Analysis of the clinicopathological features of tailgut cyst with emphasis on the development of neoplastic lesions.

Tailgut cyst is a rare congenital cyst occurring in the retrorectal space and development of neoplastic lesions in tailgut cyst has been reported. Due to the rarity of the tumor, the histogenesis of neoplastic lesions in tailgut cyst has remained elusive. In the present study, the clinicopathological features of tailgut cyst were analyzed with a particular focus on the development of neoplastic lesions. The clinicopathological features of four patients with tailgut cyst (one female and three males) were retrospectively reviewed. No symptoms were present in two patients. Perineal discomfort, and constipation and urinary retention, were described in the other two patients, respectively. Magnetic resonance imaging showed that the cystic lesions were hypointense on T1- and hyperintense on T2-weigted images in all patients. Histopathological analysis revealed that all lesions were multilocular, and cystic walls were covered by squamous and ciliated epithelia without nuclear atypia. The development of neoplastic lesions was noted in two patients. Dysplastic change composed of piling-up proliferation of glandular cells with mild to moderate nuclear atypia was present in one patient, and invasive adenocarcinoma with a dysplasia component was observed in another patient. Dysplasia of the glandular cells, as seen in two patients in the present series, may be a precursor lesion of invasive adenocarcinoma; therefore, adenocarcinoma arsing in tailgut cyst may show a dysplasia-carcinoma sequence. While the reported incidence of neoplastic lesions in tailgut cysts is ~9% or less, their frequency remains to be accurately determined. Therefore, complete surgical resection is important for the management of patients with tailgut cyst. Additional clinicopathological and molecular studies with large cohorts may be required to clarify the histogenesis of neoplastic lesion in tailgut cyst.

Laparoscopic polyglycolic acid spacer placement for locally recurrent rectal cancer.

Carbon ion radiotherapy (CIRT) has received attention for the treatment of locally recurrent rectal cancer. When the surrounding primary organs are close to the irradiation site, a spacer is required to ensure safe irradiation. This work describes a novel technique using a bioabsorbable polyglycolic acid spacer placed laparoscopically and presents a technical report with five case studies. The short-term surgical outcomes were as follows: mean operating time 235 min with blood loss of 38 mL. CIRT was planned, and the patients underwent irradiation within 2 months of surgery. No pelvic infections occurred, and all procedures were performed safely. Herein, were present a technical report with reference to a video of the surgical procedure.

Retrospective study of an incisional hernia after laparoscopic colectomy for colorectal cancer.

PURPOSE: This study aimed to examine the incidence of incisional hernia (IH) in elective laparoscopic colorectal surgery (LC) using regulated computed tomography (CT) images at intervals every 6 months. METHODS: We retrospectively examined the diagnosis of IH in patients who underwent LC for colorectal cancer at Kansai Medical University Hospital from January 2014 to August 2018. The diagnosis of IH was defined as loss of continuity of the fascia in the axial CT images. RESULTS: 470 patients were included in the analysis. IH was diagnosed in 47 cases at 1 year after LC. The IH size was 7.8 cm2 [1.3-55.6]. In total, 38 patients with IH underwent CT examination 6 months after LC, and 37 were already diagnosed with IH. The IH size was 4.1 cm2 [0-58.9]. The IH size increased in 17 cases between 6 months and 1 year postoperatively, and in 1 case, a new IH occurred. 47%(18/38) of them continued to grow until 1 year after LC. A multivariate analysis was performed on the risk of IH occurrence. SSI was most significantly associated with IH occurrence (OR:5.28 [2.14-13.05], p = 0.0003). CONCLUSION: IH occurred in 10% and 7.9% at 1 year and 6 months after LC. By examining CT images taken for the postoperative surveillance of colorectal cancer, we were able to investigate the occurrence of IH in detail.

Case report: administration of immune checkpoint inhibitor for SMARCB1 (INI1)-negative rhabdoid carcinoma with microsatellite instability (MSI)-high in the right colon.

