Staging of Peritoneal Mesothelioma
Understanding How Doctors Measure Disease Progression and Plan Treatment
Staging helps doctors understand how far peritoneal mesothelioma has spread, and it’s a critical step in developing your treatment plan. While there’s no universal staging system for this rare cancer, several methods are commonly used to assess the extent of disease and guide next steps.
This page explains the staging process, the systems used to measure it, and why your “stage” doesn’t always define your future.
Why Staging Matters
Knowing the stage of peritoneal mesothelioma helps:
Decide if surgery and HIPEC are possible
Estimate prognosis
Choose between curative or palliative treatment
Determine eligibility for clinical trials
How Peritoneal Mesothelioma Is Staged
Unlike pleural mesothelioma or lung cancer, peritoneal mesothelioma doesn’t have a single standard staging system. Instead, doctors use a combination of imaging, surgical findings, and specialized scoring systems to estimate disease burden.
The three most common systems used are:
🧮 1. Peritoneal Cancer Index (PCI)
The most widely used staging system for peritoneal mesothelioma.
How it works:
The abdomen is divided into 13 zones
Each zone is scored based on tumor size:
0 = No tumor
1 = Tumor < 0.5 cm
2 = Tumor 0.5–5 cm
3 = Tumor > 5 cm or confluence
All scores are added for a total PCI score from 0 to 39.
What it means:
Low PCI (0–10): Best candidates for CRS + HIPEC
Moderate PCI (11–20): Surgery may still be possible depending on tumor location
High PCI (21–39): Focus often shifts to palliative care or systemic therapy
PCI is typically assessed during a diagnostic laparoscopy or surgery.
🧬 2. TNM Staging System
Used broadly across many cancer types, including some cases of mesothelioma.
T (Tumor): Size and spread of the main tumor
N (Nodes): Whether cancer has reached nearby lymph nodes
M (Metastasis): Whether the cancer has spread to distant organs
This system is useful when peritoneal mesothelioma has spread beyond the abdomen.
📊 3. Butchart System (Rarely Used Today)
Originally developed for pleural mesothelioma, this older system uses four stages. It's rarely applied to peritoneal cases but may still be referenced.
Imaging and Surgical Tools for Staging
To determine your stage, doctors may use:
CT or MRI scans to identify tumors and fluid
PET scans to detect cancer activity
Laparoscopy to visually assess tumors and take biopsies
PCI scoring during cytoreductive surgery or staging procedures
What Your Stage Means for Treatment
Localized (Low PCI): You may be eligible for curative surgery + HIPEC
Widespread (High PCI): Treatment may focus on symptom relief, systemic chemotherapy, or clinical trials
Involvement of distant lymph nodes or organs: May rule out surgery, but immunotherapy or palliative options are still available
Why Stage Isn’t the Whole Story
Staging is only part of the equation. Other factors matter too, like:
Cell type (epithelioid, sarcomatoid, biphasic)
Your overall health and organ function
Nutritional status and performance level
Tumor genetics and responsiveness to treatment
Some patients with “advanced” staging still live for years—especially with modern multimodal care and access to clinical trials.
Get Support Understanding Your Stage
We can help you:
Understand what your PCI or imaging results mean
Connect with top HIPEC centers and surgical teams
Explore legal options to help pay for care
📞 Call 833-4-ASBESTOS
Or request a free staging consultation