Radiotherapy for optic nerve sheath meningioma: a case for earlier intervention?

AIMS

To assess tumour control, visual outcomes and toxicity after radiotherapy for all patients with optic nerve sheath meningiomas (ONSM) treated by a single radiation oncologist at a single institution over a 15 year period. To explore potential predictors of outcomes.

MATERIALS AND METHODS

All patients underwent ophthalmological and radiological assessments before radiotherapy. These were repeated at regular intervals after treatment. A retrospective analysis of clinical, dosimetric and radiological data was carried out. Patients with useful vision before radiotherapy were divided into two groups - those with maintained or improved vision and those with a deterioration in vision. The groups were compared using the Mann-Whitney U-test with regard to eight potential predictors of outcome.

RESULTS

Seventeen patients with 18 ONSM were treated with fractionated radiotherapy (46.8-55.8 Gy in 26-31 fractions). No evaluable tumours grew after treatment: control rate 100% (95% confidence interval 82-100%). Using the most common definition of visual function described in the literature, vision was maintained or improved in 89% (95% confidence interval 67-97%) of cases. In those with useful vision before treatment (13 evaluable eyes), visual acuity was maintained or improved in eight (62%, 95% confidence interval 36-82%). There was a suggestion that the time from the onset of symptoms to radiotherapy may influence outcome. Those with stable or better visual acuity after radiotherapy had been observed for a shorter time compared with those who had worse visual acuity (median of 18 months versus 62 months). Acute and late toxicity from radiotherapy was manageable.

CONCLUSION

Radiotherapy is an extremely effective modality in arresting the growth of ONSM. A longer time from symptom onset to the start of radiotherapy may predict for poorer outcomes.

Platinum-based adjuvant chemotherapy for early-stage epithelial ovarian cancer: single or combination chemotherapy?

OBJECTIVE

To evaluate the clinical benefit and toxicity of two regimens; single agent carboplatin (C) and a carboplatin/paclitaxel (CP) combination in early epithelial ovarian cancer.

DESIGN

A retrospective review.

SETTING

Single cancer centre serving a population of 2.1 million in the northwest of England.

POPULATION

All women treated with adjuvant chemotherapy for International Federation of Obstetrics and Gynecology stage Ia-IIc ovarian cancer between 2002 and 2005.

METHODS

Case and operation notes were reviewed. Details of the surgery performed, performance status (PS), tumour histology, stage, grade, intended chemotherapy, chemotherapy received, acute and late toxicity, relapse and death were all recorded.

MAIN OUTCOME MEASURES

Overall survival (OS), relapse-free survival (RFS), acute and late toxicity.

RESULTS

Sixty women received CP and 35 received C. Younger women (P < 0.0001) and those with a better performance status (P = 0.045) were more likely to receive CP. Median follow- up was 38 months (range 0-70). Five-year OS was 62% (95% CI 44-81%) for C and 73% (95% CI 61-85%) for CP P= = 0.316. For the subgroup with stage I disease and good PS (0/1) 5-year OS was 80% (59-100%) for C and 79% (63-95%) for CP; P = 1.0. For those with stage 2 disease, 5-year OS was 29% (95% CI 0-62%) for C and 63% (95% CI 44-82%) for CP; P = 0.025. Subgroup analyses by grade or histology showed no difference in OS. P was discontinued prematurely in nine (15%) women on account of toxicity, whereas C was not stopped early. P-related neuropathy (G1/2) was reported in ten (17%) women at 6 months and in two (3%) at 1 year.

CONCLUSIONS

Combination therapy is administered more often than carboplatin; especially in those with younger age, better PS and nonmucinous histology. Recurrence and death rates were similar with both treatments. Well-designed trials are needed to identify the optimum chemotherapy regimen in this group.

Precise measurement of the neutron magnetic form factor G(M)n in the few-GeV2 region

The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.

Search for the photoexcitation of exotic mesons in the pi+pi+pi- system

A search for exotic mesons in the pi;{+}pi;{+}pi;{-} system photoproduced by the charge exchange reaction gammap-->pi;{+}pi;{+}pi;{-}(n) was carried out by the CLAS Collaboration at Jefferson Lab. A tagged-photon beam with energies in the 4.8 to 5.4 GeV range, produced through bremsstrahlung from a 5.744 GeV electron beam, was incident on a liquid-hydrogen target. A partial wave analysis was performed on a sample of 83 000 events, the highest such statistics to date in this reaction at these energies. The main objective of this study was to look for the photoproduction of an exotic J;{PC}=1;{-+} resonant state in the 1 to 2 GeV mass range. Our partial wave analysis shows production of the a_{2}(1320) and the pi_{2}(1670) mesons, but no evidence for the a_{1}(1260), nor the pi_{1}(1600) exotic state at the expected levels. An upper limit of 13.5 nb is determined for the exotic pi_{1}(1600) cross section, less than 2% of the a_{2}(1320) production.

19 THE EFFECT OF PROGESTERONE ON FOLLICULAR DEVELOPMENT AND PREGNANCY RATE IN BEEF CATTLE

The objective was to determine the effect of the level of progesterone (P4) during the ovulatory wave on fertility. Low v. high progesterone concentrations which were expected to result in high v. low LH pulse-frequency were compared. Lactating, postpartum beef cows (n = 69) at random stages of the estrous cycle were given cloprostenol (PGF; Schering-Plough Animal Health, Pointe-Claire, QC, Canada) twice at an 11-day interval to synchronize ovulation (Day 0 = day of 2nd PGF). Cows were given 1.5 mg estradiol benzoate on Day 10 (7 days after expected ovulation). On Day 10, the Low-P4 group was given PGF and an intravaginal CueMate (Bioniche Animal Health, Belleville, ON, Canada) containing one P4 pod (expected to achieve a P4 plasma level of 1 ng mL–1). The High-P4 group also received a CueMate with one pod on Day 10, but no PGF was administered (i.e., cows were allowed to retain their CL for 4 days after expected emergence of the estradiol-induced wave). On Day 18, CueMates were removed and PGF was administered to both groups. Fifty-four to 56 h later, all animals received 12.5 mg of Lutropin-V (Bioniche) IM and were timed AI (TAI). Dominant follicle diameter was measured on Day 18 and at the time of AI. Pregnancy diagnosis was done by ultrasonography 27 days after AI to compare fertility between groups. Follicle diameter data were analyzed by Student's t-test and pregnancy rate data were compared by the chi-square test. The dominant follicle in the Low-P4 group was larger (P < 0.05) than in the high-P4 group on the day of the CueMate removal (Day 18) and on the day of the TAI (11.8 � 0.4 and 13.7 � 0.5 v. 13.3 � 0.6 and 15.3 � 0.6 in the High-P4 and Low-P4 groups, respectively). Pregnancy rate was similar (P = 0.16) between the groups (High-P4: 55.6% (20/36) and Low-P4: 44.4% (16/33)); however, a larger study is in progress to confirm these results. To conclude, Low-P4 resulted in a larger dominant follicle without any apparent effect on pregnancy rate. The project was funded by Saskatchewan ADF and NSERC. L. Pfeifer is funded through a CAPES scholarship. We acknowledge Schering-Plough and Bioniche for donation of pharmaceuticals.

Search for medium modifications of the rho meson

The photoproduction of vector mesons on various nuclei has been studied using the CLAS detector at Jefferson Laboratory. The vector mesons, rho, omega, and varphi, are observed via their decay to e;{+}e;{-}, in order to reduce the effects of final-state interactions in the nucleus. Of particular interest are possible in-medium effects on the properties of the rho meson. The rho mass spectrum is extracted from the data on various nuclei, 2H, C, Fe, and Ti. We observe no significant mass shift and some broadening consistent with expected collisional broadening for the rho meson.

Experimental study of exclusive 2H(e,e'p)n reaction mechanisms at high Q2

The reaction 2H(e,e'p)n has been studied with full kinematic coverage for photon virtuality 1.75<Q2<5.5 GeV2. Comparisons of experimental data with theory indicate that for very low values of neutron recoil momentum (p(n)<100 MeV/c) the neutron is primarily a spectator and the reaction can be described by the plane-wave impulse approximation. For 100<p(n)<750 MeV/c, proton-neutron rescattering dominates the cross section, while Delta production followed by the NDelta-->NN transition is the primary contribution at higher momenta.

