Mexiletine therapy for chronic pain: survival analysis identifies factors predicting clinical success

Mexiletine, a sodium channel blocker, treats neuropathic pain but its clinical value has been questioned due to its significant side effects and limited efficacy. We hypothesized that ongoing therapy with mexiletine would have limited patient acceptance, but that an analgesic response to intravenous (IV) lidocaine (a pharmacologically similar drug) would identify patients most likely to choose ongoing therapy with mexiletine. We identified a cohort of 37 patients with neuropathic pain who underwent IV lidocaine infusions at our institution and were subsequently prescribed mexiletine. Time until discontinuation of mexiletine was used as the primary endpoint. Time until discontinuation is a clinically relevant, discrete, objective endpoint gaining acceptance as a metric for assessing clinical performance of drugs with significant side effects and limited efficacy. We used the techniques of survival analysis to determine factors that predicted continued therapy with mexiletine. Median time to discontinuation of mexiletine was only 43 days. A stronger analgesic response to IV lidocaine significantly predicted continued acceptance of mexiletine therapy. Decreasing age and male gender also predicted continued acceptance of mexiletine therapy. Analyzing time to mexiletine discontinuation uncovers important limitations in mexiletine's clinical performance missed by studies with conventional endpoints, such as change in pain score. Despite claims of efficacy, acceptance of mexiletine therapy is poor overall. Test infusions with lidocaine identify patients most likely to continue mexiletine therapy. Further work is needed to confirm these results and evaluate the relative acceptance of mexiletine vs. other treatments of neuropathic pain.

Investigating the long-term influence of adolescent delinquency on drug use initiation

Prior research has found a positive relationship between delinquency and early onset of drug use. However, little is known about the influence of delinquency on drug initiation through mid-adulthood. This paper investigates the long-term relationship between serious adolescent delinquency and the onset of marijuana and cocaine use among an epidemiologically defined community sample of African American males and females followed from first grade through age 42. Using propensity score methods we match individuals on several etiological variables that may explain both delinquency and drug use in an attempt to examine the extent to which there may be a causal link between delinquency and drug use initiation. Through a comparison of survival curves on the unmatched and matched samples of serious delinquents and non-serious delinquents, we find that serious adolescent delinquency has at least some causal influence on drug use initiation that extends into mid-life. We discuss how these results can inform future research and delinquency and drug prevention and intervention initiatives.

CURRENT STATUS DATA WITH COMPETING RISKS: LIMITING DISTRIBUTION OF THE MLE

We study nonparametric estimation for current status data with competing risks. Our main interest is in the nonparametric maximum likelihood estimator (MLE), and for comparison we also consider a simpler 'naive estimator'. Groeneboom, Maathuis and Wellner [8] proved that both types of estimators converge globally and locally at rate n(1/3). We use these results to derive the local limiting distributions of the estimators. The limiting distribution of the naive estimator is given by the slopes of the convex minorants of correlated Brownian motion processes with parabolic drifts. The limiting distribution of the MLE involves a new self-induced limiting process. Finally, we present a simulation study showing that the MLE is superior to the naive estimator in terms of mean squared error, both for small sample sizes and asymptotically.

Bayesian Weibull tree models for survival analysis of clinico-genomic data

An important goal of research involving gene expression data for outcome prediction is to establish the ability of genomic data to define clinically relevant risk factors. Recent studies have demonstrated that microarray data can successfully cluster patients into low- and high-risk categories. However, the need exists for models which examine how genomic predictors interact with existing clinical factors and provide personalized outcome predictions. We have developed clinico-genomic tree models for survival outcomes which use recursive partitioning to subdivide the current data set into homogeneous subgroups of patients, each with a specific Weibull survival distribution. These trees can provide personalized predictive distributions of the probability of survival for individuals of interest. Our strategy is to fit multiple models; within each model we adopt a prior on the Weibull scale parameter and update this prior via Empirical Bayes whenever the sample is split at a given node. The decision to split is based on a Bayes factor criterion. The resulting trees are weighted according to their relative likelihood values and predictions are made by averaging over models. In a pilot study of survival in advanced stage ovarian cancer we demonstrate that clinical and genomic data are complementary sources of information relevant to survival, and we use the exploratory nature of the trees to identify potential genomic biomarkers worthy of further study.

The relationship between the Dimensions of Change Instrument and retention in therapeutic community treatment: the moderating influence of time in treatment

OBJECTIVES

The Dimensions of Change Instrument (DCI) (1) assesses aspects of the therapeutic community treatment process. More positive scores on two of the eight dimensions of treatment process assessed at the beginning of treatment, Clarity and Safety, and Resident Support, Sharing and Enthusiasm predict retention in treatment at 30, 90, 180, and 270 days as well as overall length of stay. This study explored whether these process subscales assessed at different phases predicted retention at the next phase, and of treatment.

METHODS

Five-hundred nineteen individuals, aged 18 to 62, undergoing therapeutic community treatment completed the DCI at baseline, one, three, six, and nine months of the therapeutic community treatment.

RESULTS

DCI scale scores at each stage of treatment predicted dropout in the subsequent period. In the early stages of treatment, higher scores predicted a higher probability of retention in the subsequent stage of treatment. In later stages, lower DCI scores predicted a higher probability of retention.

CONCLUSIONS

We conclude that predictions about retention made using the DCI scale scores are treatment stage dependent--the DCI predicts retention at the next stage but the direction of the scale prediction varies as a function of client tenure in treatment. This suggests that treatment processes that influence clients to remain early in treatment may change their valence for clients more advanced in treatment.

The TandemHeart as a bridge to a long-term axial-flow left ventricular assist device (bridge to bridge)

End-stage heart-failure patients in acute refractory cardiogenic shock with multi-organ dysfunction require aggressive medical therapy that includes inotropic support. Historically, the intra-aortic balloon pump was the last option for patients who were dying of acute cardiogenic shock. Short-term extracorporeal pulsatile or nonpulsatile cardiac assist devices or extracorporeal membrane oxygenation offered further treatment options; however, these therapies required invasive surgical procedures. Patients in this high-risk group had increased mortality rates from major procedures that required cardiopulmonary bypass. We used the TandemHeart, a percutaneously implanted device for short-term cardiac assistance, to lower the risk of death and improve hemodynamic performance and end-organ perfusion before implanting long-term assist devices in selected patients with signs of profound cardiogenic shock. Nine end-stage heart-failure patients (mean age, 37.7 yr) in acute refractory hemodynamic decompensation received a percutaneously implanted TandemHeart pump as a bridge to an implantable axial-flow pump. To determine the relative risk for these patients, prognostic scores were calculated before and after insertion of the TandemHeart. Percutaneous support times ranged from 1 to 22 days (mean, 5.9 d). The mean cardiac index before support, 1.02 L/(min.m2) (range, 0.0-1.8 L/[min.m2]) (0.0 L/[min.m2] implies active cardiopulmonary resuscitation), improved to 2.97 L/(min.m2) (range, 2.2-4.0 L/[min.m2]) during support. Three patients underwent successful cardiac transplantation; 5 are currently supported by axial-flow pumps; and 1 died of complications unrelated to the axial-flow pump, after 587 days. End-organ function and overall condition improved uniformly in our patients, thus decreasing the preoperative risk factors for implantation of the long-term device.

