作者单位:Penn State Univ, Coll Med, Dept Publ Hlth Sci, Penn State Canc Inst, Hershey, PA 17033 USA[1]Penn State Univ, Coll Med, Penn State Hershey Canc Inst, Clin Trials Off, Hershey, PA 17033 USA[2]Penn State Univ, Coll Med, Dept Microbiol & Immunol, Hershey, PA 17033 USA[3]