The role of cytopathology in defining the molecular characteristics of epithelial ovarian cancer important for treatment and in studying the immune response to the disease

Detection oh homologous recombination defficiency (HRD) is standard molecular procedure in patients with ovarian cancer. The presence of tumor infiltrative lymphocytes (TIL) provides information regarding immune response against tumor. Tumor tissue fixed in formalin represents standard material for detecting HRD and TIL. In majority of patients with advanced ovarian cancer ascites is present, offering minimally invasive procedure for obtaining cytologic material of tumor and immune cells for detecting HRD and TIL. Our previously published data showed that cytologic material is appropriate for detecting of mutations of genes involved in HRD (BRCA1/2, etc.), however there is no evidence if cytologic material is appropriate for BRCA1/2 promoter metilation, an important cause of HRD. There are limited data regarding prognostic role of TIL detected from cytologic material from ascites or malignant pleural effusion. Cytologic analysis of circulating tumor cells (CTC) or tumor DNA (ctDNA) from blood sample offers new challenge for potential prognostic value in patients with advanced ovarian cancer.

The aim of our study is to evaluate if cytologic tumor sample is suitable for:

- HRD detecting from ascites, malignant pleural effusion or lymph nodes

- immune response detecting from ascites or malignant pleural effusion

- CTC/ctDNA detecting from blood sample

Our hypotheses: cytologic material of tumor sample in advanved ovarian cancer:

- is equivalent to tumor tissue for HRD detecting

- is appropriate for immune response evaluation in ascites or malignant pleural efusion

- is appropriate for CTC/ctDNA detecting from blood sample

Expected results: We expect to confirm that cytologic material is equivalent to tumor tissue for HRD detecting, is appropriate for immune response evaluation and is appropriate for CTC/ctDNA detecting from blood sample of patients with advanced ovarian cancer.