This observational study is conducted to assess the utility of circulating tumor DNA in monitoring the response to pegylated liposomal doxorubicin in platinum-resistant ovarian cancer，and evaluate the consistency of circulating tumor DNA with imaging and CA125 in platinum-resistant ovarian cancer.

The goal of this study is to assess the utility of circulating tumor DNA in monitoring the response to pegylated liposomal doxorubicin in platinum-resistant ovarian cancer.This is a single-arm, single-center prospective clinical study.

After enrollment, patients will receive standard treatment (pegylated liposomal doxorubicin)and follow-up strategy. Peripheral blood samples will be collected from all patients before treatment and 3 weeks after the first cycle of treatment，If necessary, Peripheral blood samples also be collected after 2 cycles of treatment.Peripheral blood ctDNA will be tested for genetic variation based on next-generation sequencing (NGS).

Finally, this study will to evaluate the consistency of circulating tumor DNA with imaging and CA125 in platinum-resistant ovarian cancer.

Inclusion Criteria:

1. Female, over 18 years of age;
2. Patients with histopathological diagnosis of high-grade serous epithelial ovarian cancer;
3. pathological report:phenotype of p53 mutation；or previous genetic tests of tumor tissue indicated TP53 gene mutations;
4. ECOG≤ 2;
5. Expected survival time ≥3 months;
6. The subjects were able to understand the study process and voluntarily joined the study.

Exclusion Criteria:

1. Pregnant and lactating patients;
2. Patients with severe or uncontrolled infections;
3. Patients who are allergic or intolerant to the investigational drug;
4. Patients who are enrolled in or within a month of another clinical trial.

platinum-resistant ovarian cancer