Simple pelvimetry predicts the pelvic manipulation time in robot-assisted low and ultra-low anterior resection for rectal cancer.

PURPOSE: This study explored the difficulty factors in robot-assisted low and ultra-low anterior resection, focusing on simple measurements of the pelvic anatomy. METHODS: This was a retrospective analysis of the clinical data of 61 patients who underwent robot-assisted low and ultra-low anterior resection for rectal cancer between October 2018 and April 2023. The relationship between the operative time in the pelvic phase and clinicopathological data, especially pelvic anatomical parameters measured on X-ray and computed tomography (CT), was evaluated. The operative time in the pelvic phase was defined as the time between mobilization from the sacral promontory and rectal resection. RESULTS: Robot-assisted low and ultra-low anterior resections were performed in 32 and 29 patients, respectively. The median operative time in the pelvic phase was 126 (range, 31-332) min. A multiple linear regression analysis showed that a short distance from the anal verge to the lower edge of the cancer, a narrow area comprising the iliopectineal line, short anteroposterior and transverse pelvic diameters, and a small angle of the pelvic mesorectum were associated with a prolonged operative time in the pelvic phase. CONCLUSION: Simple pelvic anatomical measurements using abdominal radiography and CT may predict the pelvic manipulation time in robot-assisted surgery for rectal cancer.

Tumor-infiltrating monocytic myeloid-derived suppressor cells contribute to the development of an immunosuppressive tumor microenvironment in gastric cancer.

BACKGROUND: Gastric cancer (GC) is characterized by an immunosuppressive and treatment-resistant tumor immune microenvironment (TIME). Here, we investigated the roles of different immunosuppressive cell types in the development of the GC TIME. METHODS: Single-cell RNA sequencing (scRNA-seq) and multiplex immunostaining of samples from untreated or immune checkpoint inhibitor (ICI)-resistant GC patients were used to examine the correlation between certain immunosuppressive cells and the prognosis of GC patients. RESULTS: The results of the scRNA-seq analysis revealed that tumor-infiltrating monocytic myeloid-derived suppressor cells (TI-M-MDSCs) expressed higher levels of genes with immunosuppressive functions than other immunosuppressive cell types. Additionally, M-MDSCs in GC tissues expressed significantly higher levels of these markers than adjacent normal tissues. The M-MDSCs were most enriched in GC tissues relative to adjacent normal tissues. Among the immunosuppressive cell types assessed, the M-MDSCs were most enriched in GC tissues relative to adjacent normal tissues; moreover, their presence was most strongly associated with a poor prognosis. Immediate early response 3 (IER3), which we identified as a differentially expressed gene between M-MDSCs of GC and adjacent normal tissues, was an independent poor prognostic factor in GC patients (P = 0.0003). IER3+ M-MDSCs expressed higher levels of genes with immunosuppressive functions than IER3- M-MDSCs and were abundant in treatment-resistant GC patients. CONCLUSIONS: The present study suggests that TI-M-MDSCs, especially IER3+ ones, may play a predominant role in the development of the immunosuppressive and ICI-resistant GC TIME.

Multiple angiosarcomas of both breasts: a case report.

BACKGROUND: Primary angiosarcomas of the breast are rare and highly aggressive. We herein report a rare case of multiple angiosarcomas detected concurrently in both breasts. CASE PRESENTATION: A 49-year-old woman visited a doctor after noticing a lump in her right breast. At that time, mammography and ultrasonography revealed no abnormal findings in either breast. She was referred to our hospital 5 months later, because screening mammography had revealed a focal asymmetric density in her right breast. Ultrasonography showed ill-defined hyper- and hypo-echoic lesions in both breasts. Magnetic resonance imaging disclosed five heterogeneously enhanced masses (5.8 cm in maximum diameter) in the right breast and six enhanced masses (approximately 1-3 cm in diameter) in the left breast. Histological examination of core needle biopsies revealed proliferation of irregularly shaped vascular channels lined by atypical endothelial cells throughout the adipose tissue and lobules of the breasts, leading to a diagnosis of well-differentiated angiosarcoma. The lesions were assumed to be primary angiosarcomas, because she had neither a history of breast surgery nor of radiation therapy. She underwent bilateral mastectomies and postoperative chest wall irradiation. Computed tomography 11 weeks after the surgery revealed multiple, small, subcutaneous nodules in the chest wall that were suspected of being angiosarcoma metastases. We started chemotherapy (weekly paclitaxel 80 mg/m2), which achieved shrinkage of these nodules within 2 months. CONCLUSIONS: Early diagnosis, immediate initiation of local and systemic therapies, and intensive follow-up are important in improving the prognosis of angiosarcomas.

