Interval breast cancers: prognostic features and survival by subtype and time since screening

Abstract

Objectives To investigate the hypothesis that interval cancers arising soon after the previous screen and true interval cancers are biologically aggressive and have a relatively poor prognosis compared with other interval cancers, and to assess which prognostic features are relevant to interval cancers. Methods Analysis of prognostic pathological features (grade, lymph node stage, size, vascular invasion, oestrogen receptor [ER] status and histological type), radiological features (comedo/noncomedo calcification and spiculation) and survival for 538 invasive interval breast cancer cases by type and time since previous screen. Results Late interval cancers were less likely to be lymph node positive (13 versus 43%, P ¼ 0.003). Type 1 interval cancers were more likely to be histological grade 3 than type 2 (minimal signs) and type 3 (false-negative) intervals (52 versus 35%, P ¼ 0.05). Type 3 interval cancers were more likely to have lobular features than other intervals (47 versus 20%, Po0.0001). There was no significant survival difference by interval cancer type (P ¼ 0.64) or interval year (P ¼ 0.83). At univariate analysis of all interval cancers, tumour size, grade, nodal stage, ER status, vascular invasion and comedo calcification were associated with survival. On multivariate analysis of prognostic features significant at univariate analysis, nodal stage (P value ¼ 0.009), tumour size (P ¼ 0.001), ER status (Po0.0001) and vascular invasion (Po0.0001) maintained independent significance. Conclusions Our study shows that true intervals and interval cancers arising quickly after screening do not have a worse prognosis than other interval cancers, and that interval cancers have a unique set of prognostic features.

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

“…However, these results are in agreement with the hypothesis of a relationship between HRT and interval cancers, as reported by some authors [18,31]. Metastases to regional lymph nodes were more frequent among interval breast cancers (especially false negative tumors), as observed by other authors [7,8,17,32]. This finding is partly related to the longer time to diagnosis [32].…”

“…Metastases to regional lymph nodes were more frequent among interval breast cancers (especially false negative tumors), as observed by other authors [7,8,17,32]. This finding is partly related to the longer time to diagnosis [32].…”

“…This result has not previously been reported, but Tan et al [33] noted an association of p53 with triple negative phenotype tumors, which was also related to a high proportion of relapses. Studies of biomarker expression among interval subgroups also reported the lowest expression of ER and PR in true interval cancers [5,16,32], suggesting the existence of heterogeneity.…”

The epidemiology, radiology and biological characteristics of interval breast cancers in population mammography screening

“…11, 13, 14, 26, 31, 35–37, 39, 43–48 For the majority of studies, which compared interval BCs with screen-detected cancers, there were consistent findings that interval BCs had worse prognostic features, such as larger tumour size, higher frequency of node metastases, higher histologic grade, and more advanced disease compared to screen-detected BC (Table 3). Although biomarker data were not consistently reported in these studies, where reported there was evidence that interval BCs had a higher frequency of triple-negative or HER2-positive cancers and a lower frequency of hormone receptor-positive cancers than screen-detected BC (Table 3).…”

Interval breast cancers in a community screening programme: frequency, radiological classification and prognostic factors

“…These seem to represent a group of more aggressive tumours; therefore, the findings associated with this type of tumour at screening mammography should be followed up with complementary tests. The conclusions of other authors, however, have not always agreed about these possible differences (Ikeda et al, 1992), as Porter et al, 2006 point out in their recent article. Some authors have suggested the hypothesis that tumours diagnosed in the first year after a screening mammogram (earlypresenting IC) could be more aggressive, having greater lymph-node involvement and a worse histological grade than those diagnosed later (Frisell et al, 1992;Fracheboud et al, 1999).…”