Computed tomography perfusion imaging as a potential imaging biomarker of colorectal cancer

Neovascularization was reported to arise early in the adenoma-carcinoma sequence in colorectal cancer(CRC),and the importance of angiogenesis in cancer progression has been established.Computed tomography(CT)perfusion(CTP)based on high temporal resolution CT images enables evaluation of hemodynamics of tissue in vivo by modeling tracer kinetics.CTP has been reported to characterize tumor angiogenesis,and to be a sensitive marker for predicting recurrence or survival in CRC.In this review,we will discuss the biomarker value of CTP in the management of CRC patients.

New approaches for precise response evaluation in hepatocellular carcinoma

With the increasing clinical use of cytostatic and novel biologic targeted agents,conventional morphologic tumor burden assessments,including World Health Organization criteria and Response Evaluation Criteria in Solid Tumors,are confronting limitations because of their difficulties in distinguishing viable tumor from necrotic or fibrotic tissue.Therefore,the investigation for reliable quantitative biomarkers of therapeutic response such as metabolic imaging or functional imaging has been desired.In this review,we will discuss the conventional and new approaches to assess tumor burden.Since targeted therapy or locoregional therapies can induce biological changes much earlier than morphological changes,these functional tumor burden analyses are very promising.However,some of them have not gone thorough all steps for standardization and validation.Nevertheless,these new techniques and criteria will play an important role in the cancer management,and provide each patient more tailored therapy.

Arterio-biliary fistula as rare complication of chemoradiation therapy for intrahepatic cholangiocarcinoma

Significant hemobilia due to arterio-biliary fistula is a very rare complication of chemoradiation therapy(CRT) for unresectable intrahepatic cholangiocarcinoma(ICC).Here we report a case of arterio-biliary fistula after CRT for unresectable ICC demonstrated by angiographic examinations.This fistula was successfully treated by endovascular embolization.Hemobilia is a rare complication,but arterio-biliary fistula should be considered after CRT of ICC.

Imaging biomarkers for the treatment of esophageal cancer

Esophageal cancer is known as one of the malignant cancers with poor prognosis.To improve the outcome,combined multimodality treatment is attempted.On the other hand,advances in genomics and other“omic”technologies are paving way to the patient-oriented treatment called“personalized”or“precision”medicine.Recent advancements of imaging techniques such as functional imaging make it possible to use imaging features as biomarker for diagnosis,treatment response,and prognosis in cancer treatment.In this review,we will discuss how we can use imaging derived tumor features as biomarker for the treatment of esophageal cancer.

Polysomnographic assessment of respiratory disturbance during deep propofol sedation for endoscopic submucosal dissection of gastric tumors

AIM To investigate that polysomnographic monitoring can accurately evaluate respiratory disturbance incidence during sedation for gastrointestinal endoscopy compare to pulse oximetry alone.METHODS This prospective observational study included 10 elderly patients with early gastric cancer undergoing endoscopic submucosal dissection(ESD) under propofol sedation. Apart from routine cardiorespiratory monitoring, polysomnography measurements were acquired. The primary hypothesis was tested by comparing the apnea hypopnea index(AHI), defined as the number of apnea and hypopnea instances per hour during sedation, with and without hypoxemia; hypoxemia was defined as the reduction in oxygen saturation by ≥ 3% from baseline.RESULTS Polysomnography(PSG) detected 207 respiratory disturbances in the 10 patients. PSG yielded a significantly greater AHI(10.44 ± 5.68/h) compared with pulse oximetry(1.54 ± 1.81/h, P < 0.001), thus supporting our hypothesis. Obstructive AHI(9.26 ± 5.44/h) was significantly greater than central AHI(1.19 ± 0.90/h, P < 0.001). Compared with pulse oximetry, PSG detected the 25 instances of respiratory disturbances with hypoxemia 107.4 s earlier on average.CONCLUSION Compared with pulse oximetry, PSG can better detect respiratory irregularities and thus provide superior AHI values, leading to avoidance of fatal respiratory complications during ESD under propofol-induced sedation.

