title: Molecularly targeted therapy and radiotherapy in the management of localized gastrointestinal stromal tumor (GIST) of the rectum: a case report.
abstract: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. The main treatment for localized gastrointestinal stromal tumors is surgical resection. These tumors respond poorly to conventional cytotoxic chemotherapy agents and to radiotherapy. Imatinib mesylate, a small-molecule kinase inhibitor, has proved useful in the treatment of recurrent or metastatic GISTs and is now being tested in the adjuvant and neoadjuvant setting. The role of radiotherapy in the management of patients with GIST is currently restricted to symptomatic palliation. We present the case of a 54-year-old man affected by rectal GIST extending to the anal canal, with constipation, hematochezia, and anal pain. He received imatinib, 400 mg orally per day, for a week before and during radiation therapy. Irradiation was delivered to the gross tumor volume by 3D conformal therapy. The planned total dose was 50.4 Gy in fractions of 1.8 Gy daily. We observed a partial clinical response 3 weeks after the end of combination treatment. The patient then underwent a sphincter-saving surgical procedure. There was no perioperative morbidity and a complete pathological response was obtained. At the present time, the role of radiotherapy in the management of patients with GIST is restricted to symptomatic palliation. The introduction of molecularly targeted therapy combined with radiation therapy could improve the outcomes for patients diagnosed with GIST.
authors: Cattedra di Radioterapia Oncologica, Università Campus Bio-Medico, Rome, Italy. m.ciresa@unicampus.it
authors: Marzia
authors: M
authors: Ciresa
authors: Rolando Maria
authors: RM
authors: D'Angelillo
authors: Sara
authors: S
authors: Ramella
authors: Francesco
authors: F
authors: Cellini
authors: Diego
authors: D
authors: Gaudino
authors: Gerardina
authors: G
authors: Stimato
authors: Michele
authors: M
authors: Fiore
authors: Carlo
authors: C
authors: Greco
authors: Raffaele
authors: R
authors: Nudo
authors: Lucio
authors: L
authors: Trodella
mesh_terms: D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001549:Benzamides; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects; D005355:Fibrosis / Q000209:etiology; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D000068877:Imatinib Mesylate; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000209:etiology; D020360:Neoadjuvant Therapy / Q000379:methods; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use*; D011743:Pyrimidines / Q000009:adverse effects / Q000627:therapeutic use*; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D020266:Radiotherapy, Conformal / Q000009:adverse effects; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate