“A study from Karolinska Institutet in Sweden shows that a new test for prostate cancer is better at detecting aggressive cancer than PSA. The new test, which has undergone trial in 58,818 men, discovers aggressive cancer earlier and reduces the number of false positive tests and unnecessary biopsies. The results are published in the scientific journal The Lancet Oncology.
“Prostate cancer is the second most common cancer among men worldwide, with over 1.2 million diagnosed in 2012. In number of men diagnosed with prostate cancer increases and within 20 years over 2 million men are estimated to be diagnosed yearly. Currently, PSA is used to diagnose prostate cancer, but the procedure has long been controversial.”
The gist: New criteria could keep CT scan screening tests from indicating that a person has lung cancer, when they really do not. So called “false-positives” can lead to unnecessary medical procedures and distress. The Lung-RADS criteria may lower the rate of false-positive screening tests. However, there are concerns that Lung-RADS might delay diagnosis for people with true lung cancer.
“The use of Lung Imaging Reporting and Data System criteria during interpretation of low-dose CT scan results may yield lower false-positive results than observed in the National Lung Screening Trial, according to results of a retrospective study.
“However, the Lung Imaging Reporting and Data System (Lung-RADS) criteria — developed by the American College of Radiology — also were associated with reduced sensitivity.
“ ‘The findings suggest that the implementation of Lung-RADS can substantially reduce the false-positive rate in CT screening for lung cancer,’ William C. Black, MD, study author and professor of radiology at the Dartmouth-Hitchcock Medical Center, told HemOnc Today. ‘However, the findings also suggest that the diagnosis of some lung cancers may be delayed with the implementation of Lung-RADS. Whether this delay will substantively reduce the effectiveness of CT screening is unknown and will have to be further studied.’ “
“Joe Weatherly, DO, and Andrew Buelt, DO, are family medicine residents in St. Petersburg, Fla. Together, they co-produce the podcast Questioning Medicine, where they deconstruct issues confronting today’s clinicians. In this guest blog, Weatherly gives his take on breast cancer screening…
“In 2014, there will be an estimated 1,665,540 cancer diagnoses, and approximately 585,720 deaths from cancer or complications from the treatment of cancer. Estimates are that 3% to 35% of cancer patients avoid premature death by screening alone.
“This sounds wonderful. Those individuals and their stories are the poster children for preventive medicine. The cost and collateral impact on their lives is well worth it to those who prolong life and obtain ‘remission.’
“The U.S. Preventive Services Task Force recently recommended computerized tomography (CT) lung screening for people at high risk for cancer, but a potential problem with CT is that many patients will have positive results on the screening test, only to be deemed cancer-free on further testing. Many policymakers have expressed concern that this high false-positive rate will cause patients to become needlessly upset. A new study of National Lung Screening Trial participant responses to false positive diagnoses, however, finds that those who received false positive screening results did not report increased anxiety or lower quality of life compared with participants who received negative screen results.
” ‘Most people anticipated that participants who were told that they had a positive screen result would experience increased anxiety and reduced quality of life. However, we did not find this to be the case,’ said Ilana Gareen, assistant professor (research) of epidemiology in the Brown University School of Public Health and lead author of the study published in the journal Cancer.
“The NLST’s central finding, announced in 2010, was that screening with helical CT scans reduced lung cancer deaths by 20 percent compared to screening with chest X-rays. The huge trial spanned more than a decade, enrolling more than 53,000 smokers at 33 sites.”
Low-dose computed tomography (CT) scans are the currently recommended screening method for lung cancer in heavy smokers. However, these scans produce many false positives (identifying suspicious lung nodules when no cancer is actually present), needlessly exposing numerous people to the costs and risks of invasive follow-up procedures. Now, a large study has shown that a simple blood test may complement CT scans to reduce the false positive rate in lung cancer screening. The microRNA signature classifier (MSC) Lung Cancer assay measures the expression levels of several molecules called microRNAs to classify patients as low, intermediate, and high risk. In a trial of over 4,000 current or former smokers, the MSC Lung Cancer assay detected the vast majority of all lung cancers accurately, but produced a low rate of false positives. Moreover, the test detected some cancers up to 2 years before the CT scans.
With a new test, getting screened for lung cancer may be as simple as hocking up a loogie. The LuCED test analyzes coughed-up phlegm (strictly called ‘sputum’ once is has been spit out) for evidence of lung cancer. The test creates detailed three-dimensional (3-D) images of the cells inside the phlegm. In pilot tests, LuCED exhibited over 95% sensitivity (meaning it very rarely missed lung cancer when it was present) and 99.8% selectivity (meaning that it almost never falsely detected lung cancer when it was absent). In contrast, up to 96% of ‘lung cancer’ findings by computed tomography (CT) are actually false alarms. A highly specific, noninvasive test could greatly promote more effective screening and early detection of lung cancer.
A new screening method may offer a better way to monitor recurrence after lung cancer surgery. Recurrence is common, but traditional screening methods, including chest x-rays and computed tomography (CT) scans, have significant drawbacks. A new minimal dose CT (MnDCT) scan reduces radiation exposure to no more than that of standard x-rays, but it maintains superior sensitivity. In a recent study, MnDCT detected 94% of cancer recurrences in patients who had received surgery to remove stage I or II lung cancer; x-rays caught only 21%. However, MnDCT has a high rate of false positives (ie, detecting lung cancer when none is actually present), which is of concern because recurrence may call for invasive and potentially dangerous follow-up procedures.
Some patients who undergo surgery for suspected lung cancer turn out not to have the disease. Such a misdiagnosis is known as a “false positive.” A recent analysis found that the rates of lung cancer false positives vary widely from state to state, ranging from 1.3% of lung cancer diagnoses in Vermont to 25% in Hawaii, with no clear pattern across states. Possible reasons for the variation include local differences in how quickly clinicians move from a suspicious finding during lung cancer screening to surgery. Other potential factors involve conditions like chronic fungal infections, which are more common in certain regions and can be mistaken for lung cancer. The findings underline the need for caution in the interpretation of lung cancer screens, especially considering that 2.1% of the patients in the study who had received a false positive diagnosis died after surgery.