Clinical features and natural history of small intestinal tumors have not been clearly studied, as its a rare condition. Depending on the extent of the tumor at the time of diagnosis, the prognosis may vary. However, the prognosis is generally regarded as poor. Small intestine adenocarcinoma is associated with a 5 year survival rate of 20%.

• Clinical features and natural history of small intestinal tumors have not been clearly studied, as its a rare condition.^[1]
• Although, primary adenocarcinoma is the most common type of small intestine cancer, there is no known pattern of its natural history.^[2]
• Natural history of carcinoid tumors depends on several factors:^[3]
  • Size
  • Site of origin
  • Growth pattern
  • Hormone dependence
  • Neuropeptides and amines expressed by a carcinoid
  • Amount of biologically active neuro-hormones secreted

• Small intestine cancer are diagnosed in advance stage due to absence of specific symptoms and suspicion.
• Most complications appear after the resection of the tumor post-operatively.^[4]
• When tumor grow larger to obstruct the lumen of intestine symptoms of constipation and obstruction appear.
• Tumor may invade vessels of intestine and may lead to melena and hemorrhage.

• The overall 5-year survival rate for resectable adenocarcinoma is only 20%. The 5-year survival rate for resectable leiomyosarcoma, the most common primary sarcoma of the small intestine, is approximately 50%.
• The prognosis of small intestine cancer depends on the following:
  • Whether or not the tumor can be removed by surgery.
  • The stage of the cancer, the size of the tumor, whether the cancer has spread outside the small intestine.
  • The patient’s general health.
  • Whether the cancer has just been diagnosed or has recurred.
• Adenocarcinoma of the duodenum is associated with low overall survival rate compared to the tumors located in jejunum and ileum.^[5]