BH3 peptidomimetics potently activate apoptosis and demonstrate single agent efficacy in neuroblastoma.

The major impediment to cure for many malignancies is the development of therapy resistance with resultant tumor progression. Genetic alterations leading to subversion of inherent apoptosis pathways are common themes in therapy resistance. Bcl-2 family proteins play a critical role in regulating mitochondrial apoptosis that governs chemotherapeutic effects, and defective engagement of these pathways contributes to treatment failure. We have studied the efficacy of BH3 peptidomimetics consisting of the minimal death, or BH3, domains of the proapoptotic BH3-only proteins Bid and Bad to induce apoptosis using neuroblastoma (NB) as a model system. We demonstrate that BH3 peptides, modified with an arginine homopolymer for membrane transduction (called r8-BidBH3 and r8-BadBH3, respectively), potently induce apoptosis in NB cells, including those with MYCN amplification. Cell death is caspase 9 dependent, consistent with a requirement for the intrinsic mitochondrial pathway. Substitutions at highly conserved residues within the r8-BidBH3 peptide abolish apoptotic efficacy supporting activity through specific BH domain interactions. Concomitant exposure to r8-BadBH3 and r8-BidBH3 at sublethal monotherapy doses revealed potent synergy consistent with a competitive displacement model, whereby BH3 peptides displace sequestered BH3 proteins to induce cell death. Further, BH3 peptides demonstrate antitumor efficacy in a xenograft model of NB in the absence of additional genotoxic or trophic stressors. These data provide proof of principle that targeted re-engagement of apoptosis pathways may be of therapeutic utility, and BH3-like compounds are attractive lead agents to re-establish therapy-induced apoptosis in refractory malignancies.

Prognostic factors for survival in hepatocellular carcinoma.

Associations between patient characteristics and survival were investigated in 432 patients with hepatocellular carcinoma. Those patients were prospectively studied by the Eastern Cooperative Oncology Group, and each had his or her diagnosis reconfirmed by a pathology review panel. There were 301 North American and 131 South African patients. Sixty-nine % of the North American patients and 82% of the South African patients were male. There were 187 Black patients, 62 of whom were from North America. The study population is unique among hepatocellular carcinoma patients in that eligibility, evaluability, and endpoint definitions were standardized, and patients from both North America and South Africa received similar treatments at a similar time. Factors with the most significant adverse effect on survival are impaired performance status, male sex, older age, and disease symptoms (jaundice and reduced appetite). There is no apparent difference in survival between White and Black patients within North America, but North American patients survived longer than South African patients. Among the different therapies, p.o. 5-fluorouracil was associated with the poorest median survival time (6 wk), and i.v. 5-fluorouracil plus semustine with the best median survival time (24 wk).

Differential expression of pleiotrophin and midkine in advanced neuroblastomas.

Pleiotrophin (PTN) and midkine (MK) are members of a new family of neurotrophic factors whose expression is developmentally regulated. PTN also transforms NIH 3T3 cells, and MK is mitogenic to certain cell lines. Neuroblastomas are tumors derived from neural crest cells, and recent studies have revealed that the biology of these tumors is at least partly regulated by neurotrophic factors and their receptors. To examine the expression of PTN and MK in neuroblastoma, we analyzed their mRNA expression in 72 primary neuroblastomas and 11 neuroblastoma cell lines as well as other tissues and cell lines. PTN is highly expressed in favorable neuroblastomas (stages I, II, and IV-S, n = 44), whereas it is expressed at a significantly lower level in advanced tumors (stages III and IV, n = 28, P = 0.003). PTN is not expressed in either aggressive neuroblastomas with N-myc amplification or in neuroblastoma cell lines. Moreover, the expression pattern of PTN was similar to that of TRK-A, the high affinity receptor for nerve growth factor, in that it is correlated with a favorable prognosis (P < 0.004). In contrast, MK is highly expressed in almost all primary neuroblastomas and cell lines and showed no correlation with disease stage or N-myc amplification. These results suggest that differential expression of PTN and MK may have an important role in regulating growth and differentiation of neuroblastomas.

