FDA Approves DNA Screening Test for Colorectal Cancer

“Yesterday, the US Food and Drug Administration (FDA) approved the first DNA-based stool sample screening test for colorectal cancer. The new test, called the Cologuard test, was developed by Exact Sciences.

“The trial that led to the approval, which compared Cologuard to the fecal immunochemical test (FIT), included 10,023 participants. FIT is a commonly used screening test that detects blood in the stool and is also non-invasive.

“ ‘This approval offers patients and physicians another option to screen for colorectal cancer,’ said Alberto Gutierrez, PhD, director of the Office of In Vitro Diagnostics and Radiological Health at the FDA’s Center for Devices and Radiological Health, in a press release. ‘Fecal blood testing is a well-established screening tool and the clinical data showed that the test detected more cancers than a commonly used fecal occult test.’

“In clinical testing Cologuard detected 92% of colorectal cancers and 42% of advanced adenomas. FIT detected 74% of cancers and 24% of advanced adenomas. The Cologuard test detects particular DNA mutations in stool samples that can be an early sign of cancer, and people who test positive for these are recommended for colonoscopies.”

Prostate Cancer Screening Still Not Recommended for All

“A major European study has shown that blood test screening for prostate cancer saves lives, but doubts remain about whether the benefit is large enough to offset the harms caused by unnecessary biopsies and treatments that can render men incontinent and impotent.

“The study, published Wednesday in The Lancet, found that midlife screening with the prostate-specific antigen, or PSA, screening test lowers a man’s risk of dying of the disease by 21 percent. The relative benefit sounds sizable, but it is not particularly meaningful to the average middle-age man, whose risk of dying of prostate cancer without screening is about 3 percent. Based on the benefit shown in the study, routine PSA testing would lower his lifetime cancer risk to about 2.4 percent.

“Despite the fact that some men —one out of every 781 men in the screening group — were helped by PSA testing in the European study, the study authors say the finding does not support the use of widespread screening. Instead, cancer experts say, the focus should be on screening men at high risk and working to identify nonaggressive cancers so men will not be unnecessarily treated for the disease.”

Informed Consent: False Positives Not a Worry in Lung Cancer Study

“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.”

New Prostate Cancer Blood Test Now Available in the U.S.

“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.’ “

A Negative HPV Test May Predict Lower Cervical Cancer Risk than a Negative Pap

“In the US, cotesting for human papilloma virus (HPV) and Pap testing for cervical cancer every 5 years for women aged 30-65 years is now recommended. However, HPV testing alone may provide better reassurance against cervical cancer than Pap testing alone and similar reassurance to cotesting, according to a study published July 18 in the Journal of the National Cancer Institute.”In a comparison of the three strategies, Julia C. Gage, Ph.D., M.P.H., of the Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, and colleagues analyzed data from the Kaiser Permanente Northern California (KPNC) large integrated health delivery system, which screened women age 30-64 since 2003 with both HPV and Pap testing. Data were available through 2012, and over 1 million women were screened at approximately 3-year intervals, with a mean follow-up time of 4.36 years. For each testing strategy, they estimated the cumulative risk of cervical cancer after a negative test result.

“The researchers found that the 3-year cancer risks after a negative HPV-alone test result were lower than those for a Pap-alone negative result. In addition, the 3-year cancer risks after a negative HPV-alone test result were similar to the 5-year cancer risk for a co-test negative result. Gage et al. write ‘In conclusion, we find that primary HPV testing every 3 years might provide as much, if not more, reassurance against precancer and cancer, compared to primary Pap testing every 3 years and cotesting every 5 years.’ However, the authors note that a screening program based on only one or the other test alone, rather than a cotesting program like that at KPNC, might give somewhat different estimates. They urge studies of screening programs in different health-care settings and populations to identify the optimal screening strategy and interval.”

Combined eNose and Sputum Hypermethylation Tests May Help Detect Lung Cancer

“A combination of two non-invasive tests can detect a wide range of lung cancers, a new study suggests.

“Used together, a test for hypermethylation of the RASSF1A biomarker in sputum and an exhaled breath analysis done using the eNose device are complementary for lung cancer diagnosis, showing 100% sensitivity in symptomatic patients, the authors report online June 10 in Journal of Clinical Pathology.

” ‘This is one of the first studies to show that simple non-invasive tests in combination can detect lung cancer with 100% sensitivity, meaning that no lung cancers in this study have been missed,’ wrote Dr. Johann C. Brandes of Winship Cancer Institute of Emory University in Atlanta, Georgia, in an email to Reuters Health.”

