Background: when standard therapy reaches its limits
Ovarian cancer (ovarian carcinoma) is one of the most common gynaecological cancers. Many patients develop peritoneal metastases (peritoneal carcinomatosis) over the course of their disease. The tumour then spreads to the peritoneum, where systemic therapies reach it poorly.
The situation becomes particularly difficult once so-called platinum resistance sets in. The disease then no longer responds to platinum, the drug on which first-line therapy is based. Few treatment options remain, and the outlook is often poor.
What is PIPAC therapy?
In PIPAC (Pressurized IntraPeritoneal Aerosol Chemotherapy), a chemotherapy drug is delivered into the abdominal cavity as a fine mist during a minimally invasive procedure. The pressure helps the drug penetrate the tumour tissue, at a much lower dose than in systemic chemotherapy.
The study: PIPAC compared with systemic chemotherapy
Researchers led by Kumar SP et al. compared PIPAC directly with further intravenous chemotherapy in a randomised controlled trial, the study design best suited to comparing two treatments. According to the authors, this is the first such comparison. The interim results were published in 2026 in the Indian Journal of Surgical Oncology.
The trial enrolled 80 patients with unresectable peritoneal metastases from platinum-resistant ovarian cancer. By random allocation, 40 patients each were assigned to one of the two treatment groups:
- PIPAC group: three PIPAC treatments, each 6 weeks apart, following the established standard protocol
- Control group: a new intravenous chemotherapy without platinum
Patient characteristics were similar in both groups. The primary endpoint was the objective response rate (ORR), meaning how the tumour responded to treatment on computed tomography and other imaging. The researchers also recorded quality of life with standardised questionnaires, as well as side effects and complications.
The results
In the interim analysis, PIPAC was statistically significantly better than systemic chemotherapy in all outcomes examined.
Tissue samples from the PIPAC group also showed tumour cell death and scarring of tumour nodules under the microscope in 60% of cases. This indicates that the drug acts directly on the tumour tissue.
“This study is a milestone. For the first time, it also shows in a randomised controlled setting what we experience every day in clinical practice: PIPAC therapy reaches tumour cells directly where the disease is – with an efficacy that systemic chemotherapy cannot achieve in this situation.” Prof. Dr. med. Jürgen Zieren, German PIPAC Center
What this means for patients
If you have platinum-resistant ovarian cancer with peritoneal metastases, these results matter. Until now, few effective options existed at this stage. In this trial, PIPAC produced a higher response rate, better quality of life and fewer severe side effects than further chemotherapy.
The study provides randomised data for what many centres have observed in clinical practice. At the German PIPAC Center, we have used the method for years, including in patients in exactly this situation.
Outlook: more trials are needed
The publication is an interim analysis. The final data from the complete trial are still to come and will show whether the results hold. The study also shows that randomised controlled trials of PIPAC are feasible. Such trials are now needed for other cancer types as well.
Do you have questions about PIPAC therapy for ovarian cancer?
At the German PIPAC Center, we advise patients and their families individually on the treatment options for peritoneal metastases from ovarian cancer. Prof. Dr. Zieren and his team take time to go through your questions with you.
Arrange a personal consultation
Find out, without obligation, whether PIPAC could be an option for you.
