It first begins as a small growth on the inner lining of the intestine (polyp), which over time becomes cancer.

(American Cancer Society 2023) harv error: no target: CITEREFAmerican_Cancer_Society2023 (help) Approximately 50% of adenomas of the small intestine arise in the duodenum even though this location comprises only 4% of the length of the small intestine.

[4] This area is also closely associated with the pancreas, so they are treated as pancreatic cancer.

Although it is referred to as the small intestine, it is the longest section of the GI tract being approximately 20 feet long.

The duodenum is the 1st section of small intestine and only about a foot long.

Most small intestine cancers (especially adenocarcinomas) develop in the duodenum.

Small intestine cancer: Symptoms, causes, Prognosis & Treatment.