Treatment of Anal High-Grade Squamous Intraepithelial Lesions to Prevent Anal Cancer.

BACKGROUND: The incidence of anal cancer is substantially higher among persons living with the human immunodeficiency virus (HIV) than in the general population. Similar to cervical cancer, anal cancer is preceded by high-grade squamous intraepithelial lesions (HSILs). Treatment for cervical HSIL reduces progression to cervical cancer; however, data from prospective studies of treatment for anal HSIL to prevent anal cancer are lacking. METHODS: We conducted a phase 3 trial at 25 U.S. sites. Persons living with HIV who were 35 years of age or older and who had biopsy-proven anal HSIL were randomly assigned, in a 1:1 ratio, to receive either HSIL treatment or active monitoring without treatment. Treatment included office-based ablative procedures, ablation or excision under anesthesia, or the administration of topical fluorouracil or imiquimod. The primary outcome was progression to anal cancer in a time-to-event analysis. Participants in the treatment group were treated until HSIL was completely resolved. All the participants underwent high-resolution anoscopy at least every 6 months; biopsy was also performed for suspected ongoing HSIL in the treatment group, annually in the active-monitoring group, or any time there was concern for cancer. RESULTS: Of 4459 participants who underwent randomization, 4446 (99.7%) were included in the analysis of the time to progression to cancer. With a median follow-up of 25.8 months, 9 cases were diagnosed in the treatment group (173 per 100,000 person-years; 95% confidence interval [CI], 90 to 332) and 21 cases in the active-monitoring group (402 per 100,000 person-years; 95% CI, 262 to 616). The rate of progression to anal cancer was lower in the treatment group than in the active-monitoring group by 57% (95% CI, 6 to 80; P = 0.03 by log-rank test). CONCLUSIONS: Among participants with biopsy-proven anal HSIL, the risk of anal cancer was significantly lower with treatment for anal HSIL than with active monitoring. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT02135419.).

Design of the ANal Cancer/HSIL Outcomes Research study (ANCHOR study): A randomized study to prevent anal cancer among persons living with HIV.

It is well established that persons living with HIV (PLWH) have highly elevated rates of anal HSIL and anal cancer compared with those who are not living with HIV. The 5-year risk of anal cancer following anal HSIL has been reported to be as high as 14.1% among PLWH compared with 3.2% among those who are not living with HIV. To address these concerns, the AIDS Malignancy Consortium completed a large-scale, randomized trial to compare strategies for the prevention of anal cancer among PLWH with anal HSIL. The objective of the study was to determine whether treating anal HSIL was effective in reducing the incidence of anal cancer in PLWH compared with active monitoring. This paper describes the design of the ANal Cancer/HSIL Outcomes Research Study (ANCHOR) with respect to estimating the anal cancer event rate in this high risk population.

Xpert HPV as a Screening Tool for Anal Histologic High-Grade Squamous Intraepithelial Lesions in Women Living With HIV.

BACKGROUND: Women living with HIV (WLWH) experience high rates of anal cancer. Screening using anal cytology, high-resolution anoscopy (HRA) with biopsies, can histologically diagnose anal cancer precursors called high-grade squamous intraepithelial lesions (HSIL). The low specificity of screening using anal cytology results in HRA referral for many WLWH without HSIL. Screening using high-risk human papillomavirus (HR-HPV) may improve specificity. METHODS: Two hundred seven WLWH (63% non-Hispanic black) were screened for anal histologic HSIL (hHSIL) using cytology, HRA-guided biopsies, and Xpert HPV. Xpert performance for predicting anal hHSIL was compared with that of cytology. Usng Xpert 5 HPV genotypic results and accompanying cycle thresholds, receiver operator characteristic curve and recursive partitioning analyses were used to create predictive models for hHSIL. RESULTS: The performance of Xpert to predict hHSIL was not different from that of cytology with a sensitivity (Sn) of 89% and specificity (Sp) of 49%. Interpretation of Xpert was modified using genotypic results and receiver operator characteristic curve analysis, which produced a screen with an Sn and Sp of 75% and 84% for hHSIL, respectively. Another reinterpretation of Xpert was created using recursive partitioning and cycle thresholds, which predicted hHSIL with an Sn and Sp of 75% and 86%, respectively. The detection of HPV-16 was highly predictive of hHSIL in all analyses. These modified screening tests would reduce HRA referral in this population by almost half compared with anal cytology. CONCLUSIONS: Xpert HPV is an alternative to anal cytology to screen for anal HSIL and can be optimized to reduce the number of unnecessary HRAs performed in WLWH.