Identification of a consistent region of allelic loss on 1p32 in meningiomas: correlation with increased morbidity.

Meningioma is a common tumor of the central nervous system. Deletions of the short arm of chromosome 1 (1p) are the second most commonly observed chromosomal abnormality in these tumors. Here, we analyzed tumor and normal DNAs from 157 meningioma patients using PCR-based polymorphic loci. Loss of heterozygosity (LOH) for at least one informative marker on 1p was observed in 54 cases (34%), whereas LOH on 1q occurred in only 9 cases (8%). High-resolution deletion mapping defined a consensus region of deletion flanked distally by D1S2713 and proximally by D1S2134, which spans 1.5 cM within 1p32. LOH in this region has also been observed in several other malignancies, suggesting the presence of a tumor suppressor gene or genes that are important for several types of cancer. Statistical analysis revealed that 1p LOH was associated with chromosome 22 deletions and with abnormalities of the NF2 gene in meningioma. In addition, unlike other clinical and molecular characteristics, only 1p LOH was shown to be significantly associated with recurrence-free survival.

High levels of expression and nuclear localization of interleukin-1 beta converting enzyme (ICE) and CPP32 in favorable human neuroblastomas.

Neuroblastomas frequently show spontaneous regression and differentiation, which may at least partly be regulated by signaling through nerve growth factor and its receptors, TRK-A and p75LNTR. We studied 52 neuroblastic tumors to test whether the cell death-related proteases, interleukin-1 beta converting enzyme (ICE), CPP32, and Ich-1, were involved in the regression of the tumors. High levels of expression of ICE and CPP32 were significantly correlated with a high level of TRK-A expression, single copy of N-myc, younger age, lower stages, and better prognosis. The immunohistochemical studies and Western analyses as well as the terminal dUTP-biotin nick end labeling (TUNEL) method revealed that both ICE and CPP32 were translocated from the cytoplasm into the nuclei in regressing, apoptotic tumor cells. Our results suggest that ICE and CPP32 cysteine proteases may play an important role in regulating the apoptotic process of the favorable neuroblastomas.

Expression of the neurotrophin receptor TrkB is associated with unfavorable outcome in Wilms' tumor.

PURPOSE: Neurotrophins and their receptors regulate the proliferation, differentiation, and death of neuronal cells, and they have been implicated in the pathogenesis and prognosis of neuroblastomas and medulloblastomas. Tyrosine kinase (Trk) receptors also are expressed in extraneural tissues. PATIENTS AND METHODS: To study the role of neurotrophin receptors and ligands in Wilms' tumor (WT), we determined their expression by semiquantitative duplex reverse transcriptase polymerase chain reaction in 39 patients with primary WT. Comparison of mRNA expression levels with clinical variables was performed by use of Cox regression analysis. RESULTS: Children with WT that expressed high levels of full-length TrkB mRNA (TrkBfull) had a significantly greater risk of death than children whose tumors had little or no TrkBfull expression (hazard ratio, 9.7; P =.02). The 5-year relapse-free survival was 100% versus 65% for patients with low versus high tumor expression of TrkBfull (P <.003). Conversely, children with tumors that expressed high mRNA levels of a functionally inactive truncated TrkB receptor (TrkBtrunc) had a greater chance of survival than children with low levels of TrkBtrunc (hazard ratio, 0.08; P =.005). The 5-year relapse-free survival was 95% versus 68% for patients with high versus low levels of TrkBtrunc (P =.01). The hazard ratios for TrkBfull and TrkBtrunc remained significant after they were adjusted for tumor stage (P =.01 and P =.017, respectively). All WTs with high levels of TrkB expression also expressed the brain-derived nerve growth factor ligand. CONCLUSION: Expression of TrkBfull in WT is associated with worse outcome, perhaps because it provides an autocrine survival pathway. Conversely, TrkBtrunc expression is associated with excellent outcome, perhaps as a result of a dominant negative effect.

