Introduction/Background*Cancer organoids are an emerging in vitro tool to study tumorigenesis.

However, patient-specific applications, s. a. chemotherapy response prediction, remain understudied.

Organoid protocols vary considerably between different publications, impeding clinical applications.

Our aim was to examine the experimental design characteristics in current human gynaecologic cancer (GC) organoid studies.

Methodology We conducted a focused review and included publications on GC organoids in the analysis that recruited ≥ 3 patients.

Result(s)*In 7 studies, 178 patients with ovarian cancer had ≥ 1 biopsy, establishing 163 organoid cultures. Of all patients, 87 had high-grade serous histology. 22% of all biopsies were taken from chemotherapy-naïve patients. Organoid culture success rate ranged between 30-100%.

40 organoid cultures could be established from patients in 4 studies on endometrial cancers. Organoid culture success rate was inconsistently reported and ranged between 42-83%. Most cancers (45%, 18/40) were of low-grade endometrioid histology, however molecular classification was not provided.

In a single study, 22 patients with squamous cervical cancer and 4 with adenocarcinoma gave rise to 11 and 1 successful organoid culture, respectively.

To date, there are no data on human vulvar, vaginal, or malignant trophoblast organoids.

In a minority (2/12) of the studies, percentage of tumour cells in the biopsy or cell vitality was reported.

The growth factor supplementation was rarely tested for ≥3 formulations of GC organoid culture media, making a comparison between protocols difficult. In addition, different media weren’t allocated to biopsies randomly. Neither the experimental conditions nor the outcomes were blinded to researchers in any of the studies.

Conclusion*Most of the current human GC organoid studies are observational studies and do not employ statistical pre-planning for clinical subpopulations. There appears a general underreporting for failed organoid cultures. Due to heterogeneous experimental designs, robust organoid media are not available yet.