High Prevalence of Anal High-Grade Squamous Intraepithelial Lesions, and Prevention Through Human Papillomavirus Vaccination, in Young Men Who Have Sex With Men Living With Human Immunodeficiency Virus.

BACKGROUND: Men who have sex with men (MSM) are at high risk for human papillomavirus (HPV)-related anal cancer. Little is known about the prevalence of low-grade squamous intraepithelial lesions (LSILs) and the anal cancer precursor, high-grade squamous intraepithelial lesions (HSILs), among young MSM with HIV (MSMLWH). HPV vaccination is recommended in this group, but its safety, immunogenicity, and protection against vaccine-type HPV infection and associated LSILs/HSILs have not been studied. METHODS: Two hundred and sixty MSMLWH aged 18-26 years were screened at 17 US sites for a clinical trial of the quadrivalent (HPV6,11,16,18) HPV (qHPV) vaccine. Those without HSILs were vaccinated at 0, 2, and 6 months. Cytology, high-resolution anoscopy with biopsies of lesions, serology, and HPV testing of the mouth/penis/scrotum/anus/perianus were performed at screening/month 0 and months 7, 12, and 24. RESULTS: Among 260 MSMLWH screened, the most common reason for exclusion was detection of HSILs in 88/260 (34%). 144 MSMLWH were enrolled. 47% of enrollees were previously exposed to HPV16. No incident qHPV type-associated anal LSILs/HSILs were detected among men naive to that type, compared with 11.1, 2.2, 4.5, and 2.8 cases/100 person-years for HPV6,11,16,18-associated LSILs/HSILs, respectively, among those previously exposed to that type. qHPV was immunogenic and safe with no vaccine-associated serious adverse events. CONCLUSIONS: 18-26-year-old MSMLWH naive to qHPV vaccine types were protected against incident qHPV type-associated LSILs/HSILs. Given their high prevalence of HSILs, there is an urgent need to vaccinate young MSMLWH before exposure to vaccine HPV types, before initiating sexual activity, and to perform catch-up vaccination.

Screening strategies for the detection of anal high-grade squamous intraepithelial lesions in women living with HIV.

OBJECTIVE: HIV-infected women (WLHIV) have more than 10-fold higher risk for squamous cell cancer of the anus. Experts suggest cytology-based strategies developed for cervical cancer screening may prevent anal cancer by detecting anal cytologic or histological high-grade squamous intraepithelial lesion (hHSIL) for treatment. Currently, there is no consensus on anal-hHSIL screening strategies for WLHIV. DESIGN: Between 2014 and 2016, 276 WLHIV were recruited at 12 US AIDS Malignancy Consortium clinical trials sites to evaluate hHSIL prevalence and (test) screening strategies. METHODS: Participants completed detailed questionnaire, underwent anal assessments including high-risk human papillomavirus (hrHPV) testing using hrHPV-Hybrid Capture 2 (HC2) and hrHPV-APTIMA, anal cytology, and concurrent high-resolution anoscopy. Screening test characteristics for predicting hHSIL validated by central review of histologic diagnosis were estimated sensitivity, specificity, positive predictive value, and false-omission rate. Paired analyses compared sensitivity and specificity for hrHPV single tests to anal cytology alone. RESULTS: 83% (229/276) of enrolled WLHIV had complete anal assessment data and were included in this analysis. Mean age was 50, 62% black and 60 (26%) had hHSIL. Anal cyotology (>atypical squamous cells of undetermined significance), hrHPV-HC2, and hrHPV-APTIMA sensitivity estimates were similarly high (83, 77, and 75%, respectively, P values > 0.2). Specificity was higher for both hrHPV-APTIMA and hrHPV-HC2 compared with anal cytology (67 vs. 50%, P < 0.001) and (61 vs. 50%, P = 0.020), respectively. CONCLUSION: Anal hrHPV testing demonstrated similar sensitivity for anal cytology (>atypical squamous cells of undetermined significance) to predict anal hHSIL. Among tests with similar sensitivity, the specificity was significantly higher for hrHPV-APTIMA and hrHPV-HC2. Thus, anal hrHPV testing may be an important alternative strategy to anal cytology for anal hHSIL screening among WLHIV.

