Researchers learned more about what causes ovarian cancer and why some women’s tumours may not respond to therapy.
“Understanding the relationship between molecular profiles and clinical presentation of ovarian cancer not only can help guide the development of personalised therapeutic approaches, but it can also help us identify women who are at the highest risk so we can intervene before cancer even develops,” said Simon Gayther, PhD, professor of Biomedical Sciences at Cedars-Sinai and senior author of both studies. Scientists Discover Mutations that Increase the Risk of Ovarian Cancer.
The first research, published today in the Journal of the National Cancer Institute, discovered four new areas of the human genome that contain genetic variations or mutations that raise women’s chance of getting epithelial ovarian cancer, the most frequent kind of ovarian cancer.
“When it comes to ovarian cancer, prevention is how we’re truly going to effect mortality,” said Michelle Jones, PhD, the study’s corresponding author and a research scientist in the Center for Bioinformatics and Functional Genomics. “This study assists us in correctly identifying women who contain cancer-causing mutations, which can aid clinicians in developing preventative methods for these individuals.”
The researchers employed new technologies to study the structural variation of the genome, which is made up of 23 pairs of chromosomes where an individual’s genetic information is stored, to detect the mutations.
While most study looks at changes in gene sequence, the researchers looked at the amount of copies of the gene that individual had, which is known as a copy number variation.
When the genome is copied, structural variation occurs, and sections of the genome can be deleted, duplicated, or rearranged. These alterations can result in illnesses such as cancer.
The researchers worked with scientists from the University of Cambridge to examine deletions and duplications in 13,000 women with ovarian cancer and compared them to 17,000 women without ovarian cancer from the Ovarian Cancer Association Consortium in order to identify copy number variants associated with ovarian cancer risk.
They discovered large deletions and duplications in the BRCA1 and BRCA2 genes, as well as the RAD51C gene, all of which are known to have alterations in a patient’s DNA sequence that raise the risk of ovarian cancer. Four novel genes were discovered that had not previously been connected to an elevated risk of ovarian cancer.
The study, the largest to date to assess the impact of copy number variations to ovarian cancer risk, will most likely result in more accurate genetic testing for women.
“We have the technology to detect these deletions and duplications,” Jones says, “but it’s not always done consistently in clinical genetic testing.” “We hope that these data demonstrate the importance of considering copy number variations in clinical genetic testing.”
Chemotherapy Resistance in Ovarian Cancer is unlikely to be driven by gene expression.
The second study, published in the Journal of Experimental & Clinical Cancer Research, provides researchers with a better understanding of how ovarian tumours develop resistance to chemotherapy, which occurs in approximately 80% of high-grade serous ovarian cancer patients and ultimately leads to death.
Previously, experts thought that ovarian cancers evolved after being treated to chemotherapy, changing their gene expression to adapt and survive the treatment.
However, they discovered for the first time, using whole genome sequencing, that this is not the case. Instead, it is more plausible that most high-grade serous ovarian cancers have the ability to withstand chemotherapy from an early stage, according to Jones, who is also the study’s co-first author.
This research has altered our knowledge of how cancers react to treatment “Jones stated. “Previously, it was considered that we might probably discover a technique to treat chemo-resistant cancers with different medications after they had been treated with normal therapy,” says the study’s lead author.
“By enhancing our understanding of how cancers survive chemotherapy and even continue to grow during treatment, as well as discovering weaknesses in the tumours, we will be able to build better medications and save the lives of women with ovarian cancer,” Gayther continued.
Cedars-Sinai Cancer Center’s BRCA High-Risk Clinic
While Cedars-Sinai Cancer Center researchers investigate ways to more reliably identify women who possess cancer-causing mutations, physicians work to monitor and treat BRCA-positive patients as required.
Under the direction of B.J. Rimel, MD, a gynaecological oncologist and medical director of the Cedars-Sinai Cancer Clinical Trials Office, Cedars-Sinai has opened a previvor clinic for BRCA1 and 2 carriers who are at high risk of developing ovarian cancer.
The objective, according to Rimel, is to provide BRCA-positive patients with frequent screening and risk-reduction initiatives in a single-stop clinic environment.
“During the clinic appointment, our multidisciplinary care team, which includes a reproductive and infertility physician, a gynaecologist oncologist, and a genetic counsellor, spends time with each high-risk patient,” stated Rimel.
“We conduct transvaginal screening on-site, examine necessary blood work findings, and guarantee queries are answered in real-time.”
The ovarian cancer previvor clinic at Cedars-Sinai is modelled after an established and extremely effective high-risk BRCA breast cancer programme.
“Alterations in genes like BRCA in cancer or the patient’s germline have substantial consequences for therapy and prevention,” said Dan Theodorescu, MD, PhD, director of Cedars-Sinai Cancer and PHASE ONE Foundation Distinguished Chair and professor of Surgery, Pathology, and Laboratory Medicine. “As our research advances, so do our translational insights that influence and enhance the lives of patients.”