A study published in the April 4 issue of JAMA reveals that patients who receive the drug cetuximab in addition to chemotherapy after undergoing surgery for stage III colon cancer do not have improved disease-free survival. According to the researchers, the chance of cure among patients who undergo surgery for removal of stage III colon cancer is 50%. Several studies have demonstrated the benefit of chemotherapy following surgery in lowering the recurrence risk. The authors write: "Specifically, [the drugs] leucovorin, fluorouracil, and oxaliplatin (FOLFOX or slightly different method, FLOX) provides significant benefit in both disease-free and overall survival compared with the prior standard of fluorouracil and leucovorin." For patients suffering metastatic colorectal cancer, cetuximab and panitumumab, alone or in conjunction with chemotherapy, have provided additional benefit than chemotherapy alone.
A team of researchers at Case Western Reserve University School of Medicine have identified a new mechanism by which colon cancer develops. By focusing on segments of DNA located between genes, or so-called "junk DNA, " the team has discovered a set of master switches, i.e., gene enhancer elements, that turn "on and off" key genes whose altered expression is defining for colon cancers. They have coined the term Variant Enhancer Loci or "VELs, " to describe these master switches. Importantly, VELs are not mutations in the actual DNA sequence, but rather are changes in proteins that bind to DNA, a type of alteration known as "epigenetic" or "epimutations." This is a critical finding because such epimutations are potentially reversible. Over the course of three years, the team mapped the locations of hundreds of thousands of gene enhancer elements in DNA from normal and cancerous colon tissues, pinpointing key target VELs that differed between the two types.
When combined with other treatments, the drug cetuximab - which works by slowing or stopping the growth of cancer cells - has been shown to extend survival in certain types of cancer, including metastatic colorectal cancers. Unfortunately, about 40 percent of colorectal cancer patients - specifically those who carry a mutated form of a gene called KRAS - do not respond to the drug. Researchers at Fox Chase Cancer Center in Philadelphia, however, have been working on a way to overcome this resistance to cetuximab by unleashing a second cetuximab driven mechanism using a novel drug called ARI-4175. The researchers from Fox Chase presented their findings at the AACR Annual Meeting 2012. In mice that had KRAS mutated colorectal cancer, researchers found that ARI-4175 not only blocked tumor growth when used alone, but also when used in combination with cetuximab.
A study, published in the April 9 issue of Archives of Internal Medicine, reveals that patients are less likely to undergo colorectal cancer screening if their physicians only recommend a colonoscopy, compared with patients who are advised to undergo fecal occult blood testing (FOBT), or patients who are given the choice between colonoscopy or FOBT. Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths in the U.S. CRC can be diagnosed through screening, and treatment during an asymptomatic phase can often lead to a complete cure. In order to determine whether recommending colonoscopy alone, FOBT, or giving patients at average risk for CRC a choice between the two was more effective, John M. Inadomi, M.D., of the University of Washington School of Medicine, Seattle, and his team conducted a randomized clinical trial involving 997 participants.
Tales from the crypt are supposed to be scary, but new research from Vanderbilt University, the HudsonAlpha Institute for Biotechnology and colleagues shows that crypts can be places of renewal too: intestinal crypts, that is. Intestinal crypts are small areas of the intestine where new cells are formed to continuously renew the digestive tract. By focusing on one protein expressed in our intestines called Lrig1, the researchers have identified a special population of intestinal stem cells that respond to damage and help to prevent cancer. The research, published in Cell, also shows the diversity of stem cells in the intestines is greater than previously thought. "Identification of these cells and the role they likely play in response to injury or damage will help advance discoveries in cancer, " said Shawn Levy, Ph.