Ovarian cancer is a leading cause of death from gynecological malignancies, with an estimated 313,959 new cases and 207,252 deaths reported worldwide in 2020 [1]. Approximately 70% of patients with epithelial ovarian cancer (EOC) are diagnosed at an advanced stage, which is mainly attributed to the absence of early symptoms and effective screening tools and the pathogenetic origins of the disease [2]. Thus, EOC is associated with high disease recurrence and mortality rates [3]. The first-line treatment for EOC comprises cytoreductive surgery (CRS) with adjuvant platinum-based chemotherapy followed by targeted systemic maintenance therapies [2,4].

CRS aimed at total macroscopic tumor clearance is one of the strongest modifiable prognostic factors for the survival of patients with EOC [[5], [6], [7]]. Bristow et al. conducted a meta-analysis almost two decades ago and established an inextricable association between surgical outcome and survival, clearly demonstrating that each 10% increase in complete cytoreduction rates was associated with a 5.5% increase in the median overall survival (OS) of patients with advanced EOC who were treated with primary surgery followed by platinum-based chemotherapy [5]. However, therapeutic strategies for primary EOC have evolved significantly over the last two decades. The treatment landscape has been enriched by novel concepts such as maintenance, tumor biology, and genetically driven therapies. Neoadjuvant chemotherapy (NAC) is routinely introduced in patients who are not amenable to optimal debulking, especially in the presence of severe comorbidities. Landmark randomized controlled trials (RCTs), such as GOG-218 [8] and ICON7 [9], introduced the use of bevacizumab, a humanized anti-vascular endothelial growth factor monoclonal antibody, concurrent with first-line chemotherapy followed by maintenance therapy more than ten years ago. More recent RCTs, such as SOLO-1, [10] PRIMA, [11] VELIA, [12] and ATHENA-MONO, [13] have added to the maintenance use of poly (ADP-ribose) polymerase (PARP) inhibitors in EOC, bringing about a therapeutic breakthrough, especially for patients with BRCA1/2 mutations or homologous recombination deficiency (HRD). Therefore, the standard of care for advanced EOC has revolutionized.

In view of these changes in the treatment landscape of this challenging disease, updating our knowledge base from that of the initial meta-analysis study of 2002 [5] is essential to reassess the value of postoperative residual disease on patient survival with respect to current systemic treatment strategies. Therefore, this meta-analysis aimed to investigate the impact of residual disease after CRS for EOC on survival outcomes within the current paradigm of frontline ovarian cancer treatment.