Eva Maria Roes

Response to Systemic Therapies in Patient-Derived Cell Lines from Primary and Recurrent Adult Granulosa Cell Tumors

Abstract In patients with the rare adult-type granulosa cell tumor (aGCT), surgery is the primary treatment for both primary and recurrent disease. In cases of inoperable disease, systematic therapy is administered, but variable response rates and drug resistance complicate predicting the most effective therapy. Drug screen testing on patient-derived cell lines may offer a solution. In a national prospective study on aGCT, fresh tissue was cultured into 2D cell lines, testing 27 clinical and experimental drugs. Dose–response curves and synergy were calculated using GraphPad Prism and CompuSyn software. We established 34 patient-derived cell lines from tissue of 20 patients with aGCT. Of these, seven patients had a primary diagnosis of aGCT and 13 patients had recurrent disease. In eight patients, multiple tumor locations were cultured. On each cell line, 10 monotherapies and 17 combinations of drugs were tested. Carboplatin/gemcitabine showed efficacy and synergy in almost all patient-derived cell lines. Synergy could not be detected in the regular carboplatin/paclitaxel and carboplatin/etoposide combinations. Experimental combinations alpelisib/fulvestrant and alpelisib/gemcitabine showed efficacy of more than 75%. Drug screens on patient-derived tumor cell lines reflect the reality of the variable response of systemic therapy in patients with aGCT. In future research, this technique may be used to personalize the systemic treatment of patients with aGCT in a clinical study. The good response to carboplatin/gemcitabine in our patient-derived cell lines can then be confirmed in a clinical setting.

Clinicopathological and epigenetic differences between primary neuroendocrine tumors and neuroendocrine metastases in the ovary

AbstractCurrently, the available literature provides insufficient support to differentiate between primary ovarian neuroendocrine tumors (PON) and neuroendocrine ovarian metastases (NOM) in patients. For this reason, patients with a well‐differentiated ovarian neuroendocrine tumor (NET) were identified through electronic patient records and a nationwide search between 1991 and 2023. Clinical characteristics were collected from electronic patient files. This resulted in the inclusion of 71 patients with NOM and 17 patients with PON. Histologic material was stained for Ki67, SSTR2a, CDX2, PAX8, TTF1, SATB2, ISLET1, OTP, PDX1, and ARX. DNA methylation analysis was performed on a subset of cases. All PON were unilateral and nine were found within a teratoma (PON‐T+). A total of 78% of NOM were bilateral, and none were associated with a teratoma. PON without teratomous components (PON‐T−) displayed a similar insular growth pattern and immunohistochemistry as NOM (p > 0.05). When compared with PON‐T+, PON‐T− more frequently displayed ISLET1 positivity and were larger, and patients were older at diagnosis (p < 0.05). Unsupervised analysis of DNA methylation profiles from tumors of ovarian (n = 16), pancreatic (n = 22), ileal (n = 10), and rectal (n = 7) origin revealed that four of five PON‐T− clustered together with NOM and ileal NET, whereas four of five PON‐T+ grouped with rectum NET. In conclusion, unilateral ovarian NET within a teratoma should be treated as a PON. Ovarian NET localizations without teratomous components have a molecular profile analogous to midgut NET metastases. For these patients, a thorough review of imaging should be performed to identify a possible undetected midgut NET and a corresponding follow‐up strategy may be recommended.