Dalteparin low molecular weight heparin (LMWH) in ovarian cancer: A phase II randomized study

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Background: Up to 17% of women with ovarian cancer (OC) develop venous thromboembolism (VTE). LMWH reduces the risk of VTE and may have antineoplastic effects because tissue factor on OC cells stimulates tumor growth. A multicentre, open-label phase II randomized trial was undertaken to identify a potentially efficacious and safe dose of dalteparin to investigate its antineoplastic potential in OC. Methods: Women with newly diagnosed epithelial OC were randomized to receive taxane and platinum chemotherapy (CT) and one of 3 doses of dalteparin (50 IU/kg, 100 IU/kg, or 150 IU/kg) subcu daily during the first 3 cycles of CT. With each cycle of CT, patients had a CA125 and were assessed for bleeding or VTE. A response was defined as a ≥50% reduction in CA125 from baseline sustained for at least 28 days (according to GCIG criteria). To select the best LMWH group with a ≥ 80% response rate (RR) {vs. 60% with CT alone} with 90% probability, 39 patients per group were needed. Patients were followed until the end of CT. Results: 77 women were randomized and 72 of them completed follow-up. Compliance with injections was > 80%. There were no major bleeding events and 3 patients in the highest dose group had minor bleeding. There were no VTEs while on or within 7 days of finishing LMWH. There were 2 deaths attributed to the underlying OC. A 50% drop in CA125 by the start of cycle 4 was seen in 87% of the 50 IU/kg group, 92% of the100 IU/kg group, and 84% of the 150 IU/kg group, respectively. The corresponding RRs by the end of cycle 6 were 91%, 92% and 92%. Conclusions: Use of dalteparin is safe and well tolerated in women who are receiving CT for newly diagnosed OC. This therapy was effective in preventing VTE. A dose response effect on CA125 levels was not identified.

[Table: see text]

PET-CT compared to invasive mediastinal staging in non-small cell lung cancer (NSCLC)

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Background: In patients with NSCLC, preoperative staging tests including mediastinoscopy (M) are important in defining which patients are surgical candidates. 18FDG PET-CT is useful in identifying patients with mediastinal disease not evident by CT. Alternatively, M may not be required if PET-CT is negative. We have previously reported reduced rates of unnecessary thoracotomy (T) in the PET-CT arm of a trial which compared staging with PET-CT versus conventional imaging (bone scan and CT liver and adrenals) in patients with clinical stage I, II, or IIIA NSCLC being considered for surgery (J Clin Oncol 26 May 20 suppl: abstr 7502). Methods: In this analysis, we determined the accuracy of PET-CT in mediastinal staging compared to invasive surgical staging either by M alone or by M and T. Patients in the PET-CT arm had invasive mediastinal staging either by M or mediastinal nodal sampling at T. PET-CT was considered positive if N2 or N3 nodes exhibited increased 18FDG uptake. Results: M was performed in 81 of 143 patients in the PET-CT arm; the remainder had mediastinal nodal staging at T. Combining M with T, the sensitivity and specificity of PET-CT were 0.70 [95% CI: 0.48–0.85] and 0.94 [95%CI: 0.89–0.97], respectively. Of 21 patients with a positive PET-CT, 7 did not have tumor. The positive predictive value (PPV) and negative predictive value (NPV) were 0.67 [95% CI: 0.45–0.83] and 0.95 [95% CI: 0.90–0.98], respectively. The results for PET-CT versus M alone were: sensitivity, 1.0 [95% CI: 0.76–1.0]; specificity, 0.88 [95%CI: 0.79–0.94]; PPV, 0.60 [95%CI: 0.39–0.78]; NPV, 1.0 [95% CI: 0.94–1.0]. Based on PET-CT alone, 7 patients would have been denied T if PET-CT abnormalities had not been evaluated with invasive mediastinal staging. Conclusions: Mediastinal abnormalities on PET-CT should be confirmed by invasive mediastinal staging because of the risk of a false positive test. Patients should not be denied potentially curative therapy based on PET-CT alone. If PET-CT is negative in the mediastinum, the likelihood of occult metastatic disease in the mediastinum is very low and invasive staging may not be required depending on the clinical context.

No significant financial relationships to disclose.

