Ovarian cancer accounts for 1.2% of all cancers occurring in Korea (as of 2022), so it is not as common as other gynecologic cancers such as breast cancer or cervical cancer. However, it is so lethal that it ranks first in mortality among gynecologic cancers. Known as the “silent killer,” ovarian cancer has no distinct early symptoms, and about 70% of patients are diagnosed at stage 3 or 4.

Its high recurrence rate is another factor that increases its fatality. After standard first-line treatment, most patients experience recurrence on average within 1 to 1.5 years. Recurrence is particularly frequent when there is a mutation in a gene (BRCA) that predisposes to ovarian cancer or when the tumor is HRD-positive (a state in which the DNA repair system is defective).

Professor Ryu You-young of the Department of Obstetrics and Gynecology at Samsung Medical Center said, “As recurrences are repeated, treatment options become more limited and the prognosis gradually worsens,” adding, “In the past, cytotoxic chemotherapy to alleviate symptoms was the only option, and many patients died as the disease progressed rapidly after recurrence.” Professor Ryu emphasized, “For this reason, in ovarian cancer it is crucial to adopt a treatment strategy from the initial diagnosis that reduces the risk of recurrence.” She discussed the characteristics of BRCA-mutated or HRD-positive ovarian cancer and the latest treatment methods.


―What are the causes of ovarian cancer, and if early diagnosis is difficult, is prevention possible?

“Women who had an early menarche or late menopause, and those who have not experienced pregnancy, childbirth, or breastfeeding, are known to have a higher risk of developing ovarian cancer. However, because the causes of ovarian cancer are not clearly understood, there is no definite method of prevention. That said, for women with a mutation in a gene (BRCA) that predisposes to ovarian cancer, preventive surgery between the ages of 35 and 45 can reduce the risk of developing ovarian cancer. But since early diagnosis of ovarian cancer is difficult, it is important to consider an effective treatment strategy in the initial treatment after diagnosis.”

―It is said that biomarkers (substances that influence or can predict the occurrence and outcome of a disease) are now being used in ovarian cancer treatment as well.

“Given that ovarian cancer is associated with a high risk of recurrence and death, maintenance therapy to improve survival after first-line treatment and reduce the risk of recurrence is absolutely necessary. For maintenance therapy, targeted therapies (PARP inhibitors) are used, and BRCA mutations and HRD status are very important indicators that can predict response to these targeted agents. Therefore, in ovarian cancer, testing for BRCA mutations and HRD status is routinely performed.”

―How are ovarian cancer patients with confirmed BRCA mutations treated?

“Before targeted therapies became available, most patients were treated with surgery and cytotoxic chemotherapy, but recurrence within 1 to 1.5 years was common. Since the introduction of PARP inhibitors, however, treatment outcomes have improved significantly. According to research, in the group of patients who took the PARP inhibitor olaparib for two years after surgery and chemotherapy, the progression-free survival (PFS), meaning the length of time during which the disease does not progress, increased about fourfold from 13.8 months to 56 months. In addition, overall survival (OS), the most important endpoint in cancer treatment, was 67% in a seven-year long-term follow-up, a marked improvement compared with 46.5% in the placebo group (a comparison group receiving an inactive dummy drug). This means that, provided the biomarker status is appropriate after first-line treatment, ovarian cancer too can be treated with curative intent using targeted therapies such as PARP inhibitors. Accordingly, PARP inhibitors are now widely used as first-line standard therapy in ovarian cancer patients with BRCA mutations.”

―What about patients who are HRD-positive?

“HRD is also an important biomarker that can predict the efficacy of PARP inhibitors. There is sufficient evidence that using such targeted therapies can in practice reduce recurrence rates and improve survival. However, in patients who are HRD-positive but do not have BRCA mutations, monotherapy may be less effective, so the targeted agent bevacizumab, which has been used for many years, is administered in combination. In particular, in patients without BRCA mutations who have a large amount of residual disease after surgery or who are initially diagnosed with extensive lung metastases and classified as stage 4, the use of bevacizumab is considered. Studies have shown that when olaparib, a PARP inhibitor, is administered together with bevacizumab, the time to recurrence is extended by about threefold, and survival is improved, so this combination is widely used as a standard treatment.”

―To enable aggressive treatment from the outset, access to therapy seems important.

“According to domestic and international guidelines, many patients require combination therapy with a PARP inhibitor and bevacizumab. However, some are unable to receive sufficient treatment due to financial burden. Fortunately, in Korea, partial reimbursement is now applied to bevacizumab, which has somewhat reduced patients’ out-of-pocket expenses. Ultimately, both drugs should be fully reimbursed, and as reimbursement for PARP inhibitors is expected to be implemented in the second half of this year (July–December), there is likely to be good news for ovarian cancer patients.”

―Is there anything you would like to say to patients undergoing treatment for ovarian cancer?

“Since many patients are at stage 3 or 4 at the time of diagnosis, some feel their situation is hopeless. However, if screening confirms that the treatment conditions are appropriate, ovarian cancer can now be treated from the outset with the goal of cure. In particular, ovarian cancer patients who are BRCA-mutated or HRD-positive are responding well to standard treatment, and new drugs for patients without biomarkers are continually being developed. Therefore, even if diagnosed with ovarian cancer, there is no need to fall into excessive despair.”

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