RESUMEN
AIM: This study aimed to determine the recurrence rate and related risk factors of borderline ovarian tumors (BOT). METHODS: We conducted a retrospective cohort study with 433 patients who were surgically treated for primary BOT at Tu Du Hospital from 11/2008 to 09/2015. We used the life table method to estimate the cumulative recurrence rate. We used the log-rank test and Cox proportional hazard model to determine recurrence-associated factors. RESULTS: Median follow-up time was 43 months (range: 3-105 months). Eighteen patients developed recurrence. The cumulative BOT recurrence rates at year 1, 2, 3 and 4 were 1.2% (95% confidence interval [CI] = 0.5-2.8), 3.0% (95% CI = 1.7-5.2), 4.6% (95% CI = 2.9-7.4), and 5.1% (95% CI = 3.2-8.0), respectively. In the final multivariate model, a higher recurrence rate was significantly associated with primary tumor stages (stage I vs stages II and III, hazards ratio [HR] = 4.44, 95% CI = 1.60-12.38), pre-operative tumor's capsule rupture (HR = 4.14, 95% CI = 1.78-9.64), and cystectomy (HR = 5.33, 95% CI = 1.43-19.91). CONCLUSION: The overall BOT recurrence rate in women in southern Vietnam was moderate. Primary tumor stage, capsule rupture, and cystectomy were main factors associated with BOT recurrence. Appropriate follow-up strategies for patients with high-risk factors are needed for early detection and management of recurrence.