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.