TrkC expression predicts good clinical outcome in primitive neuroectodermal brain tumors.

PURPOSE: To identify biologic prognostic factors in childhood primitive neuroectodermal tumors (PNET), including medulloblastoma, that accurately define patient groups with sufficiently good prognosis to permit a reduction in treatment intensity. PATIENTS AND METHODS: We determined expression levels of the neurotrophin receptor TrkC mRNA in formalin-fixed tumor samples from 87 well characterized PNET patients using in situ hybridization. Comparison of TrkC mRNA expression levels with clinical and other laboratory variables was performed using univariate and multivariate Cox regression analysis. RESULTS: High TrkC mRNA expression was found to be associated more with higher 5-year cumulative survival rate than was low TrkC mRNA expression (89% v 46%, respectively). When compared with established clinical prognostic factors and laboratory variables of potential prognostic significance, TrkC mRNA expression, by univariate analysis, was found to be the single most powerful predictor of outcome (hazards ratio, 4.81; P <.00005), exceeding all clinical prognostic factors. In multivariate analysis, the hazards ratio remained significant (P <.00005). CONCLUSION: High TrkC mRNA expression in PNET is a powerful independent predictor of favorable clinical outcome. Assessment of TrkC mRNA levels may aid in treatment planning for patients with PNETs and should be incorporated prospectively into PNET clinical trials.

Survival and complications in thalassemia.

The life expectancy of patients with thalassemia major has significantly increased in recent years, as reported by several groups in different countries. However, complications are still frequent and affect the patients' quality of life. In a recent study from the United Kingdom, it was found that 50% of the patients had died before age 35. At that age, 65% of the patients from an Italian long-term study were still alive. Heart disease is responsible for more than half of the deaths. The prevalence of complications in Italian patients born after 1970 includes heart failure in 7%, hypogonadism in 55%, hypothyroidism in 11%, and diabetes in 6%. Similar data were reported in patients from the United States. In the Italian study, lower ferritin levels were associated with a lower probability of experiencing heart failure and with prolonged survival. Osteoporosis and osteopenia are common and affect virtually all patients. Hepatitis C virus antibodies are present in 85% of multitransfused Italian patients, 23% of patients in the United Kingdom, 35% in the United States, 34% in France, and 21% in India. Hepatocellular carcinoma can complicate the course of hepatitis. A survey of Italian centers has identified 23 such cases in patients with a thalassemia syndrome. In conclusion, rates of survival and complication-free survival continue to improve, due to better treatment strategies. New complications are appearing in long-term survivors. Iron overload of the heart remains the main cause of morbidity and mortality.

High-level expression of EPHB6, EFNB2, and EFNB3 is associated with low tumor stage and high TrkA expression in human neuroblastomas.

Neuroblastoma (NB) is a common pediatric tumor of neural crest origin that is biologically and clinically heterogeneous. EPH family receptor tyrosine kinases and ephrin ligands play fundamental roles in neurodevelopmental processes. Recently, we found that NB cell lines expressed several EPHB and EFNB transcripts, which encode EPHB subgroup receptors and ephrin-B subgroup ligands, respectively. To explore the role of EPHB receptors and ephrin-B ligands in the biology of NB, we examined the expression of EPHB and EFNB transcripts in 47 primary NB specimens. Multiple EPHB and EFNB transcripts were expressed in all of the NB tumors examined, suggesting the involvement of these transcripts in modulating the biological behavior of NB. Higher levels of EPHB6, EFNB2, and EFNB3 expression were found in low-stage tumors (stage 1, 2, and 4S) than in advanced-stage tumors (stage 3 and 4; P = 0.0013, P = 0.0048, and P = 0.027, respectively). Expression of TrkA, a well-established prognostic marker of favorable NB, was positively correlated with EPHB6, EFNB2, and EFNB3 expression (P < 0.0001, P = 0.0019, and P = 0.0001, respectively). MYCN-amplified tumors expressed lower levels of EPHB6, EFNB2, EFNB3, and TrkA transcripts compared to nonamplified tumors (P = 0.0006, P = 0.0023, P = 0.0048, and P = 0.0001, respectively). These data suggest that high-level expression of EPHB6, EFNB2, and EFNB3 is associated with favorable NB and that low-level expression of EPHB6, EFNB2, and EFNB3 correlates with aggressive MYCN-amplified NB. Thus, EPHB6, EFNB2, and EFNB3 may have biological relevance in NB. Further investigation on the biology of these genes may help provide insight into the treatment of NB.

