Prognostic value of circulating tumor DNA at diagnosis and its early decrease after one cycle of neoadjuvant chemotherapy for patients with advanced epithelial ovarian cancer. An ancillary analysis of the CHIVA phase II GINECO trial.

Objective: To evaluate the prognostic impact of circulating tumor DNA (ctDNA) detection at diagnosis (T0) and its early decrease after one cycle (T1) of neoadjuvant chemotherapy (NACT) in patients with advanced epithelial ovarian cancer (EOC) included in the CHIVA trial (NCT01583322).

Methods: Blood samples were collected at T0 and before each administration of NACT. Circulating tumor DNA detection was performed by next-generation sequencing. Multivariate analysis was performed. A p-value of 0.05 was considered significant. Progression-free survival (PFS) and overall survival (OS) were compared between groups defined by ctDNA kinetic profile. Cox survival model was used to search variables associated with PFS and OS. Kaplan-Mayer curve was used to graphically express the differences in PFS and OS. A log-rank test compared the two curves.

Results: 188 patients were included. Blood samples were available for 168 patients at T0 and for 160 patients at T0 and T1 to assess ctDNA ratio kinetics. At T0, 107 patients (63.7 %) had detectable ctDNA. At T1, 137 (85.6 %) patients had negative ctDNA or a decrease of more than 80 %. There was a significant benefit in either PFS (p = 0.0017) or OS (p = 0.0036) in favor of early decrease of ctDNA ratio. A favorable decrease was associated with a greater likelihood of being able to perform CRS (OR: 3.94 (CI95 % 1.45-10.70), p = 0.0074).

Conclusions: Early decrease of ctDNA ratio can provide prognostic information early in the management of patients, allowing a more accurate information to patients and an early preparation for CRS (prehabilitation).