Fortunately, in today's day and age, genetics counseling is becoming a more common practice and is available for whole genomes or individual genes, depending on the needs of a patient. Initial screening for FAP involves an upper GI (gastrointestinal tract) endoscopy that discerns the approximate number of polyps present in the colon. If the number of adenomatous polyps is above average, then genetics screening can take place.
The three major types of screening for genes are Protein Truncation Assays (PTA), Denaturing Gradient Gel Electrophoresis (DGGE), and gene sequencing. When familial history of FAP is unknown for a patient, PTA is the most common method for APC gene screening. This test uses the latest in protein formation technologies to determine whether or not the patient's APC protein product is functional. DGGE and gene sequencing, on the other hand, rely on previously identified cases of FAP within a family before their use can take place, thus they are far less common screening methods at this point in time. DGGE uses an identified truncation from an FAP family member to sequence that same region in a patient. Gene sequencing is only used when a concrete history of FAP has been identified within a family. Regions surrounding the gene have been identified as genetic markers for sequencing machines to use to single out the APC gene alone for screening. The truncating mutations of the family's APC genes are compared to the same regions within the patient's APC gene to identify similar mutations within the genes.
FAP cancer development really cannot be prevented. Of course, there are certain steps that can be taken to postpone or prevent cancer progression. Diet is considered an important component of cancer formation because oxidative stress can quicken the process. Oxidative stress occurs as a result of eating foods that are difficult to digest, i.e. red meat, excess dietary fat, etc. Also, annual exams should be attended to maintain up-to-date and current statuses of a patient's colonic tissues. These exams include flexible sigmoidoscopies, colonoscopies and upper GI endoscopies. Each of the exams inspects a different aspect of intestinal tissues and should be attended annually beginning in children 10 to 12 years old in the case that family medical history points to FAP. If no polyps are found in a patient by the age of 25, exams can be attended on a less-regular basis. If large numbers of polyps are found, it is imperative that the patient continue annual examination and consider more serious treatment options.
Currently, the most common and effective treatment option for FAP and other colon cancer patients is a colectomy (removal of the large intestine/colon). Years ago, this surgery resulted in a patient's loss of the ability to naturally remove waste from the body; instead, waste was collected in a bag attached to the abdomen, where a hole was made for digestive emptying. Recently, a new colectomy development was made--the J pouch. Ileoanal Anastomosis surgery involves the removal of the colon/large intestine and the implementation of a pouch that attaches the small intestine to the anus for continued natural waste removal.
The Ileoanal Anastomosis (J-pouch) surgery is a two step process. During the first surgery, the infected portion of (or the entire) colon is removed. Once the colon is removed, a small portion at the end of the small intestine is brought up to form a J-loop, and once the loop is formed, the tissue in the middle of the loop is removed to create a reservoir. Special care is taken to suture the loop such that the end of the small intestine is now closed off. The lining of the rectum is then removed, but the sphincters muscles of the anus are retained. A hole is made in the bottom of the loop/reservoir to which the top of the anal canal is connected. Finally, a temporary ileostomy is performed, where the ileum tissue is cut and a path is made to divert digested materials through the abdomen for waste release while the newly formed reservoir and its connecting channels heal. During this time, a bag will be attached to the abdominal hole for waste retrieval. After a few months time, the second surgery is performed. The second surgery solely involves the reconnection of the ileum, which finally allows for food to travel from the stomach, through the small intestine into the fully healed J pouch reservoir to the anus for waste relief. While a small amount of training and practice is involved in learning to recover continence (control over one's own bodily functions), recovery from the second surgery is usually quite quick with few to no complications. Over time, a patient retains full bodily control and maintains continence through a proper diet and relaxation.
No comments:
Post a Comment