Background- High-grade serous Carcinoma (HGSC) of the female genital tract can be divided into Four molecular subtypes (C1, C2, C4, and C5) by RNA sequencing. In addition to distinct expression profiles, the molecular subtypes also display distinct clinical features. To date, there is also no published data that relates to molecular subtype and tumor macroscopic appearance at the time of primary surgery as described by the surgical team.
Aims-
1)To explore the possible correlation between the macroscopic appearance of HGSC
at the time of primary surgery and the molecular subtype.
2. Evaluate pre-surgical MRI scans to determine if there are subtype-specific
characteristics that can be observed.
3. To validate the histopathologic classification criteria of molecular subtyping for
HGSC.
Methods- Prospective, exploratory pilot study of patients undergoing primary surgery for HGSC. Pre-operative MRI was assessed for PCI scores and lesion characterizations by a dedicated radiologist. Intra-operatively- cases underwent surgical assessment including PCI & Fagotti scores, lesions characterization, and operative findings. Tumour samples were collected and sent to molecular subtyping using the RNA-seq platform and Histopathological assessment to predict the molecular subtype by a dedicated blinded pathologist.
Results- Eighteen cases of HGSC were included in this study, with 48 samples. All molecular subtypes were represented in our patient population. Intraoperative photos show distinct features of the different subtypes. Different subtypes showed distinctive baseline features, surgical results, and clinical outcomes.
Conclusion- This pilot study suggests that different molecular subtypes of HGSC have different lesion appearance and disease spread, and can potentially be predicted by the surgeon to guide clinical management.