Digestive Disease Week, May 17-22, 2008
Digestive Disease Week 2008 took place May 17-22 in San Diego, Calif., and attracted more than 17,000 attendees from around the world. Jointly sponsored by four societies -- the American Association for the Study of Liver Diseases, the American Gastroenterological Association, the American Society for Gastrointestinal Endoscopy, and the Society for Surgery of the Alimentary Tract -- the meeting highlighted the most recent advances in basic, translational and clinical research in liver disease, gastroenterology, endoscopy and gastrointestinal surgery.
In the area of liver disease, several studies were noteworthy because they have the potential to change clinical practice, said the DDW's incoming secretary-treasurer John M. Vierling, M.D., of the Baylor College of Medicine in Houston.
"In hepatitis B, an interesting and important study assessed the relationship between viral load and the subsequent long-term risk of hepatocellular carcinoma," Vierling said. "It showed unequivocally that the initial as well as the subsequent values of hepatitis B DNA in the serum were highly correlated with hepatocellular carcinoma. I think we're going more toward an infection paradigm. This is a step in the direction of using viral load more in our treatment decisions, not necessarily only as part of the treatment decision related to liver disease as manifested by ALT elevation or evidence on liver biopsy of inflammation or scarring."
In that study, Chien-Jen Chen of the Genomics Research Center, Academia Sinica in Taipei, Taiwan, and colleagues followed 3,584 patients who were free of cirrhosis at baseline for a total of 42,878 person-years. Compared to patients with a reference hepatitis B DNA of less than 300 copies/mL, they found that patients with higher viral loads had 4.5-7.3 times the risk of developing hepatocellular carcinoma.
"These results confirm that increasing hepatitis B DNA level remains a very significant predictor of hepatocellular carcinoma after taking follow-up hepatitis DNA and change in serum ALT into account," Chen and colleagues conclude. "The persistence of high hepatitis B load leads to the highest hepatocellular carcinoma risk. Long-term monitoring of hepatitis B viral load is essential for the management of chronic hepatitis B."
"By ultimately having the capacity to safely suppress viral replication, the hope would be that we could prevent both the advancement of the baseline level of liver disease and reduce or prevent the risk of hepatocellular carcinoma," Vierling said.
A second noteworthy liver study, Vierling said, was the final result of the PROVE1, phase 2 trial of the protease inhibitor telaprevir in the treatment of patients with hepatitis C. In that trial, Gregory Everson, M.D., of Vertex Pharmaceuticals Inc., in Cambridge, Mass., and colleagues randomly assigned 175 treatment-naive subjects with genotype 1 hepatitis C to receive the standard treatment -- peginterferon Alfa-2a and ribavirin -- plus telaprevir for either 12, 36 or 48 weeks. They randomly assigned another 75 patients (the control group) to receive 48 weeks of standard treatment.
"What they found is that they had the optimal sustained virologic response when they did 12 weeks of the triple therapy followed by 24 weeks of the standard of care consolidation," Vierling said. "That showed about a 61 percent sustained virologic response compared to 41 percent for the control group."
"Compared with current treatment, telaprevir-based therapy resulted in a high rate of rapid virologic response and subsequent on-treatment response rate," Everson and colleagues conclude. "These results suggest potential for higher sustained virologic response rates with shorter duration of therapy in subjects with genotype 1. The final analysis will be executed when all subjects have completed 24-week post-treatment follow-up."
"New drug development looks robust," Vierling added. "If telaprevir is fast-tracked by the [U.S. Food and Drug Administration], it's possible it could be approved by mid-2010 or mid-2011. It would be very nice if the phase 3 trial designs allow the researchers to shorten the treatment, which is what they were able to do in the current studies."
