More Aggressive Chemo Can Extend Peritoneal Mesothelioma Survival

Malignant peritoneal mesothelioma can be more successfully combated if it is attacked with more aggressive forms of chemotherapy following cytoreductive surgery.

Long a standard of care for peritoneal mesothelioma, cytoreductive surgery involves multiple peritonectomy procedures intended to clear the abdomen and pelvis of all visible traces of mesothelioma.

The surgery is often paired with hyperthermic perioperative chemotherapy — HIPEC — consisting of heated cisplatin and doxorubicin, and then postoperatively followed by intraperitoneal chemotherapy.

A leading mesothelioma researcher, Paul Sugarbaker, M.D., of Washington Hospital Center in the District of Columbia, recently examined outcomes for peritoneal mesothelioma patients who received HIPEC and intraperitoneal chemotherapy.

He and a colleague concluded that easing up on chemo is not the way to go. In fact, Sugarbaker argues, combining chemotherapy methods and drugs can greatly extend mesothelioma survival for many patients.

Peritoneal Mesothelioma Chemo Options

According to Sugarbaker, one version of intraperitoneal chemotherapy is called EPIC, which stands for early postoperative intraperitoneal chemotherapy. It’s administered with the chemo drug paclitaxel.

Paclitaxel works by polymerizing the protein tubulin and by stabilizing microtubules. This has the effect of inhibiting the DNA, RNA and protein synthesis that otherwise would permit mesothelioma cells to grow and spread.

Another version of intraperitoneal chemotherapy discussed by Sugarbaker employs pemetrexed plus systemic cisplatin.

Pemetrexed is a folate antimetabolite that gets in the way of a trio of enzymes mesothelioma cells use to synthesize proteins they need. Similar to paclitaxel, pemetrexed works to stop DNA and RNA formation.

Cisplatin, on the other hand, is effective mainly against just DNA. It interferes with DNA synthesis by denaturing the molecule’s double-helix framework.

As already mentioned, there is also HIPEC with cisplatin and doxorubicin. Doxorubicin discourages mesothelioma cells from starting. It does this by inhibiting operation of the enzyme topoisomerase II and encouraging formation of DNA-destroying free radicals.

Sugarbaker found that 25 percent of cytoreduction surgery recipients who received HIPEC with cisplatin and doxorubicin could be expected to experience overall mesothelioma survival of 10 years.

By combining those with a five-day course of paclitaxel-based EPIC, Sugarbaker found that 37 percent of patients could be expected to enjoy overall mesothelioma survival of 10 years.

The best results came from adding to all this six cycles of long term intraperitoneal pemetrexed with systemic cisplatin. This final combination was effective enough to enable a forecasted 73 percent of the patients who received it to survive mesothelioma for 10 years.

Sugarbaker presented these findings at the June meeting of the American Society of Cancer Oncologists in Chicago.

Peritoneal Mesothelioma Is Difficult to Treat

Peritoneal mesothelioma is known for being difficult to treat. It strikes first at the peritoneum, which is a membrane that lines the wall of the abdomen and pelvis, and encases the organs contained within them.

The membrane is made up of mesothelial cells. Asbestos fibers trapped in the stomach and intestines for decades eventually mutate those cells and turn them into cancer — mesothelioma.

The reason mesothelioma doctors favor chemotherapy for peritoneal mesothelioma is because surgery by itself can never get the job done well enough to ensure survival much beyond six months to a year.

Mesothelioma doctors appreciate the intraperitoneal form of chemotherapy because they find that it helps concentrate the chemo drugs where they can do the most good for you.

Intraperitoneal chemotherapy also has a good reputation for reducing systemic toxicity.