Statin use, hyperlipidaemia, and the risk of breast cancer

Hydroxymethyl glutaryl coenzyme A inhibitors (‘statins’) are carcinogenic in rodents and an increased incidence of breast cancer was reported among pravastatin users in one randomised trial. We conducted a case–control study in the General Practice Research Database to evaluate the risk of breast cancer among 50- to 79-year old women treated with statins for hyperlipidaemia. Case and control women were matched by age, general practice, duration of prescription history in the General Practice Research Database, and index date. Adjusting for history of benign breast disease, body mass index, and use of hormone replacement therapy, women currently treated with statins had an estimated relative risk for breast cancer of 1.0 (95% confidence interval 0.6–1.6) compared to women without hyperlipidaemia. Untreated hyperlipidaemia was associated with an increased risk of breast cancer (estimated relative risk 1.6; 95% confidence interval 1.1–2.5). The estimated relative risk among women currently receiving only non-statin lipid-lowering drugs was similar to that of women with untreated hyperlipidaemia (1.8; 95% confidence interval 0.9–3.4). We found no evidence for an increasing trend in breast cancer risk with increasing duration of statin use (median duration 1.8 years, maximum 8.6 years)

Separable Roles of the Nucleus Accumbens Core and Shell in Context- and Cue-Induced Alcohol-Seeking

Conditioned responding to drug-predictive discrete cues can be strongly modulated by drug-associated contexts. We tested the hypothesis that differential recruitment of the nucleus accumbens (NAc) core and shell mediates responding to drug cues in a drug vs non-drug context. Rats were trained to discriminate between two 10-s auditory stimuli: one stimulus (CS+) was paired with ethanol (10% v/v; 0.2 ml; oral) whereas the other (CS−) was not. Training occurred in operant conditioning chambers distinguished by contextual stimuli, and resulted in increased entries into the ethanol delivery port during the CS+ when compared with the CS−. In experiment 1, port entries were then extinguished in a second context by withholding ethanol, after which context-induced renewal of ethanol-seeking was tested by presenting both stimuli without ethanol in the previous training context. This manipulation stimulated strong responding to the CS+ in rats pretreated with saline in the core (n=9) or shell (n=10), which was attenuated by pharmacologically inactivating (muscimol/baclofen; 0.1/1.0 mM; 0.3 μl/side) either subregion pretest. In experiment 2, after discrimination, training rats were habituated to a different context in which ethanol and both stimuli were withheld. Cue-induced ethanol-seeking was then elicited by presenting the CS+ and CS− without ethanol in the different context. Saline-pretreated rats responded more to the CS+ than the CS− (core n=8; shell n=9), and inactivating the core but not shell attenuated this effect. These data highlight an important role for the core in cue-induced ethanol-seeking, and suggest that the shell is required to mediate the influence of contexts on conditioned ethanol-seeking