[Significance of prolonged NC as an endpoint of chemotherapy for solid tumors]

The goals of chemotherapy in patients with cancer should be both tumor shrinkage and extension of survival time. Believing that there is a clear correlation between the extent of treatment-induced tumor reduction and survival time, we have made an effort to reduce tumor size. However, many investigators have found no positive correlation between response rate and median survival time in various cancers, including non-small cell lung cancer and gastric cancer. If this is the case, we should reconsider our therapeutic strategy. We previously reported that doctors should induce a prolonged dormant phase rather than strive to shrink tumor mass in "Tumor Dormancy Therapy," because the survival of most patients with solid tumors depends on the length of the induced dormant phase rather than on induced tumor reduction. In this paper, we analyzed two Japanese phase II studies of gastric cancer. There were no significant differences between the survival of NC patients with TTP of more than 90 days and CR + PR patients in either study. These results suggest prolonged NC could contribute to longer survival, and we concluded that NC patients with greater than 90 days of TTP, that is "prolonged NC," exhibited similar survival relative to those with effective treatments and tumor shrinkage, and should be evaluated as a positive response.