BACKGROUND: Malignant tumors with rhabdoid features are rare, highly aggressive, and some of them are characterized by SMARCB1 (INI1) loss. Although cases of rhabdoid carcinoma are extremely rare, its occurrence in the colon has been reported previously. CASE PRESENTATION: A 71-year-old Japanese female patient presented with loss of appetite, fatigue, and weight loss. Computed tomography demonstrated a tumor in the right colon that infiltrated the surrounding kidneys and swelling of the left supraclavicular and periaortic lymph nodes. Laparotomy revealed that the tumor was unresectable because it had directly invaded the head of the pancreas and duodenum. Therefore, ileocecal vascularized bulky lymph nodes were sampled, and gastrojejunostomy with Braun's anastomosis and ileotransversostomy were performed as palliative procedures. Histopathological examination of the lymph nodes revealed that the neoplastic cells had rich eosinophilic cytoplasm and eccentrically located large nuclei characteristic of rhabdoid carcinoma. In addition, these neoplastic cells lacked SMARCB1 expression; therefore, the patient was diagnosed with SMARCB1-negative rhabdoid carcinoma. The postoperative course was uneventful. Molecular analysis confirmed that the neoplastic cells had high microsatellite instability (MSI); therefore, two cycles of pembrolizumab were administered. However, no clinical benefit was noted, and the patient died 3 months postoperatively. CONCLUSION: This is the first report of a case of SMARCB1-negative rhabdoid colon carcinoma with high MSI treated with pembrolizumab. Rhabdoid carcinoma is highly aggressive; therefore, additional studies are required to determine the therapeutic strategy for SMARCB1-negative rhabdoid colorectal carcinoma.

Significance of desmoplastic reactions on tumor deposits in patients with colorectal cancer.

It has been well recognized that the tumor microenvironment serves important roles in the progression and invasion of cancer. The desmoplastic reaction (DR) is a fibrous tissue reaction around tumor cells, and the prognostic significance of DR in colorectal cancer (CRC) has been established. Tumor deposits (TD) are also an important prognostic indicator of CRC. Notably, immature type DR has been linked to poor prognosis. In addition, immature type DR is significantly associated with a higher pT stage, presence of lymphovascular invasion and lymph node metastasis; however, to the best of our knowledge, the association between DR and TD has not yet been examined. The present study aimed to clarify this association. This study included 443 consecutive patients with pT3 or pT4 CRC who underwent surgical resection. The histopathological features, including DR and TD, were evaluated. Statistical analyses of the presence of TD, DR and other clinicopathological parameters were performed. The present cohort included 205 female and 238 male patients; 293 (66.1%) and 150 (33.9%) patients were classified as pT3 and pT4, respectively. Immature, intermediate and mature DR were noted in 282 (63.7%), 91 (20.5%) and 70 patients (15.8%), respectively. TD was observed in 93 (21.0%) patients. Immature type DR was significantly associated with a higher pT stage (P<0.0001), presence of lymph node metastasis (P<0.0001), lymphatic (P=0.0007), venous (P<0.0001) and perineural invasion (P<0.0001), and higher tumor budding (TB) (P<0.0001). Moreover, immature type DR was significantly associated with the presence of TD (P<0.0001). The present study demonstrated a significant association between immature type DR and the presence of TD, and suggested a close relationship between lymphovascular invasion, DR, TB and TD. Additional studies are required to analyze the detailed mechanism underlying the development of immature DR in CRC to define novel treatment strategies.

Two cases of 18F-FDG-PET/CT positive Schloffer tumor following curative surgery of colon cancer.

We report two cases of Schloffer tumor that required resection after radical colon cancer surgery because of suspected lymph node recurrence on contrast-enhanced (CE) CT and 18F-FDG-PET/CT. Case1 is a 69-year-old man with sigmoid colon cancer pStage IIA, and case2 is a 61-year-old man with descending colon cancer pStage IIIB.

Levosimendan Increases Survival in a D-Galactosamine and Lipopolysaccharide Rat Model.

