Employing multiple synchronous outcome samples per subject to improve study efficiency.

BACKGROUND: Accuracy can be improved by taking multiple synchronous samples from each subject in a study to estimate the endpoint of interest if sample values are not highly correlated. If feasible, it is useful to assess the value of this cluster approach when planning studies. Multiple assessments may be the only method to increase power to an acceptable level if the number of subjects is limited. METHODS: The main aim is to estimate the difference in outcome between groups of subjects by taking one or more synchronous primary outcome samples or measurements. A summary statistic from multiple samples per subject will typically have a lower sampling error. The number of subjects can be balanced against the number of synchronous samples to minimize the sampling error, subject to design constraints. This approach can include estimating the optimum number of samples given the cost per subject and the cost per sample. RESULTS: The accuracy improvement achieved by taking multiple samples depends on the intra-class correlation (ICC). The lower the ICC, the greater the benefit that can accrue. If the ICC is high, then a second sample will provide little additional information about the subject's true value. If the ICC is very low, adding a sample can be equivalent to adding an extra subject. Benefits of multiple samples include the ability to reduce the number of subjects in a study and increase both the power and the available alpha. If, for example, the ICC is 35%, adding a second measurement can be equivalent to adding 48% more subjects to a single measurement study. CONCLUSION: A study's design can sometimes be improved by taking multiple synchronous samples. It is useful to evaluate this strategy as an extension of a single sample design. An Excel workbook is provided to allow researchers to explore the most appropriate number of samples to take in a given setting.

Taxane benefit in breast cancer--a role for grade and chromosomal stability.

Chromosomal instability, which is a characteristic of many human cancers, contributes to intratumour heterogeneity and has been functionally implicated in resistance to taxane therapy in tumour models. However, defining the status of tumour chromosomal instability in a given tumour to test this hypothesis remains challenging. Measurements of numerical and structural chromosomal heterogeneity demonstrate that histological grade correlates with chromosomal instability in oestrogen receptor (ER)-positive breast cancer. Using data on adjuvant taxane therapy in women with breast cancer, we propose that patients with low-grade ER-positive tumours, which are thought to be chromosomally stable, might derive unexpected benefit from taxane therapy. We discuss the implications of the relationships between tumour grade, chromosomal instability and intratumour heterogeneity, the development of high-throughput methods to define tumour chromosomal instability and the potential use of chromosomal instability to tailor therapy.

Suppression of plasma estrogen levels by letrozole and anastrozole is related to body mass index in patients with breast cancer.

PURPOSE: To investigate whether suppression of plasma estradiol and estrone sulfate levels by the aromatase inhibitors (AIs) anastrozole and letrozole is related to body mass index (BMI) in postmenopausal women with early estrogen receptor (ER) -positive breast cancer. Recent studies have reported that the AI anastrozole has lower effectiveness than tamoxifen in women with high BMI. This effect with high BMI might hypothetically be a result of reduced inhibition of aromatase and suppression of plasma estrogen levels and might be overcome by the use of an increased dose of anastrozole or, alternatively, the use of a more potent AI such as letrozole. PATIENTS AND METHODS: Plasma estradiol and estrone sulfate levels from a highly sensitive radioimmunoassay were available for 44 postmenopausal patients who received anastrozole (1 mg per day) for 3 months followed by letrozole (2.5 mg per day) for 3 months or the opposite sequence. Correlations between the estrogen suppression by each AI and BMI were assessed. RESULTS: Baseline values of estradiol and estrone sulfate were significantly correlated with BMI (r = 0.57; P < .001, and r = 0.38; P = .006, respectively). Levels of estrogen in patients receiving treatment were greater at higher levels of BMI with both AIs, but although this was significant with letrozole (r = 0.35; P = .013, and r = 0.30; P = .035 for estradiol and estrone sulfate, respectively), it was not with anastrozole. Suppression of both estrogen types was greater with letrozole across the full range of BMIs in this study. CONCLUSION: The suppressed levels of plasma estradiol and estrone sulfate in postmenopausal women with early ER-positive breast cancer treated with the AIs anastrozole and letrozole are related to BMI.

