the usefulness of ESP through our clinical experience. All GAFs were successfully managed by ESP procedures. After the procedure, the stent positioning and expansion were appropriately evaluated by radiological assessments over time. The stent was removed after endoscopic confirmation of fistula closure on days 8, 23, and 71. Only one patient with a long-term indwelling stent developed a manageable secondary gastrobronchial fistula as a procedure-related complication. In conclusion, ESP was shown to be a less-invasive and effective therapeutic modality for the treatment of GAF.

Gadoxetic acid-enhanced magnetic resonance imaging reflects co-activation of ß-catenin and hepatocyte nuclear factor 4α in hepatocellular carcinoma.

AIM: The aim of this study is to clarify the correlation of the co-activation of ß-catenin and hepatocyte nuclear factor (HNF)4α with the findings of gadoxetic acid-enhanced magnetic resonance imaging (MRI), organic anion transporting polypeptide (OATP)1B3 expression, and histological findings in hepatocellular carcinoma (HCC). METHODS: One hundred and ninety-six HCCs surgically resected from 174 patients were enrolled in this study. The HCCs were classified into four groups by immunohistochemical expression of ß-catenin, glutamine synthetase (GS), and HNF4α: (i) ß-catenin/GS (positive [+]) HNF4α (+); (ii) ß-catenin/GS (+) HNF4α (negative [-]); (iii) ß-catenin/GS (-) HNF4α (+); and (iv) ß-catenin/GS (-) HNF4α (-). We compared the four groups in terms of the enhancement ratio on the hepatobiliary phase of gadoxetic acid-enhanced MRI, immunohistochemical organic anion transporter polypeptide (OATP)1B3 (a main uptake transporter of gadoxetic acid) expression and histological features, overall survival, and no recurrence survival. The Kruskal-Wallis test, Steel-Dwass multiple comparisons test, Fisher's exact test, and log-rank (Mantel-Cox) test were used for statistical analyses. RESULTS: Enhancement ratio on gadoxetic acid-enhanced MRI in HCC with ß-catenin/GS (+) HNF4α (+) was significantly higher than those of the other three groups (P < 0.001). The OATP1B3 grade was also significantly higher in HCC with ß-catenin/GS (+) HNF4α (+) (P < 0.001). Hepatocellular carcinoma with ß-catenin/GS (+) HNF4α (+) showed the highest differentiation grade as compared to the other groups (P < 0.004). There were no significant differences in portal vein invasion, macroscopic growth pattern, or prognosis analyses between the four groups. CONCLUSION: Co-activation of ß-catenin and HNF4α would promote OATP1B3 expression, and consequently higher enhancement ratio on gadoxetic acid-enhanced MRI and higher differentiation grade in HCC.

Phosphodiesterase III inhibitor attenuates rat sinusoidal obstruction syndrome through inhibition of platelet aggregation in Disse's space.

BACKGROUND AND AIM: Sinusoidal obstruction syndrome (SOS) is a serious drug-induced liver injury. However, the pathophysiology of the disease remains unclear. This study investigated the effects of cilostazol (CZ), a phosphodiesterase III inhibitor, in a monocrotaline (MCT)-induced rat model of SOS. METHODS: Male Wistar rats were administrated MCT to induce SOS. Rats were divided into control, MCT, and MCT + CZ groups. In the MCT + CZ group, CZ was administered at 48 h, 24 h, and 30 min prior to and 8 h and 24 h after MCT administration. The MCT group was treated with water instead of CZ. At 48 h after MCT administration, blood and liver samples were collected to assess biochemistry and liver histology. Expression of rat endothelial cell antigen, CD34, CD41, P-selectin, and caspase-3 in the liver were analyzed. Plasminogen activator inhibitor-1 (PAI-1) in hepatocytes was analyzed using western blotting and polymerase chain reaction. RESULTS: In the MCT group, macroscopic findings showed a dark-red liver surface. Histological findings showed sinusoidal dilatation, coagulative necrosis of hepatocytes, and endothelial damage of the central vein. These changes were attenuated in the MCT + CZ group. Elevated serum transaminase and decreased platelet counts were observed in the MCT + CZ group compared with those in the MCT group. Treatment with CZ reduced MCT-induced damage to the liver sinusoidal endothelial cells, inhibited extravasated platelet aggregation, and suppressed hepatocyte apoptosis around the central vein. CZ attenuated hepatic PAI-1 protein and mRNA levels. CONCLUSIONS: Cilostazol attenuated MCT-induced SOS by preventing damage to liver sinusoidal endothelial cells and extravasated platelet aggregation. Hepatic PAI-1 levels were suppressed with CZ treatment.