Statin use and inflammation in prostate biopsy tissue

15624

Background: The statin class of drugs has been shown to affect tumors through a number of mechanisms including inhibiting tissue inflammation. Inflammation is a common finding in men undergoing a prostate biopsy and may play a role in prostatic tumorigenesis. We set out to determine whether the use of statin drugs was associated with altered tissue inflammation on prostate biopsy. Methods: Data were collected on all men with a PSA </= 10 ng/ml that underwent a prostate biopsy. A urinalysis to rule out the presence of infection was carried out in all men. The presence or absence of cancer and/or inflammation was determined by pathology report review. Statin data were recorded from the VA electronic pharmacy database. Statin duration and intensity variables were calculated for each subject based on total days used for each statin at each prescribed dose. Only men with a negative biopsy were considered in our analyses. Odds ratios (OR) as estimates of the relative risk for prostate inflammation associated with each level of statin use and 95 percent confidence intervals (CI) were obtained using pooled conditional logistic regression stratified on year of biopsy. Results: Out of 1,482 men with data available on inflammation, family history of prostate cancer, age and race; 436 were found to have prostatic inflammation. In final adjusted models stratified on year of biopsy (prior to 1997, 1997–2001, 2001 -2006) we found no association between any statin use (OR=0.88, 95% CI (0.70–1.11)), intensity of use (OR=0.93, 95% CI (0.86–1.01)), or duration of use (OR=0.932, 95% CI (0.86–1.01). These results did not change when individual statin types were analyzed. Conclusions: Statin use was not associated with a reduction in tissue inflammation in men undergoing a prostate biopsy. If statin use affects prostatic carcinogenesis, it is unlikely to do so by affecting tissue inflammatory networks.

No significant financial relationships to disclose.

A comparison of two chlorhexidine gel brushing regimens and a conventional toothpaste brushing regimen for the development of tooth staining over a 6-week period

AIMS

A single-centre, randomized single-blind parallel study was undertaken to compare staining seen with three brushing regimens and to determine subject perception of side effects such as staining and effects on taste.

METHODS

This 6-week parallel study used 157 volunteers who were randomized into one of three treatment groups: (i) brushing in the morning and evening with a normal dose of a 1% chlorhexidine gel, (ii) brushing with a low dose of chlorhexidine gel in the evening and a whitening dentifrice in the morning, and (iii) brushing with a standard fluoride paste in the morning and evening. Following home usage of their allocated products, the study volunteers returned after 3 and 6 weeks to record the amount of stain present. After the 6-week period, subject perception of taste and stain acceptability was determined using a questionnaire.

RESULTS

After 6 weeks of use of the low-dose chlorhexidine gel and whitening dentifrice, significantly more stain was seen compared with the use of a standard dentifrice (P<0.0001). Similarly, significantly more stain was seen with use of the normal-dose chlorhexidine gel compared with the low-dose gel and whitening dentifrice (P=0.0007). Approximately 30% of individuals on the low-dose chlorhexidine gel regimen found the amount of stain unacceptable and 10% noted an effect on their taste perception.

CONCLUSIONS

The use of low dose of chlorhexidine gel at night and a whitening paste in the morning produced a significant amount of stain that 30% of subjects considered unacceptable.

Measurement of the N-->Delta(+)(1232) transition at high-momentum transfer by pi(0) electroproduction

We report a new measurement of the exclusive electroproduction reaction gamma(*)p-->pi(0)p to explore the evolution from soft nonperturbative physics to hard processes via the Q(2) dependence of the magnetic (M(1+)), electric (E(1+)), and scalar (S(1+)) multipoles in the N-->Delta transition. 9000 differential cross section data points cover W from threshold to 1.4 GeV/c(2), 4pi center-of-mass solid angle, and Q(2) from 3 to 6 GeV(2)/c(2), the highest yet achieved. It is found that the magnetic form factor G(M)(*) decreases with Q(2) more steeply than the proton magnetic form factor, the ratio E(1+)/M(1+) is small and negative, indicating strong helicity nonconservation, and the ratio S(1+)/M(1+) is negative, while its magnitude increases with Q(2).