Patient selection for oncology phase I trials: a multi-institutional study of prognostic factors.

PURPOSE: The appropriate selection of patients for early clinical trials presents a major challenge. Previous analyses focusing on this problem were limited by small size and by interpractice heterogeneity. This study aims to define prognostic factors to guide risk-benefit assessments by using a large patient database from multiple phase I trials. PATIENTS AND METHODS: Data were collected from 2,182 eligible patients treated in phase I trials between 2005 and 2007 in 14 European institutions. We derived and validated independent prognostic factors for 90-day mortality by using multivariate logistic regression analysis. RESULTS: The 90-day mortality was 16.5% with a drug-related death rate of 0.4%. Trial discontinuation within 3 weeks occurred in 14% of patients primarily because of disease progression. Eight different prognostic variables for 90-day mortality were validated: performance status (PS), albumin, lactate dehydrogenase, alkaline phosphatase, number of metastatic sites, clinical tumor growth rate, lymphocytes, and WBC. Two different models of prognostic scores for 90-day mortality were generated by using these factors, including or excluding PS; both achieved specificities of more than 85% and sensitivities of approximately 50% when using a score cutoff of 5 or higher. These models were not superior to the previously published Royal Marsden Hospital score in their ability to predict 90-day mortality. CONCLUSION: Patient selection using any of these prognostic scores will reduce non-drug-related 90-day mortality among patients enrolled in phase I trials by 50%. However, this can be achieved only by an overall reduction in recruitment to phase I studies of 20%, more than half of whom would in fact have survived beyond 90 days.

Parotid-sparing intensity modulated versus conventional radiotherapy in head and neck cancer (PARSPORT): a phase 3 multicentre randomised controlled trial.

BACKGROUND: Xerostomia is the most common late side-effect of radiotherapy to the head and neck. Compared with conventional radiotherapy, intensity-modulated radiotherapy (IMRT) can reduce irradiation of the parotid glands. We assessed the hypothesis that parotid-sparing IMRT reduces the incidence of severe xerostomia. METHODS: We undertook a randomised controlled trial between Jan 21, 2003, and Dec 7, 2007, that compared conventional radiotherapy (control) with parotid-sparing IMRT. We randomly assigned patients with histologically confirmed pharyngeal squamous-cell carcinoma (T1-4, N0-3, M0) at six UK radiotherapy centres between the two radiotherapy techniques (1:1 ratio). A dose of 60 or 65 Gy was prescribed in 30 daily fractions given Monday to Friday. Treatment was not masked. Randomisation was by computer-generated permuted blocks and was stratified by centre and tumour site. Our primary endpoint was the proportion of patients with grade 2 or worse xerostomia at 12 months, as assessed by the Late Effects of Normal Tissue (LENT SOMA) scale. Analyses were done on an intention-to-treat basis, with all patients who had assessments included. Long-term follow-up of patients is ongoing. This study is registered with the International Standard Randomised Controlled Trial register, number ISRCTN48243537. FINDINGS: 47 patients were assigned to each treatment arm. Median follow-up was 44·0 months (IQR 30·0-59·7). Six patients from each group died before 12 months and seven patients from the conventional radiotherapy and two from the IMRT group were not assessed at 12 months. At 12 months xerostomia side-effects were reported in 73 of 82 alive patients; grade 2 or worse xerostomia at 12 months was significantly lower in the IMRT group than in the conventional radiotherapy group (25 [74%; 95% CI 56-87] of 34 patients given conventional radiotherapy vs 15 [38%; 23-55] of 39 given IMRT, p=0·0027). The only recorded acute adverse event of grade 2 or worse that differed significantly between the treatment groups was fatigue, which was more prevalent in the IMRT group (18 [41%; 99% CI 23-61] of 44 patients given conventional radiotherapy vs 35 [74%; 55-89] of 47 given IMRT, p=0·0015). At 24 months, grade 2 or worse xerostomia was significantly less common with IMRT than with conventional radiotherapy (20 [83%; 95% CI 63-95] of 24 patients given conventional radiotherapy vs nine [29%; 14-48] of 31 given IMRT; p<0·0001). At 12 and 24 months, significant benefits were seen in recovery of saliva secretion with IMRT compared with conventional radiotherapy, as were clinically significant improvements in dry-mouth-specific and global quality of life scores. At 24 months, no significant differences were seen between randomised groups in non-xerostomia late toxicities, locoregional control, or overall survival. INTERPRETATION: Sparing the parotid glands with IMRT significantly reduces the incidence of xerostomia and leads to recovery of saliva secretion and improvements in associated quality of life, and thus strongly supports a role for IMRT in squamous-cell carcinoma of the head and neck. FUNDING: Cancer Research UK (CRUK/03/005).

