Introduction/Background*The current gold standard in the surgical management of advanced ovarian cancer(AOC) recommended by ESGO and ASCO is complete resection of all visible disease. If this is not deemed possible in the upfront setting, then interval cytoreductive surgery should be undertaken after ≤4cycles of NACT. Occasionally due to the persistence of unresectable sites of disease on interval scanning or because of factors associated with fitness for surgery, surgery in the interval setting may not be possible.

Limited published data assessing outcomes from surgery delayed to after 5 or 6 cycles of NACT(delayed cytoreductive surgery) suggests a potential benefit over no surgery and suggests that if interval cytoreductive surgery is not possible, then the clinician might consider delayed surgery on a case by case basis.

We sought to review the outcomes of patients with AOC presenting to the Northern Gynaecological Oncology Centre(NGOC) who underwent delayed surgery.

Methodology This study is a retrospective analysis looking at patients with AOC referred to the Northern Gynaecological Oncology Centre(NGOC), Gateshead, UK between 2017 and 2020, who were not deemed suitable to undergo either primary cytoreductive or interval debulking surgery and instead had DDS following 5 or 6cycles of NACT .

Result(s)*Over the 3 year period, 401 patients with AOC were referred to the NGOC MDT. 25 patients had delayed surgery, 16(66.7%) patients had surgery after 5 cycles of chemotherapy, 7(28%) patients had surgery after 6 cycles and there was incomplete data in 1 patient. The median age was 64. 66.7%(16/24) presented with stage IIIc disease, 12.5%(3/24) were stage IVa and 20.8%(5/24) were stage IVb. The majority had high grade serous carcinoma(91.7%). All patients had platinum based NACT(Carboplatin), 17 had dual agent chemotherapy with Paclitaxel and 3 had additional Bevacizumab.

18/19 received post-operative chemotherapy and complete cytoreduction was achieved in 17/24(71%) patients. Sub-optimal cytoreduction was more common in patients having surgery after 6 cycles and the median overall survival was 24 months in those completely cytoreduced compared to 9.5months in those with residual disease(p=0.03).

Conclusion*A significant improvement in OS is seen in women who are completely cytoreduced after ≥5 cycles compared to those with residual disease post-operatively. Therefore, if complete clearance can be achieved, cytoreductive surgery should be offered to all patients even after ≥5 cycles.