FDG-PET/CT Shows Promise for Breast Cancer Patients Younger than 40

“Researchers at Memorial Sloan Kettering found that PET/CT imaging of patients younger than 40 who were initially diagnosed with stage I–III breast cancer resulted in change of diagnosis. As reported in the October issue of The Journal of Nuclear Medicine, while guidelines recommend FDG-PET/CT imaging only for women with stage III breast cancer, it can also help physicians more accurately diagnose young breast cancer patients initially diagnosed with earlier stages of the disease.

“Assessing if and how far breast cancer has spread throughout the body is what doctor’s refer to as staging. Most women nowadays are diagnosed at earlier stages, meaning stage 1 or 2 of possible 4 stages (stated Christopher Riedl, MD). Current National Comprehensive Cancer Network (NCCN) guidelines consider systemic FDG-PET/CT staging for only stage III breast cancer patients. More recently it has been debated whether factors other than stage should be considered in this decision. One such factor is patient age, as young breast cancer patients often have more aggressive tumors. In this study, a team of researchers from Memorial Sloan Kettering Cancer Center in New York evaluated for the first time the impact of FDG PET/CT staging specifically in a young patient cohort. The study suggests that breast cancer patients under the age of 40 may benefit from systemic staging with FDG PET/CT at earlier stages than NCCN guidelines suggest.

” ‘Proper staging right after the breast cancer has first been diagnosed will help doctors make the right treatment decisions. And figuring out which breast cancer patients will benefit most from this “advanced staging” with FDG PET/CT helps us to improve patient care while avoiding unnecessary tests,’ stated Christopher Riedl, MD, one of the team’s lead researchers. ‘Our data suggest that women younger than 40 may benefit from PET/CT staging at earlier stages than doctors previously believed.’ “

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.”

FDG-PET Distinguishes Low- and High-Risk Lung Cancer Patients After Radiotherapy

Fluorodeoxyglucose-positron emission tomography (FDG-PET) scans may be able to detect early-stage non-small cell lung cancer (NSCLC) patients who are at high risk of treatment failure after stereotactic body radiation therapy (SBRT). A retrospective study examined patients with early-stage NSCLC who were ineligible for or refused surgery and were instead treated with SBRT. Patients with lower FDG-PET readings prior to SBRT treatment survived longer, and those whose FDG-PET readings changed more after SBRT were less likely to experience treatment failure. FDG-PET scans may therefore help identify which patients are at lower or higher risk of recurrence; high-risk patients may opt for additional treatment and/or more frequent surveillance after treatment. FDG-PET has shown similar predictive value in early-stage NSCLC treated with surgery.

FDG-PET Imaging May Help Predict Survival after Treatment of Advanced Lung Cancer

People with advanced non-small cell lung cancer (NSCLC) are usually treated with chemotherapy and radiotherapy. However, radiation interferes with the standard method of scanning for lung abnormalities, computed tomography (CT), making its measurements difficult to interpret. This creates the risk that leftover tumor fragments or new cancer spread may be overlooked. A different imaging methodology, fluorodeoxyglucose-positron emission tomography (FDG-PET), may be more accurate in such patients. FDG-PET measures sucrose uptake into cells. High uptake values indicate highly active cells, suggesting the presence of cancerous tissue. In a recent clinical trial, higher standardized uptake values (SUVs) in FDG-PET scans predicted lower survival in people with stage III NSCLC who had received chemotherapy and radiotherapy, suggesting that the method accurately detected cancerous tissue.

PET Scans May Identify High-Risk, Early-Stage Lung Cancer Patients

Stage Ia non-small cell lung cancer (NSCLC) is commonly treated with surgery alone. However, the cancer frequently recurs, and only 67% of stage Ia NSCLC patients survive for 5 years or more. Adjuvant chemotherapy (chemotherapy given as a secondary treatment in addition to surgery) may increase survival, but also has severe toxic side effects. Therefore, it is important to identify stage Ia patients with high risk of recurrence, for whom the benefits of adjuvant chemotherapy would outweigh the drawbacks. A retrospective analysis of stage Ia NSCLC patients found that those with positive results from a scanning technique called a fluorodeoxyglucose PET (positron emission tomography) scan (FDG-PET) had significantly lower rates of survival. Patients with positive FDG-PET results may, therefore, be good candidates for adjuvant chemotherapy.