What is the role of retroperitoneal exploration in optimally debulked stage IIIC epithelial ovarian cancer? An NRG Oncology/Gynecologic Oncology Group ancillary data study.

BACKGROUND

The purpose of this study was to determine the effect of retroperitoneal (RP) exploration on progression-free survival (PFS) and overall survival (OS) in epithelial ovarian cancer (EOC) patients with stage IIIC disease who underwent optimal debulking surgery.

METHODS

Data were collected from records of the Gynecologic Oncology Group 182 (GOG-182) study of stage IIIC EOC patients cytoreduced to no gross residual disease (R0) or minimal gross residual (<1 cm) disease (MGRD) at primary surgery. Patients with stage IIIC disease by intraperitoneal (IP) tumor were included and divided into 3 groups: 1) > 2 cm IP tumor without lymph node involvement (IP/RP-), 2) > 2 cm IP tumor with lymph node involvement (IP/RP+), and 3) > 2 cm IP tumor with no RP exploration (IP/RP?). The effects of disease distribution and RP exploration on PFS and OS were assessed using Kaplan-Meier and proportional hazards methods.

RESULTS

There were 1871 stage IIIC patients in GOG-182 who underwent optimal primary debulking surgery. Of these, 689 (36.8%) underwent RP exploration with removal of lymph nodes from at least 1 para-aortic site, and 1182 (63.2%) did not. There were 269 patients in the IP/RP- group, 420 patients in the IP/RP + group, and 1182 patients in the IP/RP? group. Improved PFS (18.5 vs 16.0 months; P < .0001) and OS (53.3 vs 42.8 months; P < .0001) were associated with RP exploration versus no exploration. Patients with MGRD had improved PFS (16.8 vs 15.1 months, P = 0.0108) and OS (44.9 vs 40.5 months, P = 0.0076) versus no exploration.

CONCLUSIONS

RP exploration at the time of primary surgery in patients with optimally debulked stage IIIC EOC is associated with a survival benefit. Cancer 2017;123:985-93. © 2016 American Cancer Society.