[Effect of Upfront Dose Reduction in the First Cycle of Chemotherapy for Unresectable/Recurrent Gastric Cancers in Patients Aged Over 80 Years].

Chemotherapy for elderly patients requires ingenuity in treatment to mitigate its high risk. Therefore, we investigated an upfront dose reduction in the first cycle of chemotherapy for unresectable/recurrent gastric cancers in patients over 80 years old. We examined 6 patients over 80 years old, who underwent S-1 plus L-OHP therapy(SOX)for unresectable/recurrent gastric cancer in our department between January 2020 and January 2021. There were no adverse events over Grade 3 in the upfront dose reduction group(U group), while 1 case(50.0%)in the normal dose group(N group)experienced an adverse event over Grade 3. Moreover, only the U group continued treatment for 4 or more courses, whereas none from the N group did. Partial response(PR)was achieved as a therapeutic effect in 3 patients of the U group. Only 2 cases of the U group advanced to the second-line regimen and both were able to transition to the third-line regimen. However, none were able to even transition to the second-line regimen in the N group. Therefore, it was suggested that by reducing the dose of chemotherapy from the first cycle for elderly patients over 80 years old, the incidence of adverse events can be kept low, which makes it possible to continue long-term chemotherapy.