Sustained fetal hematopoiesis causes juvenile death from leukemia: evidence from a dual-age-specific mouse model.

It is not clear whether disrupted age-specific hematopoiesis contributes to the complex manifestations in leukemia patients who carry identical mutations, particularly in pediatric and adult patients with similar clinical characteristics. By studying a dual-age-specific mouse model, we demonstrate that (1) loss of Pten during the fetal-to-adult hematopoiesis switch (hematopoiesis switch) causes sustained fetal hematopoiesis, resulting in death in juvenile leukemia; (2) myeloid-biased hematopoiesis in juvenile mice is associated with the sustained fetal properties of hematopoietic stem cells (HSCs); (3) the age specificity of juvenile myelomonocytic leukemia depends on the copy number of Pten and Nf1; (4) single-allelic Pten deletion during the hematopoiesis switch causes constitutive activation of MAPK in juvenile mice with Nf1 loss of heterozygosity (LOH); and (5) Nf1 LOH causes monocytosis in juvenile mice with Pten haploinsufficiency but does not cause lethality until adulthood. Our data suggest that 1 copy of Pten is sufficient to maintain an intact negative-feedback loop of the Akt pathway and HSC function in reconstitution, despite MAPK being constitutively activated in juvenile Pten+/ΔNf1LOH mice. However, 2 copies of Pten are required to maintain the integrity of the MAPK pathway in juvenile mice with Nf1 haploinsufficiency. Our data indicate that previous investigations of Pten function in wild-type mice may not reflect the impact of Pten loss in mice with Nf1 mutations or other genetic defects. We provide a proof of concept that disassociated age-specific hematopoiesis contributes to leukemogenesis and pediatric demise.

Prevalence of and Risk Factors for Anal High-grade Squamous Intraepithelial Lesions in Women Living with Human Immunodeficiency Virus.

BACKGROUND: Women living with human immunodeficiency virus (WLHIV) have disproportionately high rates of squamous cell carcinoma of the anus compared with the general population of women. Anal high-grade squamous intraepithelial lesions (HSILs) precede anal cancer, and accurate studies of HSIL prevalence among WLHIV in the United States are lacking. METHODS: The AIDS Malignancy Consortium 084 study was a multicenter national trial to evaluate the prevalence of and risk factors for anal HSIL in a US cohort. Eligible participants were WLHIV aged ≥18 years with no history of anal HSIL. Study participants had an examination including collection of cervical/vaginal and anal specimens, followed by high-resolution anoscopy with biopsy. RESULTS: We enrolled 256 women with evaluable anal pathology. The mean age was 49.4 years, 64% women were non-Hispanic black, 67% were former or current smokers, and 56% reported ever having anal sex with a man. The median CD4 T-cell count was 664 cells/µL. The prevalence of anal histologic HSIL (hHSIL) was 27% (95% confidence interval [CI], 22%-33%). There was a strong concordance (240/254) between local and consensus pathologists for hHSIL vs less than hHSIL (κ = 0.86 [95% CI, .79-.93]). Current CD4 count of ≤200 cells/µL was the strongest predictor of consensus anal hHSIL diagnosis (adjusted odds ratio [aOR], 10.34 [95% CI, 3.47-30.87]). History of anoreceptive intercourse was also associated with hHSIL (aOR, 2.44 [95% CI, 1.22-4.76]). CONCLUSIONS: The prevalence of anal hHSIL in WLHIV in the United States was 27% in this study where all participants received high-resolution anoscopy and biopsy.

Pilot Trial AMC-063: Safety and Efficacy of Bortezomib in AIDS-associated Kaposi Sarcoma.

