Blood Types Correlate with Survival After Prostate Cancer Vaccine

Simple, inexpensive strategies to target treatment to likely responders could substantially improve efficacy while simultaneously reducing health care costs, but identification of reliable biomarkers has proven challenging.

ABO blood type influences numerous aspects of biology and medicine, such as susceptibility to infection by various pathogens and potential for complications due to blood transfusions and while there are a variety of methods for typing patients, standard methods are not ideal for all situations.

Chemical biologists at the National Cancer Institute, National Institutes of Health (Frederick, MD, USA) and their colleagues obtained 220 sera samples consisting of 93 type O individuals, 58 type A individuals, 32 type B individuals, and 37 type AB individuals. All samples were stored at -80 °C or -20 °C until used. Blood type information was available in the clinical records for eight patients with metastatic castration-resistant prostate cancer (mCRPC) who enrolled in a single-center phase II study of a prostate vaccine.

Blood typing methods were developed using the normalized antibody signals to Blood Group A (BG-A) and BG-B antigens. For two component systems, the BG-A and BG-B components were systematically varied to identify optimal pairings. For each component, the signal ranges were partitioned into three groups: positive, negative, and unclassified. The team developed a new glycan microarray-based method for determining ABO blood type. The method requires only 4 μL of serum, provides 97% accuracy, and allows simultaneous profiling of many other serum anti-glycan antibodies. After validation with 220 healthy subjects of known blood type, the method was then applied to 74 PROSTVAC-VF patients and 37 control patients from a phase II trial.

The authors concluded that that type B and O prostate vaccine trial patients demonstrated markedly improved clinical outcomes relative to A and AB patients, including longer median survival, longer median survival relative to Halabi predicted survival, and improved overall survival via Kaplan-Meier survival analysis. Consequently, blood type may provide an inexpensive screen to preselect patients likely to benefit from prostate vaccine therapy. The study was published on August 18, 2015, in the journal Oncotarget.

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US National Cancer Institute