The value of occult disease in resection margin and lymph node after extrapleural pneumonectomy for malignant mesothelioma
Wednesday, April 30th, 2008.
The Annals of Thoracic Surgery. 2008 May;85(5):1740-6. [Link]
Mineo TC, Ambrogi V, Pompeo E, Baldi A, Stella F, Aurea P, Marino M.
Department of Thoracic Surgery, Policlinico Tor Vergata University, Rome, Italy. mineo@med.uniroma2.it
Abstract
Background: The purpose of this study was to examine the prognostic impact of occult disease after extrapleural pneumonectomy for malignant mesothelioma.
Methods: We reviewed the resection margin and node specimens from 41 consecutive patients undergoing extrapleural pneumonectomy for malignant pleural mesothelioma in different institutions between 1985 and 2004. The specimens were reassessed by immunohistochemical staining with anticalretinin and antimesothelin monoclonal antibodies, and results were used to draw Kaplan–Meier survival curves and perform Cox regression analyses.
Results: Histologic examination showed 34 epithelioid, 4 biphasic, and 3 sarcomatoid subtypes. Results of postoperative TNM staging were that 14 patients were in stage I, 6 were in stage II, and 21 were in stage III. One patient died during the early postoperative period. Median survival was 13 months. Survival was affected by nonepithelial histologic type (p = 0.001), TNM stage (p = 0.007), positive resection margins (p = 0.002), and N disease (p = 0.01). Immunohistochemistry revealed occult positive resection margins in 6 patients, not correlated with T stage. Microscopic N disease was discovered in 5 patients, of whom 2 had their nodes retrieved through cervical mediastinoscopy. No correlation with nodal diameter was found. In all patients microscopic N disease could have been accessible through mediastinoscopy. Overall, the presence of occult disease was diagnosed in 5 new patients and influenced survival more than any other variable, both at univariate (p < 0.001) and multivariate Cox regression analysis (p < 0.0001; odds ratio, 5.4; 95% confidence interval, 3 to 15).
Conclusions: In malignant pleural mesothelioma, the presence of occult disease in resection margins and lymph nodes can be identified by immunohistochemistry and significantly influences the prognosis. Cervical mediastinoscopy is useful in all patients considered for radical resection, but all specimens should be processed with immunohistochemical staining.
Glossary
- staging
- the process of finding out whether cancer has spread and if so, how far. There is more than one system for staging. The TNM system, described below, is one used often. The TNM system for staging gives three key pieces of information: T refers to the size of the Tumor N describes how far the cancer has spread to nearby Nodes M shows whether the cancer has spread (Metastasized) to other organs of the body Letters or numbers after the T, N, and M give more details about each of these factors. To make this information somewhat clearer, the TNM descriptions can be grouped together into a simpler set of stages, labeled with Roman numerals. In general, the lower the number, the less the cancer has spread. A higher number means a more serious cancer.
- resection
- surgery to remove part or all of an organ or other structure.
- prognosis
- (prog-no-sis) a prediction of the course of disease; the outlook for the cure of the patient. For example, women with breast cancer that was detected early and who received prompt treatment have a good prognosis.
- monoclonal antibodies
- antibodies made in the laboratory and designed to target specific substances called antigens. Monoclonal antibodies which have been attached to chemotherapy drugs or radioactive substances are being studied to see if they can seek out antigens unique to cancer cells and deliver these treatments directly to the cancer, thus killing the cancer cells without harming healthy tissue. Monoclonal antibodies are also used in other ways, for example, to help find and classify cancer cells.
- mediastinoscopy
- (me-dee-as-tin-OS-ko-pee) examination of the chest cavity using a lighted tube replaced under the chest bone (sternum). This allows the doctor to see the lymph nodes in this area and remove samples to check for cancer.
- margin
- edge of the tissue removed during surgery. A negative margin is a sign that no cancer was left behind. A positive margin indicates that cancer cells are found at the outer edge of tissue removed during surgery. It is usually a sign that some cancer remains in the body.
- lymph nodes
- small bean-shaped collections of immune system tissue such as lymphocytes, found along lymphatic vessels. They remove cell waste and fluids from lymph and help fight infections. Also called lymph glands.
- lymph
- (limf) clear fluid that flows through the lymphatic vessels and contains cells known as lymphocytes. These cells are important in fighting infections and may also have a role in fighting cancer.
- mesothelioma
- a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.
- extrapleural pneumonectomy
- (EPP) surgery to remove the pleura, diaphragm, pericardium, and entire lung involved with the tumor. You can view a web cast from Brigham and Women's Hospital in Boston of this procedure being done by Dr. David Sugarbaker: see the extrapleural pneumonectomy (EPP) web cast here.
