1025 Revisiting the Rotterdam regime in 2021: the impact of cisplatin and oral etoposide in refractory ovarian cancer in the era of great antiemetics

Introduction/Background* Weekly Cisplatin plus oral daily Etoposide (the Rotterdam regime (RR), 2002) has been shown to be effective in platinum refractory (PR) ovarian cancer (OC), with a documented response rate of 46%, with 29% complete response and overall survival (OS) of 13 months1. The RR is schedule intensive and can be difficult to tolerate, therefore may be underutilised as an option for patients with PR OC who have maintained a good performance status (PS). We are reporting our series of patients undergoing the RR with regards to efficacy and tolerability. Methodology Retrospective case series (n=13) with PR OC, and still fit (PS Result(s)* Ten had serous, 2 had clear cell carcinoma and 1 had carcinosarcoma of OC. The patients were heavily pre-treated, with 15% 3rd line, 55% 4th line, 25% 5th line, and 5% 7th line cancer treatment. Five women have died of OC, all within one year of starting the RR. Three patients have been converted back to P-S disease post-RR (23%), with one patient now alive 5 years after completing the RR. Of the remaining 5 women: Re-challenge with platinum (n=2); referred for a clinical trial (n=1), awaiting surgery for single site disease (n=1); still on the RR (n=1). Nausea and tiredness were the main side effects affecting 80% of all patients in their first 6 weeks. The RR had an improvised protocol with 4 antiemetics, and Magnesium sachet supplement. More than 70% had low Magnesium; and required supplement up to 5 weeks from completion of the last Infusion of Cisplatin. Tiredness was common and linked to low moods, which led to us setting up a ‘buddy-system’ for those about to embark on RR. Conclusion* The RR converted 23% of PR OC back to P-S, with further results awaited. One patient is now in her sixth-year post-RR and has continued to have P-S disease. Despite significant side effects nearly half of patients maintained a PS