Extrapleural Pneumonectomy (EPP) is a radical operation in which the entire lung, and tissues of the lung space (pleura, diaphragm and pericardium) are removed. This is done as part of a cancer operation, often for an aggressive cancer called malignant mesothelioma. During cancer operations, surgeons have to remove all or as much cancer tissue as possible, including microscopic cells that are not visible to the surgeon at the time of surgery. Any tissue that is left behind may have cancer cells which will continue to grow, and spread. Due to the location of the cancer cells (in the lining), surgeons have to remove more tissue than if the cancer was centered in the lung itself. This includes replacing the diaphragm with a synthetic patch during surgery.
Mesothelioma is named after the cells it affects. These mesothelial cells make up the “linings” of the body cavities. For this reason, mesothelioma can affect other areas of the body, in the linings of the abdomen called the peritoneum, the pericardium (the lining around the heart), and most commonly, the pleura.
Inside the chest, coating the chest wall is a thin lining tissue called the pleura. The interior area of the rib cage and chest are thus called the pleural cavity. When mesothelial cancer cells invade this fragile tissue layer, it is called pleural mesothelioma, which is different from peritoneal mesothelioma. (Peritoneal mesothelioma affects the peritoneal cavity, or abdominal cavity.)
Not everyone is a candidate for this surgery. Due to the radical nature of this procedure, patients need to have good pulmonary function and overall functional status prior to surgery. (The patient is going to lose one whole lung during this procedure, so patients that are already oxygen dependent / bedridden or otherwise debilitated won’t be able to tolerate this procedure.) The best patients for this surgery (the patients who will have the best outcomes/ receive the most benefits from surgery) are patients with good functional status (able to perform normal activities of daily living) with earlier stages of the disease. In these patients – this surgery can extend their lives significantly. In patients with more advanced (stage III/ stage IV) disease, the surgery will make them live longer (months) but the quality of life may be worse post-operatively.
Prior to consideration for extrapleural pneumonectomy (or any other treatment) the doctors will want to definitively diagnose (prove the diagnosis through tissue biopsy) and do preliminary staging. (Final staging occurs after the operation when further tissue / lymph node biopsies are evaluated by the pathologist).
Preliminary staging and pre-operative evaluation is the process to try to figure out how much cancer is present (has it spread?) and whether the patient can tolerate a large operation. Mediastinoscopy; a surgical procedure to look at mediastinal lymph nodes (lymph nodes behind the sternum or breast bone), PET scans and blood for tumor markers help determine how much cancer is present. The tumor markers also help the oncologists figure out which chemotherapy drugs will work the best.
Pre-operative testing is looking at lung function, to see how well the patient will do with only one lung. Cardiac testing may be done as well since surgery can be stressful to the heart.
If the disease is controllable with surgery, and the surgeon thinks the patient can withstand surgery – the surgeon will consult with an oncologist about the timing of surgery and adjuvant treatments (chemotherapy/ radiation).
Even with radical surgery, the prognosis for malignant pleural mesothelioma is poor, but improves with combination therapies (surgery with chemotherapy/ radiation.) Currently, surgeons are investigating the use of cytoreductive hyperthermic chemotherapy (HIPEC/ Hithoc) for treatment of pleural based mesothelioma. (Previous studies by Dr. Paul Sugarbaker has shown this treatment to be effective with advanced abdominal cancers including malignant peritoneal mesothelioma.) We will discuss HIPEC further on a future post.
There are numerous studies looking at extrapleural pneumonectomy for treatment of malignant pleural mesothelioma. The links below is just a small sampling.
1. Extrapleural pneumonectomy for malignant pleural mesothelioma (2005) – Argote- Greene, Chang, and Sugarbaker. (Note: this article was co-authored by Dr. David Sugarbaker, Department of Thoracic surgery, Brigham Womens & Children’s, not Dr. Paul Sugarbaker, developer of HIPEC. I am going to attempt to contact Dr. Davis Sugarbaker for commentary for the site since he is the expert on this topic, so hopefully I’ll be able to update the site with his post in the future.
2. Radical surgery for malignant pleural mesothelioma – Japanese study comparing results for EPP versus pleurectomy / decortication. The main points to take away from this study is that stage of disease has a huge impact on prognosis, and outcomes after surgery. (The patients with stage I and II that underwent EPP did fairly well.)
3. Review of 83 cases of EPP – (2009) French study which unintentionally highlights the potential complications of surgery of this magnitude(almost 40% had major complications and had a re-operative rate of almost fifteen percent.)