Peritoneal Mesothelioma Cancer Awareness Month 2025 - In Case You Missed It

Abdominal Cancers Alliance
Sep 29
4 min read

During September we recognized Peritoneal Mesothelioma Cancer Awareness Month to bring more attention to advanced forms of this cancer. In case you missed it, here's a quick recap for the month!

Malignant mesothelioma is a rare, aggressive form of cancer that develops in the mesothelial cells that form the lining of the pleura (lungs), peritoneum (abdominal cavity), pericardium (heart), and testicles (testes).

Peritoneal mesothelioma is the second most common type of mesothelioma and forms in the lining of the abdominal cavity. Only about 500 cases of peritoneal mesothelioma are diagnosed annually in the United States accounting for 15-30% of all mesotheliomas. The average survival for patients with peritoneal mesothelioma is approximately one year; however, this can extend to 3-5 years with aggressive treatment.

Peritoneal mesothelioma is caused by exposure to asbestos, a fibrous material woven into fabrics for fire-resistant and insulating materials. There are two suggested routes of asbestos exposure into the abdominal cavity: 1) through ingestion and 2) inhaled and transferred through the lymphatic system. Peritoneal mesothelioma is slow-growing and can take up to 10-50 years from exposure for symptoms to develop.

Malignant peritoneal mesothelioma includes three subtypes: epithelioid, sarcomatoid, and biphasic (mixed epithelioid and sarcomatoid). Epitheliod is the most common type, accounting for 50-70% of cases, and associated with the best survival outcomes. Pure sarcomatoid tumors are extremely rare, with most data limited to single case reports. Regardless of subtype, complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is the treatment of choice. Factors independently associated with favorable overall survival include: cancer subtype, absence of lymph node metastases, completeness of cytoreduction, and administration of HIPEC.

Key Facts about Peritoneal Mesothelioma Cancer

1️⃣ Peritoneal mesothelioma is most commonly linked to environmental exposure to asbestos.

2️⃣ It is considered a very lethal disease that is difficult to diagnose due to vague symptoms.

3️⃣ Significant advances have been made in the treatment of peritoneal mesothelioma, improving both survival (median survival increased from less than 1 year to 3-5 years) and tolerability.

4️⃣ Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is the treatment of choice for peritoneal mesothelioma, with the best outcomes achieved when all visible disease is removed.

Risk Factors

1️⃣ Asbestos Exposure: Working at or living near an asbestos mine or processing plant; Working in high-risk occupational setting, such as automotive industry; Serving on military ships and facilities built with asbestos; Disturbing old asbestos products during home renovation

2️⃣ Gender: occurs more commonly in men

3️⃣ Age: diagnosis occurs around age 65 and older

4️⃣ Smoking: combined with asbestos exposure

5️⃣ Other health or genetic issues: Associated with a rare BAP1 mutation; unknown relationships with exposure to radiation or the Simian Virus 40.

Signs & Symptoms can be similar to other conditions and are often non-specific.

1️⃣ Abdominal pain

2️⃣ Nausea and vomiting

3️⃣ Change in bowel habits

4️⃣ Abdominal swelling

5️⃣ Early satiety when eating

6️⃣ Unintentional weight loss

Treatment

A physician may use some or all of these methods to treat peritoneal mesothelioma.

1️⃣ Surgery: Surgery is the most promising treatment for peritoneal mesothelioma. The best results are seen when removal of all visible disease from the abdomen occurs. Surgery is often extensive and may include bowel resections. Because peritoneal mesothelioma is often found when it has already spread throughout the abdomen, a complete surgical resection (surgical removal) is not always possible and surgery may be performed for symptom relief or with palliative intent.

A paracentesis may also be performed for symptom relief. This procedure drains excess abdominal fluid that builds, putting pressure on the abdominal organs and causing discomfort. It can be performed as an outpatient procedure and be repeated, if needed.

2️⃣ Chemotherapy: Systemic chemotherapy, commonly known as intravenous (IV) chemotherapy, can be used prior to surgery, after surgery, or alone. The most common systemic chemotherapy regimen is pemetrexed and cisplatin, followed by carboplatin and gemcitabine for recurrent or resistant disease. The benefit of systemic chemotherapy before (neoadjuvant setting) or after (adjuvant setting) cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) has yet to be established. Some retrospective studies failed to show any benefit of perioperative systemic chemotherapy. Until stronger, prospective data is available, the decision to use perioperative systemic chemotherapy in combination with CRS/HIPEC should be made on an individual basis, considering factors such as patient performance status, operability, and presence of high-risk features for early recurrence.

If patients are not candidates for CRS/HIPEC, systemic chemotherapy alone will likely be the treatment of choice. While the efficacy of systemic chemotherapy is limited, therapy tends to be well-tolerated and tumors respond with shrinkage or stabilization - an overall response rate of 71% (26% responded + 45% stable disease). However, the response seems to be short-term as the median overall survival with systemic chemotherapy alone is approximately 13 months.

3️⃣ CRS/HIPEC: Traditional treatment consisted of a combination of systemic chemotherapy, palliative surgery, and whole abdomen radiation. This was very toxic and the median survival was less than one year (median survival without treatment: six months). However, within the past 10-15 years considerable advances in overall survival have been made with the use of extensive cytoreductive surgery (CRS) followed by intraoperative heated intraperitoneal chemotherapy (HIPEC). Cytoreductive surgery is the aggressive surgical removal or destruction of cancer such that all visible disease is removed. Following CRS, heated chemotherapy (HIPEC) is circulated directly into the abdominal cavity to kill any remaining microscopic cancer cells. CRS/HIPEC is considered the best treatment option if the disease is able to be completely removed and should be performed by a surgeon who is experienced with peritoneal mesothelioma and the CRS/HIPEC procedure. This surgery can be very complex and prognosis is highly impacted by the quality of the surgery. With a complete cytoreduction and HIPEC, median overall survival improves to 34-92 months. However, with an incomplete cytoreduction (CC-2/3), median overall survival shortens to under 7 months.

Learn More about Peritoneal Mesothelioma Cancer

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Thank You

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