Epidemiology and persistence of rhinovirus in pediatric lung transplantation.

BACKGROUND: Infection with rhinovirus (HRV) occurs following pediatric lung transplantation. Prospective studies documenting frequencies, persistence, and progression of HRV in this at-risk population are lacking. METHODS: In the Clinical Trials in Organ Transplant in Children prospective observational study, we followed 61 lung transplant recipients for 2 years. We quantified molecular subtypes of HRV in serially collected nasopharyngeal (NP) and bronchoalveolar lavage (BAL) samples and correlated them with clinical characteristics. RESULTS: We identified 135 community-acquired respiratory infections (CARV) from 397 BAL and 480 NP samples. We detected 93 HRV events in 42 (68.8%) patients, 22 of which (23.4%) were symptomatic. HRV events were contiguous with different genotypes identified in 23 cases, but symptoms were not preferentially associated with any particular species. Nine (9.7%) HRV events persisted over multiple successive samples for a median of 36 days (range 18-408 days). Three persistent HRV were symptomatic. When we serially measured forced expiratory volume in one second (FEV1) in 23 subjects with events, we did not observe significant decreases in lung function over 12 months post-HRV. CONCLUSION: In conjunction with our previous reports, our prospectively collected data indicate that molecularly heterogeneous HRV infections occur commonly following pediatric lung transplantation, but these infections do not negatively impact clinical outcomes.

Heartland Virus and Hemophagocytic Lymphohistiocytosis in Immunocompromised Patient, Missouri, USA.

Heartland virus is a suspected tickborne pathogen in the United States. We describe a case of hemophagocytic lymphohistiocytosis, then death, in an immunosuppressed elderly man in Missouri, USA, who was infected with Heartland virus.

Detection of Viruses in Clinical Samples by Use of Metagenomic Sequencing and Targeted Sequence Capture.

Metagenomic shotgun sequencing (MSS) is a revolutionary approach to viral diagnostic testing that allows simultaneous detection of a broad range of viruses, detailed taxonomic assignment, and detection of mutations associated with antiviral drug resistance. To enhance sensitivity for virus detection, we previously developed ViroCap, a targeted sequence capture panel designed to enrich nucleic acid from a comprehensive set of eukaryotic viruses prior to sequencing. To demonstrate the utility of MSS with targeted sequence capture for detecting clinically important viruses and characterizing clinically important viral features, we used ViroCap to analyze clinical samples from a diagnostic virology laboratory containing a broad range of medically relevant viruses. From 26 samples, MSS with ViroCap detected all of the expected viruses and 30 additional viruses. Comparing sequencing after capture enrichment with standard MSS, we detected 13 viruses only with capture enrichment and observed a consistent increase in the number and percentage of viral sequence reads as well as the breadth and depth of coverage of the viral genomes. Compared with clinical testing, MSS enhanced taxonomic assignment for 15 viruses, and codons associated with antiviral drug resistance in influenza A virus, herpes simplex virus (HSV), human immunodeficiency virus (HIV), and hepatitis C virus (HCV) could be analyzed. Overall, in clinical samples, MSS with targeted sequence capture provides enhanced virus detection and information of clinical and epidemiologic relevance compared with clinical testing and MSS without targeted sequence capture.

Multicenter Clinical Evaluation of the Luminex Aries Flu A/B & RSV Assay for Pediatric and Adult Respiratory Tract Specimens.

Influenza A and B viruses and respiratory syncytial virus (RSV) are three common viruses implicated in seasonal respiratory tract infections and are a major cause of morbidity and mortality in adults and children worldwide. In recent years, an increasing number of commercial molecular tests have become available to diagnose respiratory viral infections. The Luminex Aries Flu A/B & RSV assay is a fully automated sample-to-answer molecular diagnostic assay for the detection of influenza A, influenza B, and RSV. The clinical performance of the Aries Flu A/B & RSV assay was prospectively evaluated in comparison to that of the Luminex xTAG respiratory viral panel (RVP) at four North American clinical institutions over a 2-year period. Of the 2,479 eligible nasopharyngeal swab specimens included in the prospective study, 2,371 gave concordant results between the assays. One hundred eight specimens generated results that were discordant with those from the xTAG RVP and were further analyzed by bidirectional sequencing. Final clinical sensitivity values of the Aries Flu A/B & RSV assay were 98.1% for influenza A virus, 98.0% for influenza B virus, and 97.7% for RSV. Final clinical specificities for all three pathogens ranged from 98.6% to 99.8%. Due to the low prevalence of influenza B, an additional 40 banked influenza B-positive specimens were tested at the participating clinical laboratories and were all accurately detected by the Aries Flu A/B & RSV assay. This study demonstrates that the Aries Flu A/B & RSV assay is a suitable method for rapid and accurate identification of these causative pathogens in respiratory infections.

