Outcomes by race in breast cancer screening with digital breast tomosynthesis versus digital mammography

PURPOSE: Digital breast tomosynthesis (DBT) in conjunction with digital mammography (DM) is becoming the preferred imaging modality for breast cancer screening compared with DM alone, on the basis of improved recall rates (RR) and cancer detection rates (CDRs). The aim of this study was to investigate racial differences in the utilization and performance of screening modality. METHODS: Retrospective data from 63 US breast imaging facilities from 2015 to 2019 were reviewed. Screening outcomes were linked to cancer registries. RR, CDR per 1,000 examinations, and positive predictive value for recall (cancers/recalled patients) were compared. RESULTS: A total of 385,503 women contributed 542,945 DBT and 261,359 DM screens. A lower proportion of screenings for Black women were performed using DBT plus DM (referred to as DBT) (44% for Black, 48% for other, 63% for Asian, and 61% for White). Non-White women were less likely to undergo more than one mammographic examination. RRs were lower for DBT among all women (8.74 versus 10.06, P \u3c .05) and lower across all races and within age categories. RRs were significantly higher for women with only one mammogram. CDRs were similar or higher in women undergoing DBT compared with DM, overall (4.73 versus 4.60, adjusted P = .0005) and by age and race. Positive predictive value for recall was greater for DBT overall (5.29 versus 4.45, adjusted P \u3c .0001) and by age, race, and screening frequency. CONCLUSIONS: All racial groups had improved outcomes with DBT screening, but disparities were observed in DBT utilization. These data suggest that reducing inequities in DBT utilization may improve the effectiveness of breast cancer screening

Quorum sensing and the population dependent control of virulence.

One crucial feature of almost all bacterial infections is the need for the invading pathogen to reach a critical cell population density sufficient to overcome host defences and establish the infection. Controlling the expression of virulence determinants in concert with cell population density may therefore confer a significant survival advantage on the pathogen such that the host is overwhelmed before a defence response can be fully initiated. Many different bacterial pathogens are now known to regulate diverse physiological processes including virulence in a cell-density-dependent manner through cell-cell communication. This phenomenon, which relies on the interaction of a diffusible signal molecule (e.g. an N -acylhomoserine lactone) with a sensor or transcriptional activator to couple gene expression with cell population density, has become known as 'quorum sensing' . Although the size of the 'quorum' is likely to be highly variable and influenced by the diffusibility of the signal molecule within infected tissues, nevertheless quorum-sensing signal molecules can be detected in vivo in both experimental animal model and human infections. Furthermore, certain quorum-sensing molecules have been shown to possess pharmacological and immunomodulatory activity such that they may function as virulence determinants per se. As a consequence, quorum sensing constitutes a novel therapeutic target for the design of small molecular antagonists capable of attenuating virulence through the blockade of bacterial cell-cell communication