The role of minimally invasive interval debulking surgery in advanced epithelial ovarian cancer

Ovarian cancer is the leading cause of death from gynecologic cancer in the United States [1]. In 2016, there will be 22,280 new cases of ovarian cancer and 14,240 women will die from the disease [1]. The majority of patients diagnosed with ovarian cancer have stage III or IV disease at the time of diagnosis because of an inability to screen for ovarian cancer. Survival rates for advanced disease are poor, regardless of geography, financial resources, or modality of treatment. Successful cytoreduction to minimal residual tumor burden is the most important determinant of prognosis [2]. However, extensive surgical procedures to achieve complete tumor resection are associated with postoperative morbidity and mortality. Moreover, patients with postoperative complications experience delays in initiation of chemotherapy and may not be able to receive planned therapy, thus showing decreased survival [3]. At present, neoadjuvant chemotherapy (NACT) is the preferred therapy for advanced epithelial ovarian cancer (AEOC) patients that have been preoperatively identified as having unresectable disease, stage IV disease, high tumor burden, significant medical comorbidities, or poor performance status [4,5], as suggested by recent randomized clinical trials (RCTs) [6–8]. Typically, NACT is in the form of carboplatin area under curve 5 (AUC5) or AUC6 and paclitaxel 175 mg/m [4,5] and is given between 1 and 6 cycles [9,10]. Although there has been some evidence that the addition of bevacizumab to carboplatin and paclitaxel may be beneficial in the neoadjuvant setting, it has not yet been studied in the interval debulking surgery (IDS) setting [11]. That being said, the response to NACT is equally important, as the patients who do not respond to NACT are also not likely to benefit from IDS. Therefore, it is essential to identify these patients in order to avoid the risk of unnecessary surgical complications and the delay of second-line chemotherapy. Although not ideal, computed tomography (CT) imaging and measurement of the serum tumor marker CA125 have been traditionally used for both treatment response evaluation and follow-up of epithelial ovarian cancer patients [12,13]. Currently, there are no generally accepted criteria for predicting which patients are unlikely to benefit from cytoreductive surgery. Laparoscopic evaluation before cytoreductive surgery has been suggested by many gynecologic oncologists with the rationale including the following points: (1) Intraperitoneal diffusion of disease may be assessed easily with laparoscopy, and the surgeon may be more confident having direct visualization of the cancer spread; (2) This approach might spare patients an unnecessary laparotomy resulting in suboptimal cytoreduction; (3) Patients deemed not to be candidates for cytoreduction may proceed immediately to NACT without having to recover from laparotomy-related complications; (4) Laparoscopy allows collection of tissue for tissue diagnosis and molecular analysis. In 1998, Vergote et al. published the first study evaluating laparoscopy before cytoreductive surgery in a retrospective analysis of 285 patients with advanced ovarian carcinoma [14]. Later, two Italian studies were published, in 2005 and 2006 [15,16], suggesting that laparoscopy could assist in identifying patients with advanced ovarian cancer (AOC) who are candidates for NACT versus PDS. Operative treatment for gynecologic tumors has historically been performed via laparotomy. Over the last decades, minimally invasive surgery (MIS) has progressively gained popularity in this particular field. MIS offers advantages over laparotomy in terms of a shorter hospital stay, decreased perioperative morbidity, lower wound infection and incisional hernia rates, less postoperative pain, and faster healing [17]. Moreover, optical magnification of the abdominal vessels and structures, together with the availability of modern surgical devices such as advanced bipolar, ultrasound instruments, and topical hemostatic agents, increases the feasibility of MIS procedures [18]. MIS includes several different approaches, such as standard laparoscopy, robotics, mini-laparoscopy, and single-port laparoscopy. Surgeons choose the most appropriate method based on the availability of products, patient characteristics, tumor extension, and the type of surgery needed. Specific advantages exist in performing MIS in ovarian cancer: Adjuvant chemotherapy can start sooner because smaller incisions yield shorter recovery times. Furthermore, MIS is associated with decreased adhesion formation and easier access to the retroperitoneum [19]. With that being said, specific risks also have been reported for MIS, such as port site tumor implantation; however, this risk seems very