Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2026

Patient selection for primary cytoreduction or neoadjuvant chemotherapy in the treatment of ovarian cancer over time (146531)

Tanya Ross 1 , Susan Jordan 1 2 , Renhua Na 1 2 , Michael Friedlander 3 4 , Peter Grant 5 , Anna DeFazio AM 6 7 8 9 , Sian Fereday 10 , Dinuka Ariyaratna 10 , Penelope Webb 1 2
  1. Population Health, QIMR Berghofer, Brisbane, QLD, Australia
  2. School of Public Health, University of Queensland, Herston, QLD, Australia
  3. Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
  4. Department of Medical Oncology, Prince of Wales Hospital, Sydney, NSW, Australia
  5. Department of Obstetrics, Gynaecology and Newborn Health, The University of Melbourne, Melbourne, VIC, Australia
  6. Department of Gynaecological Oncology, Westmead Hospital, Westmead, Sydney, NSW, Australia
  7. The Daffodil Centre, The University of Sydney, a joint venture with Cancer Council NSW, Sydney, NSW, Australia
  8. Centre for Cancer Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, Sydney, NSW, Australia
  9. Faculty of Medicine and Health, The University of Sydney, Sydney, NSW
  10. Peter MacCallum Cancer Centre, Melbourne, VIC, Australia

Aims: To describe temporal changes in the use of neoadjuvant chemotherapy and rates of complete cytoreduction (no macroscopic residual disease) in real-world Australian ovarian cancer cohorts.

Methods: We used data from two population-based cohort studies of adults aged 18-79 with ovarian, fallopian tube and peritoneal cancers diagnosed between 2002-2006, (the Australian Ovarian Cancer Study, AOCS), and 2012-2015 (the Ovarian cancer Prognosis And Lifestyle, OPAL study). Baseline and follow-up clinical data was collected from medical records including FIGO stage, residual disease, and treatment. Frequencies of neoadjuvant chemotherapy use and complete cytoreduction were calculated for both populations.

Results: We included 1194 AOCS and 684 OPAL participants diagnosed with FIGO stage III/IV disease. Use of neoadjuvant chemotherapy increased over the 10-year period, from 16% in AOCS to 47% in OPAL. The overall rate of complete cytoreduction also increased from 27% to 48%, with similar changes seen among those who had primary cytoreduction (26% to 45%) and interval cytoreduction (34% to 55%).

Conclusions: In parallel with the increasing use of neoadjuvant chemotherapy, rates of complete cytoreduction have increased among women with stage III/IV ovarian cancer. The observation that around half of those selected for primary cytoreduction now have no residual disease following surgery suggests selection of patients for primary cytoreduction or neoadjuvant chemotherapy is in keeping with guidelines.