Disparities in GC chemotherapy between the East and West.
Atsushi Ohtsu
Research Center for Innovative Oncology,
National Cancer Center Hospital East, Kashiwa, Japan.
There are still remarkable disparities in the treatment of gastric cancer between the East and the West. Treatment outcomes for this disease have improved in Japan and Korea due to early detection, endoscopic treatment, and increased surgical expertise with D2 resection, whereas gastric cancer remains a virulent disease in Western countries. Several disparities are also evident in the results of chemotherapy trials for advanced gastric cancer. In Western studies, two triplet regimens have already demonstrated significant prolongation of survival; however, these benefits seem to be marginal and the regimens may be replaced by newer treatments. In the East, doublet regimens particularly fluorouracil and platinum are more popular. Studies testing newer treatments in 1,300 patients in Japan, such as JCOG 9912, SPIRITS, and TOP002 studies, have proved that S-1+cisplatin become the standard regimen with favorable survival. When the outcomes of the Japanese studies were compared with those in the Westerns, overall survival seems better than Westerns, which might be caused by higher rate of administration of second line or further chemotherapy. S-1 also shows very favorable safety profile for Asian populations that may enable patients easy to receive subsequent chemotherapy. This agent as used in postoperative adjuvant chemotherapy has also provided significantly higher cure rate after D2 surgery in patients with stage II-III disease (ACTS-GS trial). Based on these results, the Japanese Gastric Cancer Association has determined that S-1+cisplatin for metastatic disease and S-1 monotherapy in stage II-III postoperative adjuvant therapy should be considered as a standard treatment. Although this agent shows remarkable ethnic differences in toxicity unfavorable for Western populations, it seems likely that this agent provide good efficacy with favorable safety profile for gastric cancer patients in Asia. This agent is also currently being evaluated in combination with other cytotoxic and molecular targeting agents. In this seminar, the latest evidences of S-1 including PK and biomarker studies will be presented.
