Clinical practice guidelines for gastrointestinal stromal tumor (GIST) in Japan: English version.

Diagnostic and treatment strategies for gastrointestinal stromal tumors (GISTs) have evolved greatly since the introduction of molecularly targeted therapies. Although several clinical practice guidelines are extant, such as those published by the National Comprehensive Cancer Network and the European Society of Medical Oncology, it is not clear as to whether these are appropriate for clinical practice in Japan. Therefore, clinical practice guidelines for the optimal diagnosis and treatment of GIST tailored for the Japanese situation have often been requested. For this reason, the Japanese Clinical Practice Guideline for GIST was proposed by the GIST Guideline Subcommittee, with the official approval of the Clinical Practice Guidelines Committee for Cancer of the Japan Society of Clinical Oncology (JSCO), and was published after assessment by the Guideline Evaluation Committee of JSCO. The GIST Guideline Subcommittee consists of members from JSCO, the Japanese Gastric Cancer Association (JGCA), and the Japanese Study Group on GIST, with the official approval of these organizations. The GIST Guideline Subcommittee is not influenced by any other organizations or third parties. Revision of the guideline may be done periodically, with the approval of the GIST Guideline Subcommittee, either every 3 years or when important new evidence that might alter the optimal diagnosis and treatment of GIST emerges. Here we present the English version of the Japanese Clinical Practice Guideline for GIST prepared by the GIST Guideline Subcommittee.

Role of the MTT chemosensitivity test in the prognosis of gastric cancer patients after postoperative adjuvant chemotherapy.

The clinical usefulness of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) chemosensitivity test (MTT assay; MTTA) in the selection of anticancer drugs against advanced gastric cancer (AGC) was evaluated. MTTA is widely used to predict patient responses to particular drugs, allowing for the selection of appropriate chemotherapeutic drugs and the avoidance of ineffective chemotherapeutic drugs, thereby improving patient survival. Since 1989, we have accumulated MTTA efficacy data from AGC patients. In this study, the present clinical roles of MTTA and the data from 202 patients with stage III or IV gastric cancer analyzed for survival outcome following surgery, with or without postoperative chemotherapy, evaluated by MTTA, are discussed. The patients were divided into 3 groups; an adapted group found to be sensitive to chemotherapy by MTTA, a non-adapted group found to be insensitive to chemotherapy by MTTA and a group that received no chemotherapy. For stage III gastric cancer patients, the adapted group had a statistically better survival rate compared to the other groups, while for stage IV patients, there was no difference in survival rate between any of the groups. However, further classification of stage IV patients as to the presence or absence of peritoneal dissemination (P) showed that the adapted group with P showed better prognoses than the other groups with P. The analysis of data collected since 2000 revealed that the 11 patients in the taxane-adapted group, who received chemotherapeutic regimens that included taxanes and were found to be sensitive to taxanes by MTTA, demonstrated better survival than the taxane non-adapted group (n=11) (p=0.045). In conclusion, MTTA results predicted patient prognoses, based on the selection of appropriate chemotherapy.

Cancer chemotherapy chemosensitivity testing is useful in evaluating the appropriate adjuvant cancer chemotherapy for stages III/IV gastric cancers without peritoneal dissemination.

BACKGROUND: Because of the low chemosensitivity of gastric cancer to conventional antitumor agents, the role of adjuvant chemotherapy for patients with advanced gastric cancer is controversial. We have previously proposed the necessity to evaluate the appropriateness of particular adjuvant cancer chemotherapies in individual advanced gastric cancer patients using chemosensitivity testing. In the present study, we compared the chemosensitivity and clinical outcomes of patients with Stages III and IV gastric cancer. PATIENTS AND METHODS: A total of 282 patients with advanced gastric cancer were analyzed retrospectively in terms of chemosensitivity as detected by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and survival outcome after surgery. Patients were split into groups according to Stage III or IV gastric cancer, then categorized into those that received surgery without chemotherapy (surgery-alone), and those that received adjuvant chemotherapy, for which all the evaluable cases were further divided into sensitive and resistant cases as determined by MTT assay. RESULTS: For Stage III gastric cancer patients, the sensitive group had a more favorable survival outcome than the other two groups. For Stage IV gastric cancer patients, the sensitive groups, had a more favorable survival outcome than the other two groups, but only in the absence of peritoneal dissemination. CONCLUSION: Chemosensitivity testing, based on the MTT assay, was useful in evaluating the appropriate cancer chemotherapy for patients with Stages III/IV gastric cancer without peritoneal dissemination.