Adipose tissue-derived stromal cells are sources of cancer-associated fibroblasts and enhance tumor progression by dense collagen matrix.

Although recent studies revealed that adipose tissue accelerates pancreatic tumor progression with excessive extracellular matrix, key players for desmoplasia in the adipose microenvironment remains unknown. Here, we investigated the roles of adipose tissue-derived stromal cells (ASCs) in desmoplastic lesions and tumor progression by in vitro and in vivo experiments. In a three-dimensional (3-D) organotypic fat invasion model using visceral fat from CAG-EGFP mice, GFP-positive fibroblastic cells infiltrated toward cancer cells. When tumor cells were inoculated into transplanted visceral fat pads in vivo, tumor weights and stromal components were enhanced compared to subcutaneous and orthotopic tumor cells inoculated without fat pads. Expression of αSMA in established human ASCs was lower compared to cancer associated fibroblasts, and the 3-D collagen matrices produced by ASCs cultured in cancer cell-conditioned medium changed from loose to dense structures that affected the motility of cancer cells. Microarray analyses revealed upregulation of S100A4 in ASCs, while S100A4-positive stromal cells were observed at extrapancreatic invasion sites of human pancreatic cancer. The present findings indicate that ASCs are recruited to extrapancreatic invasion sites and produce dense collagen matrices that lead to enhanced tumor progression. Both inhibition of ASCs recruitment and activation could lead to a novel antistromal therapy.

Pancreatic stellate cells reorganize matrix components and lead pancreatic cancer invasion via the function of Endo180.

Specific cell populations leading the local invasion of cancer are called "leading cells". However, the underlying mechanisms are unclear. Here, we identified leading cells in pancreatic cancer and determined how these cells lead and promote cancer cell invasion in the extracellular matrix (ECM). Using three-dimensional matrix remodeling assay, we found that pancreatic stellate cells (PSCs) frequently invaded the collagen matrix with pancreatic cancer cells (PCCs), which invaded behind the invading PSCs. In addition, invading PSCs changed the alignment of collagen fibers, resulting in ECM remodeling and an increase in the parallel fibers along the direction of invading PSCs. Endo180 expression was higher in PSCs than in PCCs, Endo180 knockdown in PSCs attenuated the invasive abilities of PSCs and co-cultured PCCs, and decreased the expression level of phosphorylated myosin light chain 2 (MLC2). In mouse models, Endo180-knockdown PSCs suppressed tumor growth and changes in collagen fiber orientation in co-transplantation with PCCs. Our findings suggest that PSCs lead the local invasion of PCCs by physically remodeling the ECM, possibly via the function of Endo180, which reconstructs the actin cell skeleton by phosphorylation of MLC2.

Autophagy Is Required for Activation of Pancreatic Stellate Cells, Associated With Pancreatic Cancer Progression and Promotes Growth of Pancreatic Tumors in Mice.

BACKGROUND & AIMS: Pancreatic stellate cells (PSCs) change from a quiescent to activated state in the tumor environment and secrete extracellular matrix (ECM) molecules and cytokines to increase the aggressiveness of tumors. However, it is not clear how PSCs are activated to produce these factors, or whether this process can be inhibited. PSCs have morphologic and functional similarities to hepatic stellate cells, which undergo autophagy to promote fibrosis and tumor growth. We investigated whether autophagy activates PSCs, which promotes development of the tumor stroma and growth of pancreatic tumors in mice. METHODS: We used immunofluorescence microscopy and immunohistochemistry to analyze pancreatic tumor specimens from 133 patients who underwent pancreatectomy in Japan from 2000 to 2009. PSCs were cultured from pancreatic tumor tissues or tissues of patients with chronic pancreatitis; these were analyzed by immunofluorescence microscopy, immunoblots, quantitative reverse transcription polymerase chain reaction, and in assays for invasiveness, proliferation, and lipid droplets. Autophagy was inhibited in PSCs by administration of chloroquine or transfection with small interfering RNAs. Proteins were knocked down in immortalized PSCs by expression of small hairpin RNAs. Cells were transplanted into pancreatic tails of nude mice, and tumor growth and metastasis were quantified. RESULTS: Based on immunohistochemical analyses, autophagy was significantly associated with tumor T category (P = .018), histologic grade (P = .001), lymph node metastases (P < .001), stage (P = .009), perilymphatic invasion (P = .001), and perivascular invasion (P = .003). Autophagy of PSCs was associated with shorter survival times of patients with pancreatic cancer. PSC expression of microtubule-associated protein 1 light chain 3, a marker of autophagosomes, was associated with poor outcomes (shorter survival time, disease recurrence) for patients with pancreatic cancer (relative risk of shorter survival time, 1.56). Immunoblots showed that PSCs from pancreatic tumor samples expressed higher levels of markers of autophagy than PSCs from chronic pancreatitis samples. Inhibitors of autophagy increased the number of lipid droplets of PSCs, indicating a quiescent state of PSCs, and reduced their production of ECM molecules and interleukin 6, as well as their proliferation and invasiveness in culture. PSCs exposed to autophagy inhibitors formed smaller tumors in nude mice (P = .001) and fewer liver metastases (P = .018) with less peritoneal dissemination (P = .018) compared to PSCs not exposed to autophagy inhibitors. CONCLUSIONS: Autophagic PSCs produce ECM molecules and interleukin 6 and are associated with shorter survival times and disease recurrence in patients with pancreatic cancer. Inhibitors of PSC autophagy might reduce pancreatic tumor invasiveness by altering the tumor stroma.

Cancer-associated peritoneal mesothelial cells lead the formation of pancreatic cancer peritoneal dissemination.

The interaction between the cancer cells and the peritoneal mesothelial cells (PMCs) plays an important role in the peritoneal dissemination in several types of cancer. However, the role of PMCs in the peritoneal dissemination of pancreatic cancer remains unclear. In the present study, we investigated the interaction between the pancreatic cancer cells (PCCs) and the PMCs in the formation of peritoneal dissemination in vitro and in vivo. The tumor-stromal interaction of PCCs and PMCs significantly enhanced their mobility and invasiveness and enhanced the proliferation and anoikis resistance of PCCs. In a 3D organotypic culture model of peritoneal dissemination, co-culture of PCCs and PMCs significantly increased the cells invading into the collagen gel layer compared with mono-culture of PCCs. PMCs pre-invaded into the collagen gel, remodeled collagen fibers, and increased parallel fiber orientation along the direction of cell invasion. In the tissues of peritoneal dissemination of the KPC (LSL-KrasG12D/+; LSL-Trp53R172H/+;Pdx-1-Cre) transgenic mouse, the monolayer of PMCs was preserved in tumor-free areas, whereas PMCs around the invasive front of peritoneal dissemination proliferated and invaded into the muscle layer. In vivo, intraperitoneal injection of PCCs with PMCs significantly promoted peritoneal dissemination compared with PCCs alone. The present data suggest that the cancer-associated PMCs have important promoting roles in the peritoneal dissemination of PCCs. Therapy targeting cancer-associated PMCs may improve the prognosis of patients with pancreatic cancer.

Suppression of CD51 in pancreatic stellate cells inhibits tumor growth by reducing stroma and altering tumor-stromal interaction in pancreatic cancer.

Pancreatic stellate cells (PSCs) enhance the malignant behavior of pancreatic cancer by interacting with cancer cells and producing extracellular matrix (ECM). To date, several stroma-targeted therapies for pancreatic cancer have been attempted, but these therapies are still not in practical use. Integrins expressed in stromal cells are involved in fibrosis of several organs, as well as promoting tumor malignancy. We investigated whether CD51, also known as integrin αV, expressed in PSCs was associated with stromal formation of pancreatic cancer and enhancement of tumor malignancy. We also assessed the effects of suppression of CD51 in PSCs on pancreatic cancer. Immunohistochemistry for CD51 in resected pancreatic cancer tissues showed that high expression of CD51 in the tumor stroma was associated with lymph node metastasis (P=0.025), positive pathologic margin (P=0.025), and shorter patient survival times (P=0.043). Lentivirus-mediated short hairpin RNA knockdown of CD51 decreased the proliferation and migration of PSCs. Quantitative real-time polymerase chain reaction showed that expression levels of genes related with ECM and tumor-stromal interactions were decreased by CD51 knockdown in PSCs. In a co-implantation model of pancreatic cancer cells and PSCs, tumor growth in vivo was inhibited by CD51 knockdown in PSCs (P<0.05). We also found reduced tumor stroma and decreased proliferation of cancer cells in implanted cancer tissues with CD51-silenced PSCs (P<0.05). Our results showed that CD51 expression in pancreatic cancer stroma is associated with enhanced tumor malignancy and that CD51 may be a potential therapeutic target for pancreatic cancer.

