Gastrointestinal cancer and brain metastasis: a rare and ominous sign.

Metastatic brain tumors represent 20% to 40% of all intracranial neoplasms and are found most frequently in association with lung cancer (50%) and breast cancer (12%). Although brain metastases occur in <4% of all tumors of the gastrointestinal (GI) tract, the incidence of GI brain metastasis is rising in part due to more effective systemic treatments and prolonged survival of patients with GI cancer. Data were collected from 25 studies (11 colorectal, 7 esophageal, 2 gastric, 1 pancreatic, 1 intestinal, 3 all-inclusive GI tract cancer) and 13 case reports (4 pancreatic, 4 gallbladder, and 5 small bowel cancer). Brain metastases are found in 1% of colorectal cancer, 1.2% of esophageal cancer, 0.62% of gastric cancer, and 0.33% of pancreatic cancer cases. Surgical resection with whole brain radiation therapy (WBRT) has been associated with the longest median survival (38.4-262 weeks) compared with surgery alone (16.4-70.8 weeks), stereotactic radiosurgery (20-38 weeks), WBRT alone (7.2-16 weeks), or steroids (4-7 weeks). Survival in patients with brain metastasis from GI cancer was found to be diminished compared with metastases arising from the breast, lung, or kidney. Prolonged survival and improvement in clinical symptoms has been found to be best achieved with surgical resection and WBRT. Although early treatment has been linked to prolonged survival and improved quality of life, brain metastases represent a late manifestation of GI cancers and remain an ominous sign.