Citations

Abstract Learning Objectives After completing this course, the reader will be able to: Discuss the efficacy and safety of third-generation aromatase inhibitors as therapeutic options for patients with hormone-responsive breast cancer.Describe the impact of aromatase inhibitors on comorbidities that are common in this patient population.Identify the cost-effectiveness and quality-of-life effects of aromatase inhibitors. Access and take the CME test online and receive 1 AMA PRA Category 1 Credit™ at CME.TheOncologist.com Tamoxifen, once the gold standard adjuvant endocrine therapy for early breast cancer, is being challenged by third-generation aromatase inhibitors (AIs) that have demonstrated improved disease-free survival in a variety of adjuvant settings for early breast cancer. Tamoxifen and AIs have different safety profiles, which should allow physicians to begin to individualize treatment based on a patient's comorbidities and risk factors. Because of its properties as a partial estrogen agonist, tamoxifen has a positive effect on serum lipids and may confer a cardioprotective benefit, as well as a beneficial effect on bone health. However, tamoxifen increases the risk for endometrial cancer and cerebrovascular/thromboembolic events. In comparison, the major side effect of AIs is increased bone loss, which may heighten the risk for osteoporotic fractures and bone pain. Because of their superior efficacy and manageable side effects, AIs are a cost-effective alternative to tamoxifen, and clinical guidelines now embrace AIs as appropriate adjuvant therapy for hormone-sensitive early breast cancer. The anticipated results of ongoing trials will provide further insights into the long-term safety and application of AI therapy in the adjuvant setting.

ABSTRACT Coccidioides spp. are dimorphic fungal pathogens endemic to the semiarid regions of North, Central, and South America. Currently, direct smear and culture are the most common means of identifying Coccidioides spp. While these methods offer relatively sensitive and specific means of detecting Coccidioides spp., growth in culture may take up to 3 weeks, potentially delaying the diagnosis and initiation of appropriate antifungal therapy. In addition, growth of the organism represents a significant safety risk to laboratory personnel. The need for a rapid and safe means of diagnosing coccidioidomycosis prompted us to develop a real-time PCR assay to detect Coccidioides spp. directly from clinical specimens. Primers and fluorescent resonance energy transfer (FRET) probes were designed to target the internal transcribed spacer 2 region of Coccidioides . The assay's limit of detection is below 50 targets per reaction. An analysis of 40 Coccidioides sp. clinical isolates grown in culture demonstrated 100% sensitivity of the assay. A cross-reactivity panel containing fungi, bacteria, mycobacteria, and viruses was tested and demonstrated 100% specificity for Coccidioides spp. An analysis of 266 respiratory specimens by LightCycler PCR demonstrated 100% sensitivity and 98.4% specificity for Coccidioides spp. compared with culture. Analysis of 66 fresh tissue specimens yielded 92.9% sensitivity and 98.1% specificity versus those of the culture method. The sensitivity of the assay testing 148 paraffin-embedded tissue samples is 73.4%. A rapid method for the detection of Coccidioides spp. directly from clinical material will greatly assist in the timely diagnosis and treatment of patients, while at the same time decreasing the risk of accidental exposure to laboratory personnel.

Abstract 17-Allylamino-demethoxygeldanamycin (17-AAG), currently in phase I and II clinical trials as an anticancer agent, binds to the ATP pocket of heat shock protein (Hsp90). This binding induces a cellular stress response that up-regulates many proteins including Hsp27, a member of the small heat shock protein family that has cytoprotective roles, including chaperoning of cellular proteins, regulation of apoptotic signaling, and modulation of oxidative stress. Therefore, we hypothesized that Hsp27 expression may affect cancer cell sensitivity to 17-AAG. In colony-forming assays, overexpression of Hsp27 increased cell resistance to 17-AAG whereas down-regulation of Hsp27 by siRNA increased sensitivity. Because Hsp27 is known to modulate levels of glutathione (GSH), we examined cellular levels of GSH and found that it was decreased in cells transfected with Hsp27 siRNA when compared with control siRNA. Treatment with buthionine sulfoximine, an inhibitor of GSH synthesis, also sensitized cells to 17-AAG. Conversely, treatment of Hsp27 siRNA–transfected cells with N-acetylcysteine, an antioxidant and GSH precursor, reversed their sensitivity to 17-AAG. A cell line selected for stable resistance to geldanamycin relative to parent cells showed increased Hsp27 expression. When these geldanamycin- and 17-AAG-resistant cells were transfected with Hsp27 siRNA, 17-AAG resistance was dramatically diminished. Our results suggest that Hsp27 up-regulation has a significant role in 17-AAG resistance, which may be mediated in part through GSH regulation. Clinical modulation of GSH may therefore enhance the efficacy of Hsp90-directed therapy. (Cancer Res 2006; 66(22): 10967-75)

