Early stage ovarian immature teratoma, surveillance or chemotherapy after surgery? A propensity score matched analysis

OBJECTIVE: To compare the survival outcomes between surveillance and adjuvant chemotherapy in patients with stage I ovarian immature teratomas (ITs) who underwent fertility sparing surgery. METHODS: In this retrospective cohort analysis, patients with stage IA Grade 2–3, stage IB and IC ovarian ITs who underwent surveillance after surgery between 2016 and 2021 from Peking Union Medical College Hospital were identified. A 1:1 propensity score matching was performed in patients who had adjuvant chemotherapy by age, stage, and grade. RESULTS: A total of 16 patients without adjuvant chemotherapy were identified. There were 3 stage IA and 13 stage IC patients. The median age at diagnosis was 14.5 years old (range 3–30). There were 6 patients who had grade 1 tumor, 5 grade 2, 5 grade 3. After a mean follow-up period of 27.4 months, a patient with stage IA grade 2 IT who underwent ovarian cystectomy had recurrence in the same ovary. 16 patients who received adjuvant chemotherapy were screened as controls. The tumor stage and grade were similar in two groups. The median age was older in the chemotherapy group. Of the 16 matched patients there was one recurrence. There was no statistical difference in 3-year disease-free survival (DFS) between surveillance group and chemotherapy group (p = 0.808). CONCLUSION: We did not observe survival differences or recurrence rates between patients who underwent adjuvant chemotherapy or those who did not with stage I ovarian ITs. Our study suggests surveillance may be safe and preferable in early-stage IT patients who underwent complete tumor resection.