SEMIPARAMETRIC TRANSFORMATION MODELS WITH RANDOM EFFECTS FOR CLUSTERED FAILURE TIME DATA

We propose a general class of semiparametric transformation models with random effects to formulate the effects of possibly time-dependent covariates on clustered or correlated failure times. This class encompasses all commonly used transformation models, including proportional hazards and proportional odds models, and it accommodates a variety of random-effects distributions, particularly Gaussian distributions. We show that the nonparametric maximum likelihood estimators of the model parameters are consistent, asymptotically normal and asymptotically efficient. We develop the corresponding likelihood-based inference procedures. Simulation studies demonstrate that the proposed methods perform well in practical situations. An illustration with a well-known diabetic retinopathy study is provided.

The influence of legal coercion on dropout from substance abuse treatment: results from a national survey

Legal coercion is frequently used to leverage substance abuse treatment upon persons who would otherwise not seek it voluntarily. Various methodological and conceptual problems of the existing research have prevented a clear understanding of its effectiveness. The influence of legal coercion on retention in substance abuse treatment was examined using a national survey of programs in the public sector of care and three different treatment modalities including short-term residential (N=756), long-term residential (N=757), and outpatient treatment (N=1181). Legal coercion was found to reduce the risk of dropout across all three treatment modalities. The greatest effect was among persons in short-term residential treatment. The smallest effect was observed in outpatient treatment. This study shows that legal coercion significantly reduces the risk of dropout in substance abuse treatment. However, the differential effects across treatment conditions must be carefully considered when using coercion to involve individuals in treatment.

New use of teflon to reduce bleeding in modified bentall operation

We analyzed the postoperative short- and mid-term outcomes of a series of patients with annuloaortic ectasia who underwent a modified Bentall operation in our clinic from September 2000 through March 2006. The study included 44 patients. Their average age was 53.4 +/- 14.1 years. The underlying disease was degenerative aortic aneurysm in 42 patients (95.5%) and acute aortic dissection in 2 patients (4.5%). Six patients (13.6%) had Marfan phenotype. Aortic insufficiency was moderate in 30 patients (68.2%) and severe in 14 patients (31.8%). In our modification of the Bentall technique, we completed the resection of the aortic root while leaving 5 to 10 mm of native aortic wall tissue to support the anastomosis. A long piece of Teflon felt (width, 0.5-1 cm) was laid on the annulus, and nonpledgeted 2-0 polyester sutures were passed in turn through the Teflon felt, the preserved aortic tissue, and the aortic annulus. A thin piece of Teflon felt was also used in the coronary artery reimplantation sites. Fibrin glue was routinely applied to all anastomoses. There were no intraoperative deaths. One patient died in the hospital after surgery for acute type I aortic dissection. Another patient died 1 year after the operation from prosthetic-valve endocarditis. No patient required surgical correction of excessive postoperative bleeding. Kaplan-Meier curves showed overall survival of 0.94 (95% confidence intervals, 0.9-0.99). We consider our approach an easy, effective way to minimize bleeding from the anastomoses and at the aortic root--a common challenge in aortic surgery.

Model-based estimation of the link between the daily survival probability and a time-varying covariate, application to mosquitofish survival data

The survival probability in a group of individuals may evolve in time due to the influence of a time-varying covariate. In this paper we present a model-based approach allowing the estimation of the functional link between the survival probability and a time-varying covariate when data are grouped and time-period censored. The approach is based on an underlying model consisting in non-stationary Markov processes and describing the survival of individuals. The underlying model is aggregated in time and at the group level to handle the group structure of data and the censoring. The aggregation yields a generalized non-linear mixed model. Then, a Bayesian procedure allows the estimation of the model parameters and the description of the link between the survival probability and the time-varying covariate. This approach is applied in order to explore the relationship between the daily survival probability of mosquitofish (Gambusia holbrooki) and their time-varying lengths (small mosquitofish die with a higher rate than large ones because they are more affected by predation, cannibalism and environmental stress).

Combining clinical and genomic covariates via Cov-TGDR

Clinical covariates such as age, gender, tumor grade, and smoking history have been extensively used in prediction of disease occurrence and progression. On the other hand, genomic biomarkers selected from microarray measurements may provide an alternative, satisfactory way of disease prediction. Recent studies show that better prediction can be achieved by using both clinical and genomic biomarkers. However, due to different characteristics of clinical and genomic measurements, combining those covariates in disease prediction is very challenging. We propose a new regularization method, Covariate-Adjusted Threshold Gradient Directed Regularization (Cov-TGDR), for combining different type of covariates in disease prediction. The proposed approach is capable of simultaneous biomarker selection and predictive model building. It allows different degrees of regularization for different type of covariates. We consider biomedical studies with binary outcomes and right censored survival outcomes as examples. Logistic model and Cox model are assumed, respectively. Analysis of the Breast Cancer data and the Follicular lymphoma data show that the proposed approach can have better prediction performance than using clinical or genomic covariates alone.

Application of artificial neural network-based survival analysis on two breast cancer datasets

This paper applies artificial neural networks (ANNs) to the survival analysis problem. Because ANNs can easily consider variable interactions and create a non-linear prediction model, they offer more flexible prediction of survival time than traditional methods. This study compares ANN results on two different breast cancer datasets, both of which use nuclear morphometric features. The results show that ANNs can successfully predict recurrence probability and separate patients with good (more than five years) and bad (less than five years) prognoses. Results are not as clear when the separation is done within subgroups such as lymph node positive or negative.

Survival analysis of Korean end-stage renal disease patients according to renal replacement therapy in a single center

This study was to investigate clinical characteristics and any differential trends in survival among renal replacement therapy (hemodialysis [HD], peritoneal dialysis [PD], and kidney transplantation [KT]) in Korean end-stage renal disease (ESRD) population. We tried to analyze retrospectively the survival rate adjusted by risk factors and the relative risk stratified by key risk factors among 447 ESRD patients who began dialysis or had a kidney transplant at Ajou University Hospital from 1994 to 2004. In adjusted Cox survival curves, the KT patients had the best survival rate, and the HD patients had better survival than PD patients. The consistent trends in different subgroups stratified by age and diabetes were as following: 1) The risk of death for PD and HD was not proportional over time, 2) The relative risk of PD was similar or lower than that of HD for the first 12 months, but it became higher at later period. The significant predictors for mortality were age (over 55 yr), presence of diabetes, cerebrovascular accident at ESRD onset, and more than one time of hospitalization caused by malnutrition. Further large-scaled, multicenter-based comparative study is needed in Korean ESRD patients and more meticulous attention is required in high-risk patients.

