Surgery for Peritoneal Carcinomatosis

Symptoms of peritoneal carcinomatosis

Peritoneal carcinomatosis may present with progressive abdominal distension, fluid accumulation in the abdomen (ascites), diffuse abdominal pain or discomfort, early satiety, loss of appetite and weight, and altered bowel transit that in advanced cases may lead to partial or complete obstruction. Severe fatigue is also a frequent symptom in these patients.

In many cases, symptoms appear during follow-up of a previously diagnosed digestive or gynaecological cancer. When they occur in combination, or when signs of new dissemination are detected during a routine review, it is essential to consult a team specialised in peritoneal oncology for an early assessment that allows the available therapeutic options to be evaluated.

Causes and risk factors of peritoneal carcinomatosis

Peritoneal carcinomatosis results from the spread of tumour cells from a primary tumour to the peritoneum. The most frequent origins are digestive tumours (colon, rectum, stomach, appendix and pancreas), gynaecological tumours (primarily ovarian cancer), primary peritoneal mesothelioma, and pseudomyxoma peritonei of appendiceal origin.

The risk of developing peritoneal carcinomatosis depends largely on the characteristics of the primary tumour: serosal involvement, tumour perforation during progression or surgery, and an advanced stage at the time of initial diagnosis are factors that increase the likelihood of peritoneal dissemination. Understanding these factors is key to oncological follow-up and the early detection of peritoneal involvement.

What the scientific evidence says about HIPEC

The PRODIGE 7 trial, led by Dr. François Quénet and published in The Lancet Oncology, compared cytoreductive surgery alone with cytoreductive surgery plus short-course oxaliplatin HIPEC in patients with peritoneal metastases of colorectal origin. With that specific protocol, HIPEC did not improve overall survival and was associated with a higher rate of late postoperative complications.

The meaningful reading of the trial is not that surgery has lost its role, but the opposite. Both arms exceeded 40 months of median survival, far beyond what systemic treatment alone would achieve. What sustains that result is complete cytoreduction, meaning the genuine ability to remove all visible disease. Surgical technique and patient selection weigh more heavily than the addition of the perfusion itself.

An international analysis published in BJS Open in 2024, covering more than 2,000 patients, found variable outcomes across HIPEC regimens, though its retrospective design prevents any claim of superiority. This is why HIPEC is not applied automatically at Quenet-Torrent Institute: it is indicated according to tumour origin, available protocol, prior treatment and board assessment.

The Peritoneal Cancer Index (PCI)

The Peritoneal Cancer Index is the standard tool for measuring how much disease is present and where. It divides the abdomen into 13 regions and scores the size of tumour implants in each from 0 to 3, up to a maximum of 39 points.

A low score indicates more limited disease and therefore a greater chance of achieving complete cytoreduction. However, no single figure automatically indicates or rules out surgery: the location of the implants can matter as much as the number. A moderate PCI with diffuse involvement of the small bowel and its mesentery may be far less operable than a higher PCI concentrated in accessible areas.

It is also worth knowing that imaging tends to underestimate the true PCI, since millimetric implants are not always visible. The definitive index is established in theatre, during surgical exploration.

How the case is studied before surgery

Before proposing an operation, the true extent of disease must be estimated as precisely as possible. The work-up is built in layers, adding tests only when they can genuinely change the decision.

The role of systemic chemotherapy

HIPEC does not replace intravenous chemotherapy. They act over different territories: HIPEC works locally inside the abdominal cavity, while systemic treatment reaches the whole body, including any disease that may exist outside the peritoneum.

In most cases both are combined within a single strategy. Chemotherapy given before surgery also allows the team to observe how the disease behaves, which is a selection criterion in itself: a tumour that responds presents a very different surgical scenario from one that progresses despite treatment.

What is the life expectancy in peritoneal carcinomatosis?

There is no single figure, and any answer given without reviewing your case should be treated with caution. Prognosis depends mainly on three variables: the origin of the primary tumour, the extent of disease measured by the PCI and, above all, whether complete cytoreduction is achieved.

That last factor changes the picture the most. In well-selected patients in whom all visible disease is removed, published outcomes sit far above those of systemic treatment alone, and around 20% of cases may achieve cure. In the PRODIGE 7 trial, in colorectal peritoneal disease with complete cytoreduction, median survival exceeded 40 months in both study arms.

Tumour origin also makes a substantial difference. Pseudomyxoma peritonei and peritoneal mesothelioma show the best long-term results; ovarian and colorectal origin occupy an intermediate position; gastric origin requires the strictest selection.

Translating these figures into an individual case requires reviewing the imaging, the histology and the prior clinical course. That is precisely the purpose of a second opinion at a specialised unit.

Recovery and possible complications

Cytoreductive surgery with HIPEC is a highly complex procedure, and explaining it transparently is part of the treatment. The operation usually lasts between 6 and 12 hours in a single surgical session.

Depending on its magnitude, the first hours may be spent in intensive care. Hospital stay is broadly 7 to 14 days, though this depends on the extent of surgery and individual recovery. After discharge, several weeks are usually needed to regain strength, appetite and the ability to resume daily activities.

As with any major abdominal surgery, it carries risks that should be understood: infection, bleeding, respiratory complications, thrombosis, impaired renal function, delayed return of bowel transit, healing problems at digestive anastomoses, and effects related to the drugs used during HIPEC. Team experience and case volume are consistently associated with lower rates of severe complications, but they do not eliminate them.

Follow-up after discharge includes wound review, analysis of the definitive pathology report and the decision on subsequent systemic treatment.

What happens if surgery is not indicated?

The fact that complete cytoreduction is not feasible does not mean nothing can be done. It means the goal changes: from potentially curative intent to disease control aimed at gaining time and quality of life.

In that setting systemic treatment remains the backbone, and in selected cases PIPAC may be considered, a pressurised aerosol chemotherapy delivered laparoscopically, far less aggressive than cytoreductive surgery and repeatable over several sessions. It is particularly useful in controlling ascites and the symptoms of peritoneal dissemination.

An initially unfavourable assessment is also not always final. If the disease responds well to systemic treatment, a case can be reassessed and may become surgical.