Standard Versus Extended Neoadjuvant Chemotherapy: A Canadian Tertiary Centre Cohort Study of Ovarian Cancer Care Amidst the COVID-19 Pandemic

Abstract

To compare treatment response in patients with ovarian cancers treated with extended neoadjuvant chemotherapy compared to standard chemotherapy, a strategy adopted during the COVID-19 operating room closures. This retrospective cohort study included patients with ovarian cancers treated with neoadjuvant chemotherapy before interval debulking surgery at a Canadian tertiary care centre during the COVID-19 pandemic. Patients with extended neoadjuvant chemotherapy consisting of 6 cycles of chemotherapy prior to surgery were compared to patients receiving the standard 3 cycles of neoadjuvant chemotherapy followed by 3 cycles after surgery. The primary outcome was disease response to treatment measured by percent change in the biomarker CA-125. Secondary outcomes were disease extent at time of surgery, chemotherapy response scores, perioperative morbidity, and chemotherapy adverse events. Binary outcomes were ascertained by chi-square or Fischer exact tests and continuous outcomes were obtained by the Wilcoxon-rank sum test. A total of 9 patients received extended neoadjuvant chemotherapy and 18 patients received standard chemotherapy. Percent change in CA-125 levels between cycles 0–3 were similar between the extended neoadjuvant cohort (median 88.0%, IQR 52.4, 92.1) and the standard chemotherapy cohort (median 91.7%, IQR 79.8, 96.2), P = 0.38. The 6-cycle group had statistically significant less change in CA-125 between cycles 3–6 (median 31.9%, IQR 25.0, 46.7) compared to the standard group (median 90.7, IQR 76.9, 95.3), P = 0.001. The extent of disease at the time of surgery, chemotherapy response scores, perioperative outcomes and chemotherapy adverse events were similar between groups. Biochemical disease response to neoadjuvant chemotherapy slows after 3 cycles of chemotherapy.