Earlier this month, I presented the updated colon cancer screening guidelines and commented how virtual colonoscopy may improve screening rates due to its less invasive nature than the traditional colonoscopy. My premise was that patient discomfort served as a primary deterrent to higher rates of colonoscopy use. Data from a recently published Vanderbilt study, however, beg to differ and suggest that other factors account for the inadequate rates of colon cancer screening in the United States.
The study population was derived from the Southern Community Cohort Study (SCCS), a large research endeavor to characterize cancer trends and disparities across racial and socioeconomic backgrounds. The group comprises 51,454 patients (ages 40-79 years) collected from 48 community health centers. The exclusion criteria for this particular study included the following: race other than African-American or Caucasian; uncertainty of whether the patient has had a sigmoidoscopy or colonoscopy; and, uncertainty of family cancer history. This left 41,830 participants, who were surveyed on personal demographics, personal history of colorectal polyps, family history of colon cancer, patterns of undergoing screening endoscopy, and last visit to a health care provider.
Read more … »
Late last year, I met my new 64 year-old clinic patient who just moved into town. During a brief discussion about preventive health, I asked her when she had her last colonoscopy for colon cancer screening. She emphatically responded: “Never. I will probably be dead in 10 years anyway [from an unrelated cause]“. Her view on life may have been surprising, but her reluctance to obtain a colonoscopy wasn’t. Who could blame her? The prospect of having a scope inserted into the rectum and advanced through the colon is not appealing. Fortunately, there are alternate modalities for colon cancer screening, two of which (stool DNA and virtual colonoscopy) have just been added to official guidelines.
A consortium of specialty organizations (American Cancer Society, US Multi-Society Task Force on Colorectal Cancer, and American College of Radiology) recently published in CA: A Cancer Journal for Clinicians1 the first consensus guidelines for colorectal cancer (CRC) screening. The guidelines are designed for asymptomatic average-risk adults over the age of 50; these criteria exclude individuals with a personal or family history of CRC, adenomas, inflammatory bowel disease (IBD), or other genetic risk factors.
Read more … »
Posted November 24th, 2007 in
Cases & Stories,
GastroenterologyThe latest issue of The New England Journal of Medicine features an unusual case of trichobezoar (tricho- for “hair”; bezoar for “indigestible mass in stomach or intestine”), otherwise known as a stomach hairball. The patient is an 18 year-old lady who presented to the Rush University Medical Center (Chicago, IL) with a 5-month history of abdominal pain and vomiting with meals. Computed tomography (CT) demonstrates a large mass in the stomach (see Figure A), which likely contributed to the reported symptoms. Esophagogastroduodenoscopy (EGD)–the insertion of a camera via the oral cavity and advanced to the upper segments of the digestive tract–was able to visualize the impressive bezoar (see Figure B), measuring 37.5 x 17.5 x 17.5 cm. It was later discovered the patient had a habit of eating her own hair (trichophagia). The only option for removal was open surgery. The extracted bezoar weighed 4.5 kg and can be seen in Figure C. Not surprisingly, the patient stopped eating her hair, experienced an improvement in symptoms, and eventually regained her weight.
In this week’s issue of the journal Nature, researchers at the Washington University in Saint Louis reported on bacteria and their contribution to obesity. The mouse studies indicated that certain bacterial species were more abundant in obese mice than their lean counterparts. The “obese” bacteria were also found to harvest energy from food more efficiently with less calorie content excreted as waste. Bacterial flora from obese and lean mice were introduced in “germ-free” mice, and mice with the “obese” microbiota experienced a significantly greater increase in body fat. The group had published a related study several years ago, so the idea is not completely novel. On the other hand, it is an interesting concept that has not yet reached common knowledge.
Before anybody blames their gut bacteria as the source of obesity, recall that the study was performed on mice. The findings may or may not translate to humans. The authors describe a related study (Webb et al.) that involved human subjects. Obese individuals were noted to excrete less fecal energy than lean subjects. Although the results were not statistically significant, more research is still needed before discounting bacterial involvement in human obesity. Let us also remember that obesity results from a combination of factors. Dietary intake, physical activity, and genetic composition strongly influence body weight. In the study, the authors equalized food consumption among groups to minimize this possible confounder. Five Big Macs in the mouths of “lean” mice can still produce more weight gain than in “obese” mice fed peanuts.
The implications of the study are fascinating. Consider the potential for future gut therapy (e.g., GoLytely and antibiotic bowel prep, followed by customized bacterial inoculation) to treat obesity or promote weight loss. Time to file my patent!
- Turnbaugh PJ, Ley RE, Mahowald MA, Magrini V, Mardis ER, Gordon JI. An obesity-associated gut microbiome with increased capacity for energy harvest. Nature 2006;444:1027-31.
- Backhed F, Ding H, Wang T, Hooper LV, Koh GY, Nagy A, Semenkovich CF, Gordon JI. The gut microbiota as an environmental factor that regulates fat storage. Proc Natl Acad Sci U S A 2004;101:15718-23.
- Webb P, Annis JF. Adaptation to overeating in lean and overweight men and women. Hum Nutr Clin Nutr 1983;37:117-31.
Technorati Tags:
obesity
bacteria
diet
metabolism
gastroenterology
medicine
medical
health