Levosimendan, a calcium sensitizer, has an organ protective profile through the inhibition of inflammatory mediators and cytokines in critical conditions, such as heart failure, ischemia-reperfusion injury, and sepsis. The survival effect of levosimendan for acute liver failure has not been examined yet. Male Sprague-Dawley rats were examined in the D-galactosamine hydrochloride and lipopolysaccharide (GalN/LPS) model. Levosimendan was injected intraperitoneally before GalN/LPS treatment. Survival was monitored for 7 days. For biochemical analyses, liver and blood samples were collected from the rats at 1 and 8 h after GaIN/LPS treatment. The pretreatment of levosimendan at 4 mg/kg significantly increased survival in GalN/LPS rats. In the liver specimen, levosimendan significantly inhibited the activation of nuclear factor-κB (NF-κB) at 1 h, and significantly decreased the mRNA expression of inflammatory mediators, including inducible nitric oxide synthase and tumor necrosis factor-α (TNF-α), at 8 h. In serum, levosimendan decreased the levels of nitrite, a metabolite of nitric oxide, and TNF-α protein, as well as aspartate aminotransferase and alanine aminotransferase. These results indicated that Levosimendan ameliorated liver dysfunction and survival in acute liver failure model rats through the suppression of NF-κB activation.

Efficacy of a third-generation oncolytic herpes simplex virus in refractory soft tissue sarcoma xenograft models.

Malignant soft tissue tumors, particularly highly malignant leiomyosarcomas, are resistant to chemotherapy and associated with a poor prognosis. T-01, a third-generation genetically modified herpes simplex virus type 1, replicates in tumor cells alone and exerts a cell-killing effect. The current study aimed to investigate the antitumor effect of T-01, which is a novel treatment for leiomyosarcoma. In vitro, six human cell lines and one mouse sarcoma cell line were assessed for T-01 cytotoxicity. In vivo, the efficacy of T-01 was examined in subcutaneously transplanted leiomyosarcoma (SK-LMS-1) cells and subcutaneously or intraperitoneally transplanted mouse sarcoma (CCRF S-180II) cells. Cytokines were assessed using ELISpot assay with splenocytes from the allogeneic models for immunological evaluation. T-01 showed cytotoxicity in all seven cell lines (p < 0.001). In the SK-LMS-1 xenotransplantation model, tumor growth was suppressed by T-01 administration (p = 0.02). In the CCRF S-180II subcutaneous tumor model, bilateral tumor growth was significantly suppressed in the T-01-treated group compared with the control group (p < 0.001). In the peritoneal dissemination model, T-01 treatment caused significant survival prolongation compared with the control (p < 0.01). In conclusion, third-generation genetically modified herpes simplex virus type 1 may be an effective novel therapy against refractory sarcomas.

Efficacy of Nanofiber Sheets Incorporating Lenvatinib in a Hepatocellular Carcinoma Xenograft Model.

Lenvatinib has a high response rate in unresectable advanced hepatocellular carcinoma (HCC). In this study, we investigated whether lenvatinib-incorporating poly(ε-caprolactone) sheets (lenvatinib sheets) as a drug delivery system (DDS) exerted antitumor effects in a murine HCC model. The lenvatinib sheets were designed for sustained release of approximately 1 mg lenvatinib for 14 days. For 14 days, 1 mg lenvatinib was orally administered to mice. Then, we compared the antitumor effects of lenvatinib sheets with those of oral lenvatinib. The tumor volume, body weight, and serum lenvatinib level were measured for 14 days. A peritoneal dissemination model was established to examine the survival prolongation effect of the lenvatinib sheets. Tumor growth was significantly inhibited in the lenvatinib sheet group compared with that in the no treatment and oral groups. The antitumor effect was significantly higher in the lenvatinib sheet group. Regardless of the insertion site, the serum lenvatinib levels were maintained and showed similar antitumor effects. The mitotic index was significantly inhibited in the lenvatinib sheet group compared with that in the control group. Furthermore, lenvatinib sheets improved the 30-day survival. Lenvatinib sheets showed sufficient antitumor effects and may serve as an effective novel DDS for advanced HCC.

Omeprazole Increases Survival Through the Inhibition of Inflammatory Mediaters in Two Rat Sepsis Models.

