“Two new studies published on Wednesday of patients with breast and prostate cancers add to growing evidence that detecting bits of cancer DNA circulating in the blood can guide patient treatment.
“Enthusiasm is building for ‘liquid biopsies,’ which offer a non-invasive alternative to standard tissue biopsies and are expected to be a multibillion-dollar market.
“But a key question remains: Do they really work?
“The stakes are high. At least 38 companies are working on liquid biopsies for cancer, according to analysts at investment bank PiperJaffray, who think the U.S. market alone could eventually reach $29 billion a year.”
“Beckman Coulter Diagnostics, a global leader in prostate cancer diagnostics, announces national availability of the Prostate Health Index (phi), a simple, non‐invasive blood test that is three times more specific in detecting prostate cancer than PSA (prostate‐specific antigen). The new test’s accuracy decreases the need for many men who test positive for elevated PSA levels to undergo a biopsy in order to achieve a reliable diagnosis.
“The most widely used screening test for prostate cancer is currently the PSA test, which measures the blood’s level of PSA — a protein that is naturally produced by the prostate gland and is typically increased when cancer is present. However, it is widely recognized that PSA results can often indicate the possibility of prostate cancer when none is present.
” ‘The PSA test is based on the fact that men with higher levels of the PSA protein are more likely to have prostate cancer,’ said William Catalona, MD, principal investigator on the Prostate Health Index clinical study and urologist at Northwestern Medicine and director of the Clinical Prostate Cancer Program at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, where they began using the phi test on patients in February. Dr. Catalona, who was the first physician in the U.S. to run the phi test, added, ‘However, the problem is that higher levels of PSA can also be caused by a benign enlargement or inflammation of the prostate, leading to many false‐positives for cancer and ultimately unnecessarily invasive biopsies and an increased potential for patient harm.’ “
“Researchers are using breath analysis to detect the presence of lung cancer. Preliminary data indicate that this promising noninvasive tool offers the sensitivity of PET scanning, and has almost twice the specificity of PET for distinguishing patients with benign lung disease from those with early stage cancer.”
“Recent results indicate that low-dose computed tomography (LD-CT) screening reduces lung cancer mortality in high risk subjects. However, high false positive rates, costs and potential harm highlight the need for complementary biomarkers. Led by Dr Ugo Pastorino, a group of researchers from Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, retrospectively evaluated a non-invasive plasma miRNA signature classifier in prospectively collected samples from smokers within the randomised Multicentre Italian Lung Detection (MILD) trial. Their findings indicate that microRNA signature classifier has predictive, diagnostic and prognostic value and its combined use with LD-CT may improve screening performance. The results were presented in a proffered papers session at the 4th European Lung Cancer Conference (26-29 March 2014, Geneva, Switzerland).”
Editor’s note: LD-CT is a lung cancer detection method that has been shown to reduce risk of death from lung cancer for high-risk patients. However, it sometimes leads to “false-positives,” in which suspected cancer later turns out not to be cancer. A new, non-invasive blood test to look for specific kinds of miRNA molecules was shown to be promising as a potential companion test to complement LD-CT screening.