Predictors of recurrent thrombosis and anticoagulant-related bleeding in patients with cancer

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Background: Anticoagulant therapy is treatment of choice for cancer-associated thrombosis. However, the risk of symptomatic recurrent thrombosis (RT) is approximately 9% on low molecular weight heparin (LMWH) and 17% on vitamin K antagonist (VKA) therapy, while the risk of anticoagulant-related major bleeding is about 5%. Given such complications are associated with morbidity and increased resource utilization, prognostic factors that identify patients at high risk for RT or bleeding would be useful for individualizing therapy. We performed a post-hoc analysis of the CLOT study (N Eng J Med 2003;349,146–53) for predictors of RT and bleeding in patients with proximal deep vein thrombosis (DVT) or pulmonary embolism (PE) who were randomized to receive either dalteparin LMWH or VKA for 6 months. Methods: Cox proportional hazards modeling analyses were performed using prospectively collected data from the CLOT study database. Potential baseline factors associated with RT and bleeding examined in the models were identified a priori based on published literature. Factors for RT were: dalteparin, age, gender, ECOG status, smoking status, presence of metastases, tumor site, history of DVT or PE, recent surgery, cancer treatment and body mass index. Factors for bleeding were: dalteparin, age, gender, ECOG, tumor type, major surgery, cancer treatment, platelet count, body mass index, creatinine, and concurrent use of antiplatelet agents. Results: Data from 673 cancer patients were available for the analysis. There were 80 patients with RT, 31 with major bleeds and 77 with minor bleeds. Three statistically significant predictors for RT were identified (with their hazard ratio and corresponding 95% CI): dalteparin (0.52; 0.32–0.82), every 10 year increase in age (0.77; 0.66–0.90) and presence of metastases (2.59; 1.20–6.60). Of the tumour sites investigated, lung (3.51; 1.62–7.62) and unknown primaries (3.63; 1.36–1.90) were predictive of RT. None of the factors examined in the models were found to be predictive of bleeding. Conclusions: Baseline factors may identify cancer patients with a higher risk of RT despite anticoagulant therapy. The risk of anticoagulant-related bleeding is not predictable at treatment onset.

[Table: see text]

Impact of positron emission tomography (PET) in stage III non-small cell lung cancer (NSCLC): A prospective randomized trial (PET START)

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Background: Patients with stage III NSCLC are potentially curable using combined modality therapy (CMT) with chemotherapy and radical radiation (RT). The use of PET-CT rather than conventional imaging (CI) may better identify patients for CMT by enhanced tumor staging and improved definition of RT treatment volumes. Methods: Patients with stage III NSCLC (based on histology/cytology, brain CT/MRI, CT thorax, CT/US abdomen, and bone scan) who were considered candidates for CMT were randomized to either PET-CT or CT for RT treatment planning. The primary outcome was the proportion of patients who did not receive CMT because their tumor was upstaged to Stage 4 or their intrathoracic tumor was too extensive for radical RT. Overall survival (OS) and alteration of RT treatment planning volume were secondary outcomes. Target sample size was 400 patients based on a hazard rate reduction of 30% in OS at 2 years in favor of PET-CT with 2-sided alpha = 0.05 and 80% power. We also postulated that 200 patients would be required to detect a 20% difference between arms for the primary endpoint. 5 centers in Ontario participated. Results: The trial commenced in August 2004. In November 2008 after a planned interim analysis for the primary outcome, the Data Safety Monitoring Board recommended stopping recruitment because of superior efficacy with PET-CT. 304 patients were randomized and 289 had analyzable data. 25 patients were unsuitable for CMT: 21 in the PET-CT arm (16 upstaged to Stage 4 and 5 unsuitable for radical RT) and 4 in the CT arm (unsuitable for radical RT). Thus, 21 of 140 (15%) patients in the PET-CT arm achieved the primary outcome compared with 4 of 149 (2.7%) in the CT arm, P= 0.0002. Conclusions: This is the first randomized trial in stage III NSCLC showing that PET-CT is superior to CT planning alone in selecting appropriate patients for CMT. Longer patient follow-up will determine potential impact on OS.

No significant financial relationships to disclose.