Left ventricular aneurysmal repair within 30 days after acute myocardial infarction: early and mid-term outcomes

For safe resection, left ventricular aneurysmal repair after acute myocardial infarction is usually delayed. However, delaying surgery may not be possible or prudent in some patients who are clinically unstable after acute myocardial infarction. We retrospectively reviewed the early and mid-term outcomes of left ventricular aneurysmal repair in patients who had experienced acute myocardial infarction <30 days before the repair. From September 2001 through May 2006, 127 consecutive post-infarction patients underwent concurrent anteroapical left ventricular aneurysmal repair and coronary artery bypass grafting. In Group I (38 clinically unstable patients), the surgery was performed <30 days after myocardial infarction. In Group II, 89 patients underwent the surgery > or = 30 days after infarction. The mean follow-up period was 26.16 +/- 16.41 months. One Group I patient (2.6%) died in the hospital due to graft-versus-host reaction. Three Group II patients (3.4%) died: 2 of low cardiac output and 1 of multiple-organ failure. Hospital mortality rates were not statistically significant between groups (P=0.582). All patients required similar perioperative inotropic support, intra-aortic balloon pump support, and re-exploration for bleeding or cardiac tamponade. The actuarial survival rates were 94.7% (Group I) and 94.4% (Group II). Postoperative New York Heart Association functional class improved similarly in both groups. We infer that left ventricular aneurysmal repair with coronary revascularization < 30 days after a recent myocardial infarction is a feasible procedure, with acceptable morbidity and mortality rates. Our mid-term results were comparable with those for patients who underwent this surgery > or = 30 days after acute myocardial infarction.

Clinical overview of extrapulmonary small cell carcinoma

The objective of this study was to review the natural history of extrapulmonary small cell carcinoma (EPSCC) with specific emphasis on clinical features, response to treatment and survival. The records of all patients (n=34) with EPSCC treated at Yeungnam University Medical Center and Catholic University of Daegu Medical Center between 1998 and 2005 were retrieved and reviewed. The primary sites of tumor were the esophagus and thymus in 6 patients (17.6%) each, pancreas and stomach in 5 patients each (14.7%); other sites included were the cervix, abdominal lymph nodes, abdominal wall, bladder, colon, maxillary sinus, nasal cavity, ovary, parotid gland and liver. Twenty three patients out of 34 had limited disease. The median survival of all patients was 14 months. Independent prognostic factors included stage and primary tumor location. The prognosis for the patients with extensive disease and in the gastrointestinal group was unfavorable. EPSCC is a non homogeneous disease entity. As a result of its frequent recurrence, multimodal therapy has a better outcome even in cases of limited disease. Combination chemotherapy plays a central role for treatment of extensive disease in EPSCC. Further multicenter studies are now needed to determine more details regarding disease sub-class and optimal treatment modality.

Survival probability in ataxia telangiectasia

Ataxia telangiectasia is a rare, multiorgan neurodegenerative disorder with enhanced vulnerability to cancer and infection. Median survival in two large cohorts of patients with this disease, one prospective and one retrospective, is 25 and 19 years, with a wide range. Life expectancy does not correlate well with severity of neurological impairment.

Prognostic relevance of census-derived individual respondent incomes versus household incomes

BACKGROUND

Census-based measures of income derived from median income of a geographic area are often used in health research. Many national census surveys gather information on both the respondent's individual income and the income for the entire household, giving researchers a choice of census income measures. We compared the extent to which individual respondent income and household income (both obtained from census data) are associated with outcomes in a cohort of patients with cardiac disease.

METHODS

We used data from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH), where postal codes were linked to the Postal Code Conversion File (PCCF) to determine each patient's census Dissemination Areas (DA). DA-derived median household income and median individual income were obtained from the 2001 Canadian Census and survival outcomes were then directly determined for income groupings defined by quintile. Two-year survival adjusted for age and sex was described with a proportional hazards analysis.

RESULTS

There were 9,397 patients undergoing cardiac catheterization between January 1, 2001 and March 31, 2002, with complete DA-level median income measures. Household income quintiles yielded a wider spread of survival across quintiles (range of 2-year estimated survival, 91.8% to 95.9% for household income versus 92.8% to 95.6% for respondent income), as well as a more progressive decline in survival as income decreased. This progressive decline was not seen for the respondent income measure.

CONCLUSIONS

The greater spread and progressive decline of survival for household income relative to respondent income leads us to conclude that household income is the better socio-economic determinant of health in our data and for the outcome measure we studied.

The Timing of Entry Into Fatherhood in Young, At-Risk Men

Timing of first fatherhood was examined in a sample of 206 at-risk, predominantly White men, followed prospectively for 17 years. An event history analysis was used to test a model wherein antisocial behavior, the contextual and familial factors that may contribute to the development of antisocial behavior, and common correlates of such behavior, including academic failure, substance use, and early initiation of sexual behaviors, lead both directly and indirectly to an early transition to fatherhood. Having a mother who was younger at first birth, low family SES, poor academic skills, failure to use condoms, and being in a cohabitating or marital relationship predicted entry into fatherhood. Implications of the findings for prevention of and intervention with early fathering are discussed.

Effect of canopy position on germination and seedling survival of epiphytic bromeliads in a Mexican humid montane forest

BACKGROUND AND AIMS

Seeds of epiphytes must land on branches with suitable substrates and microclimates to germinate and for the resulting seedlings to survive. It is important to understand the fate of seeds and seedlings in order to model populations, but this is often neglected when only established plants are included in analyses.

METHODS

The seeds of five bromeliad species were exposed to different canopy positions in a Mexican montane forest, and germination and early seedling survival were recorded. Additionally, the survival of naturally dispersed seedlings was monitored in a census over 2.5 years. Survival analysis, a procedure rarely used in plant ecology, was used to study the influence of branch characteristics and light on germination and seedling survival in natural and experimental populations.

KEY RESULTS

Experimental germination percentages ranged from 7.2 % in Tillandsia deppeana to 33.7 % in T. juncea, but the seeds of T. multicaulis largely failed to germinate. Twenty months after exposure between 3.5 and 9.4 % of the seedlings were still alive. There was no evidence that canopy position affected the probability of germination, but time to germination was shorter in less exposed canopy positions indicating that higher humidity accelerates germination. More experimental seedlings survived when canopy openness was high, whereas survival in census-seedlings was influenced by moss cover. While mortality decreased steadily with age in juveniles of the atmospheric Tillandsia, in the more mesomorphic Catopsis sessiliflora mortality increased dramatically in the dry season.

CONCLUSIONS

Seedling mortality, rather than the failure to germinate, accounts for the differential distribution of epiphytes within the canopy studied. With few safe sites to germinate and high seedling mortality, changes of local climate may affect epiphyte populations primarily through their seedling stage.