Epstein-Barr viral loads do not predict post-transplant lymphoproliferative disorder in pediatric lung transplant recipients: A multicenter prospective cohort study.

Prediction of PTLD after pediatric lung transplant remains difficult. Use of EBV VL in WB has been poorly predictive, while measurement of VL in BAL fluid has been suggested to have enhanced utility. The NIH-sponsored Clinical Trials in Organ Transplantation in Children (CTOTC-03) prospectively obtained serial quantitative measurements of EBV PCR in both WB and BAL fluid after pediatric lung transplantation. Descriptive statistics, contingency analyses, and Kaplan-Meier analyses evaluated possible association between EBV and PTLD. Of 61 patients, 34 (56%) had an EBV+PCR (at least once in WB or BAL). EBV donor (D)+patients more often had a positive PCR (D+/recipient (R)-: 13/18; D+/R+: 14/23) compared to EBV D- patients (6/17). Several D-/R- (5/12) patients developed EBV, but none developed PTLD. All four PTLD patients were D+/R- with EBV+PCR. Neither the time to first EBV+PCR nor the CT for PCR positivity in BAL or WB was statistically different between those with and without PTLD. Having an EBV-seropositive donor was associated with increased risk of EBV+PCR in WB. EBV load in BAL was not predictive of PTLD.

A case for the use of receiver operating characteristic analysis of potential clinical efficacy biomarkers in advanced renal cell carcinoma.

AIM: Assess patient-level utility of suggested pretreatment biomarkers of sunitinib in advanced renal cell carcinoma. PATIENTS & METHODS: Kaplan-Meier analysis of data from a randomized, Phase II study (n = 292) suggested baseline predictive value for circulating soluble Ang-2 and MMP-2 and HIF-1α percentage of tumor expression. Using this dataset, the sensitivity, specificity and area under the curve (AUC) were calculated, using receiver operating characteristic (ROC) curves. RESULTS: Based on a ROC (sensitivity vs 1 - specificity) threshold AUC value of >0.8, neither Ang-2 (0.67) nor MMP-2 (0.65), nor HIF-1α percentage of tumor expression (0.65), performed appropriately from a patient-selection standpoint. CONCLUSION: To properly assess potential biomarkers, sensitivity and specificity characteristics should be obtained by ROC analysis.

Development and Evaluation of an Enterovirus D68 Real-Time Reverse Transcriptase PCR Assay.

We have developed and evaluated a real-time reverse transcriptase PCR (RT-PCR) assay for the detection of human enterovirus D68 (EV-D68) in clinical specimens. This assay was developed in response to the unprecedented 2014 nationwide EV-D68 outbreak in the United States associated with severe respiratory illness. As part of our evaluation of the outbreak, we sequenced and published the genome sequence of the EV-D68 virus circulating in St. Louis, MO. This sequence, along with other GenBank sequences from past EV-D68 occurrences, was used to computationally select a region of EV-D68 appropriate for targeting in a strain-specific RT-PCR assay. The RT-PCR assay amplifies a segment of the VP1 gene, with an analytic limit of detection of 4 copies per reaction, and it was more sensitive than commercially available assays that detect enteroviruses and rhinoviruses without distinguishing between the two, including three multiplex respiratory panels approved for clinical use by the FDA. The assay did not detect any other enteroviruses or rhinoviruses tested and did detect divergent strains of EV-D68, including the first EV-D68 strain (Fermon) identified in California in 1962. This assay should be useful for identifying and studying current and future outbreaks of EV-D68 viruses.

Impact of antibacterials on subsequent resistance and clinical outcomes in adult patients with viral pneumonia: an opportunity for stewardship.

