The role of neoadjuvant imatinib mesylate therapy in sphincter-preserving procedures for anorectal gastrointestinal stromal tumor.
OBJECTIVE
To explore the role of neoadjuvant imatinib mesylate (IM) therapy in sphincter-preserving procedures for anorectal gastrointestinal stromal tumor (GIST).


METHODS
Between January and December of 2007, 3 patients with primary anorectal GIST who declined recommendations to receive abdominoperineal resection of the rectum, were treated with IM at a single institution. Tumor size, distance to anal edge, and the number of mitoses were compared before and after the treatment. After 12 weeks of IM therapy, conservative surgical procedures were performed.


RESULTS
After IM therapy for the 3 patients, computed tomography scan, colonoscopy, and biopsy showed a decrease in size of the rectal mass, an extension in the distance to anal edge, and a reduction in mitotic count. During this treatment regimen, the patients did not experience any side effects. A sphincter-preserving transsacral excision with direct coloanal anastomosis was performed and the resection margins were uninvolved on all sides. During 22 to 28 months postoperatively, the function of anal sphincter was satisfactory and no recurrence occurred among all 3 patients.


CONCLUSIONS
Neoadjuvant IM therapy for anorectal GIST is safe and effective. Tumor shrinkage and an extension of the distance to anal edge have a clear benefit for the local excision, in terms of feasibility, function preservation, and safety.
Wang
Jian-Ping
JP
Gastrointestinal and Anal Hospital, Sun Yat-Sen University, Guangdong, China. wjp@mail.sysu.edu.cn
Wang
Ting
T
Huang
Mei-Jin
MJ
Wang
Lei
L
Kang
Liang
L
Wu
Xiao-Jian
XJ
D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000473:pathology*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001005:Anus Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D001549:Benzamides; D005240:Feasibility Studies; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D010879:Piperazines / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011743:Pyrimidines / Q000627:therapeutic use*; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases