Statistical approach to measure the efficacy of anthelmintic treatment on horse farms

Resistance to anthelmintics in gastrointestinal nematodes of livestock is a serious problem and appropriate methods are required to identify and quantify resistance. However, quantification and assessment of resistance depend on an accurate measure of treatment efficacy, and current methodologies fail to properly address the issue. The fecal egg count reduction test (FECRT) is the practical gold standard for measuring anthelmintic efficacy on farms, but these types of data are fraught with high variability that greatly impacts the accuracy of inference on efficacy. This paper develops a statistical model to measure, assess, and evaluate the efficacy of the anthelmintic treatment on horse farms as determined by FECRT. Novel robust bootstrap methods are developed to analyse the data and are compared to other suggested methods in the literature in terms of Type I error and power. The results demonstrate that the bootstrap methods have an optimal Type I error rate and high power to detect differences between the presumed and true efficacy without the need to know the true distribution of pre-treatment egg counts. Finally, data from multiple farms are studied and statistical models developed that take into account between-farm variability. Our analysis establishes that if inter-farm variability is not taken into account, misleading conclusions about resistance can be made.

Consequences of modifying an adjuvant treatment protocol for resected gastric carcinoma: A retrospective study at a single institution in western Canada

15176

Background: Gastric adenocarcinoma has a poor outcome: surgical resection alone in stage IA-IVA is curative in < 30%. Adjuvant chemo-radiotherapy (INT-0116 protocol) increases median overall survival from 27 to 36 months but is associated with high morbidity with many patients requiring protocol modifications to complete treatment. The benefit of modified protocols in this setting has not been well studied. We set out to compare the morbidity and mortality of the INT-0116 protocol with that of modified protocols in a single institution in Western Canada. Methods: We conducted a retrospective review of stage IA-IVA gastric adenocarcinoma patients treated with adjuvant chemo-radiation at our institution after curative-intent surgical resection. Patients were identified from Tom Baker Cancer Centre records. End points were: survival, completion of therapy, local, regional and distant failure. The modified protocol was defined as: combined modality component postponed from the second to the third or fourth chemotherapy cycle or radiation given alone after two or three cycles of chemotherapy. Results: Twenty three consecutive patients were identified; 11 received standard protocol, twelve a modified protocol. Demographic characteristics / staging at resection of those two groups did not significantly differ. Outcomes are summarized in Table 1 . Conclusions: Many patients were unable to complete the INT-0116 protocol as described, while patients placed on a modified protocol had a greater chance of completing treatment. Survival at 12 and 36 months in patients treated with the modified protocol was at least as good as those who underwent the standard protocol. This limited study at a single institution suggests that modifying the INT 0116 protocol can make this treatment more palatable to patients while not compromising outcome. Further research is warranted. Data on a further nine patients more recently treated is being analyzed and will be presented.

[Table: see text]

No significant financial relationships to disclose.

How much cost can one patient bear? The influence of income and education on drug purchasing decisions in Hong Kong Chinese cancer patients

19584

Background: Inflation of anticancer drug prices is a growing problem worldwide. This problem is especially challenging in Asia, where rising healthcare expectations clash with low incomes and weak insurance. To clarify the factors influencing drug purchasing decisions in this context, we conducted a survey of Hong Kong oncology patients. Methods: A questionnaire was designed to assess the effect of cost on purchasing decisions relating to drug variables such as (1) efficacy, (2) tolerability, (3) convenience, (4) safety, (5) novelty and (6) reliability. Validation of the original 33-part survey resulted in a final set of 21 questions that was administered to 51 oncology patients. These respondents were characterised in terms of age, household income, insurance, educational level, family circumstances, occupation, ethnicity, religious beliefs, prognosis, and co-morbidity. Results: Most respondents were Hong Kong (68.8%), mainland Chinese (18.8%) or Caucasian (10.4%). There was a strong correlation between household income and education. Patients from middle-income (US$7,000–14,000 per month) households were most influenced in their decisions by costs and insurance rebates, whereas those from low-income households (less than US$3,000 per month) were keenest to purchase expensive medications, whether Western or traditional Chinese remedies. Demand for drug safety was cost-inelastic across all income groups, independent of gains in efficacy. Even when free treatment was offered, therapeutic uncertainties (e.g., early-phase drugs or randomization) proved unpopular with all income groups. Only the most affluent and well-educated patients valued overall survival above disease-free survival in making decisions, suggesting that less educated cohorts did not understand these concepts. Conclusion: These data suggest that low-income cancer patients and their families may have unrealistic expectations of high-priced medications, based either on misunderstanding or cultural pressures. Greater educational efforts targeting this large population sector may be needed to avoid worsening dissatisfaction and social unrest in the future.

No significant financial relationships to disclose.

Diarrhea events in cancer patients (pts) treated with lapatinib

9125

Introduction: Lapatinib (L) is an oral dual ErbB1/ErbB2 tyrosine kinase inhibitor administered to > 5,000 pts in clinical trials. Low grade gastrointestinal adverse events: diarrhea, nausea and vomiting were recorded. We characterize here the diarrhea events related to L. Methods: Diarrhea events were recorded in 1,514 pts from 8 completed MBC and non-breast cancer clinical trials. Non-L treated pts in these trials were the comparator for analysis of toxicity grades, relationship to dose, time to onset, duration, required interventions and outcomes. Results: The L dose ranged from 1,000–1,500mg daily as monotherapy (n=928) or in combination with chemotherapy (n=198). Capecitabine alone (n=191)and tamoxifen alone (n=197) pts served as controls. For L and non-L groups the per pt diarrhea rates were: any grade 50%v33%; of those G1 54%v53%; G2 30%v30%; G3 15%v17%; G4 <1%v0% and SAEs 3% v 3%; respectively. There were no fatal L-related SAEs. For L, early diarrhea presentation <6 days(d) was 2x more frequent (44%v21%). In the non-L grp, diarrhea presented at 6–14 d in 30% pts. Delayed onset (>28 d) was similar: 22% on L v 26%, non-L. Initial G3 diarrhea or progression from G1/G2 to G3 was similar (Lv non-L): 4%v 3% and 4% v3%, respectively. The median number of events/pt (2) was the same for both groups and median duration was 5d (L) v 6d (non-L). Events (L v non-L) resolved in 89%v93%; and resolved with sequelae <1% v 1%; resolution was not recorded in 7%v4%. Events were managed in approximately 30% of pts with standard anti-diarrhea medications (loperimide and lomitil) and when more sever with hydration, octreotide & antibiotics. Majority of G1/G2 events were not treated. Most pts (85%) did not have L interrupted or dose adjusted and both group only 2% (L)v 2% (non-L) discontinued therapy due to diarrhea. Conclusions: Diarrhea related to L therapy (mostly used as monotherapy in this analysis) is usually mild to moderate, frequently does not require intervention, but pts monitoring is crucial. Importantly, L-related diarrhea appears as early events (before day 6) and is generally responsive to standard interventions. Analyses are ongoing to further identify its natural history, characteristics and pts at risk for serious events.

No significant financial relationships to disclose.

A randomized, double-blind phase II study of the oral tyrosine kinase inhibitor (TKI) axitinib (AG-013736) in combination with docetaxel (DOC) compared to DOC plus placebo (PL) in metastatic breast cancer (MBC)

1003

Background: Single-agent DOC is commonly used to treat MBC. Axitinib (AG) is a potent TKI of VEGFRs. A phase I lead-in study identified 80 mg/m2 q3wks of DOC in combination with 5 mg BID of AG as the recommended phase 2 dose. The primary objective was to determine whether the time to progression (TTP) of AG+DOC arm is superior to DOC+PL. Methods: Pts with no prior chemotherapy for MBC and =12 mos from adjuvant chemotherapy (aCT), measurable disease, ECOG performance status (PS) of 0–2, and no uncontrolled brain metastases were randomly assigned (2:1) to receive treatment with either DOC+AG or DOC+PL without prophylactic growth factor in cycle 1. Tumor measurements were performed q9wks. Pts were stratified according to estrogen receptor (ER) status, prior aCT and PS (0–1 or 2). Results: A total of 168 pts were randomized. 92 pts had received prior aCT, 27 of whom received a prior taxane. Treatment arms were well balanced for prior adjuvant and taxane therapy. A median of 7 cycles of AG+DOC (range: 1–18) and 7 cycles of DOC+PL (range: 1–23) were administered. The most common non-hematologic adverse events observed in the AG+DOC arm included diarrhea (60%), nausea (53%), alopecia (51%), fatigue (49%), stomatitis (44%) and vomiting (40%). Grade 3/4 adverse events that were increased with AG+DOC vs DOC included febrile neutropenia (16 vs 7%), fatigue (13 vs 5%), stomatitis (13 vs 2%), diarrhea (11 vs 0%) and hypertension (5 vs 2%). Other grade 3/4 hematologic toxicities were similar in both arms. The median TTP (by RECIST) was 8.2 mo with AG+DOC arm and 7 mo with DOC+PL arm with a hazard ratio of 0.73 (prespecified, one-sided p=0.052). The overall response rate (ORR) was 40% for AG+DOC arm and 23% for DOC+PL arm (p=0.038). In a hypothesis-generating subgroup analysis, the median TTP in patients receiving prior aCT was 9.0 mo with AG+DOC arm and 6.3 mo with DOC+PL arm with a hazard ratio of 0.54 (p=0.012). Within this stratum, ORR was 45% for AG+DOC arm and 13% for DOC+PL arm (p=0.003). Conclusions: The anti-angiogenic TKI AG combined with DOC (80 mg/m2 q3wks) as first line therapy for MBC has an acceptable safety profile and promising anti-tumor activity.

