Molecular association of functioning stroma with carcinoma cells in the ovary: A preliminary study

Abstract

The cancer stroma serves an important role in tumour behaviours, including invasion, metastasis, and response to chemotherapy. The stroma of ovarian carcinoma is sometimes specialized, with luteinisation and/or hyperthecosis, and is designated as the ‘functioning stroma’ because it exerts endocrine function and produces sex steroid hormones. In the present study, 14 ovarian cancers with functioning stroma, comprising 7 endometrioid carcinomas and 7 clear cell carcinomas, were analysed to evaluate the molecular association of the functioning stroma with carcinoma cells. The median age of the patients was 67 years (range, 52-85 years); 13 patients were postmenopausal, and one was in perimenopause. Serum oestrogen values ranged from 10 to 129 ng/ml, with a median of 51 ng/ml. Sequence abnormalities in AT-rich interaction domain 1A (ARID1A), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA), Kirsten rat sarcoma viral proto-oncogene (KRAS) and phosphatase and tensin homolog (PTEN) were examined in whole tumours. For cancers positive for sequence abnormalities, their localization in carcinoma cells and/or stromal cells was examined. A total of 8 mutations - ARID1A (L2155L), PIK3CA (H1047R), KRAS (Q12V, E31K, Q61L), and PTEN (C105fs * 8) - were identified in the whole tumours of 5 patients. Seven of these eight mutations were detected only in carcinoma cells. However, one case of endometrioid carcinoma had a KRAS (E31K) mutation in both carcinoma and stromal cells. In conclusion, although functioning stromal cells of ovarian cancer are usually thought to be non-neoplastic, some may share an origin with carcinoma cells.