Surgical interventions for focal progression of advanced gastrointestinal stromal tumors during imatinib therapy.
BACKGROUND
Although imatinib has shown high activity in the majority of patients with advanced gastrointestinal stromal tumors (GIST), it has become clear that secondary resistance appears during chronic therapy. The aim of this study was to retrospectively analyze the safety and prognostic effects of surgical interventions for focal progression during imatinib treatment.


METHODS
Between January 2002 and May 2005, 16 patients who had focal lesions of secondary-resistant GIST to imatinib treatment (male/female, 12:4; median age, 62 years) underwent surgical interventions such as resection, radiofrequency ablation, and their combination.


RESULTS
Postoperative complications, including liver abscess, bile leak, wound infection, and ileus were mostly mild, and the patients recovered with conservative therapy. There was no hospital death. The median time to progression (TTP) of all patients was 5.5 months, and only one patient died of the disease; the others are alive after a median follow up of 12.4 months. Patients with complete resections of resistant lesions (n = 7) showed significantly better median TTP than those with incomplete resections (n = 9; P = 0.014). The impact of curability on focal lesions with secondary resistance was mainly significant in patients with tumors of stomach origin (P = 0.013), and a smaller number (P = 0.014) and smaller size (P = 0.018) of resistant lesions. Overall survival was 100% at 1 year and 75% at 2 years.


CONCLUSIONS
Our study indicates that surgical interventions in patients with GIST resistant to imatinib therapy are efficacious when complete resections are performed, when the lesions are of gastric origin, when the number of lesions is lower, and when the lesions are a smaller size.
Hasegawa
Junichi
J
Department of Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
Kanda
Tatsuo
T
Hirota
Seiichi
S
Fukuda
Masafumi
M
Nishitani
Akiko
A
Takahashi
Tsuyoshi
T
Kurosaki
Isao
I
Tsutsui
Shusaku
S
Hatakeyama
Katsuyoshi
K
Nishida
Toshirou
T
D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000494:pharmacology; D001549:Benzamides; D003131:Combined Modality Therapy; D019008:Drug Resistance, Neoplasm; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000601:surgery*; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010879:Piperazines / Q000008:administration & dosage* / Q000494:pharmacology; D011743:Pyrimidines / Q000008:administration & dosage* / Q000494:pharmacology; D012189:Retrospective Studies; D016019:Survival Analysis
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate