Circulating tumor cells (CTCs) and cytokeratin 19 (CK19) mRNA as prognostic factors in heavily pretreated patients with metastatic breast cancer

INTRODUCTION

Circulating tumor cell (CTC) count and cytokeratin 19 (CK19) mRNA expression have a prognostic value for patients with metastatic breast cancer (MBC), but their clinical utility remains controversial. We studied CTC count and CK19 mRNA expression in the peripheral blood samples from heavily pretreated patients with MBC and their correlations with prognosis and response to the subsequent line of therapy.

METHODS

This prospective observational study included 67 consecutive patients with MBC who were on progression to systemic therapy, and criteria for a new line of systemic treatment were proposed outside a clinical trial. CTC counts and CK19 mRNA expression were measured by the CellSearch^® and RT-PCR methods, respectively, before and after the first cycle of treatment. Progression-free survival (PFS) was defined as the time elapsed between the initiation of the treatment and either the date of clinical or radiological tumor progression or death from any cause or the last follow-up. Cox proportional hazards regression model was used to assess the univariate prognostic value of CTC and CK19 mRNA expression on PFS and Kaplan-Meier estimates. A multivariate Cox model was also used to additionally account for phenotype and visceral disease.

RESULTS

The mean age was 60 (range 35-86) years, and the average number of previous treatments was 3 (range 1-10); 42 patients (62.6%) were ER+ and 38 patients (56.7%) had visceral disease. The median PFS rate was 8 months (95% CI: 3.7-8.2). Univariate analyses showed a significant effect of the initial value of CK19 mRNA expression (HR = 2.00; 95% CI: 1.05-3.8; p = 0.03) and for the second value of CTC (HR = 2.18; 95% CI: 1.22-3.9; p = 0.009) but did not reach statistical significance for the initial value of CTC and the second value of CK19 mRNA expression. The estimated PFS rates at 6 and 12 months were 75% and 31% for patients with a low initial value of CK19 mRNA expression and 36% and 10% for those with a high initial value of CK19 mRNA expression, respectively (p: 0.022). Further, the estimated PFS rates at 6 and 12 months were 86% and 65% for patients with a low second value of CTC and 76% and 47% for those with a high second value of CTC, respectively (p: 0.004). In the multivariate analysis adjusted for phenotype, visceral disease, and the last treatment performed, only the effect of the second value of CTC remained significant (HR = 2.7, p = 0.004).

CONCLUSIONS

CK19 mRNA expression and CTC count appeared clinically meaningful in pretreated patients with MBC, even when adjusted for phenotype and visceral disease involvement. These results support the use of CK19 and CTC as relevant biomarkers for predicting clinical response in MBC.

Efficiency of the incorporation of the hepatitis A vaccine as a combined A+B vaccine to the hepatitis B vaccination programme of preadolescents in schools

In 1998, the Department of Health of Catalonia (Spain) began universal vaccination of preadolescents against hepatitis A by replacing the simple hepatitis B vaccine with a combined hepatitis A+B vaccine. Economic analyses were made of the two alternative strategies: to continue with the simple hepatitis B vaccination or to replace the simple vaccine with a combined hepatitis A+B vaccine. The analysis was made from the societal perspective and the time horizon considered was 25 years. In the base case, (estimated annual hepatitis A incidence of 15 per 100,000 and incremental price of the hepatitis A+B vaccine over the simple hepatitis B vaccine of 1.98) the net present value of the programme was positive (+533,708) and the benefit-cost ratio was 2.58. If the estimated disease incidence were reduced by half, the programme would still be efficient.

Cost-benefit and cost-effectiveness of the incorporation of the pneumococcal 7-valent conjugated vaccine in the routine vaccination schedule of Catalonia (Spain)

The health and economic costs and benefits of vaccinating a cohort of 60,000 children born in Catalonia in the year 2000 with the pneumococcal 7-valent conjugated vaccine were compared with the alternative of not implementing the vaccination programme. The time horizon fixed for the programme was 10 years for invasive disease, 2 years for all episodes of pneumonia and otitis media and 3.5 years for the placement of tympanostomy tubes. In the base case (incidence rate of invasive disease of 160 per 100,000 and price of the vaccine 50 euros) the net present value was negative, both from the societal perspective (-5.1million euros) and from the provider's perspective (-9.2million euros). The benefit-cost ratio was 0.59 euros from the societal perspective. The cost per disability adjusted life year (DALY) gained was 44,307 euros from the societal perspective and 80,291 euros from the provider's perspective.