Dehydroascorbate and glucose are taken up into Arabidopsis thaliana cell cultures by two distinct mechanisms

The possible involvement of glucose (Glc) carriers in the uptake of vitamin C in plant cells is still a matter of debate. For the first time, it was shown here that plant cells exclusively take up the oxidised dehydroascorbate (DHA) form. DHA uptake is not affected by 6-bromo-6-deoxy-ascorbate, an ascorbate (ASC) analogue, specifically demonstrating ASC uptake in animal cells. There is no competition between Glc and DHA uptake. Moreover, DHA and Glc carriers respond in the opposite manner to different inhibitors (cytochalasin B, phloretin and genistein). In conclusion, the plant plasma membrane DHA carrier is distinct from the plant Glc transporters.

Phase I clinical trial of i.v. ascorbic acid in advanced malignancy

BACKGROUND

Ascorbic acid is a widely used and controversial alternative cancer treatment. In millimolar concentrations, it is selectively cytotoxic to many cancer cell lines and has in vivo anticancer activity when administered alone or together with other agents. We carried out a dose-finding phase I and pharmacokinetic study of i.v. ascorbic acid in patients with advanced malignancies.

PATIENTS AND METHODS

Patients with advanced cancer or hematologic malignancy were assigned to sequential cohorts infused with 0.4, 0.6, 0.9 and 1.5 g ascorbic acid/kg body weight three times weekly.

RESULTS

Adverse events and toxicity were minimal at all dose levels. No patient had an objective anticancer response.

CONCLUSIONS

High-dose i.v. ascorbic acid was well tolerated but failed to demonstrate anticancer activity when administered to patients with previously treated advanced malignancies. The promise of this approach may lie in combination with cytotoxic or other redox-active molecules.

Perception of sweet taste is important for voluntary alcohol consumption in mice

To directly evaluate the association between taste perception and alcohol intake, we used three different mutant mice, each lacking a gene expressed in taste buds and critical to taste transduction: alpha-gustducin (Gnat3), Tas1r3 or Trpm5. Null mutant mice lacking any of these three genes showed lower preference score for alcohol and consumed less alcohol in a two-bottle choice test, as compared with wild-type littermates. These null mice also showed lower preference score for saccharin solutions than did wild-type littermates. In contrast, avoidance of quinine solutions was less in Gnat3 or Trpm5 knockout mice than in wild-type mice, whereas Tas1r3 null mice were not different from wild type in their response to quinine solutions. There were no differences in null vs. wild-type mice in their consumption of sodium chloride solutions. To determine the cause for reduction of ethanol intake, we studied other ethanol-induced behaviors known to be related to alcohol consumption. There were no differences between null and wild-type mice in ethanol-induced loss of righting reflex, severity of acute ethanol withdrawal or conditioned place preference for ethanol. Weaker conditioned taste aversion (CTA) to alcohol in null mice may have been caused by weaker rewarding value of the conditioned stimulus (saccharin). When saccharin was replaced by sodium chloride, no differences in CTA to alcohol between knockout and wild-type mice were seen. Thus, deletion of any one of three different genes involved in detection of sweet taste leads to a substantial reduction of alcohol intake without any changes in pharmacological actions of ethanol.

NOTES ON BACT. COLI AND BACT. AEROGENES

Accurate information on the relative incidence of Bact. coli and Bact. aërogenes in nature would oid materially in the interpretation of the colon test in water analysis. Professor Levine suggests the lines along which selective media, for the isolation of these organisms, may be devised.

Acidic proline-rich protein Db and caries in young children

Polymorphic, acidic proline-rich proteins (PRPs) in saliva influence the attachment of bacteria associated with caries. Our aims were to detect one of three acidic PRP alleles of the PRH1 locus (Db) using polymerase chain-reaction (PCR) on genomic DNA, and to determine its association with caries. DNA was obtained from buccal swabs from Caucasian and African-American children, and their caries experience was recorded. PCR primers designed around exon 3 of the PRH1 locus gave a 416-base product representing Db and a 353-base product representing the other two alleles (Pa or Pif). In Caucasians, Db gene frequency was 14%, similar to Db protein from parotid saliva. In African-Americans, however, it was 37%, 18% lower than Db from parotid saliva (reported previously). Compared with African-Americans, all Caucasians had significantly greater Streptococcus mutans colonization, but only Db-negative Caucasians had significantly more caries. Alleles linked to Db may explain racial differences in caries experience.