Liposomal doxorubicin (Doxil) receives accelerated FDA approval to treat advanced ovarian cancer that has progressed after prior treatment. The drug is unique because the active chemotherapy agent is encased in a microscopic fat bubble that releases the drug at the tumor site, delivering more of the chemotherapy directly to the tumor and less to other parts of the body, thereby limiting side effects. Full approval is granted in 2005 based on follow-up studies showing that the drug shrinks ovarian tumors and extends survival compared to standard topotecan (Hycamptin) chemotherapy. By the end of the 1990s, patients with advanced ovarian cancer have a growing number of chemotherapy options to select from.

Researchers discover that women who have mutations in the genes known as BRCA1 and BRCA2 have a 50 to 85 percent increased risk of developing breast and ovarian cancers. These mutations are found to be particularly common among women of Ashkenazi Jewish descent. The identification of this important genetic cancer risk factor enables women with these mutations to undergo more frequent screening, and in some cases to undergo preventive surgical removal of the breasts, ovaries or both. Preventive use of tamoxifen (Novaldex) or raloxifene (Evista) becomes an additional option after the drugs are proven effective for this purpose in the following years.

The chemotherapy drug carboplatin (Paraplatin, Paraplat) becomes available as a second line of therapy for ovarian cancer, after research shows that it promotes tumor shrinkage. It becomes available as an initial therapy two years later, after being shown to increase survival. This approval offers an effective treatment alternative for patients who cannot tolerate the standard chemotherapy drug, cisplatin, which carries significant side effects. It later becomes the preferred initial chemotherapy, after studies show it is as effective as cisplatin but causes fewer side effects.

Studies first begin suggesting that oral contraceptive use lowers the risk of developing ovarian cancer. Evidence continues to accumulate over the coming years, and in 2008, a review of 45 published studies concludes that "the pill" lowers ovarian cancer risk by 20 percent for every five years it is used. Authors of the 2008 study estimate that oral contraceptives had prevented some 200,000 ovarian cancers and 100,000 deaths worldwide in the 50 years since oral contraceptives were introduced, and may currently prevent 30,000 new cases of ovarian cancer each year.