Acute and Chronic Captopril, but Not Prazosin or Nifedipine, Normalize Alterations in Adrenergic Intracellular Ca2+ Handling Observed in the Mesenteric Arterial Tree of Spontaneously Hypertensive Rats

The effect of hypertension and acute (36-h) or chronic (from age 6 to 16 weeks) antihypertensive treatment with prazosin (2 mg kg(-1) per day), nifedipine (50 mg kg(-1) per day), or captopril (50 mg kg(-1) per day) on Ca2+ mobilization due to alpha1-adrenoceptor activation was analyzed in functional studies using arterial rings [four conductance/distributing vessels: aorta, main mesenteric, iliac, and tail arteries and two resistance vessels; first and second small mesenteric artery branches obtained from spontaneously hypertensive rats (SHR, 6 and 16 weeks old) and age-matched Wistar Kyoto rats (WKY)]. Maximal response to noradrenaline in the presence of extracellular Ca2+ is not affected by hypertension or by the antihypertensive treatment. The extracellular Ca2+-independent contractile responses increased with age in iliac, tail, and small mesenteric arteries (SMA) and were further increased in SHR in SMA from both young and adult animals and in the main mesenteric artery of adult SHR. In main mesenteric artery, this increased contraction in SHR was associated with a higher increase in cytosolic [Ca2+] mobilized by noradrenaline without changes in the total stored Ca2+. Acute or chronic treatment with captopril abolished the differences observed between WKY and SHR in the noradrenaline-induced contraction in mesenteric arteries loaded in Ca2+-free medium. In contrast, animals acutely treated with prazosin or chronically treated with either prazosin or nifedipine exhibit the same differences in Ca2+ handling than untreated rats. In conclusion, these differences are not a consequence of increased blood pressure but precede it and can only be normalized by inhibition of the rennin-angiotensin system.

Functional evidence of a constitutively active population of alpha(1D)-adrenoceptors in rat aorta

After depletion of intracellular calcium stores sensitive to noradrenaline, a spontaneous increase in the resting tone (IRT) when incubated in Ca(2+)-containing solution was observed in isolated rat aorta, but not in tail artery. This IRT does not depend on agonist activation of alpha(1)-adrenoceptors but it is inhibited by prazosin. A close relationship was found between the inhibitory potencies of prazosin (pIC(50) = 9.833), BMY 7378 (pIC(50) = 8.924), and 5-methylurapidil (pIC(50) = 7.883) against IRT and their affinities for cloned alpha(1D)-adrenoceptors. Chloroethylclonidine (100 micromol. l(-1)) did not inhibit the IRT. After depletion of internal calcium stores by noradrenaline in absence of the agonist, loading in Ca(2+)-containing solution also brings about an increase in the inositol phosphate (IP) levels in rat aorta (not seen in tail artery) that is inhibited by prazosin (1 micromol. l(-1)), BMY 7378 (10 micromol. l(-1)), and 5-methylurapidil (10 micromol. l(-1)), thus confirming the results obtained in contractile studies. Chloroethylclonidine (100 micromol. l(-1)) did not inhibit this IP accumulation. The fact that the IRT and the IP accumulation related to it can be selectively inhibited by different alpha(1)-adrenoceptor antagonists suggests the existence of a population of alpha(1D)-adrenoceptors that show constitutive activity in rat aorta, not in tail artery.

Resource costing for multinational neurologic clinical trials: methods and results

We present the results of a multinational resource costing study for a prospective economic evaluation of a new medical technology for treatment of subarachnoid hemorrhage within a clinical trial. The study describes a framework for the collection and analysis of international resource cost data that can contribute to a consistent and accurate intercountry estimation of cost. Of the 15 countries that participated in the clinical trial, we collected cost information in the following seven: Australia, France, Germany, the UK, Italy, Spain, and Sweden. The collection of cost data in these countries was structured through the use of worksheets to provide accurate and efficient cost reporting. We converted total average costs to average variable costs and then aggregated the data to develop study unit costs. When unit costs were unavailable, we developed an index table, based on a market-basket approach, to estimate unit costs. To estimate the cost of a given procedure, the market-basket estimation process required that cost information be available for at least one country. When cost information was unavailable in all countries for a given procedure, we estimated costs using a method based on physician-work and practice-expense resource-based relative value units. Finally, we converted study unit costs to a common currency using purchasing power parity measures. Through this costing exercise we developed a set of unit costs for patient services and per diem hospital services. We conclude by discussing the implications of our costing exercise and suggest guidelines to facilitate more effective multinational costing exercises.