Inclusion Criteria:

• Patients must be English language proficient.
• Patients must be > 18 years old.
• Must be able to provide informed consent.
• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0, 1 or 2.

NAC Cohort

• Newly Diagnosed stage III or IV invasive serous ovarian cancer, grades 2, 3 or poorly differentiated. 

PD Cohort

• Patients with an 75% or greater probability of having advanced HGSC based on the clinical judgement of investigator after review of imaging and CA 125 values and who are schedule to undergo a PD surgery;
• Patients who have advanced HGSC confirmed at PD surgery and who undergo any attempt at surgical debulking will be considered eligible and enrolled in the PD cohort;
• Patients with advanced HGSC confirmed at surgery and undergo diagnostic biopsy only without any debulking will be considered eligible and enrolled into the NAC cohort;
• Patients who have benign ovarian disease confirmed at surgery will be considered eligible and enrolled as benign surgical controls (n=10 total). 

• Scheduled to receive i.v. or combined i.v./i.p. platinum and taxane combination chemotherapy with or without bevacizumab within 4 weeks of study enrollment.
• Patients must have Abdominal-Pelvic CT or MRI scan within 28 days of study enrollment
• Organ function must include the following pre-treatment parameters: 
  • white blood count (WBC) > 3,000/ul;
  • Hb > 9 gm/dl %;
  • Platelet count > 100,000/ul;
  • serum creatinine < 1.5 mg/dl;
  • serum albumin > 3.5 gm/dl;
  • serum total bilirubin < 1.5 mg/dl;
  • alanine aminotransferase (ALT)/ aspartate aminotransferase (AST)/ alkaline phosphatase < 2 x ULN.

Exclusion Criteria:

• Patients who have received treatment of any type including systemic chemotherapy, irradiation, hormonal treatment, immunotherapy, and/or debulking surgery for their ovarian cancer prior to study enrollment. 
• Non-HGSC including adenocarcinomas of mucinous, clear cell, endometrioid or low-grade serous histology.
• Borderline ovarian cancer of any histologic subtype.
• Unable to provide bio-specimens as required by the study protocol.
• Any medical conditions that increase risk of complications from a blood draw including hemophilia or other bleeding disorders or serious anemia.
• Currently pregnant.
• Inability to provide informed consent as assessed by the study investigator or research staff.
• Other active malignancy defined as any treatment for invasive cancer of any type (excluding hormone therapy) within the last 5 years.  Exemptions include localized cancers that are considered to be cured by local excision or destructive measures (eg, basal or squamous cell skin cancer, superficial bladder cancer or carcinoma in situ of the cervix).
• Concurrent participation in another research study is potentially allowed but requires formal PI review and approval to ensure it does not conflict with the goals of the current study.