Lindor, Keith D.

AbstractBackgroundBiochemical tests have been recommended as endpoints for clinical trials in primary biliary cirrhosis (PBC) because the use of liver transplantation and death as endpoints in ursodeoxycholic acid (UDCA) therapeutic trials is unfeasible. The best inclusion criteria cut‐off values and cut‐off for demonstrating treatment success have not been defined.AimOur aim was to determine the optimal biochemical values for patient inclusion and to define values for treatment success in therapeutic trials.MethodsWe performed a retrospective review of 73 patients with PBC treated with UDCA followed over 36 months. Following one year of UDCA therapy, the likelihood of developing clinical endpoints of varices, ascites, encephalopathy, death or transplantation over the ensuing two years, based on degrees of elevation of biochemical markers, was analyzed using chi‐square or Fisher's exact test.ResultsPatients with ALP≥2 X upper limit of normal (ULN) had a 2‐fold greater likelihood of developing endpoints compared to patients with lower values (23% versus 11%), (p < 0.05). Patients with bilirubin > 1 mg/dL were 4 times more likely to develop endpoints compared to those with lower values (33% versus 8%), (p = 0.02). These values help identify the patient population for adjunctive therapy trials. Patients with ALP ≤1.67 X ULN and bilirubin ≤1mg/dL demonstrated the least likelihood of reaching adverse clinical endpoints and can be used to define treatment success.ConclusionOptimal ALP and Bilirubin levels can be used as appropriate biochemical criteria for patient selection and defining treatment success in future clinical trials in patients with PBC.

Abstract Inflammation plays a role in the progression to cancer and it is linked to the presence of senescent cells. Ulcerative colitis (UC) is a chronic inflammatory disease that predisposes to colorectal cancer. Tumorigenesis in this setting is associated with telomere shortening that can be observed in the nondysplastic epithelium of UC patients with high-grade dysplasia (HGD) or cancer (UC progressors). We hypothesized that a preneoplastic field of inflammation, telomere shortening, and senescence underlies tumor progression in UC progressors. Multiple biopsies of varying histologic grade were collected along the colon of nine UC progressors and analyzed for telomere length, DNA damage, senescence, p53, p16, and chronic and acute inflammation. Twenty biopsies from four UC nonprogressors and twenty-one biopsies from control individuals without UC were also analyzed. Short telomeres and increased DNA damage, senescence, and infiltrating leukocytes were observed in biopsies located less than 10 cm from HGD or cancer. Low-grade dysplasia (LGD) had the shortest telomeres along with the highest levels of senescence and infiltrating leukocytes, whereas HGD biopsies showed the opposite pattern. The expression of p16 and p53 was low in nondysplastic biopsies but progressively increased in LGD and HGD. In addition, high levels of infiltrating leukocytes were associated with telomere shortening, senescence, and reduced p53 expression. These results suggest that dysplasia arises in a preneoplastic field of chronic inflammation, which leads to telomere shortening, DNA damage, and senescence. Our findings argue that senescence acts as a tumor suppressor mechanism that is abrogated during the transition from LGD to HGD in UC. Cancer Res; 71(5); 1669–79. ©2011 AACR.

Background and Aims. Colorectal cancer, a leading cause of cancer death, is preventable with colonoscopic screening. Colonoscopy cost is high, and optimizing resource utilization for colonoscopy is important. This study’s aim is to evaluate resource allocation for optimal use of facilities for colonoscopy screening. Method. The authors used data from a computerized colonoscopy database to develop a discrete event simulation model of a colonoscopy suite. Operational configurations were compared by varying the number of endoscopists, procedure rooms, the patient arrival times, and procedure room turnaround time. Performance measures included the number of patients served during the clinic day and utilization of key resources. Further analysis included considering patient waiting time tradeoffs as well as the sensitivity of the system to procedure room turnaround time. Results. The maximum number of patients served is linearly related to the number of procedure rooms in the colonoscopy suite, with a fixed room to endoscopist ratio. Utilization of intake and recovery resources becomes more efficient as the number of procedure rooms increases, indicating the potential benefits of large colonoscopy suites. Procedure room turnaround time has a significant influence on patient throughput, procedure room utilization, and endoscopist utilization for varying ratios between 1:1 and 2:1 rooms per endoscopist. Finally, changes in the patient arrival schedule can reduce patient waiting time while not requiring a longer clinic day. Conclusions. Suite managers should keep a procedure room to endoscopist ratio between 1:1 and 2:1 while considering the utilization of related key resources as a decision factor as well. The sensitivity of the system to processes such as turnaround time should be evaluated before improvement efforts are made.