The clinical use of statistical permutation test methodology: a tool for identifying predictive variables of outcome

OBJECTIVES

To identify the predictive variables affecting the outcome after radical surgery for bladder cancer by a newer statistical methodology, i.e. nonparametric combination (NPC).

METHODS

A multicenter study enrolled 1,312 patients who had undergone radical cystectomy for bladder cancer in 11 Italian oncological centers from January 1982 to December 2002. A statistical analysis of their medical history and diagnostic, pathological and postoperative variables was performed using a NPC test. The patients were included in a comprehensive database with medical history and clinical and pathological data. Five-year survival was used as the dependent variable, and p values were corrected for multiplicity using a closed testing procedure. The newer nonparametric approach was used to evaluate the prognostic importance of the variables. All of the analyses were performed using routines developed in MATLAB© and the significance level was set at α = 0.05.

RESULTS

A significant prognostic predictive value (p < 0.01) for tumor clinical staging, hydronephrosis, tumor pathological staging, grading, presence of concomitant carcinoma in situ, regional lymph node involvement, corpora cavernosa invasion, microvascular invasion, lymphatic invasion and prostatic stroma involvement was found.

CONCLUSIONS

The NPC test could handle any type of variable (categorical and quantitative) and take into account the multivariate relation among variables. This newer methodology offers a significant contribution in biomedical studies with several endpoints and is recommended in presence of non-normal data and missing values, as well as solving high-dimensional data and problems relating to small sample sizes.

Results at 48 Months of a Randomized Trial on Maintenance after Early Adjuvant

Introduction and objectives

The role of maintenance regimen following early intravesical chemotherapy after TUR of intermediate risk non-muscle invasive bladder cancer (NMI-BC) is still debated. Only few studies have been published on this topic, rarely dealing with patients receiving an early treatment. The aim of the present study is to evaluate the efficacy of one-year maintenance after a 6-week cycle of early intravesical chemotherapy.

Methods

Between May 2002 and August 2003, 482 patients with intermediate risk NMI-BC after TUR and early intravesical chemotherapy (epirubicin, 80mg/50mL) were randomized between 6-week induction cycle and induction plus maintenance with 10 monthly instillations. A written informed consent was obtained. All patients underwent cytology and cystoscopy 3-monthly for 2 years and 6-monthly thereafter.

Results

Treatment interruption for toxicity was required in 39 patients. Median follow-up was 48 months. Ten patients (2.5%) progressed and 117 patients (29.6%) recurred. The tumor characteristics were equally distributed between the two arms. No statistically significant difference in recurrence free survival (RFS) was detected between the two arms (p=0.43). An advantage in terms of recurrence free rate (RFR) in favor of the maintenance arm was evident only until 18 months after TUR (p=0.03). A trend for a higher benefit from maintenance in primary and multiple tumors was detected.

Conclusions

The risk of tumor recurrence is significantly reduced by one-year maintenance only for 18 months after TUR in comparison with patients receiving a 6-week cycle of early intravesical chemotherapy. The disadvantages of prolonged intravesical chemotherapy should be taken into account.

Preliminary Report of a Multicentric Study on Environmental Risk Factors in Ta-T1 Transitional Cell Carcinoma of the Bladder

OBJECTIVE

The distribution of potential environmental risk factors among patients affected by superficial transitional cell carcinoma of the bladder (TCCB) has been analyzed.

METHODS

Patients affected by superficial TCCB underwent TUR and early intravesical chemotherapy. Detailed data about age, sex, residence, employment, active and passive cigarette smoking, water resource and hair dye use were centralized. Analysis has been conducted on 474 patients affected by Ta-T1 G1-2 TCCB at medium risk for recurrence. Patients with primary single Ta G1-2, Tis or T1G3 tumors were excluded from the present analysis.

RESULTS

Over 80% of the patients lived in urban areas, 22% were employed in industries presumed at risk for bladder cancer, 8% used hair dye and 75% were smokers. Bottled water was the only water resource in 42% of the patients. Employment in industry at risk (p = 0.01) and cigarette smoking (p = 0.04) resulted in being statistically related to tumor multiplicity. Moreover, the period of cigarette smoking was significantly longer in patients with recurrent tumors (p = 0.026). The municipal water supply represented the main water source in never-smokers (p = 0.01) rather than in smokers and in patients harboring T1 rather than Ta tumors (p = 0.03).

CONCLUSIONS

Employment in industry at risk and cigarette smoking resulted in being related to tumor multiplicity. The length of exposure to cigarette smoking was related to the natural history of the tumor. A drinkable water source emerged as a risk factor in absence of cigarette smoking.

cAMP induced modifications of HOX D gene expression in prostate cells allow the identification of a chromosomal area involved in vivo with neuroendocrine differentiation of human advanced prostate cancers

The acquisition of epithelial-neuroendocrine differentiation (ND) is a peculiarity of human advanced, androgen-independent, prostate cancers. The HOX genes are a network of transcription factors controlling embryonal development and playing an important role in crucial adult eukaryotic cell functions. The molecular organization of this 39-gene network is unique in the genome and probably acts by regulating phenotype cell identity. The expression patterns of the HOX gene network in human prostate cell phenotypes, representing different stages of prostate physiology and prostate cancer progression, make it possible to discriminate between different human prostate cell lines and to identify loci and paralogous groups harboring the HOX genes mostly involved in prostate organogenesis and cancerogenesis. Exposure of prostate epithelial phenotypes to cAMP alters the expression of lumbo-sacral HOX D genes located on the chromosomal region 2q31-33 where the cAMP effector genes CREB1, CREB2, and cAMP-GEFII are present. Interestingly, this same chromosomal area harbors: (i) a global cis-regulatory DNA control region able to coordinate the expression of HOX D and contiguous phylogenetically unrelated genes; (ii) a prostate specific ncRNA gene associated with high-risk prostate cancer (PCGEM1); (iii) a series of neurogenic-related genes involved with epithelial-neuronal cell conversion. We report the expression of neurexin 1, Neuro D1, dlx1, and dlx2 in untreated and cAMP treated epithelial prostate cells. The in vivo expression of Neuro D1 in human advanced prostate cancers correlate with the state of tumor differentiation as measured by Gleason score. Thus, we suggest that the chromosomal area 2q 31-33 might be involved in the epithelial-ND characteristic of human advanced prostate cancers.

A preoperative clinical prognostic model for non-metastatic renal cell carcinoma

OBJECTIVE

To develop a model to predict the outcome before surgery for non-metastatic renal cell carcinoma (RCC).

PATIENTS AND METHODS

The records of 660 patients with non-metastatic RCC, operated at three European medical institutes, were reviewed. Univariate and multivariate analyses were used to assess the clinical and pathological variables affecting disease-free survival.

RESULTS

The median (range) follow-up was 42 (2-180) months; the disease recurred in 110 patients (16%). The 2- and 5-year overall survival was 87% and 54%, respectively. Five variables were significant in the univariate analysis, i.e. clinical presentation, clinical and pathological size, tumour grade and stage (P < 0.05). The preoperative variables, e.g. clinical presentation and clinical tumour size, were retained from the multivariate model. A recurrence risk formula (RRF) was constructed from this model, as (1.28 x presentation (asymptomatic = 0; symptomatic = 1) + (0.13 x clinical size)). Using this equation, the 2- and 5-year disease-free survival was 96% and 93% for an RRF of < or = 1.2 and 83% and 68% for an RRF of > 1.2.

CONCLUSION

A formula was developed which, independent of stage, can be used to predict the rate of treatment failure in patients who undergo nephrectomy for non-metastatic RCC. The RRF might be useful for more accurate sub-grouping of good-prognosis patients, and for counselling patients before surgery, their personalized follow-up or adjuvant treatment once available.

[Erectile dysfunction in kidney transplanted patients]

BACKGROUND

Erectile dysfunction (ED) is the inability to achieve and/or maintain an erection for satisfactory sexual performance or intercourse. ED profoundly affects the quality of life. While the effects of dialysis on ED are documented, the benefits of renal transplantation are unknown.

