Abstract
Objective: Various studies have been conducted on differences in detection rates and characteristics of breast cancer between first and repeat mammography (MMG) screenings. The objective of the present study was to clarify the importance of recommending examinees to undergo MMG screening at Ningen Dock facilities by examining differences in breast cancer detection rates and characteristics, with the aim of reducing future breast cancer mortality rates.
Subjects and Methods: Subjects were 5,113 women (first screening group 847, repeat screening group 4,266) in whom a final diagnosis was made in MMG screenings conducted in 2010 and 2011 at our facility.
Results: Cancer was discovered in 8 subjects in the first screening group (detection rate 0.94%) and in 14 subjects in the repeat screening group (detection rate 0.33%). Thus, the detection rate in the first screening group was 2.85 times that in the repeat screening group. The rate for Stage II cancer in the first screening group was 0.47%, higher than that in the repeat screening group of 0.05%. Also, there was a greater tendency towards invasive cancer in the first screening group than in the repeat screening group with rates of 0.94% and 0.23%, respectively.
Conclusion: As compared to the repeat screening group, the cancer detection rate in the first screening group was higher and there were greater tendencies towards Stage II cancer and invasive cancer in this group. Therefore, with a view to reducing breast cancer mortality rates, it is considered necessary to make sure that examinees do not forgo repeat examinations by making them aware of the importance of discovering cancer when it is still at the non-invasive or early stage.
