High platelet levels in the blood are often associated with a worse prognosis of ovarian cancer, according to a recent study.
Platelets are blood cells that arrest the flow of blood in case of bleeding. An excessive platelet count could increase the chances of suffering from a blood clot. A study conducted in 619 women with ovarian cancer found that 31% women had an increased number of platelets in the blood. Survival was nearly halved in women with ovarian cancer with a high platelet count as compared to those with normal platelet levels.
AdvertisementStudies in mice revealed that ovarian cancer directly increases platelet levels. Researchers found that the tumor increased secretion of a substance called interleukin-6 in mice. Interleukin-6 in turn brought about an increased production of thrombopoietin by the liver. Thrombopoietin stimulates the bone marrow to produce new platelets.
Treatment with anti-interleukin-6 antibodies siltuximab reduced platelet count in mice as well as in a small number of women with ovarian cancer. The antibodies also reduced tumor growth in mice.
The study thus suggests that ovarian cancer increases the number of platelets in the blood. The platelets, in turn, support the growth of the cancer by providing growth hormones, thereby reducing survival of the patient.
Thus, drugs that inhibit the platelets like aspirin and heparin could play a role in the treatment of ovarian cancer. They could possibly prolong survival in these patients.
The antiplatelet drugs however cannot be recommended for use currently without detailed studies, since they can cause bleeding when taken along with chemotherapy for the cancer.
The study points out to one important aspect, that if a person has high platelet count in the absence of inflammation or iron deficiency, it is important to look out for the presence of a cancer.
1. Paraneoplastic Thrombocytosis in Ovarian Cancer; Rebecca Stone et al; N Engl J Med 2012; 366:610-618.