METHODS

This study evaluates the prevalence of ED and the effects of transplantation on ED in kidney transplanted patients. Erectile function was assessed using the self-administered International Index of Erectile Function (IIEF). The domains investigated by IIEF are: (1) erectile function, (2) orgasmic function, (3) sexual desire, (4) intercourse satisfaction, (5) overall satisfaction. At the entry patients underwent clinical examination by urologist and neurologist; blood was collected for biochemical analysis. One-hundred-fifteen (89%) patients filled in the questionnaire.

RESULTS

Fifty-two (45%) patients did not complain about ED, which was reported by sixty-three patients (55%). No clinical and/or biochemical difference was found between patients with and without ED. Hypertension was equally present among patients; administration of beta-blockers was significantly more frequent among patients without ED. ED was already present during dialysis in 40 patients. After transplantation ED disappeared in 8 (20%), ameliorated in 13 (32,5%), worsened in 2 (5%), remained unchanged in 17 (42,5%) and appeared "ex novo" in 27 (43%) patients. ED is significantly correlated (p<0.01) to the age of subjects.

CONCLUSIONS

The data of the present study indicate that: 1) ED is still present in many transplanted men; 2) renal transplantation cures ED in only few cases; 3) ED may appear "ex novo" after transplantation.

Not traditional prognostic factors in human conventional renal carcinoma

The evaluation of know prognostic factors is an essential step of the assessment of the patients affected by primary renal carcinoma. As long as the major biological mechanisms of renal carcinomas remain unknown, it will be impossible to achieve an accurate prognostic judgement. The TNM classification has always been the main source of information. Nevertheless, recently several investigations evaluated the prognostic power of serum and cellular markers. The aim of this study is to identify those markers which show statistical reliability and can be used in the clinical practice. A literature search was performed on MEDLINE to identify potential not traditional prognostic factors for patients with renal cell carcinoma edited from January 1997 through April 2000 using prognosis and clear cell carcinoma and kidney as keywords. We considered also articles cited in references of first selected manuscript. The analysis of serum and cellular prognostic markers does not allow the identification of specific factors, reliable, independent, easy to dose, widely useful and whose informations are repeatable. Currently classical prognostic factors (staging, grading, hystologic type, patient clinical conditions, anaemia, presentation modalities, etc.) represent the only useful elements after surgical time in RCC patients. Among serum prognostic factors, CRP and ferritin play a crucial role. These proteins appear ideal in monitoring the disease over time, due to simple test execution and specimens repeatability. Among RCC molecular markers, proliferation index result promising for their reliability and reproducibility, the easy dosage and high series number tested. Literature data suggest that the ideal marker for renal carcinomas has not been identified yet. However, C-reactive protein, ferritin and the proliferative activity indexes (Ki67 and AgNOR) appear to be, at present, the best prognostic tools. To confirm obtained results and to use biomolecolar markers on a routinary base further studies on wide surgical series will be required. The improvement of technical tool and costs reduction represent also a necessary step toward the identification of efficient prognostic markers in RCC.

Prevalence of silent prostatic adenocarcinoma in 165 patients undergone cystoprostatectomy: a retrospective study

The reported prevalence of prostatic adenocarcinoma (PCa) in adults represents only the <tip of the iceberg>. The present retrospective study was carried out to estimate the prevalence of the silent PCa in 165 subjects (median age: 69 years; range: 40-82) undergone radical cystoprostatectomy for bladder cancer. To this aim, 38 subjects had routinely prostatic sampling by histology (group A), whereas 127 had systematic pathological sampling of the gland (group B). Silent PCa was diagnosed in 17 subjects (9.7%): 1 subject was in the group A (0.7%) and 16 were in the group B (9%). The data suggest that systematic examination of the prostatic specimens should be performed in order to approach the real prevalence of silent PCa in adult population.

Detection of fetal trisomy 18 by short-term culture of maternal peripheral blood

OBJECTIVE

We report the prenatal detection by fluorescence in situ hybridization analysis of a male fetus with trisomy 18.

