The impact of varying levels of residual disease following cytoreductive surgery on survival outcomes in patients with ovarian cancer: a meta-analysis

Residual disease following cytoreductive surgery in patients with ovarian cancer has been associated with poorer survival outcomes compared with no residual disease. We performed a meta-analysis to assess the impact of varying levels of residual disease status on survival outcomes in patients with ovarian cancer who have undergone primary cytoreductive surgery or interval cytoreductive surgery in the setting of new therapies for this disease. Medline, Embase, and Cochrane databases (January 2011 – July 2020) and grey literature, bibliographic and key conference proceedings, were searched for eligible studies. Fixed and random-effects meta-analyses compared progression and survival by residual disease level across studies. Heterogeneity between comparisons was explored via type of surgery, disease stage, and type of adjuvant chemotherapy. Of 2832 database and 16 supplementary search articles screened, 50 studies were selected; most were observational studies. The meta-analysis showed that median progression-free survival and overall survival decreased progressively with increasing residual disease (residual disease categories of 0 cm, > 0–1 cm and > 1 cm). Compared with no residual disease, hazard ratios (HR) for disease progression increased with increasing residual disease category (1.75 [95