BACKGROUND: Omeprazole (OMZ) is a proton pump inhibitor that is used to reduce gastric acid secretion, but little is known about its possible liver protective effects. This study investigated whether OMZ has beneficial effects in rat septic models of LPS-induced liver injury after D-galactosamine (GalN) treatment and 70% hepatectomy (PH), and to determine the mechanisms of OMZ in an in vitro model of liver injury. METHODS: In the in vivo models, the effects of OMZ were examined 1 h before treatments in both models on survival, nuclear factor (NF)-κB activation, histopathological analysis, and proinflammatory mediator expression in the liver and serum. In the in vitro model, primary cultured rat hepatocytes were treated with IL-1ß in the presence or absence of OMZ. The influence of OMZ on nitric oxide (NO) product and inducible NO synthase (iNOS) induction and on the associated signaling pathway was analyzed. RESULTS: OMZ increased survival and decreased tumor necrosis factor-alpha, iNOS, cytokine-induced neutrophil chemoattractant 1, IL-6, and IL-1ß mRNA expression, and increased IL-10 mRNA expression in the livers of both GaIN/LPS- and PH/LPS-treated rats. Necrosis and apoptosis were inhibited by OMZ in GaIN/LPS rats, but OMZ had no effects on necrosis in PH/LPS rats. OMZ inhibited iNOS induction partially through suppression of NF-κB signaling in hepatocytes. CONCLUSIONS: OMZ inhibited the induction of several inflammatory mediators, resulting in the prevention of LPS-induced liver injury after GalN liver failure and PH, although OMZ showed different doses and mechanisms in the two models.

[A Case of Recurrent Gastric Cancer with Durable Complete Response after Short-Term Nivolumab Therapy].

We report the case of a patient with recurrent gastric cancer that showed a complete response(CR)after short-term nivolumab administration. A 76-year-old woman was diagnosed with unresectable advanced gastric cancer(T4b, N+, M0, cStage ⅣA). The patient was administered 7 courses of SOX. Since the primary lesion was reduced significantly after the chemotherapy, radical gastrectomy was performed. Although postoperative adjuvant chemotherapy with weekly nab-PTX was performed, cancer recurrence occurred in the abdominal cavity, and another surgery was performed. However, complete resection was difficult to achieve. Postoperatively, chemotherapy was continued; however, CEA levels increased, and thus RAM+PTX was administered as second-line treatment. Stable disease was maintained for a while; however, disease progression occurred eventually. Thus, RAM+PTX was discontinued after 8 courses, and nivolumab was administered as the third-line treatment. However, due to the rapid deterioration of renal function, nivolumab could not be continued after 3 courses. After nivolumab discontinuation, CEA levels normalized and the image showed CR. Approximately 1.5 years have passed since then, with no report of recurrence without any treatment. Although nivolumab has been shown to be useful as a third-line treatment for unresectable advanced/recurrent gastric cancer, there are few reports demonstrating CR and none showing maintenance of CR after short-term nivolumab administration. Moreover, the rationale of continuing nivolumab is unclear once clinical CR is achieved. Our experience shows the feasibility of discontinuation of short-term nivolumab if CR is achieved.

Efficacy of a third-generation oncolytic herpes simplex virus in neuroendocrine tumor xenograft models.

BACKGROUND: Few chemotherapies are available for neuroendocrine tumors, especially for highly malignant neuroendocrine cancers. The third-generation oncolytic herpes simplex virus type 1 (HSV-1) T-01 selectively replicates in tumor cells and shows cytotoxicity against tumor cells without damaging surrounding normal tissues. We examined the antitumor effect of T-01 to explore novel treatments for patients with neuroendocrine tumors. METHODS: The cytotoxicity of T-01 was tested in two human and one murine neuroendocrine tumor cell lines in vitro. Mouse models with subcutaneously implanted human neuroendocrine tumor QGP1 cells were used to investigate T-01 efficacy in vivo. RESULTS: T-01 showed cytotoxicity against the three cell lines in vitro. In xenograft models, the growth of tumors derived from QGP1 cells was inhibited by T-01 compared with control group. Although weight loss of mice was observed with tumor growth in the control group, it was suppressed by T-01 administration. The antitumor effects of T-01 were dependent on virus concentration and frequency of administration. CONCLUSIONS: T-01 effectively inhibits tumor cell proliferation in a poorly differentiated NEC mouse model. These results suggest that the third-generation oncolytic HSV-1 may serve as a novel treatment for patients with neuroendocrine tumors.