PURPOSE: AIDS-related Kaposi sarcoma is often incompletely controlled, requiring serial therapies. Kaposi sarcoma herpesvirus (KSHV) induces transformation of endothelial cells, where it resides in a predominately latent state. We hypothesized proteasome inhibition would have direct antitumor activity, induce lytic activation of KSHV, and inhibit HIV infectivity, improving control of both Kaposi sarcoma and HIV. The primary objective was determining the MTD of bortezomib in AIDS-Kaposi sarcoma. Secondary objectives included estimating the impact of bortezomib on Kaposi sarcoma response, KSHV plasma DNA copy number (PDCN), and HIV viral loads (VL). PATIENTS AND METHODS: A 3+3 dose escalation design was employed evaluating four dose levels of bortezomib (0.75, 1, 1.2, or 1.6 mg/m2) administered intravenously on days 1, 8, and 15 of 28-day cycles in patients with relapsed/refractory (r/r) AIDS-Kaposi sarcoma taking antiretroviral therapy. RESULTS: Seventeen patients enrolled. No dose-limiting toxicities occurred and the MTD was not reached. The most common adverse events included diarrhea, fatigue and nausea. Among 15 evaluable patients, partial response (PR) occurred in nine (60%), with a PR rate of 83% in the 1.6 mg/m2 cohort; the remainder had stable disease (SD). Median time to response was 2.1 months. Median change in KSHV PDCN was significantly different between those with PR versus SD. During cycle 1, seven of 11 evaluable patients had decreases in HIV VL. CONCLUSIONS: Bortezomib is well-tolerated and active in AIDS-Kaposi sarcoma. The 60% PR rate is notable given the dose-finding nature of the study in a r/r population. Changes in KSHV PDCN and HIV VL trended as hypothesized.

Cisplatin and radiation therapy in HIV-positive women with locally advanced cervical cancer in sub-Saharan Africa: A phase II study of the AIDS malignancy consortium.

PURPOSE: To determine the feasibility, safety, and tolerability of concomitant chemoradiotherapy administered at standard doses in HIV-infected women with locally-advanced cervical cancer (LACC) receiving antiretroviral therapy (ART). PATIENTS AND METHODS: Eligible participants had HIV infection and untreated, histologically-confirmed, invasive carcinoma of the uterine cervix, FIGO stages IB2, IIA (if tumor >4 cm), IIB, IIIA, IIIB, or IVA and met standard eligibility criteria. Subjects were prescribed 41.4-45 Gy external beam radiation therapy followed by high dose rate brachytherapy concomitant with up to six weekly doses of cisplatin 40 mg/m2 and were followed for 12 months. RESULTS: Sixty-four women were screened at two sites in sub-Saharan Africa, of whom 40 eligible participants were enrolled, for a screening ratio of 1.60. Of the 38 eligible participants who initiated study treatment, 31 (82%) completed treatment. By the 12-month follow-up visit, 7 women had died of disease and 29 of 31 (94%) returned for follow-up. One-year progression-free survival was 76.3% (95% CI, 59.4-86.9%), and did not significantly differ according to stage at entry (p = 0.581). Participant-reported adherence to ART was high; by 12 months, 93% of participants had an undetectable viral load. The most common grade 3 or 4 adverse event was decreased lymphocyte count that affected all treated participants. Non-hematologic serious adverse events were similar to those observed in women with LACC without HIV infection. CONCLUSIONS: The majority of HIV-infected women with LACC can complete concomitant chemoradiotherapy with the same cisplatin dose used in HIV-uninfected women with comparable tolerability and high ART adherence while on treatment.

A Randomized Clinical Trial of Infrared Coagulation Ablation Versus Active Monitoring of Intra-anal High-grade Dysplasia in Adults With Human Immunodeficiency Virus Infection: An AIDS Malignancy Consortium Trial.

BACKGROUND: Anal high-grade squamous intraepithelial lesions (HSILs) ablation may reduce the incidence of invasive cancer, but few data exist on treatment efficacy and natural regression without treatment. METHODS: An open-label, randomized, multisite clinical trial of human immunodeficiency virus (HIV)-infected adults aged ≥27 years with 1-3 biopsy-proven anal HSILs (index HSILs) without prior history of HSIL treatment with infrared coagulation (IRC). Participants were randomized 1:1 to HSIL ablation with IRC (treatment) or no treatment (active monitoring [AM]). Participants were followed every 3 months with high-resolution anoscopy. Treatment participants underwent anal biopsies of suspected new or recurrent HSILs. The AM participants underwent biopsies only at month 12. The primary end point was complete clearance of index HSIL at month 12. RESULTS: We randomized 120 participants. Complete index HSIL clearance occurred more frequently in the treatment group than in the AM (62% vs 30%; risk difference, 32%; 95% confidence interval [CI], 13%-48%; P < .001). Complete or partial clearance (clearance of ≥1 index HSIL) occurred more commonly in the treatment group (82% vs 47%; risk difference, 35%; 95% CI, 16%-50%; P < .001). Having a single index lesion, compared with having 2-3 lesions, was significantly associated with complete clearance (relative risk, 1.96; 95% CI, 1.22-3.10). The most common adverse events related to treatment were mild or moderate anal pain and bleeding. No serious adverse events were deemed related to treatment or study participation. CONCLUSION: IRC ablation of anal HSILs results in more clearance of HSILs than observation alone.