Letrozole suppresses plasma estradiol and estrone sulphate more completely than anastrozole in postmenopausal women with breast cancer.

PURPOSE: To compare the effects of anastrozole and letrozole on plasma estradiol (E2) and estrone sulfate (E1S) levels. PATIENTS AND METHODS: Fifty-four postmenopausal women with estrogen receptor-positive breast cancer receiving aromatase inhibitors (AIs) as part of their adjuvant therapy were randomly assigned to receive either 3 months of anastrozole (1 mg) followed by 3 months of letrozole (2.5 mg), both given orally once daily, or 3 months of the opposite sequence. Blood was taken at the same time and the same day of the week from each patient, before and after 3 months of each drug, and plasma levels of E2 and E1S were determined using highly sensitive radioimmunoassays. RESULTS: There were 27 patients in each group. The mean age of the patients was 63 years (range, 49 to 83 years). Baseline E2 levels ranged from 3 pmol/L to 91 pmol/L with a mean of 25.7 pmol/L. Only one of 54 (2%) patients had an E2 value >or= 3 pmol/L after receiving letrozole, versus 20 of 54 (37%) patients after receiving anastrozole (P < .001). Extrapolation revealed a mean E2 level after anastrozole treatment of 2.71 pmol/L (range, 2.38 to 3.08 pmol/L). Following letrozole, it was 1.56 pmol/L (range, 1.37 to 1.78 pmol/L). Mean residual E2 was 10.1% for anastrozole and 5.9% for letrozole. Residual E1S levels were 4.6% for anastrozole and 2.0% for letrozole (P = .001). CONCLUSION: Letrozole reduces plasma E2 and E1S levels to a significantly greater extent than anastrozole in postmenopausal women taking AIs as part of their adjuvant therapy for hormone receptor-positive breast cancer.

Anti-alphaGal-dependent complement-mediated cytotoxicity in metastatic melanoma.

Antibodies to the cell surface disaccharide galactose(alpha1,3)galactose (alphaGal) are the most prevalent natural antibodies in human serum. The anti-alphaGal immunoglobulin M-dependent activation of complement causes hyperacute rejection of organ transplants from discordant species by human recipients. It has been shown in vitro that human tumour cells transduced with the gene that synthesizes alphaGal become sensitive to human serum. A prerequisite for anti-alphaGal antibody-based therapeutic strategies is that patients with cancer have adequate serum levels of anti-alphaGal immunoglobulins and complement. The objective of this work was to measure the levels and function of anti-alphaGal immunoglobulins and complement in the serum of patients with metastatic melanoma and healthy volunteers. Serum complement levels were assayed by radial immunodiffusion. Anti-alphaGal immunoglobulin G and immunoglobulin M titres were measured by enzyme-linked immunosorbent assay. Disaccharide sugar blocking was used to investigate antibody specificity. The functional integrity of anti-alphaGal antibodies and complement was investigated in cell lysis assays. It was found that the levels of the complement components C1q, C3 and C4 and the function of the classical complement pathway were normal in metastatic melanoma patients. Anti-alphaGal antibody titres were as variable in metastatic melanoma patients as in healthy controls, and the lysis of alphaGal-expressing cells correlated with anti-alphaGal immunoglobulin M titre (P < 0.0001). Anti-alphaGal antibody titres, complement levels and overall cytolytic function in the serum of patients with metastatic melanoma were indistinguishable from those of healthy controls. There is thus nothing intrinsic to the disease that will limit anti-alphaGal-based therapeutic strategies for enhanced antigen presentation or induced cell lysis, including the mimicry of hyperacute rejection.

