Recent developments in the field of human genomics have led to varying predictions regarding the potential for genomic medicine to transform clinical practice. Whether health care systems are ready to establish the infrastructure and expertise necessary to derive full value from genomic and molecular medicine remains uncertain. In this study, Billings and colleagues examined the readiness of health care systems to incorporate genomic medicine, based on extensive interviews involving senior staff members and executives of relevant public and private organizations. Their results suggest that knowledge of genomic medicine, as well as investment in infrastructure with which it is associated, is limited among leading health care decision makers.
The newer atypical antipsychotic agents are thought to be less likely to produce parkinsonism compared with the older typical antipsychotic therapy, although this has not been well documented. In a retrospective cohort study of more than 25 000 older adults, the results of this study by Rochon and colleagues demonstrate that when the potency and dose of the antipsychotic therapies are considered, atypical antipsychotic therapies are not necessarily safer than typical antipsychotic therapy in relation to the development of parkinsonism. These findings suggest that caution should be used particularly when prescribing high-dose atypical antipsychotic therapy
Based on data from a population-based, prospective, randomized prostate cancer screening trial, this study by Aus and colleagues examined the cumulative risk of being diagnosed as having prostate cancer in relation to the individual baseline serum prostate-specific antigen level. The results show that it is fully possible to individualize the retesting interval for prostate-specific antigen based on the baseline prostate-specific antigen level without affecting the prostate cancer detection rate.
The absolute benefit of screening mammography varies according to the age-specific accuracy and efficacy of mammography as well as the incidence of breast cancer in the population screened. Asian women have lower breast cancer incidence and mortality rates compared with white women. Screening mammography outcomes among Asian women in the United States have received little attention. This study found that screening mammography has similar accuracy among white, Chinese, and Filipino women despite lower rates of invasive cancer in Asian women. The rate of ductal carcinoma in situ was similar in all ethnic groups. These results suggest that the absolute benefit of screening, in terms of breast cancer deaths averted, is likely to be less among Asian women, and overdiagnosis of ductal carcinoma in situ with screening mammography among Asian women is likely to be comparable to that of white women.
Although there is a strong genetic influence on the variation in bone density, the genetic impact on the causation of osteoporotic fractures is unclear. A large Swedish nationwide twin study enabled Michaëlsson and colleagues to investigate the genetic and environmental influence at various ages on fracture occurrence after the age of 50 years in elderly men and women. Genetic variation in liability to fracture differed considerably by type of fracture and age. Only a modest age-adjusted overall fracture variance was explained by genetic variation. A greater genetic influence was observed for osteoporotic fractures, especially hip fractures. The heritability of hip fractures was estimated to average 50% and was even greater for hip fractures before the age of 70 years but was negligible after the approximate median age, 80 years. These results suggest that the search for susceptibility genes and environmental factors that may modulate expression of these genes in young-old patients with hip fracture, the most devastating osteoporotic fracture, should be encouraged. Prevention of fractures in the oldest-old should be focused on lifestyle interventions.
The age-adjusted estimated heritability (black bars), shared environmental influence (gray bars), and nonshared environmental influence (white bars) of all fractures by age at first fracture within each twin pair.
In This Issue of Archives of Internal Medicine. Arch Intern Med. 2005;165(16):1812. doi:10.1001/archinte.165.16.1812