0 Pleural Mesothelioma One of Few Thoracic Cancers to Spontaneously Regress

In a study recently published in the medical journal Respiratory Medicine, researchers investigated the history of spontaneous regression of thoracic malignancies to determine the incidence and the types of thoracic cancers most likely to spontaneously regress.

Malignant mesothelioma is a rare cancer caused by asbestos exposure. The majority of cases affect the pleural lining of the lungs, which classifies this form of mesothelioma as a thoracic malignancy. It typically takes 20 to 50 years for the cancer to develop after repeated exposure to asbestos and there currently is no cure for mesothelioma. Some patients have experienced an improvement in their mesothelioma life expectancy by undergoing multimodality therapy, which combines several forms of treatment to combat the cancer.

The research for this study involved a PubMed search of the phrase “spontaneous regression of thoracic lesions” published between 1951 through December 2008. A total of 76 cases involved spontaneous regression of metastatic thoracic tumors, of which five cases reported regression of the primary thoracic tumors along with pulmonary metastasis.

Thus, researchers found only five cases that reported spontaneous regression of a primary thoracic cancer. Of the five cases, two were pleural mesothelioma, two were primary lung cancer (squamous cell) and one was adenoid cystic carcinoma.

Of the 76 cases found to include spontaneous regression of thoracic tumors, renal cell carcinoma was the most common, accounting for 60 percent of cases. Spontaneous regression of thoracic tumors was more common in men than women. Researchers observed that the rare spontaneous regression of a primary thoracic malignancy seems to follow surgical resection of the primary tumor.

Researchers concluded, “Spontaneous regression of thoracic malignancies is rare. Regression of primary thoracic malignancies has been reported only with squamous and bronchogenic carcinoma, pleural mesothelioma and adenoid cystic carcinoma. Regression of thoracic metastases, on the other hand, has been reported in many more malignancies but the overwhelming majority of cases involve metastatic renal cell carcinoma. Overall, this still appears to be a rare event, but when it occurs, it seems to follow resection of the primary tumor.”

Additional information on mesothelioma may be found through the Mesothelioma Center.