To study the performance of OCS products based on exosome detection technology in monitoring the recurrence of baseline CA125-negative ovarian cancer patients after initial treatment, and to explore reliable methods for monitoring the recurrence of baseline CA125-negative ovarian cancer patients after initial treatment.

Inclusion criteria:

1. Women over 18 years old;
2. Pathologically confirmed as stage I-IV primary epithelial ovarian malignant tumor;
3. ECOG < 2;
4. The expected survival period exceeds 6 months;
5. CA125 ≤ 35 U/ml before initial treatment;
6. Undergo surgery and adjuvant chemotherapy;
7. The period between diagnosis and enrollment does not exceed 8 weeks;
8. Be willing to provide blood samples for OCS testing during the research process;
9. Sign the informed consent form.

Exclusion criteria

1. Have had other malignant tumors within the last five years;
2. Have received any treatment for ovarian cancer;
3. Benign ovarian mass;
4. Non-primary ovarian tumors;
5. Combined with other malignant tumors;
6. Patients receiving neoadjuvant therapy;
7. Pregnancy.

Patients with ovarian cancer