INTRODUCTION: Respiratory viruses are increasingly recognized as significant etiologies of pneumonia among hospitalized patients. Advanced technologies using multiplex molecular assays and polymerase-chain reaction increase the ability to identify viral pathogens and may ultimately impact antibacterial use. METHOD: This was a single-center retrospective cohort study to evaluate the impact of antibacterials in viral pneumonia on clinical outcomes and subsequent multidrug-resistant organism (MDRO) infections/colonization. Patients admitted from March 2013 to November 2014 with positive respiratory viral panels (RVP) and radiographic findings of pneumonia were included. Patients transferred from an outside hospital or not still hospitalized 72 hours after the RVP report date were excluded. Patients were categorized based on exposure to systemic antibacterials: less than 3 days representing short-course therapy and 3 to 10 days being long-course therapy. RESULTS: A total of 174 patients (long-course, n = 67; short-course, n = 28; mixed bacterial-viral infection, n = 79) were included with most being immunocompromised (56.3 %) with active malignancy the primary etiology (69.4 %). Rhinovirus/Enterovirus (23 %), Influenza (19 %), and Parainfluenza (15.5 %) were the viruses most commonly identified. A total of 13 different systemic antibacterials were used as empiric therapy in the 95 patients with pure viral infection for a total of 466 days-of-therapy. Vancomycin (50.7 %), cefepime (40.3 %), azithromycin (40.3 %), meropenem (23.9 %), and linezolid (20.9 %) were most frequently used. In-hospital mortality did not differ between patients with viral pneumonia in the short-course and long-course groups. Subsequent infection/colonization with a MDRO was more frequent in the long-course group compared to the short-course group (53.2 vs 21.1 %; P = 0.027). CONCLUSION: This study found that long-course antibacterial use in the setting of viral pneumonia had no impact on clinical outcomes but increased the incidence of subsequent MDRO infection/colonization.

Multicenter comparison of laboratory performance in cytomegalovirus and Epstein-Barr virus viral load testing using international standards.

BACKGROUND: Infections with cytomegalovirus (CMV) and Epstein-Barr virus (EBV) remain important in solid organ transplantation. Quantitative viral nucleic acid testing is a major advance to patient management. These assays are limited by a lack of standardization, resulting in viral load measurements that differ among clinical laboratories. The variability in viral load measurements makes interpretation of multicenter clinical trials data difficult. This study compares the current practices in CMV and EBV viral load testing at four large transplant centers participating in multicenter Clinical Trials in Organ Transplantation and the Clinical Trials in Organ Transplantation in Children (CTOT and CTOTC). METHODS: Viral load testing was performed on well-defined viral preparations according to standard operating procedures at each site. RESULTS: Among centers, CMV viral load testing was accurate compared to WHO International Standards and within acceptable variation for this testing method. Epstein-Barr virus viral load data were more variable and less accurate despite the use of international standards. CONCLUSIONS: These data suggest that comparison of CMV, but not EBV, viral load measurements at these sites is possible using current assays and control standards. Standardization of these assays is facilitated using the WHO International Standards and will allow comparison of viral load results among transplant centers. Assay standardization must be performed prior to initiation of multicenter trials.

Predictive Accuracy and Densitometric Analysis of Point-of-Care Immunoassay for Adenoviral Conjunctivitis.

Purpose: Accurate diagnosis of adenoviral conjunctivitis (Ad-Cs) is important for timely and appropriate patient management to reduce disease transmission. This study assessed the diagnostic accuracy of a commercially available point-of-care adenovirus immunoassay and determined whether its predictive accuracy is influenced by signal intensities of test result bands. Methods: Point-of-care immunoassay (AdenoPlus) testing and quantitative polymerase chain reaction (qPCR) testing was performed on conjunctival swab samples obtained from eyes of 186 eligible adult participants with presumed infectious conjunctivitis and symptoms of ≤4 days. Masked observers assessed signal intensities of the immunoassay test and control bands using densitometry. Results: Ad-Cs was confirmed by qPCR in 28 of the 56 eyes that tested positive on the AdenoPlus, a 50% positive predictive value (95% confidence interval [CI] = 36.9, 63.1). No adenovirus was detected by qPCR in 128 of 130 eyes that tested negative on AdenoPlus, a 98.5% negative predictive value (CI = 96.3, 100). Sensitivity and specificity were 93% (CI = 84.4, 100) and 82% (CI = 76.0, 88.1), respectively. Viral titers significantly correlated with ratio of test band signal intensities (R2 = 0.32, P = 0.002). Higher positive predictive value was associated with higher densitometry ratios (receiver operating characteristic [ROC] area = 0.71; 95% CI = 0.59, 0.83). Conclusions: Densitometric analyses suggest that the diagnostic accuracy of AdenoPlus is influenced by the signal intensity of the test result bands. Visual comparison of the test band intensities by clinicians could reduce the false positive rate of point-of-care immunoassays and aid in the diagnosis of viral infections. Translational Relevance: Ratiometric densitometry of point-of-care immunoassays could aid clinicians' decision making in diagnosing infectious diseases, including Ad-Cs.

