A technique that turns anti-cancer drugs into a chemotherapy spray could be a breakthrough for some peritoneal mesothelioma patients who were told they were not candidates for surgery.
The procedure is called PIPAC. It stands for pressurized intraperitoneal aerosol chemotherapy. It allows doctors to apply cancer-killing medication directly to the site of peritoneal mesothelioma tumors.
A new French study suggests that the chemotherapy spray, in combination with systemic chemotherapy, can shrink some tumors enough to completely remove them – even if doctors did not initially think resection was possible.
The study tracked several cases of successful surgery after standard chemotherapy and PIPAC. The retrospective study shows patients who had surgery experienced much longer progression-free survival than those who did not.
Standard Chemotherapy vs Chemotherapy Spray
Peritoneal mesothelioma is a type of cancer that grows on the lining of the abdomen. About 20 percent of mesothelioma patients have the peritoneal form of the disease.
Surgery provides the best odds for peritoneal mesothelioma survival. Surgeons usually rinse the abdomen with heated chemotherapy drugs (HIPEC) after they remove the main tumors. This helps keep residual cells from seeding new mesothelioma tumors. The five-year survival rate for patients who have this combination ranges from 29% to 63%.
But most peritoneal mesothelioma patients are not candidates for surgery and HIPEC. It is usually because their cancer is too advanced. These patients may have systemic chemotherapy with Alimta (pemetrexed) and a platinum-based drug to help slow the cancer down.
The new research shows chemotherapy spray may be helpful for these patients. Standard chemotherapy poisons tumors from the inside. Chemotherapy spray attacks them from the outside. If the two techniques can shrink the tumors, surgeons may be able to remove them.
PIPAC, Chemotherapy, and Mesothelioma Survival
The French study focused on 26 peritoneal mesothelioma patients who had at least one PIPAC treatment. Twenty of them had never had surgery. Half of the patients had three or more treatments with the chemotherapy spray.
Eight patients (31%) had side effects from the treatment, including two severe complications. But fourteen patients (54%) went on to have surgery and HIPEC. Almost all of these were successful.
“All but one procedure among 14 patients (54%) secondarily treated by CRS-HIPEC were considered complete resections,” writes the study’s lead author Vahan Kepenekian of the University of Lyon.
The mesothelioma patients who had chemotherapy spray and systemic chemotherapy had a median survival of 12 months. But those who were able to have surgery lived much longer without cancer regrowth than those who did not (33.5 months versus 7.4 months).
Dr. Kepenekian concludes, “For patients with initially non-resectable DMPM [peritoneal mesothelioma], PIPAC is feasible for treatment with neoadjuvant intent and could facilitate complete secondary resection.”
Kepenekian, V, et al, “Non-resectable Malignant Peritoneal Mesothelioma Treated with Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) Plus Systemic Chemotherapy Could Lead to Secondary Complete Cytoreductive Surgery: A Cohort Study”, October 28, 2021, Annals of Surgical Oncology, Online ahead of print, https://link.springer.com/article/10.1245/s10434-021-10983-2
Mirarabshahii, P, et al, “Diffuse malignant peritoneal mesothelioma – An update on treatment”, November 21, 2011, Cancer Treatment Reviews, https://www.cancertreatmentreviews.com/article/S0305-7372(11)00221-0/fulltext