Citations

AbstractResults from multiple clinical trials involving aromatase inhibitors have added to the knowledge base relating to endocrine therapy of postmenopausal women with hormone receptor–positive early breast cancer. In the extended adjuvant setting, data from the Austrian Breast and Colorectal Cancer Study Group 6a trial showed an advantage for anastrozole following 5 years of tamoxifen treatment, consistent with the more robust MA.17 trial that examined letrozole versus placebo following 5 years of tamoxifen treatment. The combined analysis of the Austrian Breast and Colorectal Cancer Study Group 8 trial and the German Arimidex Nolvadex 95 trial, plus the Italian Tamoxifen Anastrozole trial, have shown the advantage of switching to anastrozole over continuing the tamoxifen to complete the full 5 years of adjuvant therapy. These trials support the previously reported larger and double-blind Intergroup Exemestane Study. The Arimidex, Tamoxifen, Alone or in Combination trial now has data out to 68 months of median follow-up showing the maintenance of a significant advantage of anastrozole over tamoxifen for disease-free survival. In this initial treatment setting, the Breast International Group 1-98 trial recently showed a significant advantage for letrozole over tamoxifen. The current debate is centered on whether the optimal strategy is to give an aromatase inhibitor initially or after several years of tamoxifen treatment. Multiple important questions remain, including the predictive value of molecular markers such as progesterone receptor, the optimal duration of aromatase inhibitor therapy, the long-term adverse effects, and the relative efficacy and toxicity of the different aromatase inhibitors.

Abstract PURPOSE: We analyzed the expression of genes to identify reliable molecular markers in the diagnosis and progression of prostate cancer. EXPERIMENTAL DESIGN: Gene expression profiling was done using HG-U133 set microarrays in 32 prostate cancer and 8 benign tissues of patients with cancer. Expression levels of 11 genes were selected for quantitative real-time PCR evaluation in 52 prostate cancer and 20 benign tissues. Further, to assess transcriptional inactivation, we analyzed the promoter methylation of genes by quantitative methylation-specific PCR in 62 tumor and 36 benign tissues. RESULTS: Our results showed a significant down-regulation in the mRNA expression levels of PRIMA1, TU3A, PDLIM4, FLJ14084, SVIL, SORBS1, C21orf63, and KIAA1210 and up-regulation of FABP5, SOX4, and MLP in prostate cancer tissues by TaqMan real-time PCR. Quantitative methylation-specific PCR of PDLIM4, SVIL, PRIMA1, GSTP1, and PTGS2 detected prostate carcinoma with a sensitivity of 94.7%, 75.4%, 47.4%, 89.5%, and 87.7%, and a specificity of 90.5%, 75%, 54.2%, 95.8%, and 90.2%, respectively. Using this panel of methylation markers in combination, we were able to distinguish between prostate cancer and adjacent benign tissues with sensitivities and specificities of about 90% to 100%. Our data provide evidence of transcriptional repression of the putative tumor suppressor gene PDLIM4 by hypermethylation. CONCLUSIONS: Our analysis revealed differential expression of eight down-regulated and three up-regulated genes, implicating their role in prostate cancer development and progression. We further showed that the hypermethylation of PDLIM4 gene could be used as a sensitive molecular tool in detection of prostate tumorigenesis.

