Is clinical breast examination effective in Japan? Consideration from the age-specific performance of breast cancer screening combining mammography with clinical breast examination.

Background: There is controversy about the value of clinical breast examination (CBE) in breast cancer screening programs that include mammography.

Methods: In Fukui Prefecture, a screening combining mammography with CBE was employed on 62,447 women from 2004 to 2009. We examined the sensitivity and specificity of mammography alone, and mammography and CBE together for each age group (40-49, 50-59, 60-69, and 70-79).

Results: 167 breast cancers and 49 false-negative cancers were detected during 5 years. For the combined screening, the sensitivities were 73.1, 74.1, 78.3, and 86.5 %, and the specificities were 83.8, 87.5, 89.8, and 90.9 % in the groups of 40-49, 50-59, 60-69, and 70-79 years, respectively. In the mammography-specific analysis, sensitivity decreased to 69.8 % (-3.3 %), 66.7 % (-7.7 %), 77.3 % (-1.0 %), and 83.8 % (-2.7 %) in the groups of 40-49, 50-59, 60-69, and 70-79 years, respectively. There were greater reductions in the groups of 40-49 and 50-59 years than in those of 60-69 and 70-79 years, but there was no statistically significant decrease. Specificity generally increased with increasing age and there was a significant improvement in specificity among all age groups, except that of 70-79 years.

Conclusions: Our findings suggest that there is a trade-off between sensitivity and specificity associated with CBE added to mammography. This tendency is greater in those 40-50 years of age than in those 60-70 years of age. We consider that CBE may be omitted from breast cancer screening among women aged 60 and 70 years. Furthermore, another modality to complement mammography screening in younger Japanese women is expected.