A Retrospective Study of a Dexamethasone-Sparing Strategy of Preventing Acute and Delayed Emesis Caused by CapeOx Regimen with Aprepitant for Colorectal Cancer.

632 Background: CapeOx therapy which is combination with oxaliplatin (L-OHP) and capecitabine is one of the standard treatments for first line chemotherapy for unresectable colorectal cancer, or for postoperative adjuvant chemotherapy for stage III colon cancer. L-OHP-based regimen is classified as moderately emetogenic chemotherapy. In the SENRI trial which we previously conducted as phase III trial, aprepitant, an NK-1 antagonist, showed the efficacy for prevention of emesis against L-OHP. On the other hand, even when in highly emetogenic chemotherapy, it is reported that dexamethasone after day 2 could be spared. Methods: We retrospectively reviewed chemo-naive 94 patients with colorectal cancer who underwent CapeOx therapy at our institution from April 2012 to March 2017. We assessed the relationship between emesis during the first cycle of CapeOx (day1-5) and the use of dexamethasone on day 2-3. Results: 10 patients underwent CapeOx plus bevacizumab, and 84 underwent CapeOx. All patients received 5-HT3 receptor antagonist (palonosetron: 87, granisetron: 7). 50 patients received aprepitant on days 1-3 and dexamethasone on day 1 (APR+D1 group). 22 patients received aprepitant on days 1-3 and dexamethasone on days 1-3 (APR+D3 group). 15 were dexamethasone on days 1-3 without aprepitant (D3 group), and 7 were dexamethasone only on day 1 without aprepitant (D1 group). Acute complete response (CR; no vomiting and no rescue anti-emetics) rates were 100% in any groups. Delayed CR rate was 56% in APR+D1 group, 86% in APR+D3 group, 53% in D3 group, and 29% in D1 group, respectively. In multivariate linear regression with aprepitant, there was a significant difference in presence of dexamethasone (p = 0.028). Conclusions: Acute emesis could be prevented by even only 1-day administration of dexamethasone when combined with the triplet prophylactics. However, in order to sufficiently prevent delayed emesis induced by L-OHP, it was suggested that addition of DEX on days 2 and 3 might be better.