Abstract Purpose: MV-CEA is an oncolytic measles virus currently being tested in patients with ovarian cancer and whose propagation can be monitored by measuring blood carcinoembryonic antigen (CEA) levels. MV-NIS is an oncolytic measles virus coding for the thyroidal sodium iodide symporter (NIS) whose propagation can be mapped by serial radioiodine imaging. Expression of both CEA and NIS genes from a single virus would combine sensitive, quantitative expression monitoring (CEA) with radioisotopic expression mapping (NIS). Because of the unfavorable replication kinetics of measles viruses expressing both CEA and NIS, we explored the feasibility of combining MV-CEA with MV-NIS for comprehensive virotherapy monitoring in ovarian cancer. Experimental Design and Results: Mice implanted with i.p. SKOV3ip.1 ovarian cancer xenografts received MV-CEA alone, MV-NIS alone, or a combination of MV-CEA plus MV-NIS. Viral gene expression was monitored by measuring blood CEA levels, and the location of virus-infected cells was monitored by gamma camera imaging. Surprisingly, mice receiving the combination of MV-CEA plus MV-NIS showed greatly superior responses to therapy, but this was associated with 10-fold lower plasma levels of CEA compared with mice treated with MV-CEA alone. In vitro studies showed superior replication kinetics of MV-NIS relative to MV-CEA. The gamma camera scans were considerably less sensitive than the plasma CEA marker for monitoring virus infection. Conclusions: Dual therapy with MV-CEA and MV-NIS is superior to treatment with either virus alone, and it allows noninvasive monitoring of virotherapy via soluble marker peptide and gamma camera imaging. This has important implications for the clinical development of oncolytic measles viruses.

Abstract Purpose: Vinorelbine (Navelbine) is an orally absorbable Vinca with broad antitumor activity. It differs from other Vinca in that it is structurally modified on the catharanthine nucleus and has differential actions on tubulin that render it less neurotoxic than other compounds in this class. We conducted a phase I study of vinorelbine given the activity of Vinca alkaloids in many pediatric tumors. Experimental Design: We evaluated the safety and pharmacokinetics of oral and i.v. vinorelbine administered weekly × 6 in children (age, 2-17 years) with different tumors. Patients with disease involvement in the bone marrow were eligible but were stratified and dose-escalated separately. Oral vinorelbine (week 1) was administered as liquid-filled gelatin capsules at thrice the i.v. dose. Intravenous vinorelbine doses of 24 to 37.5 mg/m2 were administered on weeks 2 to 6. Results: The dose-limiting toxicity in patients without marrow involvement was reversible neutropenia. Common nonhematologic toxicities included ≤ grade 2 nausea/vomiting and increased hepatic transaminases. A higher mean i.v. ClTB was observed (1.75 ± 1.0 L/h/kg) compared with adult reports, with a mean t1/2B of 16.5 ± 9.7 hours. Mean oral bioavailability was 28.5 ± 22.5%. The apparent oral clearance (12.1 ± 13.0 L/h/kg) and volume of distribution (69.4 ± 30.6 L/kg) were substantially higher than in adults given similar oral doses. Conclusions: The maximum tolerated dose in children without bone marrow involvement was 30 mg/m2, similar to that reported in adults, with myelosuppression being the dose-limiting toxicity. Higher plasma clearance resulted in lower area under the plasma concentration-time curves at a given dose compared with that reported in adults.

Abstract Purpose: The serine/threonine kinase inhibitor flavopiridol targets multiple cyclin-dependent kinases, induces checkpoint arrest, and interrupts transcriptional elongation. We designed a phase I clinical trial using a timed sequential therapy approach where flavopiridol was given for the dual purpose of initial cytoreduction and enhancing cell cycle progression of the remaining leukemia cell cohort followed by cycle-dependent drugs 1-β-d-arabinofuranosylcytosine (ara-C) and mitoxantrone. Experimental Design: Flavopiridol was given by 1-hour infusion daily for 3 days beginning day 1 followed by 2 g/m2/72 h ara-C beginning day 6 and 40 mg/m2 mitoxantrone beginning day 9. In vivo correlates included pharmacokinetics, modulation of blast cycle regulators, and serum and marrow supernatant vascular endothelial growth factor levels. Results: Of 34 adults receiving induction therapy, 16 (47%) evinced direct leukemia cytotoxicity with ≥50% drop in peripheral blast counts and tumor lysis in 9 (26%). Four (12%) died during therapy (two fungal infections and two sudden death). Dose-limiting toxicity occurred at 60 mg/m2/d with profound neutropenia >40 days duration, and maximal tolerated dose was 50 mg/m2/d. Overall response rate was 31% in 26 acute myelogenous leukemia and 12.5% in acute lymphoblastic leukemia. Pharmacokinetics showed that a linear two-compartment model with first-order elimination provided the best fit of the observed concentration versus time data. Flavopiridol down-regulated one or more target proteins in marrow blasts in vivo. Vascular endothelial growth factor was detected in sera and marrow supernatant pretreatment, and sera obtained on day 3 inhibited bovine aortic endothelial cell proliferation by a mean of 32% (range, 10-80%). Conclusions: Our data suggest that flavopiridol is cytotoxic to leukemic cells and, when followed by ara-C and mitoxantrone, exerts biological and clinical effects in patients with relapsed and refractory acute leukemias. These findings warrant continuing development of flavopiridol at 50 mg/m2/d × 3 days in combination with cytotoxic and biological agents for acute leukemias.

Abstract Osteoblastic metastases and osteosarcoma can avidly concentrate bone-seeking radiopharmaceuticals. We sought to increase effectiveness of high-dose 153Samarium ethylenediaminetetramethylenephosphonate (153Sm-EDTMP, Quadramet) on osteosarcomas using a radiosensitizer, gemcitabine. Fourteen patients with osteoblastic lesions were treated with 30 mCi/kg 153Sm-EDTMP. Gemcitabine was administered 1 day after samarium infusion. Residual total body radioactivity was within the safe range of <3.6 mCi on day +14 (1.1 ± 0.4 mCi; range, 0.67-1.8 mCi). All patients received autologous stem cell reinfusion 2 weeks after 153Sm to correct expected grade 4 hematopoietic toxicity. Peripheral blood progenitor cells were infused in 11 patients; three patients had marrow infused. Blood count recovery was uneventful after peripheral blood progenitor cells in 11 of 11 patients. Toxicity from a single infusion of gemcitabine (1,500 mg/m2) in combination with 153Sm-EDTMP was minimal (pancytopenia). However, toxicity from a daily gemcitabine regimen (250 mg/m2/d × 4-5 days) was excessive (grade 3 mucositis) in one of two patients. There were no reported episodes of hemorrhagic cystitis (hematuria) or nephrotoxicity. At the 6- to 8-week follow-up, there were six partial remissions, two mixed responses, and six patients with progressive disease. In the 12 patients followed >1 year, there have been no durable responses. Thus, although high-dose 153Sm-EDTMP + gemcitabine has moderate palliative activity (improved pain; radiologic responses) in this poor-risk population, additional measures of local and systemic control are required for durable control of relapsed osteosarcoma with osteoblastic lesions. The strategy of radioactive drug binding to a target followed by a radiosensitizer may provide synergy and improved response rate.

AbstractThe etiology of acute myeloid leukemia (AML) is relatively unknown. Incidence rates are highest in the agricultural Midwest region compared with other regions of the United States. Many studies have examined the relationship between farming and leukemia, but most have mainly focused on men. We examined the potential association between farm or rural residence and AML in the Iowa Women's Health Study. In 1986, 37,693 women who were free of prior cancer completed a lifestyle and health questionnaire, which included a question on the place of residence. Women were subsequently followed until 2002 for cancer incidence; 79 women developed AML during the time period. Women who lived on a farm at baseline were more likely (relative risk, 1.91; 95% confidence interval, 1.19-3.05) to develop AML compared with women who did not live on a farm. Further, women who reported living on a farm or in a rural area were twice as likely (relative risk, 2.38; 95% confidence interval, 1.33-4.26) to develop AML compared with women who lived in a city with a population of >10,000 people. These results provide evidence that women who live on farms or rural areas are at an increased risk of AML.

