Circulating tumor cells signal outcome in metastatic breast ca.(Gynecology)

SAN ANTONIO -- An elevated circulating tumor cell count at any point during systemic therapy for metastatic breast cancer indicates a high likelihood of rapid disease progression and mortality from that time on, Daniel F. Hayes, M.D., said at a breast cancer symposium sponsored by the Cancer Therapy and Research Center.

The implication of this observation is that circulating tumor cell count as measured by a commercially available blood test may have an important role in patient monitoring and guidance of treatment in cases of metastatic breast cancer. A randomized prospective clinical trial is now underway to evaluate the impact of switching therapy in patients who develop an elevated circulating tumor cell (CTC) count during therapy, added Dr. Hayes, clinical director of the breast cancer program at the University of Michigan Comprehensive Cancer Center, Ann Arbor.

In a previously reported double-blind multicenter study involving 177 women who were about to start a new therapy for metastatic breast cancer, Dr. Hayes and his coinvestigators showed that the presence of at least 5 CTCs per 7.5 mL of whole blood using the CellSearch test was associated with significantly reduced progression-free and overall survival.

The same held true for patients who developed a positive test at their first follow-up visit after initiation of treatment. They had a median 2.1-month progression-free survival from that time, compared with 7.0 months in women with 0-4 CTCs on the test. Their median overall survival was 8.2 months, compared with more than 18 months in those with ...