Using the common sense model to understand perceived cancer risk in individuals testing for BRCA1/2 mutations.

The common sense model posits that individuals' understanding of illness is based upon somatic symptoms and life experiences and thus may differ significantly from the biomedical view of illness. The current study used the common sense model to understand cancer risk perceptions in 99 individuals testing for BRCA1/2 mutations. Specifically, we examined change from post-counseling to post-result in (1) absolute risk (risk of developing cancer in one's lifetime) and (2) comparative risk (risk relative to the general population). Results indicated that absolute risk showed a trend such that those with a personal history of cancer receiving uninformative negative results reported decreased absolute risk. Further, individuals receiving uninformative negative results reported decreased comparative risk. Those with no personal cancer history receiving informative negative results did not decrease in risk over time nor did their risk differ from those with a personal cancer history, evidencing unrealistic pessimism regarding their risk of cancer. The reasons provided for individuals' risk perceptions could be classified in terms of attributes of the common sense model and included the: (1) causes of cancer (e.g. family history, mutation status); (2) control or cure of cancer through health behaviors and/or surgery; and (3) perceived timeline for developing cancer (e.g. time left in life to develop cancer). We conclude that key to developing interventions to improve understanding of cancer risk and promoting effective cancer control mechanisms is an understanding of the specific reasons underlying individuals' perceptions of cancer risk.

Subjective and Objective Risks of Carrying a BRCA1/2 Mutation in Individuals of Ashkenazi Jewish Descent.

This repeated measures study examines (1) the change in subjective risk of mutations pre- to postcounseling, (2) the accuracy of BRCAPRO estimates of mutations, and (3) the discrepancy between subjective risk and BRCAPRO estimates of mutations before and after genetic counseling. Ninety-nine Ashkenazi Jewish individuals pursued testing for BRCA1/2 mutations. Most had a personal cancer history (N = 51; family only: N = 48); and received uninformative negative results (N = 66; positives: N = 23; informative negative: N = 10). The coping strategy of defensive pessimism predicts that individuals will believe the worst case scenario to better cope with a potential negative outcome. Consistent with this, most felt they would have a mutation, if not mutations in both genes. The BRCAPRO model appeared to overestimate risk of having a mutation in this sample (p < .001). BRCAPRO overestimates notwithstanding, genetic counseling increased accuracy of subjective risk (p < .01). Individuals with a family-only cancer history had the least accurate estimates of risk (p < .05) and may need further intervention to either manage anxiety or improve knowledge.

A phase I trial of a potent P-glycoprotein inhibitor, Zosuquidar.3HCl trihydrochloride (LY335979), administered orally in combination with doxorubicin in patients with advanced malignancies.

PURPOSE: The purpose of this study was to investigate the safety and tolerability of Zosuquidar.3HCl, a potent inhibitor of P-glycoprotein (Pgp), when administered p.o. alone and in combination with doxorubicin and to determine whether Zosuquidar.3HCl affects doxorubicin pharmacokinetics and inhibits Pgp function in peripheral blood natural killer lymphocytes. EXPERIMENTAL DESIGN: Patients with advanced nonhematological malignancies were eligible for this Phase I trial. Zosuquidar.3HCl and doxorubicin were administered separately during the first cycle of therapy and then administered concurrently. Zosuquidar.3HCl was administered over 4 days, with doses escalated until the occurrence of dose-limiting toxicity. Subsequently, doxorubicin doses were increased from 45 to 75 mg/m(2). Zosuquidar.3HCl, doxorubicin, and doxorubicinol pharmacokinetics were analyzed, and dual fluorescence cytometry was used to determine the effects of Zosuquidar.3HCl on Pgp function in natural killer cells. RESULTS: A total of 38 patients were treated at nine dose levels. Neurotoxicity was dose-limiting for oral Zosuquidar.3HCl, characterized by cerebellar dysfunction, hallucinations, and palinopsia. The maximum-tolerated dose for oral Zosuquidar.3HCl administered every 12 h for 4 days is 300 mg/m(2). Zosuquidar.3HCl did not affect doxorubicin myelosuppression or pharmacokinetics, and Zosuquidar.3HCl pharmacokinetics were similar in the absence and presence of doxorubicin. Higher plasma concentrations of Zosuquidar.3HCl were associated with greater Pgp inhibition in natural killer cells. CONCLUSION: Zosuquidar.3HCl can be coadministered with doxorubicin using a 4-day oral dosing schedule, with little effect on doxorubicin toxicity or pharmacokinetics. Further refinement in Zosuquidar.3HCl dosing and scheduling should be explored to optimize Pgp inhibition while minimizing cerebellar toxicity.