Early warning heeded
Matthews' case highlights the need for a true early-detection test. It would be a huge lifesaver, but developing one has been enormously difficult. The current gold standard, sensitive ultrasound imaging using a probe inserted into the vagina, is too costly to use in screening, and it can miss the early stages of a cancer if it's not in the form of a lump.
Rising levels of CA 125, a blood protein, can be a signal of ovarian cancer, but the test is not reliable enough for screening. The best hope for early detection, believe Dr. Cramer and colleague Samuel Mok, PhD, may be blood tests that spot abnormal proteins secreted into the bloodstream by tumor cells as the disease develops. (The hunt for telltale patterns of proteins, called "biomarkers," is detailed in the 2004 Winter/Spring issue of Turning Point.)
As part of the SPORE, Dr. Mok is also examining stored tissue samples from ovarian tumors in search of the earliest abnormal changes to guide research on detection. Judy Garber, MD, MPH, director of the Friends of Dana-Farber Cancer Risk and Prevention Clinic, and Steven Skates, PhD, a biostatistician at Massachusetts General Hospital, will be comparing blood specimens taken before and after surgery from high-risk patients who had their ovaries removed to prevent cancer.
Working similar territory is Ronny Drapkin, MD, PhD, of Dana-Farber's Cancer Biology Department, who rounded up the most common ovarian cancer-related protein patterns described in several different studies. From this small collection, Dr. Drapkin identified a protein, HE4, as a promising biomarker for ovarian cancer. He says that HE4 might be useful as a screening test, and — because cancer cells with less HE4 don't grow as well — might even be attacked with targeted drugs as a form of treatment.