” ‘While the combined tests still falsely identify a significant proportion of patients as having lung cancer although they do not have it, this rate may be lower than with chest computed tomography (CT), which is currently the gold standard for lung cancer screening,’ he wrote.

“Although the new finding “exceeds expectations,” it will have to be validated in a larger group of patients, added Dr. Brandes, who was not involved in the study.”

New Accurate Epigenetic Test Could Eliminate Unnecessary Repeat Biopsies for Prostate Cancer

“More than one million prostate biopsies are performed each year in the U.S. alone, including many repeat biopsies for fear of cancer missed. Therefore there is a need to develop diagnostic tests that will help avoid unnecessary repeat biopsies. Two independent trials have now validated the performance of an epigenetic test that could provide physicians with a better tool to help eliminate unnecessary repeat prostate biopsies, report investigators in The Journal of Urology.

“In the previously reported independent MATLOC (Methylation Analysis To Locate Occult Cancer) trial, a multiplex epigenetic assay (ConfirmMDx for Prostate Cancer) profiling the APC, GSTP1 and RASSF1 genes demonstrated a negative predictive value of 90%. GSTP1 methylation is a specific biomarker for (prostate) cancer and this gene is methylated in up to 90% of prostate cancer cases. Additionally, APC and RASSF1 are important field effect markers and increase the diagnostic sensitivity of the assay.

“A second multicenter study, DOCUMENT (Detection Of Cancer Using Methylated Events in Negative Tissue), has validated the performance of the epigenetic assay used in the MATLOC trial as an independent predictor of prostate cancer risk to guide decision making for repeat biopsy. In the DOCUMENT study patients with a negative biopsy were evaluated to identify those at low risk for harboring cancer missed, through biopsy sampling error, who could forego an unnecessary repeat biopsy. The validation study resulted in a negative predictive value of 88%.”

Long Noncoding RNA in Gastric Juice, Plasma May be Marker for Gastric Cancer

The gist: Oncologists sometimes run tests to measure the amount of specific substances in a patient’s tumor(s) or other parts of his/her body that can help shed light on the details of the patient’s disease. These substances are known as biomarkers. Researchers recently discovered that a biomarker called “long noncoding RNA-AA174084” (also known simply as AA) could be used to help understand the severity of a patient’s gastric cancer diagnosis. Different levels of AA in tumors, gastric juice, and blood plasma were associated with disease characteristics like lymph node spread, benign tumors, tumor spread, and more.

“Changes in long noncoding RNA-AA174084 levels in the tissues, gastric juice and plasma of patients with gastric cancer were associated with clinicopathological factors, suggesting utility as a biomarker for early screening and predicting prognosis, according to research data.

“To determine the diagnostic and prognostic utility of plasma and gastric juice levels of AA174084 (AA) — a long noncoding RNA (lncRNA) found with abnormal expression in gastric cancer (GC) tissues in a previous study — researchers analyzed samples from three gastroenterology centers in China from February 2011 to November 2013. Total RNA was extracted from 860 patients and controls and measured using real-time reverse transcriptase-polymerase chain reaction analysis.

“AA levels were down-regulated in 71% of 134 GC tissue samples compared with paired adjacent normal tissues (P.001), with mean expression level 3.18 times greater in the normal samples. AA levels also were decreased in the GC samples and in 28 gastric dysplasia (GD) samples compared with 37 healthy gastric mucosa samples (P.01 and P.001, respectively). AA tissue levels negatively correlated with age (P=.031), Bormann type (P=.016) and perineural invasion (P=.032).”

Follow us on Facebook Follow us on Twitter

Prostate Cancer in Young Men: More Frequent and More Aggressive?

“The number of younger men diagnosed with prostate cancer has increased nearly 6-fold in the last 20 years, and the disease is more likely to be aggressive in these younger men, according to a new analysis from researchers at the University of Michigan Comprehensive Cancer Center.

“Typically, prostate cancer occurs more frequently as men age into their 70s or 80s. Many prostate cancers are slow-growing and many older men diagnosed with early stage prostate cancer will end up dying from causes other than prostate cancer.

“But, the researchers found, when prostate cancer strikes at a younger age, it’s likely because the tumor is growing quickly.

” ‘Early onset prostate cancer tends to be aggressive, striking down men in the prime of their life. These fast-growing tumors in young men might be entirely missed by screening because the timeframe is short before they start to show clinical symptoms,’ says Kathleen A. Cooney, M.D., professor of internal medicine and urology at the University of Michigan.”