Racial and Ethnic Disparities in Outcomes After Breast-Conserving Therapy and Endocrine Therapy for DCIS: A Post-Hoc Analysis of the NSABP B-35 Randomized Clinical Trial.

BACKGROUND: Racial and ethnic disparities in outcomes after treatment for ductal carcinoma in situ (DCIS) are largely unknown. The objective of this study was to examine breast cancer outcomes by race and ethnicity in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-35 clinical trial. PATIENTS AND METHODS: The NSABP B-35 trial randomized postmenopausal women with hormone receptor-positive DCIS treated with breast-conserving therapy to 5 years of tamoxifen or anastrozole. In total, 3104 women were enrolled between 2003 and 2006. For this analysis, patients without complete self-reported race and ethnicity or with immediate trial dropout were excluded. Kaplan-Meier curves and adjusted Cox-proportional hazards models were used for analyses. RESULTS: Of the 3061 women included, 2614 (85.4%) were non-Hispanic white (NHW), 255 (8.3%) were non-Hispanic Black (NHB), 95 (3.1%) were Hispanic, and 96 (3.1%) were Asian or Pacific Islander (API). Endocrine therapy assignment and duration were well balanced between racial and ethnic groups. Median follow-up was 9 years; unadjusted Kaplan-Meier curves did not show any racial differences in disease events. Adjusted Cox-proportional hazards models found API (versus NHW) race to be associated with higher local recurrence [hazard ratio (HzR) 2.45, p = 0.035] and NHB race to be associated with higher distant recurrence (HzR 5.03, p = 0.020) and breast cancer mortality (HzR 3.83, p = 0.046). CONCLUSIONS: Despite similar locoregional treatments and standard endocrine therapy in a clinical trial population, racial and ethnic disparities exist in long-term outcomes for hormone-receptor-positive DCIS. These findings suggest that factors outside of access and treatment may impact DCIS outcomes by race and ethnicity.

Sparse genetically defined neurons refine the canonical role of periaqueductal gray columnar organization.

During threat exposure, survival depends on defensive reactions. Prior works linked large glutamatergic populations in the midbrain periaqueductal gray (PAG) to defensive freezing and flight, and established that the overarching functional organization axis of the PAG is along anatomically-defined columns. Accordingly, broad activation of the dorsolateral column induces flight, while activation of the lateral or ventrolateral (l and vl) columns induces freezing. However, the PAG contains diverse cell types that vary in neurochemistry. How these cell types contribute to defense remains unknown, indicating that targeting sparse, genetically-defined populations may reveal how the PAG generates diverse behaviors. Though prior works showed that broad excitation of the lPAG or vlPAG causes freezing, we found in mice that activation of lateral and ventrolateral PAG (l/vlPAG) cholecystokinin-expressing (CCK) cells selectively caused flight to safer regions within an environment. Furthermore, inhibition of l/vlPAG-CCK cells reduced predator avoidance without altering other defensive behaviors like freezing. Lastly, l/vlPAG-CCK activity decreased when approaching threat and increased during movement to safer locations. These results suggest CCK cells drive threat avoidance states, which are epochs during which mice increase distance from threat and perform evasive escape. Conversely, l/vlPAG pan-neuronal activation promoted freezing, and these cells were activated near threat. Thus, CCK l/vlPAG cells have opposing function and neural activation motifs compared to the broader local ensemble defined solely by columnar boundaries. In addition to the anatomical columnar architecture of the PAG, the molecular identity of PAG cells may confer an additional axis of functional organization, revealing unexplored functional heterogeneity.

Coordination of escape and spatial navigation circuits orchestrates versatile flight from threats.

Naturalistic escape requires versatile context-specific flight with rapid evaluation of local geometry to identify and use efficient escape routes. It is unknown how spatial navigation and escape circuits are recruited to produce context-specific flight. Using mice, we show that activity in cholecystokinin-expressing hypothalamic dorsal premammillary nucleus (PMd-cck) cells is sufficient and necessary for context-specific escape that adapts to each environment's layout. In contrast, numerous other nuclei implicated in flight only induced stereotyped panic-related escape. We reasoned the dorsal premammillary nucleus (PMd) can induce context-specific escape because it projects to escape and spatial navigation nuclei. Indeed, activity in PMd-cck projections to thalamic spatial navigation circuits is necessary for context-specific escape induced by moderate threats but not panic-related stereotyped escape caused by perceived asphyxiation. Conversely, the PMd projection to the escape-inducing dorsal periaqueductal gray projection is necessary for all tested escapes. Thus, PMd-cck cells control versatile flight, engaging spatial navigation and escape circuits.