Does aggressive surgery only benefit patients with less advanced ovarian cancer? Results from an international comparison within the SCOTROC-1 trial

Abstract

5003 Background: Many small, retrospective clinical studies indicate that patients with ovarian cancer who have been ‘optimally’ debulked after primary surgery survive longer, and that although in most of these the chemotherapy has been variable, they have defined the standard of care with respect to the aims of surgery. In addition, it has been suggested that patients with ovarian cancer from the United Kingdom have an inferior survival compared to some other countries, possibly due to differences in surgical practice. We explored this within the context of a large international prospective randomised trial of 1st-line chemotherapy in advanced ovarian cancer (docetaxel/carboplatin vs. paclitaxel/carboplatin; SCOTROC-1). The SCOTROC surgical study is a prospective observational study. The aim was to evaluate the impact on progression free survival (PFS) of (a) cytoreductive surgery and (b) international variations in surgical practice. Methods: 1077 patients were recruited into SCOTROC-1; 689 from the UK and 388 from centres in Europe, USA and Australasia. Detailed surgical data were available for 889 patients. They were analysed within a Cox model. Results: There are three main observations: (1) More extensive surgery was performed in patients from non-UK centres and those patients were more likely to be optimally debulked (≤2cm) [71.3% vs 58.4%; p<.001]. (2) Optimal debulking is associated with an increase in PFS mainly for patients with less extensive disease at the outset [test for interaction p=0.003]. (3) Patients from the UK with no visible residual disease after surgery had a less favourable PFS compared to patients recruited from non-UK centres, who were similarly debulked [HR=1.85; 95%CI 1.16–2.97: p=0.010]. This observation appears to be related to surgical practice, and primarily lymphadenectomy. Conclusions: Increased PFS associated with ‘optimal’ surgery is mainly seen in those patients with less advanced disease. This argues for case selection rather than aggressive debulking in all cases irrespective of the extent of disease. Additionally lymphadenectomy may have beneficial effects on PFS in optimally debulked patients. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Chief Scientist Office, Edinburgh UK