Results for Current Smoking in Prospective Cohorts and Nested Case-Control Studies that used Incident Prostate Cancer Cont’d Study 15 = Thompson et al 1989, 16 = Heikkila et al 1999, 17 = Whittemore et al 1984. Results for ever cigs given in studies 6, 9, 17. Most of these studies that used incident prostate cancer as the outcome factor found no association between current smoking and prostate cancer. Exceptions were a cohort of Iowa elderly rural residents (3), a cohort of Californian health plan members (5) and a cohort of Swedish construction workers (10).