Residual cancer stem cells after interval cytoreductive surgery following neoadjuvant chemotherapy could result in poor treatment outcomes for ovarian cancer.

The objective of this review is to discuss the common surgical strategy of cytoreductive surgery after neoadjuvant chemotherapy, with an emphasis on incorporating extensive cytoreductive surgery to remove traces of regressed tumor. A review of the literature regarding cytoreductive surgery after neoadjuvant chemotherapy and cancer stem cells is given together with the authors' own experience and comments. Most ovarian cancer cells consist of transformed cells that regress after neoadjuvant chemotherapy. Therefore, the extent of cytoreductive surgery usually tends to be limited because only visible tumors are removed. Scar tissue, which represents tumor after neoadjuvant chemotherapy, may contain cancer stem cells. This leads to chemotherapy-resistant cancer stem cells to persist in patients who have received neoadjuvant chemotherapy. If the extent of cytoreductive surgery is preserved based on initial images, and includes all scar tissue suggestive of previously existing ovarian cancer in patients who underwent interval debulking surgery after neoadjuvant chemotherapy, treatment outcome will be improved or be comparable to patients who underwent primary cytoreductive surgery with minimal morbidity. Further basic and clinical investigation is needed to serve as a standard surgical paradigm in the management of advanced ovarian cancer. Currently, the gynecologic oncologist should remove all traces of regressed tumor after neoadjuvant chemotherapy to eradicate potential cancer stem cells. Further investigation to clarify the role of cancer stem cell in the surgical management of ovarian cancer is warranted.