RESUMO
The risk of ovarian, tubal, and peritoneal cancer is related to germline pathogenic variants, and over time, the number of known disease-associated genes has increased significantly. This study reviews the literature regarding the topic from a historical perspective. The aim is to present a timeline of the knowledge gained from the early 1900s until today. The findings are put into perspective by looking at the current gene panel used for screening for suspected hereditary ovarian cancer in Denmark compared to what is known internationally. In 1929, the first familial ovarian cancer incidents were registered, and in 1950, the involvement of a genetic component was suggested for the first time. During the 1970s, several studies reported an accumulation of ovarian cancer in certain families, and during this time, it was discovered that ovarian cancer was linked to both breast cancer and colorectal cancer. The inheritance of cancer disposition has been thoroughly investigated, leading to the discovery of the BRCA genes in the 1990s. Furthermore, new studies based on new genetic technologies have revealed several genes with germline pathogenic variants that increase the risk of ovarian cancer. The identification of these pathogenic variants has led to preventive measures and specific treatment of women with genetic disposition to ovarian cancer. In Denmark, consensus is to include at least ten genes in the screening panel for hereditary ovarian cancer, and in the future additional genes will probably be added.
RESUMO
OBJECTIVE: One way to improve the survival rate of epithelial Ovarian Cancer (EOC) is by identifying effective biomarkers useful at different stages and time points of the disease. A potential biomarker is circulating tumor DNA (ctDNA) in plasma or serum. In this systematic review, we provide an overview of applications of ctDNA in EOC to discuss the direction of future research in this field. METHODS: We performed a systematic search in Pubmed, Embase, and Scopus to identify relevant clinical studies eligible for inclusion. Furthermore, the references in the identified studies and relevant reviews were assessed to identify additional studies. The PRISMA guideline was employed to perform the systematic review, and data from the studies were extracted using piloted data extraction forms. RESULTS: A total of 36 observational studies were included. The concordance between tumor and ctDNA was assessed in 19 studies, early diagnosis in 1, diagnosis in 23, monitoring of treatment response in 7, detection of reversion mutations in 3, prognosis in 9, but no studies assessed early detection of recurrence. Data from the studies were reported descriptively. The studies had a large variation in the methods used for ctDNA analysis and limited sample sizes of 10-126 patients. Overall, the studies show that ctDNA is a potential biomarker for EOC useful in several settings during assessment and treatment of these patients. CONCLUSIONS: Although the identified studies are limited in number and their methods for ctDNA analysis vary, it is clear that ctDNA as a biomarker for EOC is promising for several applications in diagnostics, monitoring of treatment response, and prognostics. However, more studies are needed to establish the ideal methods and settings for the clinical use of ctDNA in EOC.
