Identifying Genetic Similarities in Tumors May Shed Light on Spread of Ovarian Cancer

Yale Cancer Center researchers have defined the genetic characteristics of ovarian tumors, information that could lead to new opportunities for personalized therapy, according to study findings published in Proceedings of the National Academy of Science.

The team examined 64 primary, 41 metastatic and 17 recurrent tumors from 77 patients and then matched them with normal DNA by whole-exome sequencing, which is a technique for sequencing all the protein-coding region of genes in a genome.

The researchers identified several genes, including c-MYC and PIK3CA, that are frequently mutated in primary-metastatic and chemotherapy-resistant ovarian tumors.

In addition, about half of the patients harbored a germinal (inherited) or somatic (an alteration in DNA that occurs after conception) damaging mutation in a repair gene involved in predisposition to ovarian cancer.

The findings also revealed a branching structure, suggesting that the tumors share a common ancestry before evolving on their own, wrote researchers. That characteristic, along with similarities among primary and metastatic tumors, may explain why screening programs for the disease haven’t been successful.

“We have identified striking genetic similarities between primary and metastatic ovarian tumors, as well as ovarian tumors arising simultaneously on both ovaries,” senior author Alessandro Santin, M.D., leader of the Disease Aligned Research Team of the Gynecologic Oncology Program at Yale Cancer Center, said in a press release.

“These genetic results obtained in matched tumor samples from the same patient provide support to the view that spreading to the abdominal cavity takes place very early during the natural history of ovarian cancer.”