Comparison of the Eragen Multi-Code Respiratory Virus Panel with conventional viral testing and real-time multiplex PCR assays for detection of respiratory viruses.

High-throughput multiplex assays for respiratory viruses are an important step forward in diagnostic virology. We compared one such assay, the PLx Multi-Code Respiratory Virus Panel (PLx-RVP), manufactured by Eragen Biosciences, Inc. (Madison, WI), with conventional virologic testing, consisting of fluorescent-antibody staining plus testing with the R-mix system and fibroblast tube cultures. The test set consisted of 410 archived respiratory specimens, mostly nasopharyngeal swabs, including 210 that had been positive by conventional testing for a balanced selection of common respiratory viruses. Specimens yielding discrepant results were evaluated using a panel of respiratory virus PCR assays developed, characterized, and validated with clinical specimens. PLx-RVP increased the total rate of detection of viruses by 35.8%, and there was a 25.7% increase in the rate of detection of positive specimens. Reference PCR assay results corroborated the PLx-RVP result for 54 (82%) of 66 discrepancies with conventional testing. Of the 12 specimens with discrepancies between PLx-RVp and the reference PCRs, 6 were positive for rhinovirus by PLx-RVP and the presence of rhinovirus was confirmed by nucleotide sequencing. The remaining six specimens included five in which the PLx-RVP failed to detect parainfluenza virus and one in which the detection of influenza A virus by PLx-RVP could not be confirmed by the reference PCR. Taking the results of the reference PCR assay results into account, the sensitivities of the PLx-RVP for individual viruses ranged from 94 to 100% and the specificities ranged from 99 to 100%. We conclude that PLx-RVP is a highly accurate system for the detection of respiratory viruses and significantly improves the rate of detection of these viruses compared to that by conventional virologic testing.

Panton-Valentine Leukocidin-positive methicillin-resistant Staphylococcus aureus lung infection in patients with cystic fibrosis.

BACKGROUND: Panton-Valentine Leukocidin-expressing (PVL+) methicillin-resistant Staphylococcus aureus (MRSA) is an emerging pathogen worldwide causing fatal necrotizing pneumonias in otherwise healthy individuals but has not been described in patients with cystic fibrosis (CF). Following two cases of patients with CF admitted with lung abscesses in association with PVL+ MRSA, we examined the incidence and the clinical characteristics of MRSA acquisition in our CF patient population. METHODS: Newly acquired MRSA isolates from patients with CF followed up at St. Louis Children's Hospital were analyzed for the presence of Panton-Valentine leukocidin coding region, clindamycin susceptibility, staphylococcal cassette chromosome (SCC) mec type, and multilocus sequence type. Medical records and pulmonary function studies at the time of MRSA isolation were reviewed. RESULTS: MRSA isolates from 40 CF patients were available for analysis. Six children (15%) had PVL+ MRSA infection. All PVL+ organisms were clindamycin susceptible. Patients who acquired a PVL+ organism were more likely to have a focal pulmonary infiltrate on chest radiograph, including cavitary lung lesions in two patients (p = 0.04), a markedly greater decline in FEV1 at the time of MRSA detection (p = 0.01), and a significantly higher WBC count (p = 0.04) and absolute neutrophil count (p = 0.04). These patients were more likely to be admitted for IV antibiotic therapy for respiratory illnesses (p < 0.01). CONCLUSIONS: We describe the emergence of PVL+ MRSA in our CF population in association with development of invasive lung infections including lung abscesses. Early identification and treatment of CF patients with newly acquired PVL+ MRSA may be crucial.

Roles of KLF6 and KLF6-SV1 in ovarian cancer progression and intraperitoneal dissemination.