In another hepatitis C study, Maribel Rodriguez-Torres, M.D., of Fundacion de Investigacion de Diego in San Juan, Puerto Rico, and colleagues compared virologic response rates after 48 weeks of standard treatment in 269 Hispanic patients and 300 non-Hispanic white patients. Building on previous research showing that sustained virologic response rates are lower among black patients than among whites, they found that rates for Hispanic men and women were significantly lower (32.8 percent and 34.9 percent) than for non-Hispanic white men and women (53.1 percent and 42.6 percent).
"The predictors of sustained virologic response were different for Latinos and non-Latinos, indicating the need for further study in Latinos," Rodriguez-Torres and colleagues conclude.
"We need to fully understand why African-Americans and Latinos are having this decrease in responsiveness to treatment," Vierling said. "There is a lot of good work being done in that area. Once we can figure out the reasons, perhaps we'll be able to identify the genetic and other factors that are blocking the response and develop drugs to unblock them. That could improve response rates for everyone, including whites. They, too, may have a population that's blocked. Understanding why the therapies work in some patients and don't work in others may help unravel that mystery."
DDW: Mortality May Be Lower in High-Volume Centers
WEDNESDAY, May 21 (HealthDay News) -- Hospitalization at high-volume centers may be associated with lower mortality rates for patients who undergo liver resection or surgery for inflammatory bowel disease, but outcomes also depend on other characteristics of centers, surgeons and patients, according to research presented this week at the Digestive Disease Week conference in San Diego.
DDW: Minimally Invasive Surgery May Help Obese Teens
WEDNESDAY, May 21 (HealthDay News) -- Minimally invasive per-oral suturing may benefit obese adolescents, and supplementation with probiotics may benefit patients who undergo gastric bypass surgery, according to advancements in obesity research presented this week at the Digestive Disease Week conference in San Diego.
DDW: Advancements Announced in Liver Disease
WEDNESDAY, May 21 (HealthDay News) -- Liver cells generated from embryonic stem cells could revolutionize drug-toxicity studies and also have clinical applications, while dendritic cell studies could determine which hepatitis C virus patients are likely to respond to antiviral therapy, according to research presented this week at the Digestive Disease Week conference in San Diego.
DDW: Endosonography Benefits Pancreatic Cancer Patients
WEDNESDAY, May 21 (HealthDay News) -- Recent advancements in pancreatic cancer research show that endosonographic evaluation improves patient survival, and that alcohol and tobacco use have dose-dependent effects on the age of presentation, according to study findings presented this week at the Digestive Disease Week conference in San Diego.
DDW: Advances May Benefit Celiac Disease Patients
TUESDAY, May 20 (HealthDay News) -- New research advances suggest that celiac disease may be prevented by AT-1001 -- an investigational drug that may decrease intestinal permeability. Another study suggests that the diagnostic criteria for celiac disease should be less restrictive. Both studies were presented this week at the Digestive Disease Week conference in San Diego.
DDW: New Endoscopic Surgery Technology Presented
TUESDAY, May 20 (HealthDay News) -- Natural orifice translumenal endoscopic surgery (NOTES) -- a new surgical technology -- may one day allow doctors to perform a wide range of procedures that are painless, scarless and involve less recovery time than laparoscopic surgery, according to research presented this week at the Digestive Disease Week conference in San Diego.
DDW: CT-Colonography Misses Many High-Risk Adenomas
MONDAY, May 19 (HealthDay News) -- Among a range of developments in colorectal cancer detection and sedation presented this week at the Digestive Disease Week conference in San Diego, new research suggests that computed tomographic colonography does not identify enough patients with important polyp findings, and that non-anesthesiologist-administered propofol sedation is safe.
DDW: Technique Identifies Suspicious GI Activity
MONDAY, May 19 (HealthDay News) -- Confocal laser endomicroscopy -- a new real-time microscopic technique that provides highly magnified images -- may expand endoscopy's diagnostic potential and help doctors immediately identify suspicious activity, according to research presented this week at the Digestive Disease Week conference in San Diego. Other research suggests that the current methods of using aberrant crypt foci to identify colon cancer may be unreliable due to subjective analysis.