Precancerous conditions of the small intestine have the potential to develop into small intestine cancer. The most common precancerous condition of the small intestine is adenomatous polyps (adenomasadenomasA non-cancerous (benign) tumour that starts in glandular cells (cells that release substances such as mucus, hormones and lubricating fluids).), which have the potential to turn into adenocarcinoma.
People with a polyposis syndrome have an increased risk of developing small intestine cancer. Polyposis syndromes are uncommon inherited conditions that cause people to develop large numbers of polyps. The polyposis syndromes most often associated with polyps and small intestine cancer are:
About 90% of people with FAP develop polyps in the small intestine, usually in the duodenum. People with FAP have an increased risk of developing adenocarcinoma of the small intestine some time during their lifetime. Some adenomas are more likely to progress to cancer than others, especially when there are many polyps or the polyps are large.
People with Lynch syndrome have up to 4% greater risk of developing small intestine cancer compared to people who don’t have Lynch syndrome.
The signs and symptoms of adenomatous polyps of the small intestine may include:
Doctors may recommend that people with adenomatous polyps have endoscopyendoscopyA thin, tube-like instrument with a light and lens used to examine or treat organs or structures in the body. every 3–4 years. They may need to have an endoscopy with a biopsy of large or suspicious polyps more often, if the doctor feels that the adenomas are likely to progress to cancer.
Doctors disagree on the best treatment for duodenal adenomas in people with FAP or Lynch syndrome. Treatment options may include removing the tumours through endoscopy or removing adenomas by surgery (polypectomy). However, adenomas tend to come back (recur) after they are removed.
Surgery may be an option for severe polyposis. Doctors will remove part of the small intestine (duodenum) and pancreas (pancreaticoduodenectomy), if necessary. Doctors may not need to remove the pylorus (the narrow, bottom part of the stomach near the small intestine) during this surgery (pylorus-preserving).