No significant financial relationships to disclose.

SCOTCERV: A phase II trial of docetaxel and gemcitabine as second-line chemotherapy in cervical cancer

5548

Background: Concurrent Cisplatin chemotherapy along with radiotherapy is standard therapy for locally advanced cervical cancer. There is no established second line regimen. Taxanes and Gemcitabine are not thought to share drug resistance with Cisplatin. In combination they are reasonably tolerated; myelosuppression is the dose limiting toxicity. Response is more likely in recurrences outside the irradiated area. Methods: This was a multi-centre phase II trial of Docetaxel (75mg/m2 d1) and Gemcitabine (1,000 mg/m2 d1,d8) in relapsed patients (pts) after treatment with cisplatin alone or in combination (excluding with taxanes) and/or radiotherapy. A Gehan two-stage design was used (minimum response rate requirement 25%). Pts had to have disease assessable by RECIST outside the irradiated pelvis and adequate organ function. After 12 pts the Docetaxel dose was reduced to 60 mg/m2. Results: 26 eligible pts were recruited to the study; information is available currently for 24. The median age is 43 years (range 30–62) and the median time from prior treatment is 12 months (1–55). 23 pts had prior chemoradiotherapy. Performance status: 0 (15) or 1 (9). Histology: squamous 17, adenoCa (6) mixed (1). Major metastatic sites were lung (11) and para-aortic nodes (11). The principal toxicity was neutropenia (gd 3 (8), gd 4 (8)) with 4 pts experiencing grade 3 febrile neutropenia. Dose reductions occurred in 29% of pts (Docetaxel) and 25% of pts (Gemcitabine), primarily for neutropenic fever. Haematological toxicity resulted in d8 Gemcitabine being omitted in 41% of cycles. 1 patient had gd3 SOB and 1 patient gd 3 diarrhoea. Reduction of Docetaxel dose did not reduce haematological toxicity. 5 pts have not, as yet, had response reported. In 19 pts (16 completed therapy) there was 1 CR, 4 PR, 6 stable disease, 7 progressions and 1 unevaluable. The overall response rate is 26% (95% ci 9%-51%). Conclusions: This preliminary data shows this combination has activity against platinum resistant metastatic cervical cancer, although the ability to deliver d8 Gemcitabine is compromised. Final results will be available for the meeting.

[Table: see text]

The Control of Hypertension In Pregnancy Study pilot trial

OBJECTIVE

To determine whether 'less tight' (versus 'tight') control of nonsevere hypertension results in a difference in diastolic blood pressure (dBP) between groups.

DESIGN

Randomised controlled trial (ISRCTN#57277508).

SETTING

Seventeen obstetric centres in Canada, Australia, New Zealand, and UK.

POPULATION

Inclusion: pregnant women, dBP 90-109 mmHg, pre-existing/gestational hypertension; live fetus(es); and 20-33(+6) weeks. Exclusion: systolic blood pressure > or = 170 mmHg and proteinuria, contraindication, or major fetal anomaly.

METHODS

Randomisation to less tight (target dBP, 100 mmHg) or tight (target dBP, 85 mmHg) blood pressure control.

MAIN OUTCOME MEASURES

Primary: mean dBP at 28, 32 and 36 weeks. Secondary: clinician compliance and women's satisfaction. Other: serious perinatal and maternal complications.

RESULTS

A total of 132 women were randomised to less tight (n = 66; seven had no study visit) or tight control (n= 66; one was lost to follow up; seven had no study visit). Mean dBP was significantly lower with tight control: -3.5 mmHg, 95% credible interval (-6.4, -0.6). Clinician compliance was 79% in both groups. Women were satisfied with their care. With less tight (versus tight) control, the rates of other treatments and outcomes were the following: post-randomisation antenatal antihypertensive medication use: 46 (69.7%) versus 58 (89.2%), severe hypertension: 38 (57.6%) versus 26 (40.0%), proteinuria: 16 (24.2%) versus 20 (30.8%), serious maternal complications: 3 (4.6%) versus 2 (3.1%), preterm birth: 24 (36.4%) versus 26 (40.0%), birthweight: 2675 +/- 858 versus 2501 +/- 855 g, neonatal intensive care unit (NICU) admission: 15 (22.7%) versus 22 (34.4%), and serious perinatal complications: 9 (13.6%) versus 14 (21.5%).

CONCLUSION

The CHIPS pilot trial confirms the feasibility and importance of a large definitive trial to determine the effects of less tight control on serious perinatal and maternal complications.

Single Fraction Radiotherapy for Small Superficial Carcinoma of the Skin

AIMS

To define the optimal dose and maximum tumour size of basal and squamous cell carcinoma of skin that can be treated by single fraction radiotherapy.

MATERIALS AND METHODS

A review was undertaken of 1005 lesions of basal/squamous cell carcinoma of the skin involving 806 patients treated at a single centre with 10 years of follow-up. Doses of 18, 20 and 22.5 Gy were used. The recurrence and necrosis free survival rates for different anatomical sites and radiation doses were calculated.

RESULTS

The overall disease-free and necrosis-free rates at 5 years were 90% and 84%, respectively. The crude 10-year recurrence rate was 4% (95% CI 3.4-5.4%), with late skin necrosis at 6% (95% CI 4.8-7.2%). There was no difference in tumour recurrence rates between 20 and 22.5 Gy (P=0.3), but there was a significantly higher skin necrosis rate at the treated site in the patients who had received 22.5 Gy (P=0.003). Most skin necrosis healed spontaneously, with only 16% requiring surgical intervention. Tumours involving the inner canthus had a significantly higher recurrence rate than those involving other areas of the head and neck.

CONCLUSIONS

Single fraction radiotherapy is an acceptable treatment for small superficial BCC and SCC of the head and neck region in patients who have difficulty attending multiple hospital visits as long as the field size required for treatment is no larger than 3 cm in diameter. The optimal applied dose for such a lesion on a flat surface is 20 Gy.

Quantitative objective markers for upper and lower motor neuron dysfunction in ALS

OBJECTIVE

To investigate the value of objective biomarkers for upper (UMN) and lower (LMN) motor neuron involvement in ALS.

METHODS

We prospectively studied 64 patients with ALS and its subsets using clinical measures, proton MR spectroscopic imaging ((1)H MRSI), diffusion tensor imaging, transcranial magnetic stimulation, and the motor unit number estimation (MUNE) at baseline and every 3 months for 15 months and compared them with control subjects.

RESULTS

(1)H MRSI measures of the primary motor cortex N-acetyl-aspartate (NAA) concentration were markedly reduced in ALS (p = 0.009) and all UMN syndromes combined (ALS, familial ALS [fALS], and primary lateral sclerosis; p = 0.03) vs control values. Central motor conduction time to the tibialis anterior was prolonged in ALS (p < 0.0005) and combined UMN syndromes (p = 0.001). MUNE was lower in ALS (p < 0.0005) and all LMN syndromes combined (ALS, fALS, and progressive muscular atrophy; p = 0.001) vs controls. All objective markers correlated well with the ALS Functional Rating Scale-Revised, finger and foot tapping, and strength testing, suggesting these markers related to disease activity. Regarding changes over time, MUNE changed rapidly, whereas neuroimaging markers changed more slowly and did not significantly differ from baseline.

CONCLUSIONS

(1)H MR spectroscopic imaging measures of the primary motor cortex N-acetyl-aspartate (NAA) concentration and ratio of NAA to creatine, central motor conduction time to the tibialis anterior, and motor unit number estimation significantly differed between ALS, its subsets, and control subjects, suggesting they have potential to provide insight into the pathobiology of these disorders.

Modern chemotherapy management of recurrent ovarian cancer: a multicentre study

AIMS

The natural history of ovarian cancer has changed over the last 10 years due to more effective drug treatments. The aim of this multicentre audit of the management of recurrent ovarian cancer was to examine the usage of newer drugs in light of the publication of National Institute of Clinical Excellence guidance.

MATERIALS AND METHODS

All patients presenting with a first or subsequent relapse of ovarian cancer between August 2001 and February 2003 in nine UK National Health Service centres were identified. Data were recorded retrospectively and prospectively from point of entry into the study and included the modality of primary cancer treatment, the treatment of each subsequent relapse and outcome.