STUDY DESIGN

Total nucleated cells recovered from 7 mL of maternal peripheral blood by means of double-density gradient centrifugation were cultured for 3 days in a devised medium.

RESULTS

Fetal cells with X- and Y-specific signals were detected in all the established cultures, but the yield and purity were higher in the culture from the 1077 Ficoll layer. Cumulatively, 84 fetal cells were recorded by analysis of 5640 cells. The hematopoietic lineages involved in the production of the fetal cells in culture were not assessed. For the cultures established with the 1119 Ficoll layer, the involvement of progenitors or precursors of the erythroid lineage was assumed because postculture sorting was directed toward cells expressing the erythropoietin receptor.

CONCLUSION

We conclude that culturing total nucleated cells from maternal blood is a new procedure that could prove valuable in the detection of the main fetal aneuploidies affecting pregnant populations.

["Classic" vs autolubricant catheterization for endovesicular chemotherapy. Preliminary experience]

AIM

The aim of this study was to evaluate the frequency of urinary tract infections (UTI) after catheterisation for instillation comparing two systems: the "classic" method and the catheterisation using a new autolubricant device: EasiCath Coloplast.

METHODS

During the period of endovesical chemotherapy (between 4 and 48 weeks), 22 patients (6 females and 18 males) were studied, aged between 53 and 78 years old. We have performed 139 instillations using Nelaton Ch 14 or 12 type catheters lubricated with gel based on lidocaine, neomicyn and fluocinolone ("classic" method). Instead 135 patients have been treated with autolubricant devices according to the manufacturer's instructions. After 48 hours from instillation, a total of 274 catheterisation have been examined using urine tests and urine culture with antibiogram. We administered a 5-point visual analogic score to the patients weighing the post-instillation dysuria.

RESULTS

With "classic" method UTI frequency is 7.19% (10/139). The most common pathogen has been E. coli (7/10). With autolubricant catheters UTI frequency is 2.96 (4/135). Klebsiella, Enterobacter, as well as E. coli (2/4) have been identified as pathogen. All patients with infections have been treated with targeted antibiotics based on the antibiogram.

CONCLUSIONS

We have observed the people with autolubricant catheters left more comfort then those undergoing to the "classic" catheterisation. The frequency of post-catheterisation, dysuria was also reduced. Our data show that the new method is safer and easier to handle then the "classic" one. Moreover, common anaesthetic/antibiotic lubricant have important bacteriostatic effects that reduce the BCG viability.

galectin-1 and galectin-3 expression in human bladder transitional-cell carcinomas

Galectin-1 and galectin-3 are galactoside-binding proteins involved in different steps of tumor progression and potential targets for therapy. We have investigated the expression of these galectins in 38 human bladder transitional-cell carcinomas of different histological grade and clinical stage and in 5 normal urothelium samples. Galectin-1 mRNA levels were highly increased in most high-grade tumors compared with normal bladder or low-grade tumors. Western blot and immuno-histochemical analysis of normal and neoplastic tissues revealed a higher content of galectin-1 in tumors. Galectin-3 mRNA levels were also increased in most tumors compared with normal urothelium, but levels were comparable among tumors of different histological grade.

Characterization of fetal haematopoietic progenitors circulating in maternal blood of seven aneuploid pregnancies

A retrospective study was carried out in order to investigate the phenotype of fetal haematopoietic progenitors circulating in the maternal blood of seven aneuploid pregnancies. Five of the blood samples were taken during pregnancies affected by various fetal aneuploidies, while the other two were collected after therapeutic abortion due to prenatal cytogenetic diagnosis of trisomies 21 and 18. Haematopoietic progenitor cells, isolated by labelling the erythropoietin receptors with the biotinylated ligand before magnetic sorting and/or fibronectin cell adhesion assay, were cultured in a suitable semisolid medium. Single- or dual-colour fluorescence in situ hybridization (FISH) was utilized to identify and enumerate fetal cells amplified in culture. Fetal trisomies were confirmed in the FISH analysis with chromosome-specific probes in all the cases analysed. The fetal purity rate ranged from 16 to 26 per cent. Haematopoietic progenitors of fetal origin were found to include CFU-E, CFU-GEMM, and possibly also M-BFU-E. Interestingly, a more immature progenitor with high self-renewal capacity (CFU-blast cell) isolated by fibronectin sorting was shown to have a relatively high frequency in one case of Down syndrome. In general, the results of this study demonstrate the feasibility of diagnosing the major fetal chromosomopathies by culturing fetal cells taken from maternal blood. Furthermore, our initial data on the sequential sorting for fibronectin and erythropoietin receptors lead us to believe that this approach may broaden the range of fetal haematopoietic progenitors retrievable from the maternal circulation.

