Similarly, the
CNBSS I* trial, (14) which randomized women aged 40-49 years either to receive annual mammography and physical breast examination, or to receive a single physical breast examination and instruction on how to conduct self-breast examination, found no reduction in breast cancer mortality after 11 to 16 years of follow-up.
The HIP screening was carried out in the 1960s, while both
CNBSS trials were conducted in the 1980s.
Patients with abnormal findings were referred to the Canadian National Breast Screening Study (
CNBSS) clinic for further evaluation by a surgeon.