Peritoneal mesothelioma is too rarely treated surgically

A scientific study by Universitätsklinik Regensburg has used nationwide hospital data from InEK (Institut für das Entgeltsystem im Krankenhaus, the German Institute for the Hospital Remuneration System) to analyse how often mesothelioma of the peritoneum occurs in Germany and how it is treated. The finding: only a small proportion of patients receive the surgical therapy that the guidelines recommend.

What is peritoneal mesothelioma?

Mesothelioma is the most common primary malignant tumour of the lining of the abdominal cavity (peritoneum). According to the Regensburg analysis, the annual incidence in Germany averages 0.68 per 100,000 inhabitants, which makes it a rare disease. A total of 3,394 patients were recorded in the study period from 2019 to 2024.

Histologically, three types are distinguished:

• Epithelioid type
• Mixed (biphasic) type
• Sarcomatoid type, which has a very poor prognosis

Except for the sarcomatoid type, these tumours should be treated surgically as the first approach, provided the patient's general condition allows it.

What the guidelines recommend

This recommendation has been in place for many years and appears in many national and international guidelines. After assessment by an interdisciplinary tumour board, the tumour deposits are removed in open surgery and the abdominal cavity is then rinsed with a heated chemotherapy solution. This procedure is known as cytoreductive surgery (CRS) with HIPEC.

For patients in reduced general condition, or for those who decline major open surgery, PIPAC has been available for around 15 years as a less invasive alternative.

The result: only 20% undergo surgery

The Regensburg study shows that in Germany only 20% of patients are referred for surgical treatment at all after a diagnosis of peritoneal mesothelioma. Most patients therefore do not receive the treatment the guidelines recommend as standard. Broken down:

• only 9% received HIPEC,
• 15% some form of peritonectomy (surgical removal of the affected peritoneum),
• just 5% PIPAC.

Because some patients received more than one of these procedures, the overall proportion is 20%. The authors describe a serious gap between guideline recommendations and clinical practice.

The authors name the following possible causes:

• a continuing lack of awareness of the surgical options (CRS, HIPEC, PIPAC)
• missing information and a wrong assessment of what modern surgical therapy can achieve
• possibly also economic incentives in the healthcare system that favour chemotherapy alone

The role of PIPAC in peritoneal mesothelioma

Studies report that repeated PIPAC, each session with a small operation and a short hospital stay, can allow long disease courses with good quality of life. This is relevant in three situations:

• when open surgery (CRS/HIPEC) is not an option because of reduced general condition,
• when patients decline major surgery,
• when the disease has come back some time after CRS/HIPEC.

If you have been diagnosed with peritoneal mesothelioma, have the surgical options assessed at a specialised centre before you rely on systemic chemotherapy alone.

Do you have questions about the treatment of peritoneal mesothelioma?

At the German PIPAC Center, we advise patients and their families individually on the treatment of peritoneal cancer, including whether CRS/HIPEC or PIPAC is an option in your situation.