Analgesic therapy in postherpetic neuralgia: a quantitative systematic review.

BACKGROUND: Postherpetic neuralgia (PHN) is a complication of acute herpes zoster, which is emerging as a preferred clinical trial model for chronic neuropathic pain. Although there are published meta-analyses of analgesic therapy in PHN, and neuropathic pain in general, the evidence base has been substantially enhanced by the recent publication of several major trials. Therefore, we have conducted a systematic review and meta-analysis for both efficacy and adverse events of analgesic therapy for PHN. METHODS AND FINDINGS: We systematically searched databases (MEDLINE 1966-2004, EMBASE 1988-2004, CINAHL 1982-2002, and PubMed [29 October 2004]) for trials of PHN. We also searched references of retrieved studies and review articles for further trials. We included trials that examined adult patients with PHN of greater duration than 3 mo, that were blinded, randomised, and had at least one measure of pain outcome. Dichotomous pain outcome data were extracted for 50% decrease in baseline pain using a hierarchy of pain/pain-relief measurement tools. Where available, dichotomous data were also collected for adverse events. Calculated estimates of efficacy included relative benefit and number needed to treat. Of 62 studies identified, 35 were randomised controlled trials. Of these, 31 were placebo controlled and suitable for meta-analysis, from which it was possible to extract dichotomous efficacy outcome data from 25. This meta-analysis revealed that there is evidence to support the use of the following orally administered therapies: tricyclic antidepressants, "strong" opioids, gabapentin, tramadol, and pregabalin. Topical therapies associated with efficacy were lidocaine 5% patch and capsaicin. Finally, a single study of spinal intrathecal administration of lidocaine and methyl prednisolone demonstrated efficacy, although this has yet to be replicated. Data suggest that the following therapies are not associated with efficacy in PHN: certain NMDA receptor antagonists (e.g., oral memantine, oral dextromethorphan, intravenous ketamine), codeine, ibuprofen, lorazepam, certain 5HT1 receptor agonists, and acyclovir. Topical administration of benzydamine, diclofenac/diethyl ether, and vincristine (iontophoresis) are similarly not associated with efficacy, nor are intrathecal administration of lidocaine alone or epidural administration of lidocaine and methylprednisolone, intravenous therapy with lidocaine, subcutaneous injection of Cronassial, or acupuncture. However, many of the trials that demonstrated a lack of efficacy represented comparatively low numbers of patient episodes or were single-dose studies, so it may be appropriate to regard such interventions as "not yet adequately tested" rather than demonstrating "no evidence of efficacy." Topical aspirin/diethyl ether has not been adequately tested. CONCLUSION: The evidence base supports the oral use of tricyclic antidepressants, certain opioids, and gabapentinoids in PHN. Topical therapy with lidocaine patches and capsaicin is similarly supported. Intrathecal administration of methylprednisolone appears to be associated with high efficacy, but its safety requires further evaluation.

Widening eligibility to phase II trials: constant arcsine difference phase II trials.