Interval estimators of relative potency in toxicology and radiation countermeasure studies: comparing methods and experimental designs.

The relative potency of one agent to another is commonly represented by the ratio of two quantal response parameters; for example, the LD50 of animals receiving a treatment to the LD50 of control animals, where LD50 is the dose of toxin that is lethal to 50% of animals. Though others have considered interval estimators of LD50, here, we extend Bayesian, bootstrap, likelihood ratio, Fieller's and Wald's methods to estimate intervals for relative potency in a parallel-line assay context. In addition to comparing their coverage probabilities, we also consider their power in two types of dose designs: one assigning treatment and control the same doses vs. one choosing doses for treatment and control to achieve same lethality targets. We explore these methods in realistic contexts of relative potency of radiation countermeasures. For larger experiments (e.g., ≥100 animals), the methods return similar results regardless of the interval estimation method or experiment design. For smaller experiments (e.g., < 60 animals), Wald's method stands out among the others, producing intervals that hold closely to nominal levels and providing more power than the other methods in statistically efficient designs. Using this simple statistical method within a statistically efficient design, researchers can reduce animal numbers.

An Adaptive Chlamydia trachomatis-Specific IFN-γ-Producing CD4+ T Cell Response Is Associated With Protection Against Chlamydia Reinfection in Women.

Background: Adaptive immune responses that mediate protection against Chlamydia trachomatis (CT) remain poorly defined in humans. Animal chlamydia models have demonstrated that CD4+ Th1 cytokine responses mediate protective immunity against reinfection. To better understand protective immunity to CT in humans, we investigated whether select CT-specific CD4+ Th1 and CD8+ T cell cytokine responses were associated with protection against CT reinfection in women. Methods: Peripheral blood mononuclear cells were collected from 135 CT-infected women at treatment and follow-up visits and stimulated with CT antigens. CD4+ and CD8+ T-cells expressing IFN-γ, TNF-α, and/or IL-2 were assessed using intracellular cytokine staining and cytokine responses were compared between visits and between women with vs. without CT reinfection at follow-up. Results: A CD4+TNF-α response was detected in the majority (77%) of study participants at the treatment visit, but a lower proportion had this response at follow-up (62%). CD4+ IFN-γ and CD4+ IL-2 responses occurred less frequently at the treatment visit (32 and 18%, respectively), but increased at follow-up (51 and 41%, respectively). CD8+ IFN-γ and CD8+ TNF-α responses were detected more often at follow-up (59% for both responses) compared to the treatment visit (30% for both responses). At follow-up, a CD4+IFN-γ response was detected more often in women without vs. with reinfection (60 vs. 33%, P = 0.005). Conclusions: Our findings suggest that a CT-specific CD4+ IFN-γ response is associated with protective immunity against CT reinfection and is thus an important component of adaptive immunity to CT in women.

Prognostic Value of Late Gadolinium Enhancement CMR in Systemic Amyloidosis.

OBJECTIVES: The aim of this study was to access the prognostic implication of late gadolinium enhancement (LGE) in patients with systemic amyloidosis undergoing cardiac magnetic resonance (CMR). BACKGROUND: Cardiac amyloidosis confers significantly worse prognosis in patients with systemic amyloidosis. CMR imaging has emerged as an attractive noninvasive modality to diagnose cardiac involvement in patients with systemic amyloidosis. We performed a systemic review and meta-analysis to evaluate the prognostic role of LGE-CMR imaging in patients with systemic amyloidosis. METHODS: Electronic databases MEDLINE, PubMed, Embase, and Cochrane were systematically searched to identify studies evaluating the association between LGE-CMR and prognosis in systemic amyloidosis with cardiac involvement. The present study was designed to systematically review and assess the association between LGE and the primary endpoint of all-cause mortality. A random effects model was used to calculate a pooled odds ratio using inverse-variance weighting. RESULTS: Data were included from 7 studies with a total of 425 patients and a mean follow-up of 25 months. Patients had a weighted average age of 64 years and left ventricular ejection fraction of 59.2%; 67% were male. Endomyocardial biopsy was positive for amyloidosis in 20%, whereas LGE was present in 73% of patients. LGE-positive patients had increased overall mortality compared with those without LGE (pooled odds ratio: 4.96; 95% confidence interval [CI]: 1.90 to 12.93; p = 0.001). For the LGE group, the pooled death rate was 0.07 (95% CI: 0.03 to 0.19) events per year and for the LGE+ group, the rate was 0.25 (95% CI: 0.16 to 0.39 per year; p = 0.001). The proportion of patients with cardiac biopsy within each study ranged from 3% to 68%, and the relationship between LGE status and death did not vary according to cardiac biopsy proportion across studies. CONCLUSIONS: LGE on CMR in patients with systemic amyloidosis with known or suspected cardiac amyloidosis is associated with increased risk of all-cause mortality.