Is herpes zoster a marker for occult or subsequent malignancy?

BACKGROUND

It has been suggested that herpes zoster may be a marker for occult malignancy.

AIM

To examine the emergence of a subsequent cancer diagnosis in patients with and without herpes zoster.

DESIGN OF STUDY

Retrospective cohort study.

SETTING

Results were based on the database of Intego, an ongoing Belgian general practice-based morbidity registry, covering 37 general practitioners and including about 311 000 patient years between the years 1994 and 2000.

METHOD

Survival analysis comparing the emergence of malignancy in patients with and without herpes zoster.

RESULTS

The number of patients below the age of 65 years with herpes zoster, cancer or both was too low to draw any sensible conclusions. Above the age of 65 years we identified a significant increase of cancer emergence in the whole group and in females (hazard ratio = 2.65, 95% confidence interval = 1.43 to 4.90), but not in males. No difference could be identified in the first year after the herpes zoster infection.

CONCLUSION

Our results do not justify extensive testing for cancer in herpes zoster patients. The association we identified, however, leaves open a number of questions with respect to the physiopathology behind it.

Assessing lung cancer risk in railroad workers using a first hitting time regression model

This article examines the application of a first hitting time (FHT) model, using an operational time scale, to assess mortality risk differentials of the work environment. A major case application is presented that applies the model to three job categories of railroad workers. The data set involves a study of more than 50 000 workers with mortality assessed from 1959 to 1996. Lung cancer mortality was assessed because of a suspected link to diesel exhaust exposure. Based on a model that stipulates that death occurs when the disease state of a subject first hits a threshold value, the FHT model provides insights into factors influencing disease progression. In this application, in particular, the findings suggest that a job category in 1959 alters the risk of death from lung cancer.

Transmyocardial laser revascularization as an adjunct to coronary artery bypass grafting: a randomized, multicenter study with 4-year follow-up

We evaluated transmyocardial laser revascularization (TMLR) with coronary artery bypass grafting (CABG) versus CABG alone for severe coronary artery disease involving 21 myocardial region unsuited for CABG. At 4 centers, 44 consecutive patients were randomized for CABG+TMLR (n = 23) or CABG alone (n = 21). Operative and in-hospital mortality and morbidity rates were monitored. Clinical status was evaluated at hospital discharge, 1 year, and 4 years. Success was characterized by relief of angina and freedom from repeat revascularization and death. Preoperatively, 20 patients (47%) were at high risk. The CABG technique, number of grafts, and target vessels were similar in both groups. Patients undergoing CABG+TMLR received 25 +/- 11 laser channels. Their < or = 30-day mortality was 13% (3/23) compared with 28% (6/21) after CABG alone (P = 0.21). There were no significant intergroup differences in the number of intraoperative or in-hospital adverse events. The follow-up period was 50.3 +/- 17.8 months for CABG alone and 48.1 +/- 16.8 months for CABG+TMLR. Both groups had substantially improved angina and functional status at 1 and 4 years, with no significant differences in cumulative 4-year mortality. The incidence of repeat revascularization was 24% after CABG alone versus none after CABG+TMLR (P < 0.05). The 4-year event-free survival rate was 14% versus 39%, respectively (P < 0.064). In conclusion, CABG+TMLR appears safe and poses no additional threat for high-risk patients. Improved overall success and repeat revascularization rates may be due to better perfusion of ischemic areas not amenable to bypass. Further studies are warranted to determine whether these trends are indeed significant.

Neoadjuvant chemotherapy for locally advanced cervix cancer

BACKGROUND

Despite the enrollment of more than 3000 women in randomised trials, the benefits and risks of neoadjuvant chemotherapy in the treatment of locally advanced cervical cancer remained uncertain.

OBJECTIVES

This systematic review and individual patient data (IPD) meta-analysis aimed to assess the effect of neoadjuvant chemotherapy in two comparisons: (1) neoadjuvant chemotherapy followed by radical radiotherapy compared to the same radiotherapy alone; and (2) neoadjuvant chemotherapy followed by surgery compared to radical radiotherapy alone.

SEARCH STRATEGY

Medline and CancerLit searches were supplemented with information from trial registers and by hand searching relevant meeting proceedings and by discussion with relevant trialists and organisations. These searches have been updated regularly until December 2002.

SELECTION CRITERIA

To be included, trials had to be properly randomised and had to include patients with locally advanced cervical cancer who had received neoadjuvant cytotoxic chemotherapy before radiotherapy or surgery or both treatments. Concurrent chemoradiotherapy trials were not included. The comparisons had to be unconfounded by use of additional agents or interventions. Patient enrollment should have started after 1 January 1975 and be completed by September 2000.

DATA COLLECTION AND ANALYSIS

We collected, validated and re-analysed updated trial data on all randomised patients from all relevant trials. Any queries were resolved and the final database entries verified by the responsible trial investigator, data manager or statistician. Two separate sets of analyses (by intention-to-treat) were carried out according to the treatment comparisons (1 and 2) already described. For all outcomes, we obtained overall pooled hazard ratios using the fixed effect model. To explore the potential impact of trial design, we pre-planned analyses that grouped trials by important aspects of their design that might influence the treatment effect. To investigate the effects of neoadjuvant chemotherapy within pre-specified subgroups of patients stratified logrank analyses were done on the primary endpoint of survival.

MAIN RESULTS

In the first comparison, we obtained data from 18 trials and 2074 patients. When all trials were considered together, a high level of statistical heterogeneity suggested that the results could not be combined indiscriminately. A substantial amount of heterogeneity was explained by separate analyses of groups of trials. Trials using chemotherapy cycle lengths shorter than 14 days (HR = 0.83, 95% CI = 0.69 to 1.00, p = 0.046) or cisplatin dose intensities greater than 25 mg/m2 per week (HR = 0.91, 95% CI = 0.78 to 1.05, p = 0.20) tended to show an advantage for neoadjuvant chemotherapy on survival. In contrast, trials using cycle lengths longer than 14 days (HR = 1.25, 95% CI = 1.07 to 1.46, p = 0.005) or cisplatin dose intensities lower than 25 mg/m2 per week (HR = 1.35, 95% CI = 1.11 to 1.14, p = 0.002) tended to show a detrimental effect of neoadjuvant chemotherapy on survival. In the second comparison, data from 5 trials and 872 patients were obtained. The combined results from all trials (HR = 0.65, 95% CI = 0.53 to 0.80, p = 0.0004) indicated a highly significant reduction in the risk of death with neoadjuvant chemotherapy, but there were some differences between trials in their design and results.

REVIEWERS' CONCLUSIONS

Despite some unexplained heterogeneity, the timing and dose intensity of cisplatin-based neoadjuvant chemotherapy appears to have an important impact on whether or not it benefits women with locally advanced cervical cancer and warrants further exploration.

