Seattle - Non-invasive imaging can measure how well patients with the most common form of breast cancer - estrogen receptor positive type - respond to standard aromatase inhibitor therapy after only two weeks and shows similar findings that more invasive needle sampling identifies, according to a poster presentation to be presented at the ASCO annual meeting next week.
Using Positron Emission Tomography (PET) scanning and a glucose analogue called FDG, a research team led by Hannah Linden, M.D. and David Mankoff M.D., of the Seattle Cancer Care Alliance and the University of Washington, scanned 21 patients before and after two weeks of aromatase inhibitor therapy. Many of the patients also underwent a needle biopsy as a control measure to compare the two techniques.
The results - 16 of the 21 patients had a greater than 20 percent decline in FDG values - "paralleled perfectly" earlier work done by UK-based researchers who used needle biopsies to measure whether the proliferation of cancer cells was slowed by therapy, according to Linden, who is a breast cancer oncologist.
"Our findings are exciting because they suggest that we can measure a patient's response to therapy noninvasively, and PET scanning provides us simultaneous quantitative metabolic measurements at multiple tumor sites," Linden said. "PET has the potential to be a powerful tool to help doctors make important treatment decisions in as little as two weeks instead of two or more months."
It's common for patients with estrogen receptor positive cancer to a bone-dominant type yet they have remained largely unstudied in clinical trials because they are very difficult to image, according to Linden. "Our work allowed us to study a common problem in a way that's not been done before and to help more people," she said. "More work needs to be done but in my mind this was a homerun," Linden said. The study was funded by a "Progress for Patients" grant from the National Cancer Institute and the Avon Foundation. Joining Linden were researchers from the University of Washington, Fred Hutchinson Cancer Research Center and the University of Arizona Cancer Center.
About Seattle Cancer Care Alliance
Seattle Cancer Care Alliance, established in 1998, unites the adult and pediatric cancer-care services of Fred Hutchinson Cancer Research Center, UW Medicine and Seattle Children's. A major focus of SCCA is to speed the transfer of new diagnostic and treatment techniques from the research setting to the patient bedside while providing premier, patient-focused cancer care. Patients who come to SCCA receive the latest research-based cancer therapies as well as cutting-edge treatments for a number of non-malignant diseases under development by its partner organizations. SCCA has three clinical-care sites: an outpatient clinic on the Fred Hutchinson campus, a pediatric-inpatient unit at Children's and an adult-inpatient unit at UW Medical Center. For more information about SCCA, visit www.seattlecca.org.