Peritoneal Mesothelioma and Multi-Modality Treatment

Combining surgery, localized chemotherapy and gamma-interferon-1b, and radiation can increase survival for patients with peritoneal mesothelioma, according to a recent study in the American Journal of Clinical Oncology.

Currently, no standard treatment exists for peritoneal mesothelioma, a rare cancer of the abdominal lining (peritoneum). Because the disease is typically confined to the abdomen, treatment usually consists of local therapies such as surgery or chemotherapy. In the current study, researchers investigated whether combining surgery with locally delivered chemotherapy, biological therapy (gamma-interferon-1b), and radiation might slow the progression of the disease and improve survival.

The study involved 27 patients (average age, 53) with malignant peritoneal mesothelioma. All of the participants underwent surgery in which doctors removed all traces of visible disease—a time-intensive procedure known as debulking.

“If you open the abdominal cavity, the cancer will form a pattern of salt-and-pepper sprinkled throughout the abdomen. It’s hard to take out because it doesn’t grow in discrete masses,” explains Mary Hesdorffer, MS, APRN, nurse practitioner with the Mesothelioma Applied Research Foundation, and medical liaison for the Mesothelioma Foundation. “Surgery is normally an eight or nine hour operation in which the surgeon painstakingly removes all of these little bits and pieces of disease to prepare for chemotherapy.”

After surgery, patients received chemotherapy and then biological therapy with gamma interferon-1b delivered directly into the peritoneal space. Then they had a second surgery to remove whatever cancer remained, followed by radiation to the abdomen and pelvis.

Patients who underwent this treatment lived for an average of nearly six years and had a three-year survival rate of 67%, a lifespan that is particularly significant considering that patients with the disease typically survive only six to nine months. Patients with epithelial form of the disease had the best odds of treatment success (a three-year survival rate of 78%), while those with the sarcomatoid form of the disease fared worst (all four patients in the study died within 11 months).

Seven patients in the study had no evidence of disease after more than seven years of follow-up—a promising outcome, although Hesdorffer is hesitant to label it a “cure.” “We can say that they’re in a substantial remission, but I don’t know if we can say cure yet because “cure” hasn’t yet been defined in this disease,” she says.

Still, the results suggest that the combination of surgery, chemotherapy, and radiation should be “considered the standard of care for patients with peritoneal mesothelioma,” says Hesdorffer. She says it’s important for doctors to be aware of the outcome of studies such as this one, because they are often reluctant to aggressively treat patients they believe to have a poor overall prognosis. “Most doctors tell them to go home and prepare to die.”

The best way to target this disease is to enroll patients in clinical trials at centers specializing in peritoneal mesothelioma, according to Hesdorffer.

Source:
Hesdorffer ME, et al. Combined resection, intraperitoneal chemotherapy, and whole abdominal radiation for the treatment of malignant peritoneal mesothelioma. Am J Clin Oncol. 2008;31:49-54

PERITONEAL MESOTHELIOMA (ABDOMINAL MESOTHELIOMA)

Peritoneal Mesothelioma accounts for approximately twenty percent of all mesothelioma cases diagnosed annually. There are only several hundred cases of mesothelioma of the peritoneum, and associated abdominal mesothelioma diagnosed each year. When asbestos is breathed in, the small fibers enter the deep recesses of the lung. Some asbestos fibers remain in the lung tissue (known as the lung parenchyma) where they can cause scarring (asbestosis) or primary lung cancer. However, when fibers move from the lung to other areas of the body, including the peritoneum, this may cause abdominal mesothelioma from asbestos. The peritoneum is the lining of the abdominal cavity. The peritoneum supports the abdominal organs and assists in blood flow and with the lymph system. The peritoneum consists of two layers: the parietal peritoneum and visceral peritoneum. In a healthy person, a fluid known as "serous" fluid allows these two layers of the peritoneum to slide freely and facilitate abdominal functions including digestion. The formation of cancerous tumors on the peritoneum is known as peritoneal mesothelioma, which is often characterized by excessive fluid-build up in the abdomen. Also, the tumor itself is commonly spread out in "sheets" on the peritoneal surface. A person with advanced peritoneal mesothelioma may visibly appear to have a distended stomach.

All types of mesothelioma are caused by asbestos, including abdominal or peritoneal mesothelioma. Studies have shown that short thin asbestos fibers, particularly the chrysotile variety are most prevalent in cases of mesothelioma of the peritoneum.

Mesothelioma surgeons have performed different types of surgeries on patients with peritoneal mesothelioma. One of the most common types of surgery for abdominal mesothelioma is a surgical debulking followed by post-surgical intraperitoneal chemotherapy. With this procedure, a heated chemotherapy agent is directly administered into the peritoneal space immediately after the debulking portion of the surgery. (See Feldman et al., Analysis of Factors Associated with Outcome in Patients with Malignant Mesothelioma Undergoing Surgical Debulking and Intraperitoneal Chemotherapy, Journal of Clinical Oncology, Vol 21, Issue 24, 2003). This new approach to treating peritoneal mesothelioma is also referred to as cytoreductive surgery (debulking) plus perioperative intraperitoneal chemotherapy. Hundreds of patients have now undergone this procedure and results have been reported by the National Cancer Institute (USA); The Washington Cancer Institute; The Columbia University Mesothelioma Center; and the National Cancer Institute (Italy). Asbestos litigation affords victims of abdominal or peritoneal mesothelioma the opportunity to retain a experienced mesothelioma cancer attorney and obtain monetary compensation from the companies responsible for causing this disease.