The use of PIPAC (pressurized intraperitoneal aerosol chemotherapy) in gynecological oncology: a statement by the German "Arbeitsgemeinschaft Gynaekologische Onkologie Studiengruppe Ovarialkarzinom (AGO-OVAR)", the Swiss and Austrian AGO, and the North-Eastern German Society of Gynaecologic Oncology

Ovarian, tubal, and peritoneal carcinomas primarily affect the peritoneal cavity, and they are typically diagnosed at an advanced tumor stage (Foley, Rauh-Hain, del Carmen in Oncology (Williston Park) 27:288-294, 2013). In the course of primary surgery, postoperative tumor residuals are, apart from the tumor stage, the strongest independent factors of prognosis (du Bois, Reuss, Pujade-Lauraine, Harter, Ray-Coquard, Pfisterer in Cancer 115:1234-1244, 2009). Due to improved surgical techniques, including the use of multi-visceral procedures, macroscopic tumor clearance can be achieved in oncological centers, in most cases (Harter, Muallem, Buhrmann et al in Gynecol Oncol 121:615-619, 2011). However, to date, it has not been shown that peritoneal carcinomatosis is, per se, an independent factor of prognosis or that it excludes the achievement of tumor clearance. Several studies have shown that a preceding drug therapy in peritoneal carcinomatosis could positively influence the overall prognosis (Trimbos, Trimbos, Vergote et al in J Natl Cancer Inst 95:105-112, 2003). In relapses of ovarian carcinoma, studies have shown that peritoneal carcinomatosis is a negative predictor of complete tumor resection; however, when it is possible to resect the tumor completely, peritoneal carcinomatosis does not play a role in the prognosis (Harter, Hahmann, Lueck et al in Ann Surg Oncol 16:1324-1330, 2009). PIPAC is a highly experimental method for treating patients with ovarian, tubal, and peritoneal cancer. To date, only three studies have investigated a total of 184 patients with peritoneal carcinomatosis (Grass, Vuagniaux, Teixeira-Farinha, Lehmann, Demartines, Hubner in Br J Surg 104:669-678, 2017). Only some of those studies were phase I/II studies that included PIPAC for patients with different indications and different cancer entities. It is important to keep in mind that the PIPAC approach is associated with relatively high toxicity. To date, no systematic dose-finding studies have been reported. Moreover, no studies have reported improvements in progression-free or overall survival associated with PIPAC therapy. Randomized phase III studies are required to evaluate the effect of this therapy compared to other standard treatments (sequential or simultaneous applications with systemic chemotherapy). In cases of ovarian, tubal, and peritoneal cancer, PIPAC should not be performed outside the framework of prospective, controlled studies.