High Platelet Levels Linked with Poor Survival in Ovarian Cancer ► NCI Cancer Bulletin for February 21, 2012 - National Cancer Institute

High Platelet Levels Linked with Poor Survival in Ovarian Cancer

Excessively high platelet levels are associated with poor survival in women with ovarian cancer, according to findings from a new study. Funded in part by NCI, the study showed that women with elevated platelet levels (thrombocytosis) had substantially worse progression-free survival and overall survival, and were more likely to have advanced cancer at diagnosis, than women with normal platelet levels. The findings were published February 16 in the New England Journal of Medicine.
The researchers identified the association between thrombocytosis and survival through an analysis of blood samples from more than 600 women with ovarian cancer. Experiments using mouse models of ovarian cancer confirmed the findings and suggested a potential mechanism by which tumors can cause platelet levels to climb.
According to the study’s senior author, Dr. Anil Sood of the University of Texas M. D. Anderson Cancer Center, the findings point to potential new treatment avenues for ovarian cancer and suggest that platelet levels could possibly serve as diagnostic and prognostic markers. “We need to do much more work to further evaluate all of these findings and develop them,” he cautioned.
Researchers found that thrombocytosis was also associated with increased levels of thrombopoietin, a hormone that regulates platelet production, and the cytokine interleukin-6 (IL-6), which can increase thrombopoietin production.
In the mouse model experiments, the research team found that IL-6 secreted by tumor cells and thrombopoietin are critical components of a “feed-forward loop” that promotes thrombocytosis and tumor growth. They also showed that an investigational monoclonal antibody that targets IL-6 called siltuximab slowed ovarian tumor growth in mice, and that siltuximab was even more effective when used in combination with the chemotherapy drug paclitaxel.
In a small clinical trial that was part of the larger multi-institutional study, 3 weeks of siltuximab treatment substantially reduced platelet levels in 18 women with ovarian cancer.
Additional studies are ongoing, Dr. Sood explained, including those focused more closely on how platelets may promote tumor growth. Additional early stage clinical trials to test anti-IL-6 treatment in women with ovarian cancer are being planned, he noted.

NCI Cancer Bulletin for February 21, 2012 - National Cancer Institute: - Enviado mediante la barra Google