Ovarian cancer (OC) usually presents at an advanced stage due to the lack of efficient screening programs and the absence of pathognomonic clinical symptoms. For example, in a large series of 1009 women with epithelial OC, 78% of women initially diagnosed with this disease had Fédération Internationale des Gynécologues et Obstétriciens (FIGO) stage III or IV disease [
1]. In women with advanced OC, the tumor typically metastasizes into the abdominal cavity involving the abdominal side walls, the small and large bowel, the mesentery, and the diaphragm. Between 40% and 80% of these women successfully undergo cytoreduction with no residual disease or residual disease <1 cm [
2]. However, a substantial proportion of patients is deemed unresectable upon diagnostic laparoscopy or exploratory laparotomy. In these patients, palliative chemotherapy or - alternatively - neoadjuvant chemotherapy with three or four cycles of carboplatin and paclitaxel followed by a second attempt at surgery, i.e. intervention debulking, is the therapy of choice [
2,
3]. A number of cytotoxic agents have shown activity in this situation, among them liposomal doxorubicin, topotecan, gemcitabine, and trabectedin [
4]. These substances, alone or in combination, achieve a wide range of response rates. For example, Ferrero et al. described a response rate of 49% with gemcitabine and vinorelbine in platinum-sensitive patients [
5], whereas Burger et al. found a response rate of 29% in a mixed resistant-sensitive population [
6]. Lower response rates are seen among platinum-resistant patients with response rates of 25% [
7], 21% [
8], 11% [
9], and even 3% [
10] with doxorubicin and gemcitabine, topotecan and oxaliplatin, gemcitabine and vinorelbine, and vinorelbine in various combinations and dosages, respectively. Regarding survival, palliative chemotherapy regimens achieve median overall survival rates after the first, second, third, fourth, and fifth relapse of 17.6 (95% CI 16.4–18.6), 11.3 (10.4–12.9), 8.9 (7.8–9.9), 6.2 (5.1–7.7) and 5.0 (3.8–10.4) months, respectively [
11].
Women with unresectable OC are in a palliative situation and therefore, side effects of toxic chemotherapy and quality of life become important issues when judging the pros and cons of standard treatment regimens. Palliative systemic chemotherapy has a considerable morbidity, especially when given as polychemotherapy with or without targeted therapies such as bevacizumab or olaparib. Common Terminology Criteria for Adverse Events (CTCAE) grade 3 to 4 are seen in up to 50% of patients [
4‐
10]. Thus, effective and less morbid alternatives to systemic palliative chemotherapy are an unmet medical need for women with primary unresectable OC.
Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new form of intraperitoneal chemotherapy taking advantage of the physical properties of gas and pressure. PIPAC has been shown to increase the distribution and infiltration depth of intraperitoneal chemotherapy, while at the same time reducing the chemotherapy dose by a factor of 10 as compared with systemic intravenous applications [
12]. Furthermore, PIPAC can be administered repeatedly and has been shown to induce regression of peritoneal tumor nodules with limited hepatic and renal toxicity [
13]. In a prospective phase II trial of women with recurrent OC, PIPAC with cisplatin and doxorubicin achieved a clinical benefit rate of 62% according to Response Evaluation Criteria In Solid Tumors (RECIST) criteria and a histological tumor regression rate of 76% [
13]. In addition, PIPAC has been shown to be well tolerated with a stabilization and even an increase of the quality of life of patients with peritoneal carcinomatosis (PC) from ovarian, gastric, and colon cancer [
13,
14].
The documented good tolerability and positive effects on quality of life make PIPAC a candidate for a maintenance chemotherapy in women with unresectable OC. As of yet, however, there are no data describing PIPAC as a possible means of maintenance therapy in patients with primary unresectable OC. Here we report the case of a successful long-term maintenance treatment over two years with intraperitoneal cisplatin and doxorubicin applied as PIPAC.