Patients with recurrent malignant mesothelioma or mesothelioma that doesn’t respond to standard therapies, like cytoreductive surgery and systemic chemotherapy, may often be left with limited treatment options as the cancer becomes more advanced. Researchers in Europe are testing the safety and efficacy of an aerosol chemotherapy called Pressurized IntraPeritoneal Aerosol Chemotherapy or Thoracal Aerosol Chemotherapy (PIPAC/PITAC) for patients with malignant peritoneal mesothelioma.
In this prospective study, which is being conducted by researchers at the Ruhr University Bochum in Germany, this application of chemotherapy consisted of a combination of drugs often used in treating mesothelioma, doxorubicin and cisplatin. PIPAC is a new drug delivery technique for targeted intraperitoneal chemotherapy, similar to hyperthermic intraperitoneal chemotherapy (HIPEC), which has been found to be successful in achieving longer survival in peritoneal mesothelioma cancer patients.
While HIPEC uses a targeted heated liquid chemotherapy wash, PIPAC differs in that the targeted chemotherapy is delivered to the abdomen in a pressurized aerosol form during a short laparoscopic operation. The theory behind the PIPAC procedure is that the pressure of the gas will help spread the chemotherapy throughout the abdominal cavity and abdominal wall to combat remaining cancerous cells.
PIPAC has also been tested on other cancers, like colorectal cancer, gastric cancer, recurrent ovarian cancer, peritoneal carcinomatosis, and other instances of gastric peritoneal metastasis. PIPAC for these other cancers often includes different chemotherapy drugs, such as oxaliplatin.
The clinical study included 29 peritoneal mesothelioma patients who were observed from June 2012 to October 2017. The majority of these patients had already had at least one round of surgery to remove tumors, with many of these patients also treated with one or more rounds of HIPEC. Researchers found that most patients had some form of chemotherapy, whether HIPEC or systemic, though eight patients had no prior chemotherapy treatment because of potential severe adverse events.
In this early-phase clinical trial, researchers were able to successfully treat 25 of the 29 patients with at least one round of PIPAC. In this initial treatment, only minimal tumor regression was achieved in six patients. However, 20 patients were able to undergo at least one additional round of PIPAC treatment. Researchers observed 15 of these patients achieve significant tumor regression, with complete tumor regression observed in another four patients after several applications of PIPAC.
Researchers noted some side effects from the novel treatment including nausea and vomiting, abdominal pain, and temporary ascites (accumulation of fluid in the abdominal region). Overall, the researchers noted this treatment technique was safe and tolerable.
After a follow up period, patients experienced a median survival of 26.6 months. This is an improvement on the 12 months average life expectancy for peritoneal mesothelioma patients, though not as effective as HIPEC in this initial study. Researchers have found at least 50% patients who undergo HIPEC can extend their survival to five years or more.
Regardless, this early-phase clinical trial shows promise as a potential new treatment for peritoneal mesothelioma. Hopefully with further study and retrospective analysis, researchers can find other combinations of chemotherapy applied by this method that may lead to longer survival.