This paper presents a method for undertaking Phase II trials in which not all patients are considered equally likely to respond to treatment. In ovarian cancer, for example, it has been shown that response is less likely in patients who have failed the previous treatment after only a short interval compared to those who have a protracted failure-free interval [Gynecol. Oncol. 36 (1990) 207]. The method is analogous to those used in phase III trials which estimate relative rather than absolute effects; a constant odds ratio, for example, encompasses multiple relationships between response rates. Phase II trials commonly test the null hypothesis H(0): Por=p(1), where the response rate p(1) is the minimum required level of efficacy and p(0) the highest level which would indicate that the treatment is of no further interest. This approach can be extended by using the arcsine transformation to allow p(0) and p(1) to vary between patients, thus for the ith patient p(0i)=(sin c(i))(2) and the efficacy level is set to p(1i)=(sin (c(i)+b))(2). The value of the arcsine parameter b therefore determines efficacy and the test for efficacy in the trial then becomes a test of the null hypothesis H(0): Bor=b. The value of b is determined by considering representative values of p(0) and p(1) and setting b=(sin(-1) radical p(1)-sin(-1) radical p(0)); b is thus the constant arcsine difference (CAD) between p(0i) and p(1i). The variance of B is 1/4n, which is independent of P, trial designs are therefore independent of P, implying that all patients for whom this difference is identical can be entered into the same trial. This paper considers single-stage and two-stage CAD Phase II trials.

A quality-of-life study in high-risk (thickness > = or 2 mm) cutaneous melanoma patients in a randomized trial of 1-cm versus 3-cm surgical excision margins.

A quality-of-life study was carried out to test the hypothesis that melanoma patients treated with a 3-cm margin of excision suffer greater impairment of their quality of life than those treated with a 1-cm margin. The secondary aim was to determine the predictors of a poor patient perception of their excision scar. A postal questionnaire study was carried out using Hospital Anxiety and Depression (HAD), Psychosocial Adjustment of Illness Scale-Self-Report (PAIS-SR), Medical Outcomes Survey-Short Form 36 (MOS-SF36), and the Cassileth Scar questionnaires. Data were collected from 426 of the 537 patients who were mailed the questionnaires (response rate 79%). Fourteen percent had clinically significant anxiety and 5% had significant depression. A poor attitude toward quality of health care was associated with youth. Patients treated with a 3-cm margin excision had significantly poorer mental and physical function 1 mo after surgery, which disappeared within 6 mo. The greater difficulties experienced by the 3-cm margin group were particularly in their domestic, sexual, and social roles. Women, younger patients, those with poor physical and mental function after surgery, and those treated by a 3-cm margin were more likely to report a poorer perception of their scar. The poorer scar perception of patients in the 3-cm group persisted throughout the study period. Use of a 3-cm margin of excision for melanoma is associated with significantly more morbidity than use of a 1-cm margin, but this effect disappears in 6 mo. Patients treated by 3-cm excision were more likely, however, to have a persistent poor view of their scar. Youth and being female were also predictors of poor perception of the scar.

CD38 expression as a prognostic indicator in chronic lymphocytic leukaemia.

Staging systems and laboratory features help predict survival in chronic lymphocytic leukaemia but they do not distinguish patients who will progress from those whose disease will remain indolent. CD38 expression has emerged as an independent prognostic factor, yet there is debate as to what level of CD38 affects prognosis. We plotted the hazard ratios for the treatment-free interval (TFI) between the higher and lower groups defined by CD38 cut-offs from 0 to 100%. The maximum hazard ratio was achieved for a cut-off of 7%. We examined by triple colour analysis the values for CD38 in 289 untreated patients using both >or=30 and >or=7% as thresholds for prognosis. Using a >or=7% threshold (but not >or=30%), we showed a significant correlation with advanced stage and male sex. The interval from diagnosis to first therapy or TFI was longer (median 36 months) in patients with <7% CD38 positive cells than those with >or= 30% (8.7 months) or with intermediate values between 7 and 29% (P<0.00005). The <7% threshold also identified patients in stage A with a long TFI (P=0.0001). Multivariate analysis showed that CD38 has independent prognostic value for TFI in all patients. In 135 patients tested for deletions of p53, 13q14 and 11q23 and for trisomy 12, we showed a correlation between 13q14 deletion and <30%/<7% CD38 positive cells and a tendency for trisomy 12 to be associated with >or=30%/>or=7% CD38 positive cells. We conclude that 7% may be a more useful threshold for disease progression than higher values of CD38.

Epithelial ovarian cancer metastasizing to the brain: a late manifestation of the disease with an increasing incidence.