Predictor of respiratory disturbances during gastric endoscopic submucosal dissection under deep sedation

BACKGROUND Sedation is commonly performed for the endoscopic submucosal dissection(ESD)of early gastric cancer.Severe hypoxemia occasionally occurs due to the respiratory depression during sedation.AIM To establish predictive models for respiratory depression during sedation for ESD.METHODS Thirty-five adult patients undergoing sedation using propofol and pentazocine for gastric ESDs participated in this prospective observational study.Preoperatively,a portable sleep monitor and STOP questionnaires,which are the established screening tools for sleep apnea syndrome,were utilized.Respiration during sedation was assessed by a standard polysomnography technique including the pulse oximeter,nasal pressure sensor,nasal thermistor sensor,and chest and abdominal respiratory motion sensors.The apnea-hypopnea index(AHI)was obtained using a preoperative portable sleep monitor and polysomnography during ESD.A predictive model for the AHI during sedation was developed using either the preoperative AHI or STOP questionnaire score.RESULTS All ESDs were completed successfully and without complications.Seventeen patients(49%)had a preoperative AHI greater than 5/h.The intraoperative AHI was significantly greater than the preoperative AHI(12.8±7.6 events/h vs 9.35±11.0 events/h,P=0.049).Among the potential predictive variables,age,body mass index,STOP questionnaire score,and preoperative AHI were significantly correlated with AHI during sedation.Multiple linear regression analysis determined either STOP questionnaire score or preoperative AHI as independent predictors for intraoperative AHI≥30/h(area under the curve[AUC]:0.707 and 0.833,respectively)and AHI between 15 and 30/h(AUC:0.761 and 0.778,respectively).CONCLUSION The cost-effective STOP questionnaire shows performance for predicting abnormal breathing during sedation for ESD that was equivalent to that of preoperative portable sleep monitoring.

Role of sirtuins in esophageal cancer:Current status and future prospects

Esophageal cancer(EC)is a malignant cancer that still has a poor prognosis,although its prognosis has been improving with the development of multidisciplinary treatment modalities such as surgery,chemotherapy and radiotherapy.Therefore,identifying specific molecular markers that can be served as biomarkers for the prognosis and treatment response of EC is highly desirable to aid in the personalization and improvement of the precision of medical treatment.Sirtuins are a family of nicotinamide adenine dinucleotide(NAD+)-dependent proteins consisting of seven members(SIRT1-7).These proteins have been reported to be involved in the regulation of a variety of biological functions including apoptosis,metabolism,stress response,senescence,differentiation and cell cycle progression.Given the variety of functions of sirtuins,they are speculated to be associated in some manner with cancer progression.However,while the role of sirtuins in cancer progression has been investigated over the past few years,their precise role remains difficult to characterize,as they have both cancer-promoting and cancer-suppressing properties,depending on the type of cancer.These conflicting characteristics make research into the nature of sirtuins all the more fascinating.However,the role of sirtuins in EC remains unclear due to the limited number of reports concerning sirtuins in EC.We herein review the current findings and future prospects of sirtuins in EC.

Long-term submergence of non-methanogenic oxic upland field soils helps to develop the methanogenic archaeal community as revealed by pot and field experiments

The community structure of methanogenic archaea is relatively stable,i.e.,it is sustained at a high abundance with minimal changes in composition,in paddy field soils irrespective of submergence and drainage.In contrast,the abundance in non-methanogenic oxic soils is much lower than that in paddy field soils.This study aimed to describe methanogenic archaeal community development following the long-term submergence of non-methanogenic oxic upland field soils in pot and field experiments.In the pot experiment,a soil sample obtained from an upland field was incubated under submerged conditions for 275 d.Soil samples periodically collected were subjected to culture-dependent most probable number(MPN)enumeration,polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)analysis of archaeal 16 S r RNA gene,and quantitative PCR analysis of the methyl-coenzyme M reductase alpha subunit gene(mcr A)of methanogenic archaea.The abundance of methanogenic archaea increased from 102 to 103 cells g-1 dry soil and 104 to 107 copies of mcr A gene g-1 dry soil after submergence.Although no methanogenic archaeon was detected prior to incubation by the DGGE analysis,members from Methanocellales,Methanosarcinaceae,and Methanosaetaceae proliferated in the soils,and the community structure was relatively stable once established.In the field experiment,the number of viable methanogenic archaea in a rice paddy field converted from meadow(reclaimed paddy field)was monitored by MPN enumeration over five annual cycles of field operations.Viability was also determined simultaneously in a paddy field where the plow layer soil from a farmer’s paddy field was dressed onto the meadow(dressed paddy field)and an upland crop field converted from the meadow(reclaimed upland field).The number of viable methanogenic archaea in the reclaimed paddy field was below the detection limit before the first cultivation of rice and in the reclaimed upland field.Then,the number gradually increased over five years and finally reached 103–104 cells g-1 dry soil,which was comparable to that in the dressed paddy field.These findings showed that the low abundance of autochthonous methanogenic archaea in the non-methanogenic oxic upland field soils steadily proliferated,and the community structure was developed following repeated and long-term submergence.These results suggest that habitats suitable for methanogenic archaea were established in soil following repeated and long-term submergence.