Lung Cancer Test Less Effective in Areas Where Infectious Lung Disease is More Common

“A new analysis of published studies found that FDG-PET technology is less accurate in diagnosing lung cancer versus benign disease in regions where infections like histoplasmosis or tuberculosis are common. Misdiagnosis of lung lesions suspicious for cancer could lead to unnecessary tests and surgeries for patients, with additional potential complications and mortality.

“Histoplasmosis and other fungal diseases are linked to fungi that are often concentrated in bird droppings and are found in soils.

“The study by investigators at Vanderbilt University and the Tennessee Valley Healthcare System-Veterans Affairs was led by Vanderbilt first author Stephen Deppen, Ph.D., and principal investigator Eric Grogan, M.D., MPH, and appeared in the Sept. 24 issue of JAMA.

“Positron emission tomography (PET) combined with fludeoxyglucose F18 (FDG) is currently recommended for the noninvasive diagnosis of lung nodules suspicious for lung cancer. To estimate FDG-PET diagnostic accuracy, the authors reviewed lung cancer abstracts published in a 14 year period and included 70 studies in the meta-analysis. The studies included 8,511 nodules, 60 percent of which were malignant.”


18F-FGD-PET Measures Predict mRCC TKI Response

“Positron emission tomography (PET) could be used to predict the response of metastatic renal cell carcinoma (mRCC) to tyrosine kinase inhibitor (TKI) therapy within a couple of weeks of a patient beginning treatment, research suggests.

“Changes in volume-based metabolic parameters of 18F-fluorodeoxyglucose (FDG) before and after 14 days of treatment with sunitinib, sorafenib or pazopanib significantly correlated with progression-free and overall survival, say Jacob Farnebo (Karokinska University Hospital, Stockholm, Sweden) and co-authors.”

Editor’s note: Doctors and patients can make more informed treatment decisions if they can more closely monitor how well a treatment is working and predict how well it is likely to work in the long run. This story discusses how monitoring with positron emission tomography (PET) within the first couple of weeks of treatment might help predict how well certain drugs will work. PET scanning produces 3-D images of the inside of the body. Scientists conducted a study in which they gave PET scans to volunteer patients who were being treated with the drugs sunitinib, sorafenib, or pazopanib for metastatic renal cell carcinoma (mRCC). They found that, within two weeks of the patients starting treatment, they could use information from the PET scans to determine the effectiveness of the treatment. They were able to link these PET scan results to how long the patients lived and how much time passed before patients’ disease worsened.