To see the potential of proteomic fingerprints, consider the limitations of the best-known biomarker for ovarian cancer: cancer antigen 125 (CA125). Ovarian cancer is usually discovered when it has already reached an advanced stage and metastasized. That CA125 levels are abnormal in 80% of advanced-stage cases is a fact of limited clinical utility, because therapy for advanced-stage ovarian cancer is not very good; the five-year survival rate is about 35%. What physicians need is a biomarker that alerts them to early-stage disease, when cancer is confined to the ovary, and surgery can cure nine out of 10 patients. Unfortunately, in early stages CA125 levels are abnormal no more than 60% of the time.
In contrast, the Lancet paper reported that in a masked set of 116 serum samples, the five-protein pattern discovered by Hitt's software correctly identified all 18 cases of stage I disease, and, in fact ,identified all 50 ...
