Ovarian cancer is the fifth leading cause of cancer deaths among women in the United States. Last year more than 14,000 deaths were reported. Despite treatment advances, overall five–year survival after diagnosis remains abysmally low at 45 percent.

ABO blood type has been linked to multiple diseases including pancreatic and ovarian cancer risk. Two small studies previously reported shorter survival rates among ovarian cancer cases with blood type A.

In a much larger study of 694 patients – the largest such study conducted to date – Alicia Beeghly–Fadiel, MPH, PhD, and colleagues found just the opposite. They reported in the journal PLOS ONE that cases with type A blood were associated with significantly longer ovarian cancer survival.

Blood type antigens are expressed not only on red blood cells but also on epithelial and endothelial cells. Dysregulation of the enzyme encoded by the ABO gene could also affect cellular adhesion, cell membrane signaling, and the host immune response.

Further studies on blood type and ovarian cancer survival are warranted.