Elevated substance P levels in HIV-infected men.

The neuropeptide, substance P, is a potent modulator of neuroimmunoregulation. Substance P and its receptor modulate HIV infection. HIV-seropositive men had significantly higher plasma substance P levels compared with uninfected controls, which were associated with decreased CD16 and CD56 natural killer (NK) cell populations. The changes in plasma substance P levels and decreases in NK subsets did not correlate with CD4 cell levels, but a diurnal pattern was suggested for substance P. The balance between substance P expression and functions of immune cells may be important in the immunopathogenesis of HIV infection.

Design and baseline characteristics for the ACE Inhibitor After Anthracycline (AAA) study of cardiac dysfunction in long-term pediatric cancer survivors.

PURPOSE: The ACE Inhibitor After Anthracycline (AAA) study is a randomized, double-blind, controlled clinical trial comparing enalapril with placebo to determine whether treatment can slow the progression of cardiac decline in patients who screen positive for anthracycline cardiotoxicity. METHODS: The primary outcome measure is the rate of decline, over time, in maximal cardiac index (in liters per minute per meters squared) at peak exercise; the secondary outcome measure is the rate of increase in left ventricular end systolic wall stress (in grams per centimeters squared). Patients >2 years off therapy and <4 years from diagnosis, aged 8 years and older, were eligible if they had received anthracyclines and had at least one cardiac abnormality identified at any time after anthracycline exposure. RESULTS: A total of 135 patients were randomized to enalapril or placebo. Baseline characteristics were similar across treatment groups. CONCLUSIONS: The AAA study will provide important information concerning the efficacy of using angiotensin-converting enzyme inhibitors to offset the effects of late anthracycline cardiotoxicity.

Cranial ultrasound prediction of disabling and nondisabling cerebral palsy at age two in a low birth weight population.

OBJECTIVE: To employ multivariate analytic techniques to assess the association between neonatal cranial ultrasound (US) abnormalities and subsequent cerebral palsy (CP), defined as disabling CP (DCP) or nondisabling CP (NDCP) depending on the level of motor dysfunction. DESIGN: Prospective cohort study. SUBJECTS AND METHODS: The Neonatal Brain Hemorrhage Study enrolled a geographically representative sample of 1105 newborns 501 to 2000 g and obtained follow-up data on 777 (86%) of the 901 survivors at age two. One hundred thirteen children (14.6%) had motor findings severe enough to classify them as having CP. The 61 (7.9%) of these children who were disabled by their motor impairment we classified as having DCP. The remaining 52 (6.7%) who had definite neurologic findings (usually mild spastic diplegia) but without evidence of interference with daily living, we classified as having NDCP. RESULTS: In a multivariate logistic regression model of perinatal and postnatal variables, the following factors were found to be significant risk factors for DCP: parenchymal echodensities/lucencies or ventricular enlargement (PEL/VE) on cranial US (OR = 15.4; 7.6, 31.1), germinal matrix/intraventricular hemorrhage (GM/IVH) (OR = 3.5; 1.7, 6.9) and mechanical ventilation (OR = 2.9; 1.2, 7.1). Fully 93.4% of infants were correctly classified as to presence or absence of DCP on the basis of this model. Birth weight, gestational age, length of hospital stay, gender, race, plurality, presence of labor and Apgar score were not significant independent predictors of DCP. For NDCP, the only risk factor significant in the multivariate model was PEL/VE (OR = 5.3; 2.2, 12.6). CONCLUSIONS: Among perinatal and postnatal factors, cranial US abnormalities are by far the most powerful predictors of disabling CP in low birth weight infants. Although PEL/VE was the strongest predictor, GM/IVH also appeared to independently contribute to the risk of DCP. NDCP in low birth weight infants appears to have a different risk profile than DCP. In particular, it is less closely related to US evidence of perinatal brain injury.