Isolation of fetal erythroid cells from maternal blood based on expression of erythropoietin receptors

Fetal nucleated red cells which pass into the maternal circulation during pregnancy are a potential cell source for non-invasive prenatal genetic diagnosis. To sort these rare cells with a high degree of specificity, we focussed our attention on the erythropoietin receptor, a strictly erythroid-specific antigen. We first labelled these receptors with biotin-(sialyl)-erythropoietin, then isolated the erythroid cells by magnetic beads conjugated with streptavidin in a MiniMACS (magnetic cell separator). The effectiveness of this strategy for the enrichment of fetal cells was evaluated by assessing its accuracy for gender prediction in 18 male-bearing pregnancies. Polymerase chain reaction (PCR) results on maternal blood samples sorted for Epo-r and CD71 antigens displayed similar sensitivity (55% Epo-r, 61% CD71) in detecting Y-specific sequences while immunocytochemical studies on four maternal blood samples, sorted after increasing the binding time of the ligand to Epo-r (8 h), showed a substantial improvement in fetal cell recovery and purity. We conclude that sorting by Epo-r/biotin-(sialyl)-erythropoietin provides effective enrichment of fetal nucleated red cells allowing the possibility of direct prenatal cytogenetic analysis by multiprobe fluorescent in-situ hybridization (FISH).

Culture of fetal erythroid progenitor cells from maternal blood for non-invasive prenatal genetic diagnosis

Fetal committed erythroid progenitors CFU-E and M-BFU-E released into the maternal circulation during pregnancy are ideal candidates for in vitro proliferation since their lifespan is short and they can form colonies of 100-1000 cells in a semi-solid medium. In order to propagate these cells with a high rate of purity, a strategy was devised based on their prior enrichment with biotin-labelled human erythropoietin ligand and magnetic sorting before culturing in a suitable medium. Eight euploid pregnancies investigated in order to address this issue produced fetal clones in cultures with 18 per cent purity as assessed by polymerase chain reaction (PCR) analysis for Y-specific sequences, immunocytochemical staining for fetal gamma-globin, and fluorescence in situ hybridization (FISH) study. The CFU-E-type colony was the most represented progenitor, followed by M-BFU-E, and only occasionally was the detection of CFU-GEMM recorded. The retrospective diagnosis of two cases of fetal Down's syndrome by culturing fetal cells from maternal blood was accomplished for the first time. FISH analysis disclosed a strong presence of fetal trisomic cells (70 per cent and 40 per cent in the two cases). This strong presence would suggest a preferential leakage into maternal blood. The overall results of this study demonstrate that fetal cells can be cultured in vitro with reliable reproducibility, thus making the prospect of a non-invasive prenatal genetic diagnosis realistic.

[Cytogenic characterization of chromosome markers detected at amniocentesis: implications for karyotype-phenotype correlations]

The detection of marker chromosomes at prenatal diagnosis raises serious concerns regarding the phenotypic consequences on the fetus. Traditionally the classical approach to the problem relied upon the cytogenetic analysis of the marker chromosome by different banding techniques to ascertain its euchromatic content. This indirect methodology doesn't allow to trace the origin of the marker and to properly narrow the molecular boundaries of the euchromatic region. FISH technology by means of DNA probes regionally localized is a powerful tool to address these issues, allowing to determine the exact origin of the markers and more refined criteria for studying karyotype-phenotype correlations. This facilitates genetic counseling and the decision making for the parents. Here we describe our experience of integrated approach (molecular and classical cytogenetics) in two de novo cases of marker chromosomes (iso 18p and inv dup 15), detected at amniocentesis.

