- Patients with confirmed p53 mutation by molecular analysis and/or evidence of p53 overexpression by immunohistochemistry (>= 10% of cells within tumor staining positive) will be eligible; this will be assessed by a Clinical Laboratory Improvement Act (CLIA) approved pathology core pathologist, using CLIA approved mutational analysis or immuno-histochemistry techniques on formalin-fixed paraffin-embedded tissue; in the case of equivocal immunohistochemistry (IHC) results, p53 involvement may be confirmed by detection of p53 molecular analysis on tumor deoxyribonucleic acid (DNA); patients on whom molecular analysis of p53 mutations is already available, will not require IHC analysis; molecular analysis may be performed as an additional research procedure at the end of the study (distinct from eligibility determination) if the principal investigator (PI) deems it of scientific value and research funding is available to cover the cost; patients must have PD-L1 positive ovarian cancer in order to be eligible for this clinical trial (defined as >= 1% PD-L1 expression within the tumor section, assessed by immunohistochemical staining)