Estimating the efficacy of interventions to prevent mother-to-child transmission of human immunodeficiency virus in breastfeeding populations: comparing statistical methods

Postnatal transmission of human immunodeficiency virus infection through breastfeeding complicates evaluating the efficacy of interventions aimed to reduce mother-to-child transmission risk. Results from trials in Africa evaluating either peripartum antiretroviral therapy or refraining from breastfeeding show an estimated long-term efficacy at 15-24 months of age between 25 and 50 percent. Differences in statistical methods, duration of follow-up, and age at weaning hinder direct comparison between trials. The authors recently outlined theoretically preferred statistical methods for evaluating interventions aimed to reduce risk of mother-to-child transmission of human immunodeficiency virus. When multiple test results and/or supplementary information is available, the more sophisticated methods account for the fact that exact age at infection is unknown, that risk for infection ends at weaning, or that censoring due to death may be informative. The authors apply these methods to four scenarios, using data from four randomized trials carried out in Africa between 1995 and 2000. The authors' findings suggest that, to estimate the cumulative proportion infected at age 6 weeks, a standard Kaplan-Meier approach is likely to give valid results. For estimation of this proportion at age 18 months, more sophisticated methods, such as the extension of the Kaplan-Meier procedure to interval-censored data and competing risks, would be preferred.

Carbonic anhydrase-9 expression levels and prognosis in human breast cancer: association with treatment outcome

Here, we set out to assess CA9 expression levels by real-time quantitative RT-PCR in breast cancer tissue samples obtained from 253 patients, and correlated those with relapse-free (RFS) survival. The median follow-up time was 75 months (range 2-168 months). CA9 expression was mainly found in high-grade, steroid receptor negative cancer tissues. CA9 levels were not significantly associated with RFS (P=0.926, hazard ratio (HR)=0.99, 95% CI=0.80-1.22) in the total cohort of 253 patients. In multivariate analysis with other clinicopathological factors, CA9 (P=0.018, HR=0.77, 95% CI=0.62-0.96), the interaction of adjuvant chemotherapy with CA9 (P=0.009, HR=1.31, 95% CI=1.07-1.61) and the interaction of adjuvant endocrine therapy with CA9 (P<0.001, HR=1.41, 95% CI=1.20-1.66) all contributed significantly to the final model. These results indicate that patients with low CA9 levels benefit more from adjuvant treatment than do patients with high levels. Thus, the determination of CA9 levels could aid in the selection of patients who will not benefit from adjuvant therapy, and whose prognosis will more likely improve with other treatment modalities.

Influence of dietary factors on colorectal cancer survival

BACKGROUND

Diet has been identified as a major determinant of colorectal cancer (CRC) but little is known of its influence on CRC survival.

AIMS

To study the influence of dietary factors on survival in patients who had undergone potentially curative CRC surgery.

PATIENTS

Among 171 patients included in a case control study of CRC aetiological factors, 10 year survival data on 148 patients who underwent resection of the tumour for potential cure were obtained from a Registry of Digestive Tumours.

METHODS

Tertiles of food and nutrient intakes were entered into Cox proportional hazards survival models, controlling for age, sex, tumour stage, and tumour location.

RESULTS

Only five year survival was influenced by the pre-diagnosis diet. High energy intake, as a result of high carbohydrate, protein, and lipid intake, was strongly related to increased survival. Five year relative risk of death for the highest versus the two lowest tertiles of energy intake was 0.18 (95% confidence interval 0.07; 0.44). This effect was similar in both sexes, for the colon and for the rectum. It was stronger in patients with N+/M+ tumours (relative risk 0.06) than in those with less advanced tumours (relative risk 0.37; stage-energy interaction term non-significant). No specific food or nutrient could be identified as having prognostic significance.

CONCLUSIONS

Whether high energy intake selects less severe tumoral clones or modifies antitumoral immunity remains unclear. Larger series need to be investigated before conducting intervention studies but our findings should prompt nutritional follow up in CRC patients.

Investigating leaf lifespans with interval-censored failure time analysis

•  Here leaf lifespans were investigated using interval-censored failure time analysis. The utility of this relatively novel approach is illustrated by comparing the leaf lifespan of winter-deciduous fuchsia (Fuchsia excorticata) and annual-evergreen wineberry (Aristotelia serrata). •  Leaf emergence and mortality were first described using growth equations. Individual leaf lifespans were investigated using a parametric failure-time regression model that accounted for the interval-censored nature of leaf lifespan data. •  Bud burst began 7 d earlier, the rate of leaf emergence was 0.06 leaves per shoot d^-1 faster, and emergence ended 44 d earlier in fuchsia than in wineberry. The rate of leaf mortality was greatest in mid-summer in fuchsia, but nearly constant over the year for wineberry. There was a highly significant effect of the date of leaf emergence on leaf lifespan. Leaves emerging earlier in the growing season had shorter lifespans relative to later emerged leaves in fuchsia, whereas the reverse was true for wineberry. There was no significant effect of shoot height, branch order, or the number leaves of per shoot length on leaf lifespan. •  These results highlight the utility of studying phenology at the individual leaf level using failure time analysis. Although growth equations precisely describe leaf emergence and mortality in wineberry and fuchsia, they obscured key differences between the species that were identified using failure time analysis.

Maximum penalized likelihood estimation in a gamma-frailty model

The shared frailty models allow for unobserved heterogeneity or for statistical dependence between observed survival data. The most commonly used estimation procedure in frailty models is the EM algorithm, but this approach yields a discrete estimator of the distribution and consequently does not allow direct estimation of the hazard function. We show how maximum penalized likelihood estimation can be applied to nonparametric estimation of a continuous hazard function in a shared gamma-frailty model withright-censored and left-truncated data. We examine the problem of obtaining variance estimators for regression coefficients, the frailty parameter and baseline hazard functions. Some simulations for the proposed estimation procedure are presented. A prospective cohort (Paquid) with grouped survival data serves to illustrate the method which was used to analyze the relationship between environmental factors and the risk of dementia.

Reporting of prognostic markers: current problems and development of guidelines for evidence-based practice in the future

Prognostic markers help to stratify patients for treatment by identifying patients with different risks of outcome (e.g. recurrence of disease), and are important tools in the management of cancer and many other diseases. Systematic review and meta-analytical approaches to identifying the most valuable prognostic markers are needed because (sometimes conflicting) evidence relating to markers is often published across a number of studies. To investigate the practicality of this approach, an empirical investigation of a systematic review of tumour markers for neuroblastoma was performed; 260 studies of prognostic markers were identified, which considered 130 different markers. The reporting of these studies was often inadequate, in terms of both statistical analysis and presentation, and there was considerable heterogeneity for many important clinical/statistical factors. These problems restricted both the extraction of data and the meta-analysis of results from the primary studies, limiting feasibility of the evidence-based approach.Guidelines for reporting the results of primary prognostic marker studies in cancer, and other diseases, are given in order to facilitate both the interpretation of individual studies and the undertaking of systematic reviews, meta-analysis and, ultimately, evidence-based practice. General availability of full individual patient data is a necessary step forward and would overcome the majority of problems encountered, including poorly reported summary statistics and variability in cutoff level, outcome assessed and adjustment factors used. It would also limit the problem of reporting bias, although publication bias will remain a concern until studies are prospectively registered. Such changes in practice would help important evidence-based reviews to be conducted in order to establish the most appropriate prognostic markers for clinical use, which should ultimately improve patient care.

The effect of cigarette smoking on musculoskeletal-related disability

BACKGROUND

This study describes cigarette smoking's effect on development of physical disability following initial musculoskeletal-related hospitalization.

METHODS

We followed 15,140 US Army personnel hospitalized for common musculoskeletal disorders between 1989-1996 for up to 8 years (1997) to assess risk for long-term physical disability.

RESULTS

Trends between increased smoking level and long-term disability were identified for persons with knee injuries, rotator cuff injuries, and intervertebral disc displacement. In proportional hazards models, disability was significantly associated with heavy smoking among all subjects (relative hazard (RH) = 1.21). Both heavy smokers (RH = 1.49) and light to moderate smokers (RH = 1.44) were at greater risk for disability following meniscal injuries. Excess fraction due to smoking among subjects with meniscal injuries who currently smoke was 38%.

CONCLUSIONS

Findings suggest an association between smoking and development of disability following meniscal injury. Given the high excess fraction of disability associated with smoking, other studies are needed to confirm this association.

Staging quality is related to the survival of women with endometrial cancer: a Scottish population based study. Deficient surgical staging and omission of adjuvant radiotherapy is associated with poorer survival of women diagnosed with endometrial cancer in Scotland during 1996 and 1997

The association between treatment variation and survival of women with endometrial cancer was investigated. A retrospective cohort based upon the complete Scottish population registered on in-patient and day-case hospital discharge data (Scottish Morbidity Record-1) and cancer registration (Scottish Morbidity Record-6) coded C54 and C55 in ICD10, between 1st January 1996 to 31st December 1997 were analysed. Seven hundred and three patients who underwent surgical treatment out of 781 patients that were diagnosed with endometrial cancer in Scotland during 1996 and 1997. The overall quality of surgical staging was poor. The quality of staging was related to both the year that the surgeon passed the Member of the Royal College of Obstetricians and Gynaecologists examination and also to 'specialist' status but was not related to surgeon caseload. Two clinically important prognostic factors were found to be associated with survival; whether the International Federation of Obstetrics and Gynaecology stage was documented, RHR=2.0 (95% CI=1.3 to 3.1) and also to the use of adjuvant radiotherapy, RHR=2.2 (95% CI=1.5 to 3.5). The associations with survival were strongest in patients with advanced disease, International Federation of Obstetrics and Gynaecology stages 1C through to stage 3. Deficiencies in staging and variations in the use of adjuvant radiotherapy represent a possible source of avoidable mortality in patients with endometrial cancer. Consequently, there should be a greater emphasis on improving the overall quality of surgical staging in endometrial cancer.

Inactivation of O6-methylguanine-DNA methyltransferase by promoter CpG island hypermethylation in gastric cancers

Promoter hypermethylation of CpG islands in tumour suppressor genes can lead to transcriptional inactivation. To investigate the association between methylation and expression at O6-methylguanine-DNA methyltransferase, we performed methylation-specific PCR and immunohistochemistry in 149 gastric carcinomas. Promoter methylation was found in 14.1% of tumours and loss of expression was detected in 11.4% of tumours. To examine correlation between the O6-methylguanine-DNA methyltransferase expression and the clinical data, we investigated O6-methylguanine-DNA methyltransferase expression in 315 consecutive gastric carcinomas. A similar frequency of loss of O6-methylguanine-DNA methyltransferase expression was confirmed in these cases. The loss of O6-methylguanine-DNA methyltransferase expression was significantly associated with pTNM stage (P=0.037), tumour invasion (P=0.02), microsatellite instability (P=0.041) and overall survival (P=0.01). Among 11 gastric cancer cell lines, SNU-620 showed the loss of O6-methylguanine-DNA methyltransferase expression as well as promoter methylation. After treatment with 5-aza-2-deoxycytidine, a demethylating agent, SNU-620 re-expressed O6-methylguanine-DNA methyltransferase mRNA. In summary, we suggest that during gastric carcinogenesis, the loss of O6-methylguanine-DNA methyltransferase expression frequently occurs via the hypermethylation of the CpG islands of the promoter region, and that this is significantly associated with the clinicopathological characteristics.

Human kallikrein gene 5 (KLK5) expression is an indicator of poor prognosis in ovarian cancer

Kallikrein gene 5 (KLK5, also known as KLK-L2), located on chromosome 19q13.4, is one of the newly identified members of the kallikrein gene family, which is a subgroup of the serine protease enzyme family. In normal human tissues, KLK5 is highly expressed in skin, mammary gland and testis. Preliminary RT-PCR analysis has indicated that KLK5 is expressed in a subset of ovarian tumours. We have thus hypothesized that KLK5 may be a new prognostic indicator in ovarian cancer. We have examined the mRNA expression of KLK5 in 142 malignant ovarian tissues. Tumours were pulverized, total RNA was extracted, and cDNA was prepared by reverse transcription. KLK5 was amplified by PCR using gene specific primers, and the identity of the PCR product was verified by sequencing. Ovarian tissues were then classified as KLK5 positive or negative, based on ethidium bromide staining of the PCR product on agarose gels. KLK5 was found to be highly expressed in 58/142 (41%) of ovarian cancer samples while its level of expression was very low in normal ovarian tissues. We found a strong positive relation between KLK5 expression and tumour grade (P = 0.006) and disease stage (P = 0.027). Univariate survival analysis revealed that patients with ovarian tumours positive for KLK5 expression had an increased risk for relapse and death (P = 0.018 and 0.022, respectively). In multivariate analysis, KLK5 expression showed independent prognostic value only in the subset of tumours with lower grade disease (grades I and II). We conclude that KLK5 expression is associated with more aggressive forms of epithelial ovarian carcinoma and has indepdent prognostic value in low grade tumours.

