Borderline tumors account for 10% to 20% of epithelial ovarian tumors, and their prognosis is outstanding; nevertheless, a mortality of up to 20% has been reported, particularly in earlier reports. There is a lack of information about the actual mortality and the rate of progression into invasive carcinoma in large and prospectively accrued populations.

All women with borderline ovarian tumors undergoing primary surgery in our department or referred within 3 months from surgery performed elsewhere from 1982 to 1997 were prospectively accrued and observed.

We studied 339 women (83.4% stage I, 7.9% stage II, and 8.5% stage III). The median age at diagnosis was 39 years. A total of 150 women underwent radical surgery, and 189 underwent fertility-sparing surgery. After surgery, 13 women had macroscopic residual disease. With a median follow-up of 70 months, 317 women are alive with no clinical disease (eight with documented subclinical persistence of implants), three are alive with clinical disease, two died of disease, 10 died of other reasons, and seven women have been lost to follow-up. The recurrence of disease was higher after fertility-sparing surgery (35 of 189 cases) than after radical surgery (seven of 150 cases); nevertheless, all but one woman with recurrence of borderline tumor or progression to carcinoma after conservative surgery were salvaged. We observed seven progressions (2.0%) into invasive carcinoma, five in serous tumors (2.4%), and two in mucinous tumors (1.6%). The disease-free survival is 99.6% in stage I patients, 95.8% in stage II, and 89% in stage III.

The survival of patients with borderline tumors is higher than previously described in some retrospective studies. Conservative surgery is safe and may be proposed to several patients with early and disseminated disease after thorough discussion of all therapeutic options. Progression to carcinoma is approximately 2% and may be observed in both mucinous and serous tumors.