GIstromaalikasvaimissa

Gastrointestinal stromal tumors, often abbreviated as GISTs, are the most common mesenchymal tumors of the gastrointestinal tract. They arise from the interstitial cells of Cajal, which are specialized cells in the wall of the digestive system that act as pacemakers for gut motility. GISTs can occur anywhere along the GI tract, but the stomach and small intestine are the most frequent locations. They can also be found in the esophagus, colon, and rectum.

The majority of GISTs are sporadic, meaning they occur by chance and are not inherited. However, a small percentage are associated with inherited genetic syndromes such as neurofibromatosis type 1 and the Carney-Stratakis syndrome. These syndromes are linked to specific gene mutations that increase the risk of developing GISTs.

Symptoms of GISTs can vary widely depending on the tumor's size and location. Many small GISTs are asymptomatic and are discovered incidentally during investigations for other conditions. When symptoms do occur, they can include abdominal pain or discomfort, nausea, vomiting, bleeding from the GI tract (which may manifest as blood in the stool or vomiting blood), and a palpable mass in the abdomen. Significant weight loss and anemia can also be present.

Diagnosis typically involves imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) to identify the tumor. Endoscopy may also be used to visualize the tumor and obtain a biopsy. Definitive diagnosis is made through microscopic examination of a biopsy sample, which reveals characteristic cellular features and often specific molecular markers.

Treatment for GISTs depends on factors such as tumor size, location, stage, and the presence of specific gene mutations. Surgery to remove the tumor is the primary treatment for localized GISTs. For unresectable or metastatic GISTs, targeted therapy with tyrosine kinase inhibitors, such as imatinib, is the standard of care. These drugs work by inhibiting the signaling pathways that drive GIST growth, often leading to significant tumor shrinkage and improved survival. Ongoing research continues to explore new therapeutic strategies and improve outcomes for patients with GISTs.