1. From the Departments of Medicine (D.S.S., B.M.P., L.C.), Epidemiology (D.S.S., B.M.P., S.M.S., J.T.G.), Health Services (B.M.P.), Pathobiology (J.T.G., S.P.W.), Biostatistics (R.A.K.), and Laboratory Medicine (L.C., R.A.), University of Washington and Fred Hutchinson Cancer Research Center (S.M.S., L.C.) (Seattle); Department of Epidemiology (L.H.K.), University of Pittsburgh, Pittsburgh, Pa; and Department of Pathology (R.P.T.), University of Vermont (Burlington).