Factors associated with response to neoadjuvant chemotherapy in advanced stage ovarian cancer

To evaluate the factors associated with response to neoadjuvant chemotherapy (NACT) and the ability to undergo interval tumor reductive surgery (iTRS) in patients with advanced ovarian cancer.

We performed a retrospective review from April 2013 to March 2019 of patients with advanced stage ovarian cancer triaged to NACT based on our standard triage algorithm. Clinicopathologic and treatment data were analyzed for factors associated with response to NACT, outcomes at iTRS, and their impact on progression-free survival (PFS).

562 patients met inclusion criteria and triaged to NACT following laparoscopy (n = 132) or without laparoscopy (n = 430). 413 patients underwent iTRS (74%). Factors that correlated with a patient reaching iTRS included increasing age (p < 0.001), higher Charlson comorbidity index (p < 0.001), ECOG status 2 or 3 (<0.001), and laparoscopic assessment (<0.001). Patients with CA-125 ≤ 35 U/mL at iTRS had higher rates of complete gross resection (88% vs. 65%, p < 0.001) and improved PFS (16.8 vs. 12.7 months, p < 0.001). Patients receiving dose-dense paclitaxel (76% vs. 60%, p = 0.004) and CA-125 ≤ 35 U/mL at iTRS (85% vs. 66%, p < 0.001) had higher rates of complete radiographic response. On multivariate analysis, germline BRCA 1/2 mutation (p = 0.001), iTRS vs. no surgery (R0, p < 0.001; ≤1 cm, p < 0.001; >1 cm, p < 0.001), dose-dense chemotherapy (p = 0.01), and CA-125 ≤ 35 U/mL at iTRS (p = 0.001) were independent significant factors affecting PFS.

Normalization of CA-125 at the time of iTRS following NACT may serve as a surrogate marker for prognosis in this high-risk population. Our NACT cohort experienced improved response rates and PFS with dose-dense therapy compared to conventional dosing.