Maternal serum screening of fetal chromosomal abnormalities by AFP, UE3, hCG and free-beta hCG. Prospective and retrospective results

We have conducted a prospective study to ascertain the reliability of the triple test in detecting aneuploid fetuses in a Mediterranean, pregnant population. 2978 singleton pregnancies in the 15-22 completed week's gestational range were enrolled in this study between January 1992 and June 1994. The measurements of the analytes AFP, hCG and UE3 in the maternal serum combined with maternal age in a multivariate risk approach were utilized to detect pregnancies at increased risk (cut of > or = 1:270) to undergo prenatal diagnosis by amniocentesis. This screening was preferentially reserved to young patients (median age of the population 29 years). 212 pregnancies resulted screen positive to triple test and 178 accepted fetal chromosomal analysis. Three Down's syndrome, a Turner 45XO and a triploidy 69XXY were detected in the sample undergoing prenatal diagnosis. One aneuploid pregnancy (Down's syndrome) was recorded in the population with negative result (risk < 1:270). As part of this study we have subsequently compared the sensitivity of the test substituting total hCG with free-beta marker in samples from aneuploid pregnancies (16 cases) and unaffected pregnancies (300 cases). The detection rate for the two combinations was identical (81%) as well as the false positive rate (5.7% versus 5.3%) derived from the normal samples. All together these combined results of our study support the increasing call for triple test in screening programmes and indicate that further data be collected before recommending the replacement of total hCG with free-beta analyte.

[Imaging diagnosis of non-lymph node metastasis of bladder carcinoma]

Assessment of presence of metastatic disease (m.d.) in bladder cancer (b.c.) can represent a main problem as influencing the appropriate therapeutic policy (mostly the indication to radical surgery). Evaluation of the real cost-effectiveness ratio of radiographic and radionuclide diagnostic work-up induced us to retrospectively review historical data about our b.c. patients (pts). From March 1988 to June 1991, 76 not consecutive pts with histologically proven bladder cancer were included in this study. 5 Pts were staged as T1, 25 as T2, 18 as T3a, 23 as T3b, 5 as T4. 2 Pts were graded as G1, 27 as G2, 44 as G3, 3 as Gx. Age varied from 39 to 89 years (average: 62.3). 79 Pts underwent the "basic work-up" (including chest plain film, bone and liver scans) and at least one follow-up control. 266 chest plain films, 22 chest x-ray tomograms, 2 chest CT scans, 27 bone x-ray tomograms, 231 bone scans, 240 liver scans, 17 liver ultrasonographies were totally realized. All pts underwent at least an abdomen-pelvic CT, but related results are not considered in the study. Fine needle aspiration cytologic biopsies were realized in selected cases; also these results are not selectively reported here. Together with cytologic positive results, only progression of m.d. was considered as its definite presence. Conventional x-ray examination (plain film integrated by x-ray tomograms of "suspicious" findings) resulted sufficiently complete and accurate to reveal chest m.d. Concerning skeletal diagnostic survey, only 6 pts (26%) out of 23 pts with "positive" bone scans really resulted affected by m.d.(ABSTRACT TRUNCATED AT 250 WORDS)

[Changes in some plasma parameters in the course of dextran 40]

Changes in certainplasma parameters (Hc, arterial and venous VP, creatinine clearance, potassium, PA and FC) induced by Dextran 40 perfusions (500 ml at 40 drops/min and 250 ml at 20 drops/min) were examined in 50 patients. The expander effect was more intense, though less protracted when the larger quantity was used. A rebound effect 24 hr after the test was also more frequent percentage-wise in this group. Significant changes in Hc were not observed for 24 hr and 96 hr respectively with the higher and the lower dose. The venous district was primarily concerned. There were also increases in blood potassium, FC and max PA, while min PA and blood proteins fell. No relation could be demonstrated between creatinine clearance and diuresis at the end of the test with respect to the amount of Dextran employed. None of these latter modifications was significant. There were no signs of intolerance.