Aim of our study was to identify the prognostic factors of secondary cytoreductive surgery on survival in patients with recurrent epithelial ovarian cancer. In our study, recurrent disease in the pelvis which can be easily removed and long disease free interval are independent prognostic factors.1

Kim et al. asked the benefit of secondary cytoreduction for platinum-sensitive and resectable tumors. Our clinical experience and published report support the curative role of secondary cytoreductive surgery in such patients.2 As Kim et al. described, the GOG 213 study may provided the answer for the role of secondary cytoreductive surgery compared to chemotherapy.3 However, we do not expect that patients should undergo secondary cytoreductive surgery from the results of GOG 213, because surgical candidates are determined tentatively and arbitrarily by surgeons before the first randomization in the GOG 213 trial. Before randomization, the surgeon's decision is the initial step in deciding which patients should be included and excluded. For example, some surgeons think that resection of a tumor at the porta hepatis or cardiophrenic lymph node,4 or a diaphragmatic tumor near the hepatic vein or conglomerated lymph node metastases near great vessel is feasible: they are surgical candidates for the GOG213 trial. Some surgeons do not think so, and they are excluded. The results from the GOG213 trial may offer clues for the role of secondary cytoreductive surgery but, true benefits at the bottom line we may not find. Every surgical trial has a big bias from surgeons themselves. For ovarian cancer, the bias could be enlarged because extensiveness of cytoreductive surgery quite differs between surgeons and/or hospitals.

We agree the Kim et al.'s comment on external validation of the criteria for secondary cytoreductive surgery. Currently, historical comparison is not allowed because patients' characteristics are quite different as far as we know. Our study included a significant number of ovarian cancer patients who underwent primary cytoreductive surgery at other hospitals: therefore the application of extensive cytoreductive surgery is quite questionable. Application of extensive cytoreductive effort at primary cytoreductive surgery may be another variable in the analysis of the role of secondary cytoreductive surgery.

In conclusion, we believe that extensive cytoreductive effort to remove tumor burden while allowing minimal surgical morbidity may be attempted for patients with recurrent ovarian cancer in moderation to the surgeon's experience and hospital facility.