“U.S. regulators have approved a first-of-a-kind test that looks for mutations in hundreds of cancer genes at once, giving a more complete picture of what’s driving a patient’s tumor and aiding efforts to match treatments to those flaws.
“The U.S. Food and Drug Administration approved Foundation Medicine’s test for patients with advanced or widely spread cancers, and the Centers for Medicare and Medicaid Services proposed covering it.
“The dual decisions, announced late Thursday, will make tumor-gene profiling available to far more cancer patients than the few who get it now and will lead more insurers to cover it.”
“A couple years ago, Sibel Blau, an oncologist outside of Seattle, was working with the company Guardant Health to test their novel ‘liquid biopsies’ in patients. The idea behind liquid biopsies is both elegant and promising. A doctor takes a blood sample from a patient, and then Guardant looks for tumor DNA floating in the blood, allowing doctors to identify the tumor’s unique mutations and offer a personalized drug regimen—all without an invasive tissue biopsy. Blau was excited to be on board.
“When that study wrapped up, Blau still had Guardant test kits left over, so she offered some to her patients at no cost to them. At this point, Blau was routinely ordering DNA sequencing of traditional tissue biopsies, so some patients got both tests. The tissue DNA test from Foundation Medicine was “routine” in her practice, but even that test had only become available in 2012. The field of cancer DNA has been changing fast.”
“The promise of personalized cancer medicine is still a long way off, and it’s questionable whether any personalized approach will ever benefit patients to any significant degree, say two researchers writing in a “sounding board” article published online September 29 in the New England Journal of Medicine.
” ‘Patients love the idea that they have a specific mutation in their tumour and that if they have their cancer gene sequenced, there will be a specific and effective drug that targets their mutation,’ coauthor Ian Tannock, MD, PhD, Princess Margaret Cancer Center and the University of Toronto, Ontario, Canada, toldMedscape Medical News in an email.”
The gist: Recent research suggests that women whose tumors have a mutation in the PIK3CA gene may be resistant to treatment with the drugs trastuzumab (Herceptin) and lapatinib. However, two new studies say that PIK3CA mutations can’t be used to predict how well Herceptin and lapatinib will work.
“While preclinical studies indicate that PIK3CA mutations result in resistance to the two HER2-targeted therapies trastuzumab and lapatinib, two recently published studies suggest that this mutation cannot be used as a predictive biomarker to guide therapy.
“The first study found that PIK3CA mutations are associated with a decreased benefit to neoadjuvant HER2-directed therapies. The second study showed that PIK3CA mutations did not affect outcomes for HER2-positive patients receiving adjuvant trastuzumab treatment.
“Preclinical studies using HER2-positive cell lines have previously shown that an additional mutation in PIK3CA, the alpha-catalytic subunit of PI3K, results in downstream constitutive signaling, making breast tumor cells that harbor both aberrations resistant to trastuzumab and lapatinib. PIK3CA is among the most commonly mutated oncogene in breast cancer and is present in about one-fourth of all HER2-positive breast cancers. Because of this prevalence and the effect of PI3K pathway activation on HER2 therapy, clinicians have posited that PIK3CA mutations may serve as predictive biomarkers, both preventing ineffectual therapy in some patients and guiding appropriate treatment choices.”
Every year, thousands of people gather in Chicago, Illinois, for the American Society of Clinical Oncology (ASCO) Annual Meeting. The largest meeting of its kind, ASCO brings together doctors, researchers, nurses, patient advocates, pharmaceutical company representatives, and more to discuss the latest in cancer research. Here are some of the most exciting new developments in lung cancer research presented last week at ASCO 2014: Continue reading…