Successful secondary radical operation on unretractable metastatic platinum-sensitive recurrent ovarian cancer by immunotherapy: a case report.

Background: Although rechallenge with platinum-based chemotherapy is effective for most platinum-sensitive recurrent ovarian cancer (ROC) patients, there is still a subset of patients who have no responses to the standard care. Overcoming multidrug resistance (MDR) is a top priority in oncology clinics, but it remains intricate. It is difficult for clinicians to manage unretractable ROC when conventional therapy yields no results. The rational and effective use of immunotherapy will contribute to the clinical benefit of these patients, especially in patients without approved immunotherapy biomarkers. Here we present a case of successful secondary radical surgery for unretractable metastatic MDR ROC by immunotherapy based on her immune-infiltrating tumor microenvironment signatures. Case Description: A 57-year-old woman, diagnosed with IC2 stage high-grade serous ovarian cancer in 2015, underwent immediate ultra-radical cytoreductive surgery followed by 6 cycles of platinum-containing adjuvant chemotherapy. After nearly 37 months of disease-free status, the woman complained of spontaneous pain from the right subcostal margin for 1 month and was diagnosed with ROC accompanied by multiple unretractable colorectal and hepatic metastases. Standard chemotherapies were ineffective and quickly resulted in disease progression and grade IV myelosuppression followed impaired gastrointestinal function. Notably, after standard chemotherapy, the patient was tested negative for all immune biomarkers, but multiple fluorescence immunohistochemistry indicated that her tumor tissue was significantly infiltrated with the cluster of differentiation 8 (CD8) T cells and natural killer (NK) cells, implying potential benefits of immunotherapy. Then changed to 3 cycles of intravenous pembrolizumab, the main pelvic tumor and hepatic metastases showed significant shrinkage and achieved partial response, but the disease progressed after 8.7 months. Subsequently, arterial perfusion with pembrolizumab was performed combined with the chemotherapy. A comfortingly partial response was achieved again that enabled the patient to successfully undergo a secondary radical surgery for colorectal and liver metastases. Since that time the patient's postoperative course has been favorable, and she remains disease-free at present for at least 17 months. Conclusions: Immune infiltration signatures of the tumor microenvironment could serve as an indication for immunotherapy in patients with unretractable platinum-sensitive ROC with MDR. In addition, the introduction of immunotherapy might bring some degree of chemotherapy resensitization.