Higher Detection Rates of Biologically Aggressive Breast Cancers in Mammography Screening than in the Biennial Interval.

PURPOSE:  Assessment of age group-dependent detection rates of invasive breast cancers among participants in mammography screening including the interval, classified into immunohistochemical subtypes indicating the intrinsic tumor aggressiveness.

MATERIALS UND METHODS:  The target population comprises women aged 50 - 69 years. All invasive breast cancers diagnosed in one screening (sc) unit during the implementation phase 1/2006 - 12/2010 or identified by the cancer registry during the biennial interval (iv) were categorized based on hormonal-receptor status (HR) and Her2-expression (Her2) into the following subtypes: a) HR+ Her2-, b) HR+ Her2 +, c) HR- Her2 + or d) HR- Her2- (triple-negative); Her2 + and triple-negative types were defined as aggressive. The calculated detection rates (DR, ‰) were based on 53 375 sc-examinations and for the interval on 52 887 sc-negative examinations.

RESULTS:  The DRs of all subtypes were higher in screening versus the interval: (a) 4.95 ‰ (n = 264) vs. 1.00 ‰ (n = 53); b) 0.92 ‰ (n = 49) vs. 0.25 ‰ (n = 13); c) 0.36 ‰ (n = 19) vs. 0.06 ‰ (n = 3); d) 0.39 ‰ (n = 21) vs. 0.19 ‰ (n = 10). 77.4 ‰ (89/115) of all aggressive breast cancers including the following 2-year interval were diagnosed by screening. The sum of the DR of aggressive cancers was 1.67 ‰ in screening and 0.49 ‰ in the interval; the corresponding DRs for women aged 60 - 69 years [sc: 2.24 ‰ (51/22 814), iv: 0.58 ‰ (13/22 536)] were higher than among women aged 50 - 59 years [sc: 1.24 ‰ (38/30 561), iv: 0.43 ‰ (13/30 351)].

CONCLUSION:  Screening has the potential for earlier diagnosis of aggressive tumor types as its detection rate is about three-fold higher compared to the interval. Within the target group, participants aged 60 - 69 years are at risk based on absolute numbers. They show a nearly two-fold higher detection rate of Her2-positive or triple-negative tumors compared to the age group 50 - 59 years.

KEY POINTS:   · Her2-positive and triple-negative detection rates are higher in screening than in the interval.. · 77 % of aggressive subtypes are diagnosed by screening, 23 % during the 2-year interval.. · The detection rate is highest among women aged 60 - 69 years in screening..

CITATION FORMAT: · Prange A, Bokhof B, Polzer P et al. Higher Detection Rates of Biologically Aggressive Breast Cancers in Mammography Screening than in the Biennial Interval. Fortschr Röntgenstr 2018; DOI: 10.1055/a-0657-3970.