Accuracy of Perceived Breast Cancer Risk in Black and White Women with an Elevated Risk.

Introduction: Perceived breast cancer risk predicts screening behaviors. However, perceived risk is often inaccurate, notably in Black women, who often underestimate their risk despite having higher disease-specific mortality rates. We examined predictors of perceived breast cancer risk, and its impact on surveillance. Methods: We used baseline data from a randomized trial targeting unaffected women recruited by relatives with early-onset breast cancer. Data collection occurred between 2012 and 2013. Accuracy of perceived risk was assessed by comparing perceived risk to objective lifetime breast cancer risks, calculated with the Gail and Claus models. A multivariate mixed model regression examined predictors of accuracy of perceived risk. The impact of perceived risk on breast cancer surveillance was assessed with one-way ANOVAS comparing Black to White women. Results: Among participants, 21.4% self-identified as Black and 78.6% as White. Overall, 72.9% (n=247/339), 16.2% (n=55/339), and 10.9% (n=37/339) of participants overestimated, accurately perceived, and underestimated, respectively, their lifetime breast cancer risk. Race did not predict the accuracy of risk perception. Younger participants were more likely to overestimate their risk (ß=-.455; CI [-.772, -.138]; P=.005). MRI utilization was predicted by a higher objective risk (F 1,263 [= 30.271]; P<.001) and more accurate risk perception (P=.010; Fisher's exact test). Conclusions: Most women with a family history of early-onset breast cancer inaccurately perceived their risk for developing the disease. Younger women were more likely to overestimate their risk. Findings can guide the development of tailored interventions to improve adherence to breast cancer surveillance recommendations.

Ecologically-relevant exposure to methylmercury during early development does not affect adult phenotype in zebra finches (Taeniopygia guttata).

Methylmercury causes behavioural and reproductive effects in adult mammals via early developmental exposure. Similar studies in birds are limited and mostly focussed on aquatic systems, but recent work has reported high blood mercury concentrations in terrestrial, passerine songbirds. We used the zebra finch (Taeniopygia guttata) as a model to explore the long-term effects of early developmental exposure to methylmercury exposure. Chicks were dosed orally with either the vehicle control, 0.0315 µg Hg/g bw/day, or 0.075 µg Hg/g bw/day throughout the nestling period (days 1-21 post-hatching). We then measured (a) short-term effects on growth, development, and behaviour (time to self-feeding, neophobia) until 30 days of age (independence), and (b) long-term effects on courtship behaviour and song (males) and reproduction (females) once methylmercury-exposed birds reached sexual maturity (90 days post-hatching). High methylmercury treated birds had mean blood mercury of 0.734 ± 0.163 µg/g at 30 days post-hatching, within the range of values reported for field-sampled songbirds at mercury contaminated sites. However, there were no short-term effects of treatment on growth, development, and behaviour of chicks, and no long-term effects on courtship behaviour and song in males or reproductive performance in females. These results suggest that the nestling period is not a critical window for sensitivity to mercury exposure in zebra finches. Growing nestlings can reduce blood mercury levels through somatic growth and depuration into newly growing feathers, and as a result they might actually be less susceptible compared to adult birds receiving the same level of exposure.