Adjuvant PIPAC in advanced ovarian cancer: Longer survival in a new randomised trial

When surgery for advanced ovarian cancer cannot remove the entire tumour, the outlook is often poor. A randomised phase II trial (PIPAC-OVA), recently published in BMC Cancer, found that patients in this situation lived longer when they received PIPAC therapy in addition to standard chemotherapy. The treatment was well tolerated.

Background: when the entire tumour cannot be removed

Ovarian cancer (ovarian carcinoma) is often only discovered at an advanced stage, when the tumour has already spread to the peritoneum. The aim of surgery is to remove all visible tumour deposits if possible (complete cytoreduction). If this is not achieved (incomplete or suboptimal cytoreduction), microscopic or small tumour residues remain in the abdominal cavity.

These residues are where the disease usually comes back. The intravenous chemotherapy given afterwards reaches the peritoneum only to a limited extent, so these patients have had few ways to lower their risk of recurrence.

The study: standard chemotherapy with and without additional PIPAC

In the randomised phase II trial PIPAC-OVA, a research team led by Dzasokhov AS et al. investigated whether additional PIPAC therapy after incomplete tumour removal offers a benefit. The results were published in 2026 in the journal BMC Cancer.

All participating patients had previously undergone surgery for advanced ovarian cancer with incomplete tumour removal. They were randomly assigned to one of two treatment groups:

• Control group (standard): 6 cycles of standard chemotherapy (carboplatin / paclitaxel)
• PIPAC group: the same standard chemotherapy plus an additional 3 cycles of PIPAC therapy

The trial measured progression-free survival (the time until the disease progresses or recurs), overall survival, control of fluid build-up in the abdomen (ascites) and side effects.

The results

Patients who also received PIPAC did better on both progression-free and overall survival.

Additional PIPAC therapy prolonged progression-free survival by around 7 months (median 19.7 vs 12.5 months) and overall survival by around 8 months (median 46.2 vs 38.1 months). Both differences were statistically significant. In 98.8% of patients in the PIPAC group, ascites was brought under control. Ascites is one of the most distressing symptoms of advanced peritoneal disease, and controlling it can make a real difference to quality of life.

“It is precisely the patients in whom we cannot remove the tumour completely who need every additional effective option. This randomised controlled study shows that PIPAC acts exactly where systemic chemotherapy reaches its limits – directly on the peritoneum.” Prof. Dr. med. Urs Pabst-Giger, German PIPAC Center

What this means for patients

The trial is relevant if you have advanced ovarian cancer and the tumour could not be removed completely. Earlier studies looked mainly at PIPAC for recurrent disease. PIPAC-OVA tested it in addition to standard therapy (adjuvant) and found longer progression-free and overall survival as well as good control of ascites.

At the German PIPAC Center, we have used PIPAC for years, including in patients in this situation.

Outlook: phase III trials needed

As a randomised phase II trial, PIPAC-OVA gives strong indications that PIPAC works in ovarian cancer that has spread within the abdomen after incomplete tumour removal. It is not yet proof. The authors recommend confirming the results in phase III trials. PIPAC-OVA adds to a growing number of randomised trials on PIPAC.

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 advanced ovarian cancer with peritoneal involvement. Prof. Dr. Pabst-Giger and his team take time to go through your questions with you.