Risk of lymph node metastases in patients with T1b oesophageal adenocarcinoma: A retrospective single centre experience

AIM To assess clinical outcomes for submucosal (T1b) oesophageal adenocarcinoma (OAC) patients managed with either surgery or endoscopic eradication therapy.METHODS Patients found to have T1b OAC following endoscopic resection between January 2008 to February 2016 at University College London Hospital were retrospectively analysed. Patients were split into low-risk and high-risk groups according to established histopathological criteria and were then further categorised according to whether they underwent surgical resection or conservative management. Study outcomes include the presence of lymphnode metastases, disease-specific mortality and overall survival. RESULTS A total of 60 patients were included; 22 patients were surgically managed (1 low-risk and 21 high-risk patients) whilst 38 patients were treated conservatively (12 low-risk and 26 high-risk). Overall, lymph node metastases (LNM) were detected in 10 patients (17%); six of these patients had undergone conservative management and LNM were detected at a median of 4 mo after endoscopic mucosal resection (EMR). All LNM occurred in patients with highrisk lesions and this represented 21% of the total high-risk lesions. Importantly, there was no statistically significant difference in tumor-related deaths between those treated surgically or conservatively (P = 0.636) and disease-specific survival time was also comparable between the two treatment strategies (P = 0.376).CONCLUSION T1b tumours without histopathological high-risk markers of LNM can be treated endoscopically with good outcomes. In selected patients, endoscopic therapy may be appropriate for high-risk lesions.

OPTICAL MEASUREMENT OF PHOTOSENSITIZER CONCENTRATION IN VIVO

Most techniques for measuring tissue concentrations of drugs are invasive,time-consuming,and often require the removal of tissue or bodyfluids.Optical pharmacokinetics(OP)is a minimally invasive alternative giving an immediate result.Pulses of white light are directed at the tissue of interest using afiber optic probe.Scattered light is detected by a secondfiber immediately adjacent to thefirst in the same probe(separation 1.7 mm).Using the photosensitizer disulfonated aluminium phthalocyanine(AlS_(2)Pc),OP measurements were made in phantoms and on the mouth,stomach,colon,skin,and liver of normal rats 1 and 24 h after intravenous AlS_(2)Pc administration.AlS_(2)Pc concentration was determined by calculating the area under the curve(AUC)in the spectral region around the peak drug absorption or measuring the height of the peak.Spectral baseline interpolation removed the need for pre-drug,control optical measurements.OP measurements correlated well with values from alkali chemical extraction(CE)of the corresponding tissues,(R^(2)0.87=0.97).OP measurements in the mouth also correlated with CE of less accessible internal organs(R^(2)0.77-0.88).In phantoms,the lowest detectable concentration was 0.1μg/g.In vivo,results were limited by the lower accuracy in the CE measurements but were almost certainly comparable.An incidentalfinding was a 12-15nm red shifted component in the spectra observed 1 h after drug administration,suggesting partitioning of the drug in different microenvironment compartments,which could prove to be of considerable interest in future studies.In conclusion,OP shows promise for real-time measurement of concentrations of drugs with suitable absorption peaks.