Results of IDS (after three to four courses of induction chemotherapy) were compared with PDS followed by chemotherapy in patients treated for advanced stage ovarian cancer (stage IIIC or IV).

A retrospective study was done on a group of 57 patients who underwent IDS (because of an unresectable tumor) compared with a group of 28 patients treated with PDS (for resectable disease) followed by chemotherapy. All patients were treated between 1996 and 2001 by the same team of surgeons and received the same regimen of chemotherapy (platinum based plus paclitaxel).

Optimal cytoreductive surgery (residual disease ≤ 2 cm) was achieved in IDS and PDS groups in 84% (48 of 57) and 100% (28 of 28) of patients, respectively. Complete resection was observed in 51% (29 of 57) of patients in the IDS group and 54% (15 of 28) of patients in the PDS group. The rates of bowel resection, large peritoneal resection, and postoperative morbidity were significantly reduced in the IDS group. After adjusting for the size of residual disease (≤ 2 cm and absence of residual tumor), overall and event-free survival were not different in the two groups.

Survival rates were similar in patients with advanced stage ovarian cancer who underwent IDS or PDS. The rates of surgical resection and morbidity were reduced after IDS. IDS can be safely used in unresectable advanced stage ovarian cancer.