Systemic Chemotherapy Ineffective in Peritoneal Mesothelioma?

Peritoneal mesothelioma is a rare cancer that occurs in the membranous lining of the abdomen. This virulent cancer is caused by exposure to asbestos. Because it is so aggressive, most patients with peritoneal mesothelioma are treated with multiple modalities, or a variety of different treatments, in an effort to attack the cancer from all sides.

For patients whose mesothelioma is considered operable, surgery is frequently preceded by a round of preoperative chemotherapy. Also referred to as neoadjuvant chemotherapy, preoperative chemotherapy aims to shrink the tumor as much as possible before cytoreductive surgery. Later, during surgery, the same peritoneal mesothelioma patient may have intraoperative chemotherapy (HIPEC) in which chemotherapy drugs are washed through the body cavity where the cancer was found. The procedure may be followed by postoperative systemic chemotherapy and/or radiotherapy.

But a new study of peritoneal mesothelioma patients who had cytoreductive surgery and HIPEC states that having systemic chemotherapy either before or after surgery may not have much effect on outcomes. The study was conducted in Italy on patients who had diffuse malignant peritoneal mesothelioma. The study included 116 cytoreductive surgery/HIPEC patients. Sixty of the patients also had preoperative chemotherapy, 30 patients had postoperative chemotherapy, and 26 had no chemotherapy, other than HIPEC.

When the research team compiled their results, they found that patients who had a low performance status (a positive measure of their current functionality) and a low peritoneal cancer index score were the most likely to have greater completeness of cytoreduction (CC). Postoperative complications were most likely to arise in patients with a higher performance status score or those who had had certain intestinal or peritoneal procedures in the past.

But the biggest surprise was that having preoperative or postoperative chemotherapy did not seem to have any impact on either completeness of cytoreduction or the number of postoperative problems. It also did not appear to effect mesothelioma survival. In a report on their findings the authors state that there was no significant difference in survival between mesothelioma patients who had systemic chemotherapy before or after surgery or those who had no systemic chemotherapy at all.

They concluded, “The completeness of cytoreduction, G3-5 [complications] and overall survival were not influenced by aspects related to perioperative systemic chemotherapy.” They suggest that their data be confirmed by larger comparative analyses involving more mesothelioma patients from multiple institutions.

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