Comparison of model-projected and SEER-observed DCIS incidence. (a) age-adjusted (25ā99 years) using the 2000 US standard population; (b)ā(e) age-specific rates. Model-projected DCIS incidence data, solid line; SEER data, dotted line; APC-baseline data, dashed line. SEER, Surveillance, Epidemiology and End Results; DCIS, ductal carcinoma in situ; APC, age-period-cohort.