Low-grade high-grade serous ovarian cancer: comparison of surgical outcomes after secondary cytoreductive surgery.

Objective: Retrospective series have shown secondary cytoreductive surgery improves oncological outcomes in recurrent low-grade serous ovarian cancer. We aim to compare surgical procedures and complications between patients with low-grade and high-grade recurrent serous ovarian cancer.

Methods: This retrospective single-institution study includes patients with recurrent low-grade and high-grade serous ovarian cancer undergoing surgery between January 2012 to December 2021. Patients were propensity matched 1:3 for residual tumor at first surgery, presence of ascites and performance status. Complexity of surgery and postoperative complications were analyzed.

Results: A total of 116 patients undergoing secondary cytoreductive surgery were included with 29 patients (25%) having low-grade ovarian cancer. The median age of the patients was 54 years (range: 19-85) and 57 years (range: 29-78) in low-grade and high-grade ovarian cancer, respectively (p=0.13). Stages III/IV at diagnosis were more frequent in patients with high-grade ovarian cancers (p<0.001). Peritoneal involvement was higher in low-grade compared with high-grade ovarian cancer as shown by the higher rate of diaphragmatic (41.4% vs 21.8%, p=0.05), abdominal wall (41.4% vs 18.4%, p=0.02) and pelvic (51.7% vs 21.8%, p=0.01) peritonectomy. Multiple bowel resections were higher in low-grade ovarian cancer (24.1% vs 8.0%, p=0.04), while high-grade ovarian cancer had a higher rate of nodal recurrences (73.2%% vs 37.9%, p=0.03). Overall, surgical complexity was higher in low-grade ovarian cancer (58.6% vs 36.8%; p=0.05), with higher median estimated blood loss (400 vs 200 mL; p=0.01) compared with high-grade. Complete cytoreduction was achieved in 26 patients (89.7%) with low-grade and 84 (96.6%) with high-grade (p=0.16) ovarian cancer, with no significant differences in postoperative complications.

Conclusions: Secondary cytoreductive surgery in low-grade serous ovarian cancer patients was associated with higher complexity, multiple bowel resections, and higher median estimated blood loss than in high-grade serous ovarian cancer. The comparable rate of postoperative complications suggests that secondary cytoreductive surgery in this group of patients is feasible in expert centers.