Impact of the time interval from completion of neoadjuvant chemotherapy to initiation of postoperative adjuvant chemotherapy on the survival of patients with advanced ovarian cancer

Objective To investigate the relationship of the time interval from the completion of neoadjuvant chemotherapy (NAC) to the initiation of postoperative adjuvant chemotherapy (POAC) with the survival outcomes in patients with ovarian cancer. Methods We retrospectively investigated 220 patients with pathologically confirmed epithelial ovarian cancer who received NAC at Yonsei Cancer Hospital between 2006 and 2016. The time interval was defined as the period from the completion of NAC, spanning interval debulking surgery (IDS), to the initiation of POAC. Results The median time interval was 42 (range 16–178) days; 103 patients (53.1%) received POAC within 42 days after NAC while 91 patients (46.9%) received it after 42 days. There were no significant differences in patient characteristics between these 2 groups. Kaplan-Meier analysis showed that patients with longer time intervals (> 42 days) had poorer progression-free survival and overall survival (P = 0.039 and 0.005, respectively). In the multivariate analysis, patients with longer time intervals had significantly poorer progression-free (hazard ratio, 1.41; 95% confidence interval, 0.98–2.03; not significant) and overall survivals (hazard ratio, 2.03; 95% confidence interval, 1.16–3.54). When the patients were categorized according to time interval quartiles (≤ 37, 38–42, 43–50, and > 50 days), longer time intervals were associated with higher risks of recurrence and death (P for trend: 0.006 and < 0.001, respectively). Conclusion The time interval from the completion of NAC to the initiation of POAC appears to influence survival. Efforts to reduce the time interval might improve the outcomes in ovarian cancer patients undergoing NAC.