Measurement of deeply virtual compton scattering with a polarized-proton target

The longitudinal target-spin asymmetry AUL for the exclusive electroproduction of high-energy photons was measured for the first time in ep-->e;'pgamma. The data have been accumulated at JLab with the CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized NH3 target. A significant azimuthal angular dependence was observed, resulting from the interference of the deeply virtual Compton scattering and Bethe-Heitler processes. The amplitude of the sinvarphi moment is 0.252+/-0.042stat+/-0.020sys. Theoretical calculations are in good agreement with the magnitude and the kinematic dependence of the target-spin asymmetry, which is sensitive to the generalized parton distributions H and H.

Search for the Theta+ Pentaquark in the gammad--> DeltanK+ reaction measured with the CLAS spectrometer

For the first time, the reaction gammad-->DeltanK+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Laboratory, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant-mass distribution. The upper limit on the gammad-->DeltaTheta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported.

High affinity promotes more effective ADCC by anti-HER2/neu monoclonal antibodies

2538

Background: Although monoclonal antibodies have emerged as useful cancer therapeutics, the antibody structural features and biologic properties that maximize therapeutic benefit are not fully understood. Antibody-dependent cellular cytotoxicity (ADCC) is believed to be a major mechanism of some anti-cancer antibodies. Herein, we describe the relationship between antibody affinity and the biologic properties of ADCC. Methods: A series of human IgG1 antibodies was created from the anti-HER2/neu C6.5 scFv and its affinity mutants (affinity ranging from 10−7 to 10−11 M). The IgGs were tested for their ability to elicit ADCC using a standard 51Cr-release assay. The ability of these IgGs to inhibit tumor cell proliferation and to induce apoptosis was evaluated using a colorimetric cell proliferation assay and homogeneous caspase assay/Annexin-V-FLUOS assay, respectively. Three tumor cell lines with differing levels of HER2/neu expression were used as target cells, and unactivated human PBMC from healthy donors were the effector cells. Results: There was a clear influence of both intrinsic and functional affinity on ADCC, with higher levels of peak cytotoxicity as apparent affinity approached 10−11 M. Among the antibodies with apparent affinity of 10−11 M, antibodies with higher intrinsic affinities elicited more ADCC. There also was an affinity-dependent increase in cytotoxicity at lower antibody concentrations and lower effector: target ratios. These antibodies elicited more cytotoxicity against tumor cells expressing high levels of HER2/neu than against cells expressing lower amounts of HER2/neu. None of these IgGs inhibited tumor cell proliferation, or induced apoptosis. Conclusions: Additional studies are needed to determine why, at the same functional avidity, ADCC is improved in antibodies with higher intrinsic affinities. These findings justify the examination of high affinity antibodies for ADCC promotion, although the impaired tumor targeting associated with high affinity may be an important confounding factor in the design of unconjugated anti-tumor antibodies. A careful examination of antibody structure: function relationships is required to develop optimized therapeutic unconjugated antibodies.

No significant financial relationships to disclose.

Measurement of two- and three-nucleon short-range correlation probabilities in nuclei

The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured at 1 < xB <. At Q2 > 1.4 GeV2, the ratios exhibit two separate plateaus, at 1.5 < xB < 2 and at xB > 2.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A = 3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A = 4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei.

Eta' photoproduction on the proton for photon energies from 1.527 to 2.227 GeV

Differential cross sections for the reaction gamma p --> eta' p have been measured with the CLAS spectrometer and a tagged photon beam with energies from 1.527 to 2.227 GeV. The results reported here possess much greater accuracy than previous measurements. Analyses of these data suggest for the first time the coupling of the eta'N channel to both the S11(1535) and P11(1710) resonances, known to couple strongly to the etaN channel in photoproduction on the proton, and the importance of J = 3/2 resonances in the process.