Abstract Aim: To examine medical and lifestyle preventive behaviors among women with varying levels of familial breast cancer risk. Methods: Using cross-sectional data from the Minnesota Breast Cancer Family Study, a historical cohort of 426 families, we compared medical (mammography adherence, antiestrogen use, and prophylactic surgery) and lifestyle (physical activity, smoking, alcohol, and diet) behaviors across three groups of cancer-free women ages 18 to 95 defined by their family history of breast cancer. Family history was classified as high-risk, moderate-risk, or average to low-risk depending on the number and degree of relationship of family members with breast cancer. Results: After adjusting for age and education, high-risk women were twice as likely to have ever used an antiestrogenic agent (9.0% versus 4.6% among moderate-risk and 4.1% among average to low-risk; P = 0.002). Among women ages <40, the high-risk group were more likely to have ever had a mammogram (82% versus 47% among moderate-risk and 35% among average to low-risk; P < 0.001). Average to low-risk women were the least likely to be current smokers and high-risk women may consume slightly fewer fruits and vegetables compared with the other groups, but there were no other differences in lifestyle behaviors, including physical activity and alcohol use. Conclusions: Women with strong family histories of breast cancer are more likely to undertake medical but not lifestyle preventive behaviors.

Abstract Recent experimental evidence has shown that catechol estrogens can be activated through metabolism to form depurinating DNA adducts and thereby initiate cancer. Limited data are available regarding this pathway in epithelial ovarian cancer. We conducted a case-control study of 503 incident epithelial ovarian cancer cases at the Mayo Clinic in Rochester, MN, and Jacksonville, FL, and a 48-county region in North Carolina. Six hundred nine cancer-free controls were frequency matched to the cases on age, race, and residence. After an interview to obtain data on risk factors, a sample of blood was collected for DNA isolation. Subjects were genotyped for seven common single nucleotide polymorphisms in four genes involved in catechol estrogen formation (CYP1A1 and CYP1B1) or conjugation (COMT and SULT1A1). Data were analyzed using logistic regression, stratified by race, and with adjustment for design factors and potential confounders. None of the individual genotypes were significantly associated with ovarian cancer risk. However, an oligogenic model that considered the joint effects of the four candidate genes provided evidence for an association between combinations of these genes and ovarian cancer status (P = 0.015). Although preliminary, this study provides some support for the hypothesis that low-penetrance susceptibility alleles may influence risk of epithelial ovarian cancer.

Abstract Purpose: Gemcitabine is a nucleoside analogue with activity against solid tumors. Gemcitabine metabolic inactivation is catalyzed by cytidine deaminase (CDA) or, after phosphorylation, by deoxycytidylate deaminase (DCTD). We set out to study the pharmacogenomics of CDA and DCTD. Experimental Design: The genes encoding CDA and DCTD were resequenced using DNA from 60 African American and 60 Caucasian American subjects. Expression constructs were created for nonsynonymous coding single nucleotide polymorphisms (cSNP) and reporter gene constructs were created for 5′-flanking region polymorphisms. Functional genomic studies were then conducted after the transfection of mammalian cells. Results: CDA resequencing revealed 17 polymorphisms, including one common nonsynonymous cSNP, 79 A>C (Lys27Gln). Recombinant Gln27 CDA had 66 ± 5.1% (mean ± SE) of the wild-type (WT) activity for gemcitabine but without a significant decrease in level of immunoreactive protein. The apparent Km (397 ± 40 μmol/L) for the Gln27 allozyme was significantly higher than that for the WT (289 ± 20 μmol/L; P < 0.025). CDA 5′-flanking region reporter gene studies showed significant differences among 5′-flanking region haplotypes in their ability to drive transcription. There were 29 SNPs in DCTD, including one nonsynonymous cSNP, 172 A>G (Asn58Asp), in Caucasian American DNA. Recombinant Asp58 DCTD had 11 ± 1.4% of WT activity for gemcitabine monophosphate with a significantly elevated level of immunoreactive protein. No DCTD polymorphisms were observed in the initial 500 bp of the 5′-flanking region. Conclusions: These results suggest that pharmacogenomic variation in the deamination of gemcitabine and its monophosphate might contribute to variation in therapeutic response to this antineoplastic agent.