Interval breast cancer characteristics before, during and after the transition from screen-film to full-field digital screening mammography

Abstract

BackgroundTo determine the proportion of “true” interval cancers and tumor characteristics of interval breast cancers prior to, during and after the transition from screen-film mammography screening (SFM) to full-field digital mammography screening (FFDM).MethodsWe included all women with interval cancers detected between January 2006 and January 2014. Breast imaging reports, biopsy results and breast surgery reports of all women recalled at screening mammography and of all women with interval breast cancers were collected. Two experienced screening radiologists reviewed the diagnostic mammograms, on which the interval cancers were diagnosed, as well as the prior screening mammograms and determined whether or not the interval cancer had been missed on the most recent screening mammogram. If not missed, the cancer was considered an occult (“true”) interval cancer.ResultsA total of 442 interval cancers had been diagnosed, of which 144 at SFM with a prior SFM (SFM-SFM), 159 at FFDM with a prior SFM (FFDM-SFM) and 139 at FFDM with a prior FFDM (FFDM-FFDM). The transition from SFM to FFDM screening resulted in the diagnosis of more occult (“true”) interval cancers at FFDM-SFM than at SFM-SFM (65.4% (104/159) versus 49.3% (71/144), P < 0.01), but this increase was no longer statistically significant in women who had been screened digitally for the second time (57.6% (80/139) at FFDM-FFDM versus 49.3% (71/144) at SFM-SFM). Tumor characteristics were comparable for the three interval cancer cohorts, except of a lower porportion (75.7 and 78.0% versus 67.2% af FFDM-FFDM, P < 0.05) of invasive ductal cancers at FFDM with prior FFDM.ConclusionsAn increase in the proportion of occult interval cancers is observed during the transition from SFM to FFDM screening mammography. However, this increase seems temporary and is no longer detectable after the second round of digital screening. Tumor characteristics and type of surgery are comparable for interval cancers detected prior to, during and after the transition from SFM to FFDM screening mammography, except of a lower proportion of invasive ductal cancers after the transition.

Interval breast cancer is associated with other types of tumors

“…Furthermore, the variable was missing from the LIBRO-1 study. In addition, the frequency of estrogen receptor-positive tumors is somewhat higher in our IC cases compared with the frequencies observed in IC patients from other studies 39–41 , which can be attributed to different periods of inclusion and differences in recruitment strategy. However, those differences should not affect the main conclusions of this study.…”

Breast cancer subtype and screening sensitivity in the Quebec Mammography Screening Program

“…During the study period, screen-film was the norm, whereas digital technology now dominates, but recent studies suggest that both technologies have similar screening sensitivity and generate screen-detected and interval cancers with comparable characteristics. 37,38…”

“…During the study period, screen-film was the norm, whereas digital technology now dominates, but recent studies suggest that both technologies have similar screening sensitivity and generate screen-detected and interval cancers with comparable characteristics. 37,38 Fourth, surrogate subtypes are based on tests that distinguish various immunoreactive cells. During the study period, the positivity threshold for hormone receptors was of at least 10% of immunoreactive cells, rather than the 1% now recommended.…”

Breast cancers missed during screening in a tertiary-care hospital mammography facility

“…14 An increase in the incidence of true (occult) breast cancer has been observed in the transition from film screen to digital mammography. 15 Although our study was of a small scale and short duration, we discovered some important findings. We observed relatively higher percentages of both incident (15 cases, 1.6%) and missed (7 out of 15, 46%) breast cancers in our study.…”