In their May 6th Journal, the National Cancer Institute is reporting the results of a test analyzing gene structures in patients with malignant pleural mesothelioma that accurately predicted survival times. The “four gene expression ration” analysis was used to develop prognosis information. “Molecular profiling may seem complex, but it can be easily simplified for specific cases for clinical use so that any physician can find it useful,” according to Dr. Raphael Bueno of the Harvard Medical School.
Dr. Bueno and his colleagues used the results of a prospective clinical trial to evaluate the ability of the 4-gene expression ratio test to predict both overall survival and cancer-specific survival in 120 patients undergoing surgery for malignant pleural mesothelioma.
Based on test results, patients were assigned to one of two groups: a “good outcome” group and a “poor outcome” group. The results showed that members of the good outcome group had better median overall survival rates (16.8 months) and median cancer-specific survival (21.9 months) than did patients assigned by the test to the poor outcome group (9.5 months and 15.9 months, respectively).
Based on a multivariable analysis, the gene ratio test appeared to provide additional predictive information beyond that provided by current pathological staging methods. Essentially, the gene profiling provided an extremely accurate predictive model for both outcomes and patient response to mesothelioma treatment.
The repeatability of the test results was 88.5% for tumor specimen analyses and 93.4% for pleural biopsy specimens, the researchers note. This statistic reflects the accuracy of the test with regard to predicting medical outcomes.
“Patients assigned to the predicted poor outcome group, particularly when other established prognostic factors such as histology and lymph node status are also suggestive of poor outcome, could be counseled to forgo surgery, which would not benefit them, and to seek best supportive care,” the researchers suggest.
“Patients whose gene ratio test results predict a good prognosis after surgery may more confidently select the treatment option that includes surgery.” Dr. Bueno also pointed out that using this molecular modeling scheme could prove useful in other, more common forms of cancer such as lung cancer, prostate and bladder cancer, etc.
For malignant pleural mesothelioma, a six-to-seven month extension of survival period is a significant improvement, worthy of surgical intervention. For other forms of cancer, surgery can sometimes be the difference between lengthy periods of remission and cancer that metastasizes into an unmanageable disease.