PURPOSE: We present the Royal Marsden Hospital experience of cerebral metastases from primary epithelial ovarian carcinoma (EOC) over the last 20 years and examine the evidence for an increasing incidence of EOC metastasizing to this site. PATIENTS AND METHODS: A total of 3,690 women with EOC were seen at the Royal Marsden Hospital from 1980 to 2000. Eighteen of these patients developed cerebral metastases. RESULTS: Median age at diagnosis of EOC was 52 years (range, 39 to 67). All patients received at least one line of platinum-based chemotherapy; 56% (10 of 18) received more than one line of treatment; 17% (three of 18), two lines; 11% (two of 18), three lines; and 28% (five of 18), four lines. The median treatment interval between each line of chemotherapy was 12, 18, and 4 months. The median interval between diagnosis and CNS relapse was 46 months (range, 12 to 113), in comparison with 5 and 7.5 months for hematogenous relapse in lung or liver, respectively (P <.001). The incidence of CNS metastases in our population from 1980 to 1984 was 0.2%; from 1985 to 1989, 0%; from 1990 to 1994, 0.3%; and from 1995 to 1999, 1.3% (P <.001). An analysis of data from the literature also suggests that the incidence of cerebral metastases from EOC has increased over time. CONCLUSION: CNS metastases in EOC are a rare and late manifestation of the disease, occurring in patients with a prolonged survival caused by repeated chemosensitive relapses. An analysis of our data and the data from the literature suggests that the incidence of metastasis at this site in patients with EOC is increasing.

Pelvic nerve plexus trauma at radical and simple hysterectomy: a quantitative study of nerve types in the uterine supporting ligaments.

OBJECTIVE: Using neuropeptide and enzyme markers to autonomic nerves, we sought to demonstrate and quantify the nerve types contained within the uterosacral ligaments (USLs) and cardinal ligaments (CLs) that are divided during radical hysterectomy (RH). METHODS: Cross-sectional biopsies were collected from the lateral third of the USL and the CL in 24 women who had an RH for cervical cancer, and from the uterine insertion of these ligaments in 11 women who had a simple hysterectomy for benign disease. We applied indirect immunofluorescence with FITC-conjugated secondary antibodies, using polyclonal primary antibodies to neuropeptide markers that predominate within somatic and autonomic nerves, to show different populations of the following nerve types within the biopsies: neuropeptide Y (NPY) and tyrosine hydroxylase (TH) for sympathetic nerves; vasoactive intestinal polypeptide (VIP) for parasympathetic nerves; substance P (SP) for nociceptive and sensory-motor nerves; and calcitonin gene-related peptide (CGRP) for sensory and sensory-motor nerves. The percentage area of immunoreactivity (PAI), determined by a computer-assisted image analyzer attached to a fluorescent microscope, was used as an objective quantitative measure of nerve density. Confocal microscopy was used to determine the composition and spatial arrangement of nerve fibers in the ligaments. RESULTS: The PAI was greater for all markers tested in both the USL and CL (P <.001) in RH compared with simple hysterectomy biopsies. For RH specimens, the PAI was greater for the sympathetic, sensory, and sensory-motor nerve markers in the USL compared with the CL (P <.01), but the PAI for VIP was similar (P >.05). Conversely, excluding the large trunks and associated ganglia, the free nerve fiber PAI in the CL was greater than that of the USL for all nerve markers (P <.001). The staining of peripheral autonomic ganglia and associated fibers, for NPY and TH, indicates that some sympathetic nerves are preganglionic with their cell bodies within the pelvic plexus. CONCLUSIONS: Significantly more autonomic nerves are transected in the more lateral division of the uterine supporting ligaments during a radical hysterectomy than during a simple hysterectomy. Sympathetic, parasympathetic, sensory, and sensory-motor nerve types are present within the CL and USL. The proportions of each nerve type differ between the two ligaments, and sympathetic nerves in the USL are the single largest nerve type. The uterine supporting ligaments are a major pathway for autonomic nerves to the pelvic organs.