PURPOSE: We investigated the role of the KLF6 tumor suppressor gene and its alternatively spliced isoform KLF6-SV1 in epithelial ovarian cancer (EOC). EXPERIMENTAL DESIGN: We first analyzed tumors from 68 females with EOC for KLF6 gene inactivation using fluorescent loss of heterozygosity (LOH) analysis and direct DNA sequencing and then defined changes in KLF6 and KLF6-SV1 expression levels by quantitative real-time PCR. We then directly tested the effect of KLF6 and KLF6-SV1 inhibition in SKOV-3 stable cell lines on cellular invasion and proliferation in culture and tumor growth, i.p. dissemination, ascites production, and angiogenesis in vivo using BALB/c nu/nu mice. All statistical tests were two sided. RESULTS: LOH was present in 59% of samples in a cell type-specific manner, highest in serous (72%) and endometrioid (75%) subtypes, but absent in clear cell tumors. LOH was significantly correlated with tumor stage and grade. In addition, KLF6 expression was decreased in tumors when compared with ovarian surface epithelial cells. In contrast, KLF6-SV1 expression was increased approximately 5-fold and was associated with increased tumor grade regardless of LOH status. Consistent with these findings, KLF6 silencing increased cellular and tumor growth, angiogenesis, and vascular endothelial growth factor expression, i.p. dissemination, and ascites production. Conversely, KLF6-SV1 down-regulation decreased cell proliferation and invasion and completely suppressed in vivo tumor formation. CONCLUSION: Our results show that KLF6 and KLF6-SV1 are associated with key clinical features of EOC and suggest that their therapeutic targeting may alter ovarian cancer growth, progression, and dissemination.

The relationship of molecular markers of p53 function and angiogenesis to prognosis of stage I epithelial ovarian cancer.

PURPOSE: Multiple angiogenic factors may influence tumor progression and metastasis. Several are modified by the p53 gene. We sought to identify molecular markers for high-risk stage I epithelial ovarian cancers. EXPERIMENTAL DESIGN: Seventy-seven consecutive stage I epithelial ovarian cancers were evaluated for p53, CD31 microvessel density, thrombospondin-1, vascular endothelial growth factor (VEGF), p21 immunohistochemical staining, and p53 gene mutations. Molecular marker impact upon disease-specific survival, disease recurrence, and distant recurrence was evaluated with Cox regression. RESULTS: There were 12 deaths from disease. Twelve of the 77 tumors contained p53 mutations-10 missense and 3 null (one tumor had two mutations). Fesddration Internationale des Gynaecologistes et Obstetristes substage (IA/IB versus IC; P < 0.001) and VEGF staining (P = 0.02) were significant in bivariate models with relationship to disease-specific survival. Stage (P = 0.0004), grade (P = 0.008), histology (P = 0.0025), p53 dysfunction (positive stain and/or mutation; P = 0.048), and microvessel density (P = 0.04) were significant in bivariate models with relationship to time to recurrence. In multivariate analyses among stage IC patients, failure to receive chemotherapy and microvessel density were associated with disease-specific survival, time to recurrence, and time to distant recurrence with hazard ratios of 4.8 to 44.1. CONCLUSIONS: The p53-dependent molecular markers of angiogenesis are of limited utility in developing a clinical strategy for postoperative management of stage I ovarian carcinoma. Microvessel density impacts survival and metastasis for high-risk stage IC disease. Adjuvant chemotherapy is necessary, but not sufficient, for cure of high-risk stage I epithelial ovarian cancers.

Frequency of BRCA1 dysfunction in ovarian cancer.

BACKGROUND: Ovarian cancer is one of the most common hereditary cancers in women. Mutations in the BRCA1 gene increase a woman's risk of ovarian cancer. Testing for BRCA1 mutations is cumbersome and impractical for large populations. Therefore, we developed an efficient strategy to detect various types of BRCA1 dysfunction and also determined the relative frequency of BRCA1 dysfunction in ovarian cancer. METHODS: Tumors from 221 patients with epithelial ovarian cancer were screened for loss of heterozygosity (LOH) at the BRCA1 locus. BRCA1 complementary DNA (cDNA) and genomic DNA from all cancers with BRCA1 LOH (106 tumors) or noninformative status (15 tumors) were polymerase chain reaction (PCR) amplified and analyzed for protein truncation in a coupled transcription/translation test. When truncated BRCA1 protein was detected, the BRCA1 gene from both the tumor and a paired blood sample was sequenced. When BRCA1 expression in tumor cDNA was not detected with a protein truncation test, a methylation-specific PCR was used to determine whether the promoter region of BRCA1 was methylated and thus inactivated. All statistical tests were two-sided. RESULTS: Fifty-one (23.1%) of 221 tumors had BRCA1 dysfunction, including 18 with germline mutations, 15 with somatic mutations, and 18 with monoallelic or biallelic hypermethylated promoters. By the consideration of only tumors with LOH or that were noninformative, the efficiency for detecting BRCA1 dysfunction improved to 45 (37.2%) of 121 tumors. Therefore, LOH/noninformative was a strong predictor of mutation status (Fisher's exact test, P<.001). However, this subset of tumors did not include those with BRCA1 missense mutations (estimated at six [2.7%] of 221 not detected by our method) or biallelic promoter methylation (estimated at six [2.7%] of 221). CONCLUSIONS: BRCA1 dysfunction in ovarian cancer is common and occurs via multiple mechanisms. The use of LOH, rather than a family history of ovarian cancer, as a first step in a screening strategy, followed by protein truncation testing, appears to increase the chance of identifying tumors with BRCA1 dysfunction.