Hypoxic stellate cells of pancreatic cancer stroma regulate extracellular matrix fiber organization and cancer cell motility.

Desmoplasia and hypoxia in pancreatic cancer mutually affect each other and create a tumor-supportive microenvironment. Here, we show that microenvironment remodeling by hypoxic pancreatic stellate cells (PSCs) promotes cancer cell motility through alteration of extracellular matrix (ECM) fiber architecture. Three-dimensional (3-D) matrices derived from PSCs under hypoxia exhibited highly organized parallel-patterned matrix fibers compared with 3-D matrices derived from PSCs under normoxia, and promoted cancer cell motility by inducing directional migration of cancer cells due to the parallel fiber architecture. Microarray analysis revealed that procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) in PSCs was the gene that potentially regulates ECM fiber architecture under hypoxia. Stromal PLOD2 expression in surgical specimens of pancreatic cancer was confirmed by immunohistochemistry. RNA interference-mediated knockdown of PLOD2 in PSCs blocked parallel fiber architecture of 3-D matrices, leading to decreased directional migration of cancer cells within the matrices. In conclusion, these findings indicate that hypoxia-induced PLOD2 expression in PSCs creates a permissive microenvironment for migration of cancer cells through architectural regulation of stromal ECM in pancreatic cancer.

CD146 attenuation in cancer-associated fibroblasts promotes pancreatic cancer progression.

Cancer-associated fibroblasts (CAFs) are heterogeneous cell populations that influence tumor initiation and progression. CD146 is a cell membrane protein whose expression has been implicated in multiple human cancers. CD146 expression is also detected in pancreatic cancer stroma; however, the role it plays in this context remains unclear. This study aimed to clarify the function and significance of CD146 expression in pancreatic cancer. We performed immunohistochemical staining to investigate the prevalence of CD146 expression in stromal fibroblasts in pancreatic cancer. We also examined the influence of CD146 on CAF-mediated tumor invasion and migration and CAF activation using CD146 small interfering RNA or overexpression plasmids in primary cultures of CAFs derived from pancreatic cancer tissues. CD146 expression in CAFs was associated with high-grade pancreatic intraepithelial neoplasia and low histological grade invasive ductal carcinoma of the pancreas, while patients with low CD146 expression had a poorer prognosis. Blocking CD146 expression in CAFs significantly enhanced tumor cell migration and invasion in a co-culture system. CD146 knockdown also promoted CAF activation, possibly by inducing the production of pro-tumorigenic factors through modulation of NF-κB activity. Consistently, overexpression of CD146 in CAFs inhibited migration and invasion of co-cultured cancer cells. Finally, CD146 expression in CAFs was reduced by interaction with cancer cells. Our findings suggest that decreased CD146 expression in CAFs promotes pancreatic cancer progression. © 2015 Wiley Periodicals, Inc.

CD166/ALCAM expression is characteristic of tumorigenicity and invasive and migratory activities of pancreatic cancer cells.