RESULTS

In total, 245 evaluable patients were entered on to the database. The mean age was 62 years. All patients received a platinum-based chemotherapy regimen as first-line treatment. One hundred and fifty-five patients (63%) went on to receive third-line chemotherapy and 82 (34%) received fourth-line chemotherapy. The median survival from first relapse was estimated to be in excess of 12 months from our data. The efficacies of the chemotherapy agents used are comparable with the results of published phase III trials.

CONCLUSION

This study shows that multicentre audit is feasible and provides useful information on current clinical practice on which to base future research.

p-53 gene mutations as a predictive marker in a population of advanced breast cancer patients randomly treated with doxorubicin or docetaxel in the context of a phase III clinical trial

BACKGROUND

Preclinical data indicate that p-53 gene mutations predict resistance to doxorubicin (A) but not to docetaxel (Taxotere) (T). In the TAX 303 trial, A and T have been compared with advanced breast cancer patients.

PATIENTS AND METHODS

Primary tumor samples from patients participating in the TAX 303 trial were collected. p-53 gene mutations were evaluated by denaturing high-performance liquid chromatography (DHPLC) and confirmed by sequencing. Topoisomerase II alpha (topo II alpha) protein levels were evaluated by immunohistochemistry. Clinical and biological data were correlated.

RESULTS

Tumor samples for DHPLC analysis were available for 108 of 326 patients from the clinical trial. p-53 gene mutations were observed in 20% of patients. In patients with a mutated p-53 gene, a trend for a lower percentage of responders was observed in the A arm (17%) compared with the T arm (50%). In the wild-type p-53 cohort, response rates to A and T were 27% and 36%, respectively. Of the 16 patients carrying wild-type p-53- and topo II protein-positive tumors, seven (44%) responded to anthracyclines, while response rate to the same drug was 13% in the remaining cohorts [odds ratio 5.06 (95% confidence interval 1.19-21.41), P = 0.03]. The combination of the two markers had no predictive value in patients treated with docetaxel.

CONCLUSIONS

(i) p-53 gene analysis indicates that gene mutations may compromise the efficacy of A while they do not interfere with the antitumor activity of T; and (ii) the evaluation of multiple molecular markers including p-53 and proliferation markers as topo II protein levels looks more promising in predicting response to anthracyclines.

A randomized open study to assess the efficacy and tolerability of dihydroartemisinin-piperaquine for the treatment of uncomplicated falciparum malaria in Cambodia

OBJECTIVES

To compare the efficacy and tolerability of dihydroartemisinin-piperaquine (DHA-PQP) with that of a 3-day regimen of mefloquine and artesunate (MAS3) for the treatment of uncomplicated falciparum malaria in Cambodia.

METHOD

Randomized open-label non-inferiority study over 64 days.

RESULTS

Four hundred and sixty-four patients were included in the study. The polymerase chain reaction genotyping-adjusted cure rates on day 63 were 97.5% (95% confidence interval, CI, 93.8-99.3) for DHA-PQP and 97.5% (95% CI, 93.8-99.3) for MAS3, P = 1. There were no serious adverse events, but significantly more episodes of vomiting (P = 0.03), dizziness (P = 0.002), palpitations (P = 0.04), and sleep disorders (P = 0.03) reported in the MAS3 treatment group, consistent with the side-effect profile of mefloquine.

CONCLUSIONS

DHA-PQP was as efficacious as MAS3, but much better tolerated, making it more appropriate for use in a routine programme setting. This highly efficacious, safe and more affordable fixed-dose combination could become the treatment of choice for Plasmodium falciparum malaria in Cambodia.

[The management of stroke in Phnom Penh, Cambodia]

Stroke ranks first among nervous pathologies in Kampuchea. It's a main cause of disability and mortality in our country. We conducted a prospective study including 100 patients hospitalized in the service of general medicine at the Calmette hospital in Phnom Penh. We analyzed the principal risk factors, clinical signs, nature of stroke, complications and markers of the vital and functional prognosis. This work shows the difficulties encountered in the initial care of stroke: delay or absence of hospitalization, cost of complementary examinations to be carried out to determine the nature and the aetiology of stroke and very low level of follow-up to ensure secondary prevention and functional rehabilitation. It can be explained in part by the socioeconomic and cultural level. Research like this one which assesses local needs for stroke prevention, treatment and rehabilitation should be conducted in developing countries to inform the planning and allocation of health care resources in order to reduce the burden of illness associated with stroke. The progressive improvement of the medical structures, and of the socioeconomic and cultural level will facilitate stroke care management.

Cord blood banking: what are the real issues?

More impetus needs to be placed on cord blood donation