Hidden spears: handlebars as injury hazards to children.

OBJECTIVES: To delineate the mechanism of serious bicycle handlebar-related injuries in children and make recommendations for preventive strategies. METHODS: Prospective cross-sectional surveillance system of seriously injured child bicyclists supplemented by in-depth, on-site crash investigation to delineate specific injury mechanisms. Interdisciplinary analyses involved engineers, clinicians, epidemiologists, and biostatisticians. SETTING: The emergency department and in-patient trauma service of an urban level one pediatric trauma center between October 1995 and September 1997. PARTICIPANTS: Patients under 18 years of age who were treated for serious bicycle-related injuries (Abbreviated Injury Scale scores of 2 or greater). RESULTS: The surveillance system identified two distinct circumstances for serious child bicyclist injury: 1) handlebar-related injuries associated with minor incidents (falls from bicycles) and 2) nonhandlebar-related injuries associated with severe incidents (bicycle-motor vehicle crashes). Crash investigations explored the minor incidents that resulted in serious handlebar-associated injuries. In the typical mechanism, as the child lost control of the bicycle and began to fall, the front wheel rotated into a plane perpendicular to the child's body. The child then landed on the end of the handlebar resulting in serious truncal injuries. CONCLUSIONS: A discordancy exists between the apparently minor circumstances and serious injuries sustained by child bicyclists who impact bicycle handlebars. Recognition of the mechanism of handlebar-related injuries might aid the practitioner in early diagnosis of serious abdominal injuries in child bicyclists. This injury mechanism may be avoided through bicycle redesign that would involve both limiting rotation of the front wheel and modifying the ends of handlebars. An integrated approach involving a surveillance system to identify an injury hazard supplemented by in-depth, on-site crash investigations effectively provided the detailed mechanism of injury needed to develop interventions.

Substance P modulates human immunodeficiency virus replication in human peripheral blood monocyte-derived macrophages.

Substance P (SP), a member of the tachykinin family of neuropeptides, is an important immunomodulator of lymphocyte and monocyte/macrophage function. We have examined the effects of SP on human immunodeficiency virus type 1 (HIV-1) infection of peripheral blood monocyte-derived macrophages (MDMs) in vitro. Human monocytes isolated by Ficoll gradient followed by adherence were maintained in vitro for 10 days and infected with HIV-1. The addition of SP resulted in a 2- to 8-fold-enhanced HIV-1 expression in the MDMs isolated from 7 of 13 healthy donors as determined by reverse transcriptase (RT) activity and p24 protein expression assays, as compared to control cultures incubated with HIV-1 alone. There was no correlation observed, however, between SP-stimulated TNF production and HIV-1 expression in MDMs obtained from a subset of these donors. These effects of SP on HIV-1 expression in MDMs in vitro may have in vivo implications relevant to modulation of monocyte/macrophage functions, to HIV-1 infection of monocytes/macrophages, and to the immunopathogenesis of HIV-1 infection.

Frequency of carriers of chronic (type I) Gaucher disease in Ashkenazi Jews.

