Low Radiation Scans Help Identify Cancer in Earliest Stages
Embargo expired: 21-May-2013 2:00 PM EDT
Source Newsroom: American Thoracic Society (ATS)
Newswise — ATS 2013, PHILADELPHIA ─ A study of veterans at high risk for developing lung cancer shows that low-dose computed tomography (LDCT) can be highly effective in helping clinicians spot tiny lung nodules which, in a small number of patients, may indicate the earliest stages of the disease. LDCT uses less than a quarter of the radiation of a conventional CT scan.
Results of the study will be presented at the ATS 2013 International Conference.
“Lung cancer is the leading cause of cancer-related death and has a poor survival rate,” said Sue Yoon, nurse practitioner at VA Boston HealthCare West Roxbury Division. “Most of our veterans in these ages have a heavy smoking history and early screening is desirable to improve outcomes. Our study was undertaken to learn how often we would discover significant abnormalities and how to adapt our existing processes and interdisciplinary approaches to accommodate additional patients.”
Conducted according to guidelines set forth by the National Comprehensive Cancer Network (NCCN), the study was based in part on the results of the National Lung Cancer Screening Trial (NLST) which found that LDCT resulted in a 20 percent reduction of lung cancer mortality compared to chest x-ray among heavy smokers aged 55 to 74 years.
The study enrolled 56 patients with a median age of 61 to 65 years and who had a smoking history of more than 30 pack years or 20 pack years and one additional cancer risk factor, such as occupational exposure to carcinogens or personal or family history of cancer or COPD.
After reviewing LDCT scans of each patient, the researchers found that 31 patients had a nodule of 4mm or larger or another abnormal opacity, six of which were deemed suspicious for malignancy. The study also found that 34 patients had more than one nodule. Four patients were diagnosed with biopsy-proven lung cancer.
“Our preliminary rate of lung cancer diagnosis after the first round of screening was 7 percent, which was significantly higher than NLST group, which had a preliminary rate of 3.8 percent at its first round,” Ms. Yoon said.“ In addition, detection of nodules larger than 4mm was 55 percent in our group compared to 27 percent in the NLST group.”
The difference in nodule prevalence rates between the current study and the NLST are likely due to three primary factors, she noted: First, the current study hadmuch smaller numbers than the multicenter NLST; second, the scanning technology used during the current trial had advanced since the earlier NLST trial was conducted; and finally, the populations studied in the NLST and the current study had significant differences - for instance, the VA population was predominantly male and most patients had COPD.
While the results of both this study and the NLST suggest regular screening with LDCT technology can help identify patients in the early stages of cancer, establishing and supporting a regular screening program requires significant resources and may not be feasible in all locations or for all populations, Ms. Yoon added. In addition, because the LDCT is highly sensitive, most of the nodules it spots are benign, and are often due to inflammation or scarring.
“Our previous experience with diagnosing and managing a high volume of incidentally discovered pulmonary nodules suggested that a low dose CT scan screening program, in which patients are screened annually, could be a substantial undertaking,” Ms. Yoon said. “Considerable effort goes into each step of the process: selecting patients, tracking abnormalities, further selecting patients with suspicious abnormalities for additional diagnostic and therapeutic interventions.
“Although we plan to continue and expand the LDCT screening program, this will require additional planning and, potentially, resources,” she added. “Currently we are using a gatekeeper approach, to ensure tracking of nodules and other abnormalities that are discovered during screening LDCT.”
* Please note that numbers in this release may differ slightly from those in the abstract. Many of these investigations are ongoing; the release represents the most up-to-date data available at press time.
Low Dose CT Lung Cancer Screening Experience At A VA Medical Center
Type: Scientific Abstract
Category: 02.05 - Health Education/Disease Prevention/Patient Education (NUR)
Authors: S.H. Yoon1, R. Goldstein2, A. Jati1, W. Arndt1; 1VA Boston HealthCare - Boston, MA/US, 2VA Boston HealthCare - Boston/US
Introduction: Lung cancer is the leading cause of cancer-related death and has a poor survival rate. Recently NLST (National Lung Cancer Screening Trial) has shown a 20% reduction of lung cancer mortality among a Low Dose CT (LDCT) screening group compared to a chest x-ray control group, in ages 55 to 74 with a heavy smoking history. Most of our veterans in these ages have a heavy smoking history and early screening is desirable.
Methods: Our institution started the LDCT program in January 2012. For monitoring purposes, our Radiology department limits LDCT ordering to two providers: one pulmonary physician and one pulmonary nurse practitioner. From January to October 31, 2012, we enrolled consecutive patients who had either a history of more than 30 pack years or 20 pack years with one additional risk factor. All CT results were reviewed by the ordering providers and communicated to patients. Cases suspicious for malignancy were presented to our weekly Multidisciplinary Tumor Conference.
Results: A total of 57 patients were enrolled but one did not come for the CT scan. Median age was between 61 to 65. Fifty six patients were male and one was female. Forty eight patients (80%) had over 30 pack year smoking history and half of these were current smokers.Out of 56 patients, 31 (55%) had a nodule size 4mm or larger, or other abnormal opacity. Thirty four (60%) had more than 1 nodule. Three patients did not have nodules. Of 31 patients with nodules larger than 4mm, 6 were deemed suspicious for malignancy based on size and morphology. Four patients (7%) were diagnosed with biopsy proven lung cancer: 1 with stage 1A adenocarcinoma, 1 stage 1B adenocarcinoma, 1 stage 3A adenocarcinoma, and 1 stage 3B squamous cell carcinoma with neuroendocrine differentiation. Two others had positron emission tomography (PET) avid lesions. One had bronchial obstruction but bronchoscopic evaluation was negative for malignancy. The other had a 1.3 cm nodule but declined further diagnostic procedure. Screening will continue per NCCN guidelines for all patients except those with confirmed diagnosis.
Conclusions: Our preliminary rate of lung cancer diagnosis after first round of screening was 7%. This is significantly higher than NLST group (3.8%) at its first round. Detection of nodules larger than 4mm was 55% while NLST group was 27%. Low dose screening CT (LDCT) is an effective tool for early detection of lung cancer in our high risk veterans.