Safety of diagnostic hysteroscopy for the investigation of type II endometrial cancer: systematic review with meta-analysis

Aim The goal of this study is to evaluate the safety of diagnostic hysteroscopy (HSC) in type II endometrial cancer (EC).Methods We searched PubMed, the Cochrane Library and the Chinese Medical Journal Full-Text Database until December 2023. Eligible trials were all cohort studies in which patients were allocated to diagnostic HSC group or dilation and curettage (D&C) group. Quality assessments of eligible studies were performed using the Newcastle-Ottawa scales. Risk ratios (RRs) with 95% CIs were calculated as a measure of effects.Results Three trials were included in our analysis, which were all retrospective cohort studies. 696 patients with histologically proven type II EC were allocated to HSC or D&C before surgery. 257 patients underwent preoperative HSC, and 439 patients underwent D&C. The positive peritoneal cytology rate did not statistically differ between the groups (RR, 1.9; 95% CI, 1.00 to 3.61; p=0.05). There was no significant difference in the incidence of International Federation of Gynecology and Obstetrics (FIGO) stage between the HSC and D&C groups (stage I/II: RR, 1.08; 95% CI, 0.95 to 1.24; p=0.25; stage III/IV: RR, 0.82; 95% CI, 0.62 to 1.09; p=0.18). There was no significant difference in recurrence between the HSC and D&C groups (RR, 0.92; 95% CI, 0.66 to 1.32; p=0.66); the heterogeneity of the two included studies was acceptable (p=0.54, I2=0%).Conclusions Preoperative HSC in patients with type II EC does not increase the risk for cancer cell dissemination within the peritoneal cavity. Preoperative HSC does not progress the FIGO staging in patients with type II EC and does not increase the risk of tumour recurrence. There is no reason to avoid HSC for the diagnosis of type II EC currently. However, type II tumours generally are less well differentiated and have poorer prognoses than type I tumours. More prospective and adequately powered trials are required to clarify whether preoperative HSC in patients with type II EC is safe.