Serrated Polyposis Syndrome/Hyperplastic Polyposis Syndrome
What is serrated polyposis syndrome (SPS)?
Serrated polyposis syndrome (SPS) was formerly called hyperplastic polyposis syndrome. SPS is a rare condition that is characterized by serrated polyps in the colon and/or rectum.
Serrated polyps are a type of growth that stick out from the surface of the colon or rectum. The polyps are defined by their saw-toothed appearance under the microscope. They can often be hard to find. The only way to determine the types of polyps is by removing them and examining them under a microscope.
There are different types of serrated polyps, including:
- Hyperplastic polyps: These are the most common and are usually located on the left side of the colon. They are not usually precancerous. However, they might call attention to right-sided serrated spots.
- Sessile serrated polyps [(SSPs), also called sessile serrated adenomas (SSAs)]: These polyps are bigger and are located on the right side. They are not attached by stalks. They are hard to find on endoscopic examination and can turn into cancer somewhat quickly.
- Serrated adenomas (also called traditional serrated adenomas, or TSAs): These polyps are less common but have dysplasia (abnormal cells) and can progress to cancer.
SPS is defined and diagnosed by criteria set out by the World Health Organization (WHO). People with SPS have a higher risk of developing colorectal cancer and should have a colonoscopy every year once a diagnosis is made. It might be necessary to have colonoscopies every three to six month initially.
Who gets serrated polyposis syndrome (SPS)?
It appears that men and women get SPS at a similar rate. Diagnosis usually occurs when the person is in their 50s or 60s.
Is my family at risk for getting serrated polyposis syndrome (SPS)?
Various studies have suggested that SPS can be inherited, but the inheritance pattern is unknown. First-degree relatives (i.e., parents, siblings and children) of someone with SPS have an increased risk of developing SPS, as well as other colorectal polyps. Approximately 40% of first-degree relatives of people with SPS had polyps found on screening colonoscopy. First-degree relatives should be offered colonoscopy to start at one of the following times, whichever is the soonest: the age of the earliest diagnosis of SPS in the family; at age 40; or 10 years earlier than a diagnosis of colorectal cancer in an SPS family member. Following a baseline exam, colonoscopy should be repeated every five years if no polyps are found. If proximal serrated polyps or multiple adenomatous polyps are found, consider colonoscopy every 1 to 3 years.
Symptoms and Causes
What causes serrated polyposis syndrome (SPS)?
SPS results from a tendency to develop serrated polyps in the colon and/or rectum. The exact cause is unknown. Although SPS is believed to be hereditary, no genetic defect has been identified to cause SPS. This means that there is no genetic test that can diagnose SPS.
What are the symptoms of serrated polyposis syndrome (SPS)?
Symptoms are generally caused by the polyps or cancer that develop and are not specific to serrated polyps or to SPS. Common symptoms include:
Patients may not have any symptoms. If you do have any of the above symptoms, you should be evaluated by a physician.
Diagnosis and Tests
How is serrated polyposis syndrome (SPS) diagnosed?
SPS is a condition that is defined by WHO. The diagnosis is based on what the doctor sees during a colonoscopy (an endoscopic evaluation of the colon and rectum). The diagnosis is confirmed by a pathologist who looks at the polyps under a microscope. A patient meeting any one of the following criteria is diagnosed with SPS:
- The presence of 20 or more serrated polyps located anywhere in the colon
- The presence of 5 or more serrated polyps proximal to the sigmoid colon, at least two greater than 1 cm in size
- The presence of any serrated polyp in the colon in a patient with a family history of SPS
Some researchers are asking whether or not the WHO guidelines are too strict. They suggest that people who have multiple serrated polyps who do not meet the diagnosis of SPS are at a similar risk of developing colorectal cancer.
Management and Treatment
How is serrated polyposis syndrome (SPS) treated?
There is no cure for SPS. The treatment is directed at curing symptoms and removing polyps or cancers that are caused by SPS. What this means is having a colonoscopy and removal of polyps greater than 5 mm. This should be followed up with a colonoscopy every 1 to 3 years, depending on the number and size of polyps. Clearing of all polyps is preferable.
If the polyps cannot be safely or completely removed, or if a cancer is found, surgery is recommended. The usual approach to a colon cancer is to remove the entire colon and reconnect the small bowel to the rectum. The entire colon and rectum is at risk to developing these polyps and cancer. Therefore, any remaining colon or rectum still needs to be evaluated by endoscopy every year.
How is serrated polyposis syndrome (SPS) prevented?
Currently, we do not know any way to prevent SPS. However, the yearly colonoscopies are designed to prevent colorectal cancer or catch it at its earliest and most treatable stages.
Outlook / Prognosis
What are the cancer risks associated with serrated polyposis syndrome (SPS)?
People with SPS have an increased risk of developing colorectal cancer. About 25-40% of people with SPS will develop colorectal cancer. There are not any other cancer risks that have definitively been established to be associated with SPS and screening of other organs is not recommended.
When should I call the doctor if I have serrated polyposis syndrome (SPS)?
If you have SPS, or even if you do not, you should contact your doctor if you have blood in the stool or changes in bowel habits.
Are there any resources for people and families with serrated polyposis syndrome (SPS)?
Here are a few places to start:
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