Predictive 5-year survivorship model of cystic fibrosis

The objective of this study was to create a 5-year survivorship model to identify key clinical features of cystic fibrosis. Such a model could help researchers and clinicians to evaluate therapies, improve the design of prospective studies, monitor practice patterns, counsel individual patients, and determine the best candidates for lung transplantation. The authors used information from the Cystic Fibrosis Foundation Patient Registry (CFFPR), which has collected longitudinal data on approximately 90% of cystic fibrosis patients diagnosed in the United States since 1986. They developed multivariate logistic regression models by using data on 5,820 patients randomly selected from 11,630 in the CFFPR in 1993. Models were tested for goodness of fit and were validated for the remaining 5,810 patients for 1993. The validated 5-year survivorship model included age, forced expiratory volume in 1 second as a percentage of predicted normal, gender, weight-for-age z score, pancreatic sufficiency, diabetes mellitus, Staphylococcus aureus infection, Burkerholderia cepacia infection, and annual number of acute pulmonary exacerbations. The model provides insights into the complex nature of cystic fibrosis and supplies a rigorous tool for clinical practice and research.

IVF births and pregnancies: an exploration of two methods of assessment using life-table analysis

PURPOSE

Our purpose was to explore two methods of expressing the performance of IVF programs.

METHODS

Using life-table methods, hazard and cure rates and a "monthly fecundability rate" were calculated for an Ontario IVF clinic. The rates were evaluated for their meaningfulness as indicators of the clinic's performance.

RESULTS AND CONCLUSIONS

While the hazard rate describes monthly fertility among those who will eventually become pregnant, the fecundability rate describes fertility for all patients who enter the program, making it the more appropriate index for program comparisons. However, from a prospective patient's perspective, both methods are valid indices for summarizing a program's performance.

Relationships between type and longevity in the Holstein breed

The relationship between type traits and longevity was studied in the French Holstein breed using a survival analysis model. In this model, the phenotypic value adjusted for systematic fixed effects, the estimated breeding value, or the residual value (defined as the difference between the adjusted phenotypic value and the estimated breeding value) of the cow for each type trait was included as a risk factor. This was done separately for two subpopulations (registered and nonregistered herds) and with or without adjustment for production traits, i.e., considering true or functional longevity. For both types of herds, udder traits (and above all, udder depth) clearly influenced the length of productive life. There seemed to be a more pronounced voluntary culling on type traits in registered herds. The correction for the within herd-year class of production traits, as a way to approximate functional longevity, increased the importance of udder traits and decreased the weight of capacity traits. The same results were obtained when the phenotypic value of the cow for type was replaced by her estimated breeding value, whereas residuals had little impact. The relationship between longevity and type traits was most often nonlinear, in particular for udder traits, but in this study, no trait with a clear intermediate optimum was found.

Survival of patients transferred to tertiary intensive care from rural community hospitals

BACKGROUND

Accessibility to tertiary intensive care resources differs among hospitals within a rural region. Determining whether accessibility is associated with outcome is important for understanding the role of regionalization when providing critical care to a rural population.

METHODS

In a prospective design, we identified and recorded the mortality ratio, percentage of unanticipated deaths, length of stay in the intensive care unit (ICU), and survival time of 147 patients transferred directly from other hospitals and 178 transferred from the wards within a rural tertiary-care hospital.

RESULTS

The two groups did not differ significantly in the characteristics measured. Differences in access to tertiary critical care in this rural region did not affect survival or length of stay after admission to this tertiary ICU. The odds ratio (1.14; 95% confidence interval 0.72-1.83) for mortality associated with transfer from a rural community hospital was not statistically significant.

CONCLUSIONS

Patients at community hospitals in this area who develop need for tertiary critical care are just as likely to survive as patients who develop ICU needs on the wards of this rural tertiary-care hospital, despite different accessibility to tertiary intensive-care services.

Review of 336 patients with hepatocellular carcinoma at Songklanagarind Hospital

AIM: To determine the clinical presentations, survival and prognostic factors of hepatocellular carcinoma (HCC) in Southern Thailand.

METHODS: Retrospective analysis was performed on the 336 hepatocellular carcinoma patients treated at Songklanagarind hospital between 1 January 1991 and 31 January 1999.

RESULTS: Of these 336 patients, 276 were males and 60 were females. The mean age was 54.4 years. The common symptoms and signs were abdominal pain and hepatomegaly. The most common presentation of tumor was a dominant mass with daughter nodules. Portal vein involvement was found in 50% of total. Extra hepatic metastasis was found in 13%, and the lung was the most common site. There were 65.4% with evidence of cirrhosis and half of them were in Child's class B. HBsAg was positive in 72.6%. Regarding Okuda's tumor staging, 15%, 61% and 24% were stage I, II and III, respectively. Overall median survival was 2.1 months (11.5, 2.6 and 0.7 months for stage I, II and III respectively). Treatments of HCC improved patient survival (5.5 months vs 1.6 months for untreated patients). Most common causes of death were hepatic failure. Using multivariate analysis, the prognostic factors identified were tumor staging, alpha-fetoprotein level above 10000 μg·L^-1, extrahepatic metastasis, portal vein thrombosis and treatment.

CONCLUSION: HCC in Thailand is a fatal disease with poor outcome due to late presentation and high prevalence of liver cirrhosis. Early detection and proper management may improve outcome.

Survival benefit of chemotherapy in metastatic colorectal cancer: a meta-analysis of randomized controlled trials

To estimate the magnitude of benefit of chemotherapy in prolonging survival for patients with metastatic colorectal cancer, a meta-analysis of randomized controlled trial was performed. A systematic search was performed to identify randomized trials comparing chemotherapy with observation or supportive care alone. Trials were assessed for quality of reporting, publication bias and heterogeneity. Relative risks for outcomes from published data were pooled using a random-effects model. Seven trials with 614 patients were included. All trials used fluoropyrimidine-based chemotherapy, through a variety of routes and schedules, including intravenous, intra-portal and hepatic arterial infusion. Compared with the 'no-chemotherapy' arm, chemotherapy significantly reduced 1-year mortality (risk ratio 0.69; 95% confidence interval (CI) 0.60-0.81, P < 0.00001). The mortality at 2 years was not significantly different (risk ratio 0.93; 95% CI 0.87-1.00, P = 0.053). Between-trial comparisons demonstrated benefit with a variety of routes and schedules. Chemotherapy significantly prolongs 1-year survival for patients with metastatic colorectal cancer, and should be offered to those with good performance status.

Prognostic factors of survival of HIV-infected patients with cytomegalovirus disease: Aquitaine Cohort, 1986-1997. Groupe d'Epidémiologie Clinique du SIDA en Aquitaine (GECSA)

OBJECTIVE

To analyse survival of HIV-infected patients who developed cytomegalovirus (CMV) disease and to identify prognostic factors of their survival.

METHODS

Cases of CMV disease diagnosed in the Aquitaine Cohort of HIV-infected patients (n = 4297) during the 1986-1996 period, were reviewed using standardised definitions. Follow-up was extended to December 1997. Cox model was used to determine factors associated with survival after the initial manifestations of CMV disease, considering protease inhibitor (PI) prescription and anti-CMV treatment as time dependent covariates.