In this study we estimate the frequency of carriers of chronic (type I) Gaucher disease among Ashkenazi Jews by examining the glucocerebrosidase activity in leukocytes in a population of 635 blood donors (441 Ashkenazi) and 57 obligatory heterozygotes. Estimation using the defect in the enzyme glucocerebrosidase (beta-glucosidase) in leukocytes is complicated by the existence of considerable overlap between enzyme activity in normals and in heterozygotes. The assay was carried out with a natural substrate labeled with 14C. Discriminant analysis was used to establish an optimal cutoff point between the obligatory heterozygotes and normal (non-Ashkenazi) subjects for the purpose of estimating frequency of carriers. Applied to the Ashkenazi group, the cutoff point identified 3.17% as heterozygotes. Corrected for errors in classification, the carrier rate was estimated as 4.67%. This figure is in good agreement with a carrier rate of 4% estimated from the number of known cases of clinical Gaucher disease ascertained in Israel.

Randomized trial of busulfan vs total body irradiation containing conditioning regimens for children with acute lymphoblastic leukemia: a Pediatric Blood and Marrow Transplant Consortium study.

Conditioning regimens for children with ALL have generally included total body irradiation (TBI), which may result in significant sequelae. The primary aim of this study was to evaluate the outcome for children with ALL undergoing allogeneic stem cell transplant (SCT) with either busulfan (Bu) or TBI regimens. Patients <21 years with ALL undergoing allogeneic SCT were eligible. Conditioning included either Bu or TBI, with etoposide 40 mg/kg and cyclophosphamide 120 mg/kg. Randomization was stratified based upon duration of remission, remission status, and prior cranial irradiation. A total of 43 patients were enrolled; 21 received Bu and 22 TBI. Median patient age was 8 years (0.5-20 years). Remission status included 12 patients in CR1, 25 in CR2, and six in CR3. At a median follow-up of 43 months, event-free survival (EFS) is 45% at 3 years, with 29% EFS in the Bu arm and 58% in the TBI arm (P=0.03). There was no significant difference between Bu and TBI for patients who received stem cells from related donors (36 vs 58%, P=0.3). However, for URD, EFS was 20% for Bu and 57% for TBI (P=0.04). Relapses were similar in both arms. This randomized prospective study suggests that Bu is inferior to TBI for pediatric patients with ALL undergoing allogeneic SCT.

Impact of changes in catheter management on infectious complications among children with central venous catheters.

OBJECTIVES: To characterize and enumerate central venous catheter (CVC)-related complications among children with chronic illnesses, and to reduce the complication rate through changes in CVC management and education. DESIGN: A prospective observational study followed by an educational program and a nonrandomized interventional trial. SETTING: The Children's Hospital of Philadelphia, a tertiary, pediatric facility. PATIENTS: 268 children with Broviac, Hickman, or Infusaport catheters in place during 58,290 catheter days. INTERVENTIONS: Development and implementation of protocols for cleaning insertion site and hub, use of nonocclusive dressings, and manipulation of access; formal staff and parental education about protocols. RESULTS: CVC-related infections fell from 4.58/1,000 catheter-days preintervention to 3.83 postintervention (risk ratio [RR], 0.20; 95% confidence interval [CI95], 0.89-1.622; P = .25); exit-site infections fell from 0.58 to 0.11 (CI95, 1.22-45.64; P = .02); rates among infants on the surgical service fell from 15.46 to 6.67 (RR, 2.31; CI95, 1.10-4.30; P = .02). CONCLUSIONS: Education and changes in management protocols reduced the incidence of exit-site infections among all patients and reduced the overall infectious complication rate among the infants receiving parenteral nutrition on the surgical service. Other interventions are needed to decrease further the infectious complications in these children.

erbB-2 oncoprotein expression in breast carcinoma. Poor prognosis associated with high degree of cytoplasmic positivity using CB-11 antibody.