BACKGROUND: CD166, also known as activated leukocyte cell adhesion molecule (ALCAM), is expressed by various cells in several tissues including cancer. However, the role of CD166 in malignant tumors is controversial, especially in pancreatic cancer. This study aimed to clarify the role and significance of CD166 expression in pancreatic cancer. METHODS: We performed immunohistochemistry and flow cytometry to analyze the expression of CD166 in surgical pancreatic tissues and pancreatic cancer cell lines. The differences between isolated CD166+ and CD166- pancreatic cancer cells were analyzed by invasion and migration assays, and in mouse xenograft models. We also performed quantitative RT-PCR and microarray analyses to evaluate the expression levels of CD166 and related genes in cultured cells. RESULTS: Immunohistochemistry revealed high expression of CD166 in pancreatic cancer tissues (12.2%; 12/98) compared with that in normal pancreas controls (0%; 0/17) (p = 0.0435). Flow cytometry indicated that CD166 was expressed in 33.8-70.2% of cells in surgical pancreatic tissues and 0-99.5% of pancreatic cancer cell lines. Invasion and migration assays demonstrated that CD166- pancreatic cancer cells showed stronger invasive and migratory activities than those of CD166+ cancer cells (p<0.05). On the other hand, CD166+ Panc-1 cells showed a significantly stronger colony formation activity than that of CD166- Panc-1 cells (p<0.05). In vivo analysis revealed that CD166+ cells elicited significantly greater tumor growth than that of CD166- cells (p<0.05) in both subcutaneous and orthotopic mouse tumor models. mRNA expression of the epithelial-mesenchymal transition activator Zeb1 was over-expressed in CD166- cells (p<0.001). Microarray analysis showed that TSPAN8 and BST2 were over-expressed in CD166+ cells, while BMP7 and Col6A1 were over-expressed in CD166- cells. CONCLUSIONS: CD166+ pancreatic cancer cells are strongly tumorigenic, while CD166- pancreatic cancer cells exhibit comparatively stronger invasive and migratory activities. These findings suggest that CD166 expression is related to different functions in pancreatic cancer cells.

[A case of locally advanced sigmoid colon cancer curatively resected after neoadjuvant chemotherapy with FOLFIRI plus panitumumab].

A 72-year-old woman having abdominal pain and high fever was diagnosed with KRAS wild-type sigmoid colon cancer, invading the urinary bladder and uterus with a pelvic abscess. Considering the difficulty of curative resection, we first performed sigmoid colostomy and abscess drainage. Remarkable tumor regression was indicated by CT and colonoscopy after 1 course of FOLFIRI and 5 courses of FOLFIRI+panitumumab. Following an additional 2 courses of panitumumab, sigmoidectomy and partialcystectomy were performed. Six courses of FOLFIRI+panitumumab were administered postoperatively and no recurrence has been observed for 7 months. FOLFIRI+panitumumab may be an effective preoperative chemotherapy for patients with KRAS wild-type locally advanced colon cancer.

Single-incision laparoscopic cholecystectomy with needle graspers.

BACKGROUND/AIMS: Single-incision laparoscopic cholecystectomy (SILC) is a promising alternative to standard multi-incision laparoscopic cholecystectomy (LC). However, generalization of SILC is still hampered by technical difficulties mainly associated with the lack of trocars used for retraction of the gallbladder. We therefore developed a modified method of SILC with the use of needle graspers (SILC-N) for optimal retraction and exposure. METHODOLOGY: In addition to two trocars inserted through a single transumbilical incision, two needle ports were placed on the right subcostal and lateral abdominal wall, through which needle graspers were used for retraction of the gallbladder. Since December, 2009, 12 patients with symptomatic cholelithiasis were treated by SILC-N. RESULTS: SILC-N was successfully performed in all but one patient requiring a conversion to the 4-port LC with a mean operative time of 71.5 (48-107) minutes. None of the patients experienced intraoperative or postoperative complications. The transumbilical incision and pinholes for needle graspers were almost invisible on discharge. CONCLUSIONS: Our preliminary results suggest that SILC-N is a simple, safe and feasible technique of cholecystectomy offering similar postoperative recovery and better cosmetic outcome as compared to conventional LC.

[A brainstem variant of reversible posterior leukoencephalopathy syndrome (RPLS) presenting with visual disturbance].

A 40-year-old woman noticed blurred vision of the right eye. The optic disc edema of bilateral eyegrounds was noted, and brain MRI showed abnormal signals of the brainstem at a neurosurgical clinic. On her first visit, blood pressure was as remarkably high as 250/130 mmHg. Neurologically, only optic disc edema of bilateral eye-grounds was found. Both T2-weighted MRI and FLAIR showed hyperintense signal areas mainly from the ventral pons to medulla oblongata. These areas were not enhanced with gadolinium. About three weeks after the administration of an antihypertensive agent, brain MRI revealed no abnormal signal. About three months later, the blurred vision disappeared and ophthalmological abnormalities subsided. We diagnosed her with a brainstem variant of RPLS, presenting with visual disturbance caused by hypertensive retinopathy.