RESULTS

253 patients presented a CMV disease of which 221 (87.3%) died (median survival: 7 months). A better prognosis for survival was associated with: PI prescription [relative hazard (RH): 0.26; 95% confidence interval (CI): 0.11-0.59], anti-CMV treatment (RH: 0.37; CI: 0.25-0.54), CD4+ lymphocyte cell count > 50/mm3 (RH: 0.66; CI: 0.47-0.94) and absence of neoplasia (RH: 0.70; CI: 0.52-0.94) whereas the disseminated CMV disease worsened prognosis (RH: 1.83; CI: 1.20-2.80).

CONCLUSION

Antiretroviral treatment including PI, improved short-term prognosis of CMV disease regardless of its clinical manifestations.

Longevity of breeding sows in relation to leg weakness symptoms at six months of age

The objective of this study was to evaluate the influence of leg weakness symptoms measured early in life (at 6 months of age) on the longevity of the sows, i.e. the age at culling due to locomotory problems in a Danish pig herd. One hundred and eighty-seven gilts at 6 months of age were selected according to different leg weakness symptoms and were followed until culling and judged for leg weakness once in every gestation using a scale from 1 (normal) to 4 (severe changes). Age at culling, and the main and secondary reasons for culling were recorded. The influence of leg weakness symptoms on longevity was evaluated by survival analysis. Though only 12% of the gilts showed a stiff locomotion half of the sows had suffered from this and nearly one third had been distinctly lame at some time in their life. Buck-kneed forelegs, upright pasterns, legs turned out, standing under position and swaying hindquarters were associated with stiff locomotion or lameness, whereas weak pasterns on hind legs and splayed digits on forelegs were associated with brisk movement (freedom from locomotor problems). The following leg weakness symptoms at the gilt stage were found to have significant negative effects on longevity: buck-kneed forelegs, swaying hindquarters, and standing under position on hind legs.

Therapeutic Strategies for Localized Prostate Cancer II: Perineal Prostatectomy, X-Rays, Protons, Neutrons, and Combination Brachytherapy

Application of improved imaging, diagnostic, and computer techniques is beginning to have an impact on the management of localized prostate cancer. It is possible to perform a range of surgical and radiation procedures with less morbidity than in the past. The changes in therapy for patients with localized disease derive from better knowledge of anatomy for invasive procedures and optimization of virtual planning for noninvasive methods. Perineal prostatectomy and combinations of beam and seed radiation offer both patient and physician reasonable therapeutic options.

Influence of stage at diagnosis on survival differences for rectal cancer in three European populations

Important differences have recently been highlighted between European countries in the survival of colorectal cancer patients. As data on stage at diagnosis were available for rectal cancers in three European population-based registries (Geneva Switzerland; Côte d'Or, France; Mallorca, Spain), we compared relative survival while assessing the effect of stage in a multiple regression model. We analysed 1005 rectal cancer cases diagnosed between 1982 and 1987 and followed up for at least 5 years. In the Mallorca registry, 16% of the patients were diagnosed in the TNM stage I (versus 21% in the Côte d'Or registry and 29% in the Geneva registry, P < 10(-4)) and the 5-year relative survival rate was lower (35%) than in the other two registries (Côte d'Or 47%, Geneva 48%, P = 0.01). In the multivariate analysis, stage was the only independent prognostic factor, whereas the excess death risk did not vary significantly among registries (compared to Geneva, Côte d'Or relative risk was 1.0, Mallorca relative risk 1.11, 95% confidence interval 0.76-1.32 and 0.85-1.44 respectively). Survival differences between the registries were mainly due to stage at diagnosis. Thus, diagnostic conditions appear to be the main determinant of the survival inequalities found in those three European populations.

p27KIP1 is abnormally expressed in Diffuse Large B-cell Lymphomas and is associated with an adverse clinical outcome

Cell cycle progression is regulated by the combined action of cyclins, cyclin-dependent kinases (CDKs), and CDK-inhibitors (CDKi), which are negative cell cycle regulators. p27KIP1 is a CDKi key in cell cycle regulation, whose degradation is required for G1/S transition. In spite of the absence of p27KIP1 expression in proliferating lymphocytes, some aggressive B-cell lymphomas have been reported to show an anomalous p27KIP1 staining. We analysed p27KIP1 expression in a series of Diffuse Large B-cell Lymphoma (DLBCL), correlating it with the proliferative index and clinical outcome, to characterize the implications of this anomalous staining in lymphomagenesis in greater depth. For the above mentioned purposes, an immunohistochemical technique in paraffin-embedded tissues was employed, using commercially available antibodies, in a series of 133 patients with known clinical outcomes. Statistical analysis was performed in order to ascertain which clinical and molecular variables may influence outcome, in terms of disease-free survival (DFS) and overall survival (OS). The relationships between p27KIP1 and MIB-1 (Ki-67) were also tested. An abnormally high expression of p27KIP1 was found in lymphomas of this type. The overall correlation between p27KIP1 and MIB-1 showed there to be no significant relationship between these two parameters, this differing from observations in reactive lymphoid and other tissues. Analysis of the clinical relevance of these findings showed that a high level of p27KIP1 expression in this type of tumour is an adverse prognostic marker, in both univariate and multivariate analysis. These results show that there is abnormal p27KIP1 expression in DLBCL, with adverse clinical significance, suggesting that this anomalous p27KIP1 protein may be rendered non-functional through interaction with other cell cycle regulator proteins.

Prognostic value of uPA and p53 accumulation measured by quantitative biochemical assays in 1245 primary breast cancer patients: a multicentre study

The purpose of this retrospective multicentre study was to assess the prognostic value of urokinase plasminogen activator (uPA) and p53 levels in a large series of primary breast cancer, using an automatic quantitative luminometric method. Samples of 1245 operable breast tumours were collected from seven French institutions and patients were followed for a median of 75 months. The median uPA and p53 levels assayed in cytosols by means of the immunoluminometric technique (LIA) were 0.31 and 0.20 ng mg(-1) of protein respectively. In univariate analysis, high levels of uPA and p53 were associated with shorter disease-specific survival, disease-free interval, and distant recurrence-free interval. The 5-year survival rates were 95.5% among patients with uPA values below the 20th percentile, and 77.5% in those with values above the 80th percentile. The 5-year survival rates were 91.0% in patients with p53 values below the 20th percentile, and 77.6% in those with values above the 80th percentile. In multivariate analysis, the risk of disease-related death increased with uPA levels after adjustment for tumour size, histological grade, lymph node involvement, and estrogen receptor status. A high level of uPA was also related to a shorter disease-free interval and distant recurrence-free interval. In node-negative patients, a high level of uPA remained strongly related to the three outcomes. When adjusted for other prognostic factors, p53 was no longer significantly related to the outcomes. Given its rapidity and simple application to routinely prepared cytosols, this LIA may be useful for evaluating the prognostic impact of uPA in primary breast cancer, particularly in node-negative patients. According to our results, the prognostic value of p53 accumulation is limited when uPA is included in multivariate analysis.