The relationship between immunohistochemically measured membranous expression of erbB-2 oncoprotein and prognosis in breast cancer is controversial, and the relationship between cytoplasmic positivity and prognosis has been minimally investigated. The clinical course of 300 women with infiltrating breast carcinoma, whose tumors were stained for erbB-2 oncoprotein with CB-11 monoclonal antibody, was followed for 5 to 79 months (median, 41 months). Higher numbers of cancer-related deaths were observed in patients with moderate-to-strong cytoplasmic positivity (15/60, 25%) and strong membranous positivity (9/29, 31%) than in patients with negatively stained tumors (8/53, 15%) or tumors with weaker degrees of cytoplasmic or membranous positivity (rate similar to or less than negative tumors). Relapse-free survival was also significantly shorter in patients with tumors with strong membranous positivity and moderate-to-strong cytoplasmic positivity; much of the latter relationship was due to a high number of patients who had erbB-2-positive tumors and who were never disease free. A significant association between decreased relapse-free survival and moderate-to-strong cytoplasmic (but not membranous) positivity persisted even after correction for other variables associated with poor outcome (histologic grade, tumor size, lymph node involvement, and hormone receptor status). Moderate-to-strong erbB-2 oncoprotein cytoplasmic positivity, measured with CB-11 antibody, is associated with a poor prognosis and seems to have biologic significance.

Proliferation markers in breast carcinoma. Mitotic figure count, S-phase fraction, proliferating cell nuclear antigen, Ki-67 and MIB-1.

Proliferative rate is an important prognostic marker in breast carcinoma. However, the best measurement method has not been established. This study evaluated mitotic figure counts (MFC) as mitoses per 10 high power fields (HPF) and per 1,000 cells, S-phase fraction by flow cytometry, and Ki-67, MIB-1, and proliferating cell nuclear antigen (PCNA) positivity by immunohistochemistry in 135 breast carcinomas. There was strong correlation between the two MFC methods and significant correlation between MIB-1 positivity and all proliferation markers except Ki-67. S-phase fraction showed significant correlation with all proliferation markers except PCNA. Ki-67 positivity correlated only with S-phase fraction, and PCNA positivity only with MIB-1 and mitoses per 10 HPF. High MFC was associated with other prognostic factors: high histologic tumor grade, absence of biochemical and immunohistochemical hormone receptors, and DNA aneuploidy, but not lymph node involvement or tumor size. MIB-1 positivity was also associated with these parameters, except lymph node involvement, tumor size, and DNA aneuploidy. Mitotic figure count and MIB-1 positivity were associated strongly with disease-free survival, up to 46 months. The other proliferation markers were associated with fewer prognostic factors and showed weak or absent association with disease-free survival. The best proliferation markers are mitotic figure counting (either method) or MIB-1 positivity.

Bcl-2 oncoprotein positivity and high MIB-1 (Ki-67) proliferative rate are independent predictive markers for recurrence in prostate carcinoma.

Predicting the clinical behavior of prostate carcinoma can be difficult; one approach is to identify molecular prognostic markers. We evaluated proliferative rate (MIB-1 antibody) and expression of bcl-2, p53, and retinoblastoma (pRB) proteins, which have cell cycle-related functions, in 208 consecutive radical prostatectomy specimens. Values were correlated with histopathologic parameters (Gleason tumor score, tumor amount, capsule invasion, and involvement of surgical margins, seminal vesicles, or lymph nodes) and with recurrence-free survival (4-year median follow-up). A high MIB-1 proliferative rate was associated with all of the measured histopathologic parameters, p53 overexpression with tumor amount, and pRB expression with positive lymph nodes. pRB and p53 expression levels were not associated with differences in recurrence-free survival. A high MIB-1 proliferative rate and bcl-2 positivity were associated with increased recurrence, both considered individually, and also independently and additively when examined together and with the most predictive histopathologic factors (Gleason tumor score and seminal vesicle involvement). MIB-1 proliferative rate and bcl-2 positivity may prove to be useful markers for poor prognosis in prostate carcinoma.