Impact of venous thromboembolism on timing and outcomes of interval debulking surgery among patients treated with neoadjuvant chemotherapy for advanced ovarian cancer (370)

Abstract

Objectives: Patients with advanced ovarian cancer receiving neoadjuvant chemotherapy (NACT) are at risk for venous thromboembolism (VTE). Timely interval debulking surgery (IDS) remains an important component of treatment for this population, but the impact of VTE on IDS outcomes is not well-defined. Our primary objective was to describe the effect of VTE on the length of time between cancer diagnosis and IDS. Our secondary objective was to evaluate the relationships between VTE and outcomes at the time of IDS. Methods: A retrospective cohort study was conducted among patients with advanced ovarian, fallopian tube, or peritoneal cancer receiving 3-6 cycles of NACT prior to IDS from 2000-2019 at two academic institutions. Patients who developed a new VTE (deep venous thrombosis or pulmonary embolism) from the time of cancer diagnosis until IDS were compared to those who did not. The primary outcome of interest was the duration of time from cancer diagnosis to IDS (days). Secondary outcomes included achievement of optimal debulking (defined as either no gross residual disease or residual disease < 1 cm), estimated blood loss (EBL) > 500 cc, route of surgery (laparotomy vs minimally invasive), and duration of surgery (minutes) at the time of IDS. Baseline characteristics and clinical variables were abstracted. Simple descriptive statistics, t-tests, Chisquare, and multiple linear regression were employed. A p-value < 0.05 defined statistical significance. Results: There were 217 patients in the overall cohort. Of these, 38 experienced a VTE (17.5%), including 24 at diagnosis and 14 after initiating NACT. Baseline characteristics (age, body mass index, CA-125, and stage) were similar between the two cohorts. Patients with VTE had a longer time to IDS (141.9 vs 122.8 days, p=0.02) and received a greater number of NACT cycles (4.5 vs 4.0, p=0.046). After adjusting for confounders (age, stage, and performance status), the association between VTE and time to IDS was maintained with a mean increase in time to IDS of 21.5 days for those with VTE (95% CI: 6.0-37.1, p=0.007). As summarized in Table 1, there were no significant differences in any of the secondary IDS outcomes, including optimal debulking, EBL > 500 cc, route of surgery, or duration of surgery. Conclusions: Patients developing new VTE from the time of cancer diagnosis to completion of NACT experience significant delays to IDS compared to those without VTE. IDS outcomes, including optimal debulking rates, blood loss, route of surgery, and duration of surgery, were not impacted by VTE in this small sample. Further prospective work is needed to elucidate the effect of VTE events on long-term outcomes among patients with advanced ovarian cancer treated with NACT. Objectives: Patients with advanced ovarian cancer receiving neoadjuvant chemotherapy (NACT) are at risk for venous thromboembolism (VTE). Timely interval debulking surgery (IDS) remains an important component of treatment for this population, but the impact of VTE on IDS outcomes is not well-defined. Our primary objective was to describe the effect of VTE on the length of time between cancer diagnosis and IDS. Our secondary objective was to evaluate the relationships between VTE and outcomes at the time of IDS. Methods: A retrospective cohort study was conducted among patients with advanced ovarian, fallopian tube, or peritoneal cancer receiving 3-6 cycles of NACT prior to IDS from 2000-2019 at two academic institutions. Patients who developed a new VTE (deep venous thrombosis or pulmonary embolism) from the time of cancer diagnosis until IDS were compared to those who did not. The primary outcome of interest was the duration of time from cancer diagnosis to IDS (days). Secondary outcomes included achievement of optimal debulking (defined as either no gross residual disease or residual disease < 1 cm), estimated blood loss (EBL) > 500 cc, route of surgery (laparotomy vs minimally invasive), and duration of surgery (minutes) at the time of IDS. Baseline characteristics and clinical variables were abstracted. Simple descriptive statistics, t-tests, Chisquare, and multiple linear regression were employed. A p-value < 0.05 defined statistical significance. Results: There were 217 patients in the overall cohort. Of these, 38 experienced a VTE (17.5%), including 24 at diagnosis and 14 after initiating NACT. Baseline characteristics (age, body mass index, CA-125, and stage) were similar between the two cohorts. Patients with VTE had a longer time to IDS (141.9 vs 122.8 days, p=0.02) and received a greater number of NACT cycles (4.5 vs 4.0, p=0.046). After adjusting for confounders (age, stage, and performance status), the association between VTE and time to IDS was maintained with a mean increase in time to IDS of 21.5 days for those with VTE (95% CI: 6.0-37.1, p=0.007). As summarized in Table 1, there were no significant differences in any of the secondary IDS outcomes, including optimal debulking, EBL > 500 cc, route of surgery, or duration of surgery. Conclusions: Patients developing new VTE from the time of cancer diagnosis to completion of NACT experience significant delays to IDS compared to those without VTE. IDS outcomes, including optimal debulking rates, blood loss, route of surgery, and duration of surgery, were not impacted by VTE in this small sample. Further prospective work is needed to elucidate the effect of VTE events on long-term outcomes among patients with advanced ovarian cancer treated with NACT.