Clapper, Patti, Schweizer and Mason

New research from the University of Pennsylvania shows that even stage III and stage IV mesothelioma patients may benefit from pleurectomy procedures when combined with intraoperative photodynamic chemotherapy.  Indeed, the study confirms that not only does this multimodal approach increase the overall life expectancy of malignant pleural mesothelioma patients to what researchers classified as “unusually long” but it did so in spite of disease recurrence.

The mesothelioma treatment research study, authored by Joseph S. Friedberg et al., was presented at the Forty-seventh Annual Meeting of The Society of Thoracic Surgeons in San Diego in January of last year. 

Thirty-eight individual mesothelioma patients between the ages of 48 and 81 years were examined during the study.  Thirty-seven of those patients were suffering from either stage III or stage IV mesothelioma; 30 were diagnosed with epithelial mesothelioma and 7 with nonepithelial subtypes.  Surgeons were able to completely remove the diseased pleural tissue in 97% of those patients with only 1 post-operative death related to a post-surgical stroke and not the asbestos cancer itself.

What is a Pleurectomy?

A pleurectomy (or pleurctomy/decortication (P/D)) is a surgical procedure during which the pleura (thin membrane around the lungs) is partially or completely removed.  Though partial removal can be done through thorascopic procedures, total removal requires opening the patient’s chest in order to gain access to all of the tissue. 

Recent studies have found that this procedure, once limited to “last chance’ mesothelioma patients, may have greater benefits especially when combined with chemotherapy than previously believed.  Indeed, many mesothelioma specialists now say that this procedure is preferable to more common invasive procedures such as extrapleural pneumonectomies (EPP) which involve complete removal of the diseased lung and surrounding tissues.

What is Photodynamic Therapy?

Photodynamic therapy refers to a procedure during which chemical agents are added to the body which increase sensitivity to light.  These agents typically are targeted toward cancer cells.  They reduce the cells natural resistance to UV radiation.  Therefore, when light is applied (usually on a tightly modulated spectrum) the cells actually suffer apoptosis, or cell death. 

This procedure has been successfully used to treat a wide variety of diseases and, as this study shows, has shown great promise in mesothelioma treatments as well.

Study Results

The overall median survival rate for all of the patients was 31.7 months.  Those with epithelial mesothelioma fared better with median survival rates of 41.2 months whereas those suffering from more aggressive and less treatable sarcomatoid and biphasic mesothelioma experienced survival rates of only 6.8 months.

These survival rates fall within expectations based on other studies of similar procedures, however, where they vary is in terms of survival rates of disease recurrence.  The respective median progression-free survival for these groups of patients fell between 9.6 and 15.1 months, with non-epithelial patients experiencing just 4.8 months.

Mesothelioma, like many other cancers, is incredibly hard to remove completely.  Indeed, mesothelioma has no cure and patients can only hope to extend their life spans as recurrence is a constant threat.  However patients in this study experienced “unusually long” survival rates after recurrence leading researchers to speculate that “...the reason for this prolonged survival despite recurrence...is potentially related to preservation of the lung or some PDT-induced effect, or both.”

Because results could not pinpoint the exact mechanism for survival, the researchers were left recommending this course of therapy simply because this type of lung sparing surgery is safe and warrants much more consideration for treating mesothelioma.