Timing of the loss of Pten protein determines disease severity in a mouse model of myeloid malignancy.

Juvenile myelomonocytic leukemia (JMML) is an aggressive pediatric mixed myelodysplastic/myeloproliferative neoplasm (MDS/MPN). JMML leukemogenesis is linked to a hyperactivated RAS pathway, with driver mutations in the KRAS, NRAS, NF1, PTPN11, or CBL genes. Previous murine models demonstrated how those genes contributed to the selective hypersensitivity of JMML cells to granulocyte macrophage-colony-stimulating factor (GM-CSF), a unifying characteristic in the disease. However, it is unclear what causes the early death in children with JMML, because transformation to acute leukemia is rare. Here, we demonstrate that loss of Pten (phosphatase and tensin homolog) protein at postnatal day 8 in mice harboring Nf1 haploinsufficiency results in an aggressive MPN with death at a murine prepubertal age of 20 to 35 days (equivalent to an early juvenile age in JMML patients). The death in the mice was due to organ infiltration with monocytes/macrophages. There were elevated activities of protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) in cells at physiological concentrations of GM-CSF. These were more pronounced in mice with Nf1 haploinsufficiency than in littermates with wild-type Nf1,but this model is insufficient to cause cells to be GM-CSF hypersensitive. This new model represents a murine MPN model with features of a pediatric unclassifiable mixed MDS/MPN and mimics many clinical manifestations of JMML in terms of age of onset, aggressiveness, and organ infiltration with monocytes/macrophages. Our data suggest that the timing of the loss of PTEN protein plays a critical role in determining the disease severity in myeloid malignancies. This model may be useful for studying the pathogenesis of pediatric diseases with alterations in the Ras pathway.

New generation aspiration catheter: Feasibility in the treatment of pulmonary embolism.

AIM: To report our preliminary experience with a new generation aspiration catheter in the treatment of symptomatic pulmonary embolism (PE). METHODS: A retrospective database search for pulmonary artery embolectomy since introduction of the Pronto .035" and XL extraction catheter (Vascular Solutions, Minneapolis, MN) at our institution in 10/2009 was performed. Ten consecutive patients were identified in which the Pronto .035" or XL catheter was used between 01/2010 and 03/2013. All patients were referred for catheter based embolectomy due to contraindications to systemic lysis, or for being in such a critical clinical condition that immediate percutaneous treatment deemed warranted. The computed tomography (CT) right to left heart ratio as predictor for the severity of the PE was retrospectively evaluated on standard axial views. The difference between pre- and post-procedure pulmonary pressure measures was taken to assess the procedural effect. RESULTS: Extensive PE was confirmed angiographically in all patients. Measured right- to left ventricle (RV/LV) ratios were elevated beyond one in seven of the eight available CTs. Acute procedural success defined as clinical removal of visible thrombus and improvement in mean pulmonary artery pressure was seen in all recorded patients (n = 8), the mean pulmonary pressures declined from a median (range) of 35.5 (19-46) to 23 (10-37, P = 0.008) mmHg. Neither death nor other complications occurred intra- or immediately periprocedural, yet short term mortality within 30 d was found in 6 out of 9 patients, one patient was lost in follow up. The cause of death within 30 d in the 6 patients was identified as: Circulatory failure in direct connection with the PE (n = 2), stroke, sepsis, or succumbing to malignancy in a hospice setting (n = 2). CONCLUSION: Success in thrombus removal with improved pulmonary hypertension and systemic hypotension suggests this aspiration technique to be effective. Aspiration catheters should be part of further trials.

Practical advice on calculating confidence intervals for radioprotection effects and reducing animal numbers in radiation countermeasure experiments.

