PARIS, France--University of Chicago researchers have discovered that the combination of a molecular marker of tumor virulence and a marker of metastatic potential can be used to reliably predict outcome in women with node-negative breast cancer, Ruth Heimann, MD, PhD, reported at the annual meeting of the American Radium Society.
"Scoring tumor microvascular density adds significant prognostic information in addition to tumor size, nuclear grade, and estrogen-receptor (ER) status," Dr. Heimann said.
From a database of 826 node-negative mastectomy patients, few of whom had received adjuvant chemotherapy, Dr. Heimann and her colleagues were able to retrieve archival material on 184 women with mostly small tumors.
They chose ER status as an indicator of virulence, or the pace of tumor growth, and used microvascular density, assessed with factor VIII(Drug information on factor viii) antibody, as a marker for metastagenicity, or the ultimate likelihood of distant metastases.
Although in postmenopausal women, ER status had no impact on 20-year disease-free survival, premenopausal women who were ER positive did significantly worse than their receptor-negative counterparts, Dr. Heimann noted.
She hypothesized that these apparently paradoxical results might be attributable to the maturity of the database, pointing out that the same phenomenon has been documented at Sloan-Kettering.
"When we looked at disease-free survival based on microvessel density, we identified a group of patients with low microvessel density who had significantly better long-term disease-free survival than those with high microvessel density," Dr. Heimann said. She emphasized that the favorable prognostic weight of low microvascular density held for women with ER-positive tumors as well as for those with nuclear grade 2 or 3 tumors.