Abstract NKX3.1 is a homeobox gene located at chromosome 8p21.2, and one copy is frequently deleted in prostate carcinoma. Prior studies of NKX3.1 mRNA and protein in human prostate cancer and prostatic intraepithelial neoplasia (PIN) have been conflicting, and expression in focal prostate atrophy lesions has not been investigated. Immunohistochemical staining for NKX3.1 on human tissue microarrays was decreased in most focal atrophy and PIN lesions. In carcinoma, staining was inversely correlated with Gleason grade. Fluorescence in situ hybridization showed that no cases of atrophy had loss or gain of 8p, 8 centromere, or 8q24 (C-MYC) and only 12% of high-grade PIN lesions harbored loss of 8p. By contrast, NKX3.1 staining in carcinoma was correlated with 8p loss and allelic loss was inversely related to Gleason pattern. Quantitative reverse transcription-PCR for NKX3.1 mRNA using microdissected atrophy revealed a concordance with protein in five of seven cases. In carcinoma, mRNA levels were decreased in 6 of 12 cases but mRNA levels correlated with protein levels in only 4 of 12 cases, indicating translational or post-translational control. In summary, NKX3.1 protein is reduced in focal atrophy and PIN but is not related to 8p allelic loss in these lesions. Therefore, whereas genetic disruption of NKX3.1 in mice leads to PIN, nongenetic mechanisms reduce NKX3.1 protein levels early in human prostate carcinogenesis, which may facilitate both proliferation and DNA damage in atrophic and PIN cells. Monoallelic deletions on chromosome 8p are associated with more advanced invasive and aggressive disease. (Cancer Res 2006; 66(22): 10683-90)

ABSTRACT Purpose. A widely advocated approach to increasing spectacle magnification in minus lenses is to increase center thickness and reduce vertex distance. Conventionally, a steeper base curve is to be avoided because of the accompanying increased vertex distance in a minus lens and the reduction of spectacle magnification that results. This approach works when small amounts of spectacle magnification are needed. However, when large amounts are needed for high minus lenses with flat base curves, the conventional approach does not provide sufficient magnification. Facial features such as eyelash length limit the contribution of reducing vertex distance, and the flat base curves limit the efficacy of increasing center thickness. Steeper base curves are required to increase the optical “leverage” of increasing center thickness. Methods. Through use of an example, a steeper base curve is shown to increase the spectacle magnification of a high minus lens. The gain in spectacle magnification is preserved by maintaining a nearly constant vertex distance through bevel location. Results. In the example, changing the base curve of a −6.50‐D lens by +4.50 D while increasing the center thickness by 4.1 mm resulted in a +4.4% increase in spectacle magnification. The lens bevel was kept as close as possible to the front surface, allowing the increased center thickness to keep the back vertex at essentially a constant vertex distance in the presence of the steeper base curve. Without the steeper base curve, it was not possible to attain the needed spectacle magnification. Conclusions. When large amounts of spectacle magnification are needed for high minus lenses, both steeper base curves and increased center thicknesses are necessary. The reduction in spectacle magnification from increased vertex distance that is expected with steeper base curves can be neutralized by keeping the bevel close to the front surface on the thicker lens.