Inactivation of BRCA1 and BRCA2 in ovarian cancer.

BACKGROUND: Although BRCA1 and BRCA2 play important roles in hereditary ovarian cancers, the extent of their role in sporadic ovarian cancers and their mechanisms of inactivation are not yet well understood. Our goal was to characterize BRCA2 mutations and mRNA expression in a group of ovarian tumors previously evaluated for BRCA1 mutations and mRNA expression. METHODS: The tumors of 92 unrelated women with "ovarian" cancer (i.e., ovarian, peritoneal, or fallopian tube cancer) were screened for BRCA2 null mutations using a protein truncation test. Methylation-specific polymerase chain reaction (PCR) was used to examine the BRCA2 promoter for hypermethylation in tumors that did not express BRCA2 mRNA. All statistical tests were two-sided. RESULTS: Nine tumors had a germline (n = 5) or somatic (n = 4) BRCA2 mutation; each was associated with loss of heterozygosity. All of the somatic (1445delC, E880X, 4286del8, and 5783delT) and one of the germline (5984ins4) mutations were unique to this study. One tumor had somatic mutations in both BRCA1 and BRCA2. Two tumors are, to our knowledge, the first cases of germline BRCA2-associated peritoneal cancer. Twelve additional tumors lacked detectable BRCA2 mRNA, but the BRCA2 promoter was hypermethylated in only one of them, suggesting that other mechanisms effect transcriptional silencing of BRCA2. Tumors lacking BRCA1 mRNA were more likely to lack BRCA2 mRNA than tumors expressing BRCA1 mRNA (P<.001). Overall, 82% (95% confidence interval [CI] = 74% to 90%) of the tumors contained alterations in BRCA1, BRCA2, or both genes. Of 41 informative tumors with some alteration in BRCA2, 36 also had an alteration in BRCA1. The frequency, but not the mechanism, of BRCA1 or BRCA2 dysfunction in ovarian cancer was independent of family history. CONCLUSIONS: Multiple mechanisms cause nearly universal dysfunction of BRCA1 and/or BRCA2 in hereditary and sporadic ovarian carcinoma. Ovarian cancers with BRCA2 dysfunction often have simultaneous BRCA1 dysfunction.

Topotecan in the treatment of elderly patients with relapsed small-cell lung cancer.

BACKGROUND: Almost 70% of all patients with lung cancer in the United States are>65 years of age, and the incidence of small-cell lung cancer (SCLC) increases with age until the eighth decade of life. However, elderly patients are underrepresented in clinical trials and are often suboptimally treated. The validity of age as a prognostic factor for toxicity or survival remains controversial. PATIENTS AND METHODS: To investigate the safety and efficacy of topotecan (an approved treatment for relapsed SCLC) in older patients, we performed a retrospective analysis in patients >or= 65 years of age versus patients < 65 years of age from 5 large topotecan trials. In all 5 trials, patients received topotecan 1.5 mg/m2 per day via a 30-minute intravenous infusion on days 1 through 5 of a 21-day cycle. Efficacy and tolerability outcomes were assessed for both age groups. RESULTS: Topotecan was similarly tolerated in both age groups, with generally manageable hematologic toxicity. The incidence, duration, and onset of severe hematologic toxicities did not vary significantly with age. In the<65 age group, grade 4 neutropenia and leukopenia were reported in 72% and 32% of patients, respectively; in the >or= 65 age group, grade 4 neutropenia and leukopenia were reported in 77% and 31% of patients, respectively. Grade 4 thrombocytopenia was less common in the<65 age group. Nonhematologic toxicities, median time to progression, and overall survival were comparable between groups. CONCLUSION: This is the first demonstration of the safety and efficacy of topotecan in older patients with recurrent SCLC. Future studies are needed to fully characterize the role of topotecan in the treatment of older patients.