[1] Johns Hopkins Med Inst, Dept Pathol, Baltimore, MD 21205 USA
[2] Johns Hopkins Med Inst, Dept Oncol, Baltimore, MD 21205 USA
[3] Milton S Hershey Med Ctr, Dept Med, Hershey, PA USA
[4] York Oncol Associates, York, N Yorkshire, England
[5] York Hosp, Dept Pathol, York, PA USA