Clapper, Patti, Schweizer and Mason

A study out of Green Templeton College, University of Oxford in Oxford, England (authored by Nagendran M, Pallis T, Patel K, and Scarci M. and published in the Journal of Interactive and Cardiovascular Thoracic Surgery) suggests that a common cancer therapy called prophylactic irradiation therapy (PIT) may not only have no benefit for mesothelioma patients but it may also be harmful to them as well. 

The study was a retrospective account of over 300 individual reports.  Out of those 300 the researchers concentrated on 9 which presented the best data and research methods.  The Oxford team found that while the radiation treatment did treat the tumors locally, it also contributed to spreading mesothelioma to other parts of the body and created longer recovery times for patients—significantly decreasing the quality of life they enjoyed in their final days.  The conclusion these researchers drew was that prophylactic irradiation therapy may actually be doing more harm than good in most cases.

Prophylactic irradiation therapy (sometimes called PIT) is a procedure during which doctors use video-assisted thoracoscopic surgery (called VATS) to insert an endoscope with a camera attached into the thoracic cavity (the interior of the chest and abdomen) and locate mesothelioma tumors.  Once the tumors are located, radioactive solutions are injected locally to attack and hopefully kill the cancerous cells within the tumor. 

Usually the surgery requires only local anesthetics and has been used successfully to treat a wide range of conditions including other types of cancer.  Often multiple punctures are needed to get the endoscopes and the solutions to where they need to be.  This, it is theorized, is one reason why PIT increases the potential for development of metastases, sometimes called cancer seeds, which can spread inside the body. 

In addition, the speed with which these metastases developed was nearly tripled from 6.4 months on average within one control group to 2.4 months in the corresponding experimental group. 

However, there was some contradictory data within the individual case studies compiled for the Oxford report.  Four of them recommended PIT while 3 found it completely unnecessary.  Of the handful of randomized controlled trials which exist surrounding this form of mesothelioma treatment, one showed that “seeding of metastatic tumor to the intervention site occurred in 7% of RT sites vs. 10% of control sites.” 

Another trail showed that “. . . 23% of radiotherapy patients developed tract metastases compared to 10% of control patients. . . .”  Yet another put the percentage of patients who suffer increased metastases at 40% compared to 10% in the control group.  There was even one report which noted the exact opposite- that metastases occurrence in the control group was higher than in the experimental. 

The Oxford team took into account these wild variations in collected data and the fact that PIT has not been found to significantly extend the life expectancy of mesothelioma patients when they concluded that there was no good reason to suggest this type of therapy.