INTRODUCTION
Epithelial ovarian carcinoma (EOC) has an annual incidence of 11.0 and a
mortality rate of 7.3 cases per 100.000 women within the
Netherlands1. Approximately 30% of the EOC patients
present with clinically early-stage (i.e., FIGO stage I-II) disease at
initial evaluation2. The treatment plan of clinically
early-stage EOC is determined by comprehensive surgical staging,
enabling valid prognosis estimates and, more importantly, determines
adjuvant treatment.
The ten-year follow-up data from the European Organisation for Research
and Treatment of Cancer – Adjuvant ChemoTherapy in Ovarian Neoplasm
(EORTC-ACTION) – trial demonstrated complete staging surgery was
significantly associated with a superior recurrence-free and overall
survival. Adjuvant chemotherapy appeared only beneficial in clinically
early-stage EOC patients with possible unidentified residual disease due
to absent or incomplete staging surgery3,4.
As recommended by the International Federation of Gynecology and
Obstetrics (FIGO), a comprehensive staging surgery should include a
hysterectomy, bilateral salpingo-oophorectomy, cytology of ascites or
peritoneal washings, peritoneal biopsies, infracolic omentectomy, and
pelvic- and para-aortic lymphadenectomy5,6. Although
the clinical relevance of surgical staging has been unequivocally proven
based on multiple trials, the variation in upstaging rates in literature
hinders the adequate selection of patients who will benefit from
adjuvant chemotherapy. Up to one-third of these clinically early-stage
EOC patients are reported to be upstaged following staging surgery.
However, exact upstaging rates vary widely between individual studies,
mainly due to case-mix differences7,8.
With this systematic review and meta-analysis, we aim to determine the
upstaging rate after comprehensive surgical staging, and its components,
in patients with clinically early-stage EOC. The influence of clinical
factors, such as histological type, differentiation grade, and lymph
node assessment method, will be studied. Furthermore, we aim to clarify
the difference between finding metastatic disease and its contribution
in the upstaging rate in patients.