A study of interval breast cancer within the NHS breast screening programme

Abstract

Aim-To define the biological nature and malignant potential of interval cancers presenting to a breast unit within the NHS breast screening programme. Methods-112 interval cancers were compared with matched, screen detected and symptomatic cancers in terms of their radiographic, histopathological, and immunohistochemical features. Results-Interval cancers, strictly defined, showed no characteristic radiographic pattern. In terms of size, vascular invasion, lymph node status, and prognosis they were intermediate between screen detected and symptomatic cancers. Within the interval cancers there was an excess of grade 1 and grade 3 tumours, and lesions with a high Ki67 index but immunohistochemistry otherwise failed to discriminate between the three groups. Inclusion of data from false negative "interval cancers" did not significantly alter the results. Conclusions-Interval cancers are more aggressive than screen detected cancers but in general less aggressive than symptomatic cancers. However, within a heterogeneous group, occasional interval cancers are exceptionally malignant.

A Basal Epithelial Phenotype Is More Frequent in Interval Breast Cancers Compared with Screen Detected Tumors

“…Furthermore, loss of TP53 function eliminates the growth arrest response to DNA damage and impairs the apoptotic programme. Consequently, tumors with TP53 mutations may have a higher frequency of mutations in other genes and this might also contribute to explain the higher proliferative rate of interval cancers (1,7,8,43), as found in the present study.…”

Is Clinical Breast Examination Important for Breast Cancer Detection?

“…In addition, another study showed that 13% of women with a palpable breast mass and a diagnosis of invasive cancer had had a normal mammogram within the preceding year 36 . Interval cancers often show aggressive features 37 , and it is not impossible that some of the cancers detected by cbe alone in the present study were interval cancers. Triple-negative cancers are often found in BRCA mutation carriers, but according to a systematic review 38 , the exact value of cbe for hereditary cancers might be controversial.…”

Phenotypic characterization and risk factors for interval breast cancers in a population-based breast cancer screening program in Barcelona, Spain

“…There is consensus that interval breast cancers have a lessfavorable prognosis than screen-detected cancers [6][7][8][9][10]. A delay in diagnosis could potentially worsen prognosis and consequently impair the efficiency of the screening program.…”