The dose of a substance that causes death in P% of a population is called an LDP, where LD stands for lethal dose. In radiation research, a common LDP of interest is the radiation dose that kills 50% of the population by a specified time, i.e., lethal dose 50 or LD50. When comparing LD50 between two populations, relative potency is the parameter of interest. In radiation research, this is commonly known as the dose reduction factor (DRF). Unfortunately, statistical inference on dose reduction factor is seldom reported. We illustrate how to calculate confidence intervals for dose reduction factor, which may then be used for statistical inference. Further, most dose reduction factor experiments use hundreds, rather than tens of animals. Through better dosing strategies and the use of a recently available sample size formula, we also show how animal numbers may be reduced while maintaining high statistical power. The illustrations center on realistic examples comparing LD50 values between a radiation countermeasure group and a radiation-only control. We also provide easy-to-use spreadsheets for sample size calculations and confidence interval calculations, as well as SAS® and R code for the latter.

High-grade anal intraepithelial neoplasia among HIV-1-infected men screening for a multicenter clinical trial of a human papillomavirus vaccine.

PURPOSE: High-grade anal intraepithelial neoplasia (HGAIN) is the precursor lesion to invasive anal cancer. Human papillomavirus (HPV) vaccination holds great promise for preventing anal cancer. METHODS: We examined 235 HIV-1-infected men screening for participation in a multisite clinical trial of a quadrivalent HPV vaccine. All participants had anal swabs obtained for HPV testing and cytology and high-resolution anoscopy with biopsies of visible lesions to assess for HGAIN. RESULTS: HPV types 16 and 18 were detected in 23% and 10%, respectively; abnormal anal cytology was found in 56% and HGAIN in 30%. HGAIN prevalence was significantly higher in those with HPV16 detection compared to those without (38% vs 17%; P = .01). Use of antiretroviral therapy and nadir and current CD4+ cell count were not associated with abnormal anal cytology or HGAIN. CONCLUSION: HGAIN is highly prevalent in HIV-infected men. Further studies are needed on treatment and prevention of HGAIN.

Estimating misclassification error: a closer look at cross-validation based methods.

BACKGROUND: To estimate a classifier's error in predicting future observations, bootstrap methods have been proposed as reduced-variation alternatives to traditional cross-validation (CV) methods based on sampling without replacement. Monte Carlo (MC) simulation studies aimed at estimating the true misclassification error conditional on the training set are commonly used to compare CV methods. We conducted an MC simulation study to compare a new method of bootstrap CV (BCV) to k-fold CV for estimating clasification error. FINDINGS: For the low-dimensional conditions simulated, the modest positive bias of k-fold CV contrasted sharply with the substantial negative bias of the new BCV method. This behavior was corroborated using a real-world dataset of prognostic gene-expression profiles in breast cancer patients. Our simulation results demonstrate some extreme characteristics of variance and bias that can occur due to a fault in the design of CV exercises aimed at estimating the true conditional error of a classifier, and that appear not to have been fully appreciated in previous studies. Although CV is a sound practice for estimating a classifier's generalization error, using CV to estimate the fixed misclassification error of a trained classifier conditional on the training set is problematic. While MC simulation of this estimation exercise can correctly represent the average bias of a classifier, it will overstate the between-run variance of the bias. CONCLUSIONS: We recommend k-fold CV over the new BCV method for estimating a classifier's generalization error. The extreme negative bias of BCV is too high a price to pay for its reduced variance.

Impact of HIV Infection on Medicare Beneficiaries with Lung Cancer.

The incidence of lung cancer among individuals infected with the human immunodeficiency virus (HIV) is elevated compared to that among the general population. This study examines the prevalence of HIV and its impact on outcomes among Medicare beneficiaries who are 65 years of age or older and were diagnosed with nonsmall cell lung cancer (NSCLC) between 1997 and 2008. Prevalence of HIV was estimated using the Poisson point estimate and its 95% confidence interval. Relative risks for potential risk factors were estimated using the log-binomial model. A total of 111,219 Medicare beneficiaries met the study criteria. The prevalence of HIV was 156.4 per 100,000 (95% CI: 140.8 to 173.8) and has increased with time. Stage at NSCLC diagnosis did not vary by HIV status. Mortality rates due to all causes were 44%, 76%, and 88% for patients with stage I/II, III, and IV NSCLC, respectively. Across stages of disease, there was no difference between those who were HIV-infected and those who were not with respect to overall mortality. HIV patients, however, were more likely to die of causes other than lung cancer than their immunocompetent counterparts.