Mark Sadorra

National Cancer Institute (USA), 베서스다, Maryland, United States

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Publications (7)27.88 Total impact

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    ABSTRACT: Anal HPV infections are common and anal cancer incidence is high in HIV-infected men who have sex with men (MSM). To evaluate the performance of HPV assays in anal samples, we compared the cobas HPV test (cobas) to Linear Array and cytology in HIV-infected MSM. Cytology, cobas and LA HPV testing were conducted in 342 subjects. We calculated agreement between HPV assays and clinical performance of HPV testing and HPV genotyping alone and in combination with anal cytology. We observed high agreement between cobas and LA, with cobas more likely to test positive than LA for HPV16, HPV18, and other carcinogenic types. Specimens testing positive for cobas, but not LA, were more likely to be positive for other markers of HPV-related disease compared to those testing negative for both assays, suggesting that at least some of these were true positives for HPV. Both cobas and LA showed a high sensitivity, but low specificity for detection of AIN2/3 in this population (100% sensitivity and 26% specificity for cobas vs. 98.4% sensitivity and 28.9% specificity for LA, respectively). Combinations of anal cytology and HPV genotyping had the highest accuracy for detecting anal precancer. Higher HPV load was associated with higher risk of AIN2/3 for HPV16 (ptrend < 0.001), HPV18 (ptrend = 0.07), and other carcinogenic types (ptrend < 0.001). We demonstrate that cobas can be used for HPV detection in anal cytology specimens. Additional tests are necessary to identify men at highest risk of anal cancer among those infected with high-risk HPV.
    Journal of Clinical Microbiology 06/2014; 52(8). DOI:10.1128/JCM.03517-13 · 3.99 Impact Factor
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    ABSTRACT: Background: The prevention of human papillomavirus (HPV)-induced anal cancer in high-risk populations such as human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) remains an urgent priority, given rising incidence rates despite widespread antiretroviral therapy use. Methods: HPV genotypes and anal disease prevalence, by cytology and histopathologic findings, were evaluated among 363 HIV-infected MSM. We modeled fractions of high-grade anal intraepithelial neoplasia (HGAIN) attributable to individual carcinogenic HPV genotypes and estimated the range of the proportion of HGAIN cases potentially preventable by prophylactic HPV vaccines. Results: HPV16 was the most common genotype overall (26.4% of cases) and among HGAIN cases (55%). Prevalence of multiple (≥ 2) carcinogenic HPV genotypes increased from 30.9% in cases of AIN grade <1 to 76.3% in cases of AIN grade 3 (P(trend) < .001). The fractions of HGAIN cases attributable to carcinogenic HPV16/18 targeted by currently licensed bivalent and quadrivalent HPV vaccines ranged from 12% to 61.5%, and the fractions attributable to carcinogenic HPV16/18/31/33/45/52/58 targeted by an investigational nonavalent HPV vaccine ranged from 39% to 89.4%. Conclusions: Our analytical framework allows estimation of HGAIN cases attributable to individual HPV genotypes in the context of multiple concurrent HPV infections, which are very common among HIV-infected MSM. Our results suggest that licensed and investigational HPV prophylactic vaccines have the potential to prevent a substantial proportion of HGAIN cases in this population.
    The Journal of Infectious Diseases 11/2012; 207(3). DOI:10.1093/infdis/jis694 · 6.00 Impact Factor
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    ABSTRACT: The cobas human papillomavirus (HPV) test (cobas) was recently approved by the U.S. Food and Drug Administration (FDA) and identifies HPV16 and HPV18 separately as well as detecting a pool of 11 HR-HPV genotypes (HPV31, -33, -35, -39, -45, -51, -52, -56, -58, -59, -68) and also HPV66. We compared cobas, Linear Array (LA), and Hybrid Capture 2 (HC2) assays for detection of carcinogenic HPV DNA, and cobas and LA for detection of HPV16 and HPV18 DNA, among the first 1,852 women enrolled in the HPV Persistence and Progression Cohort (PaP Cohort) study. Specimens were tested by all 3 assays 1 year after an HC2-positive result. In 1,824 specimens with cobas results, cobas had an 85.9% agreement with HC2 and 91.0% agreement with LA for carcinogenic HPV detection. When results between cobas and HC2 disagreed, cobas tended to call more women HPV positive (P < 0.01). Categorizing cobas and LA results hierarchically according to cancer risk (HPV16, HPV18, other carcinogenic HPV genotypes, or carcinogen negative), there was a 90% agreement for all categories of HPV (n = 1,824). We found good agreement between the two U.S. FDA-approved HPV tests, with discrepancies between the two assays due to specific characteristics of the individual assays. Additional studies are needed to compare HC2 and cobas for detecting and predicting CIN3 to understand the clinical implications of the discrepant test results between the two tests.
    Journal of clinical microbiology 11/2011; 50(1):61-5. DOI:10.1128/JCM.05989-11 · 3.99 Impact Factor
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    ABSTRACT: Results from a prototype real-time PCR assay that separately detected human papillomavirus genotype 16 (HPV16), HPV18, and 12 other carcinogenic HPV genotypes in aggregate (cobas 4800 HPV test) and results from a PCR assay that detects 37 HPV genotypes individually (Linear Array) were compared using a convenience sample of cervical specimens (n = 531). The percentage of total agreement between the two assays was 94.7% (95% confidence interval, 92.5 to 96.5%). The Linear Array test was more likely than cobas 4800 HPV test to test positive for the 12 other carcinogenic HPV genotypes among women without evidence of cervical disease (P = 0.004).
    Journal of clinical microbiology 09/2009; 47(10):3344-7. DOI:10.1128/JCM.00725-09 · 3.99 Impact Factor
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    ABSTRACT: Human papillomavirus (HPV) genotyping could be clinically useful, depending on the results of large, prospective studies like the HPV persistence and progression (PaP) cohort. The cohort is based on genotyping and follow-up of Hybrid Capture-positive women at Kaiser Permanente, Northern California. HPV DNA testing by Hybrid Capture 2 requires denaturation with alkali, possibly damaging the DNA for optimal PCR-based genotyping. A feasibility study was conducted on paired aliquots of anonymized specimens from 100 women with low-grade intraepithelial lesion cytology. Test aliquots were left in denaturant for 10 or 18h at 4 degrees C and then neutralized; comparison aliquots were not denatured but diluted to match the timing, temperature, concentration and salt conditions of the treated specimens. The masked aliquots were tested using a commercialized PCR-based assay that detects of 37 HPV genotypes. There was no overall effect of treatment on test positivity or number of types. HPV16 was marginally more likely to be detected in untreated versus treated aliquots (P=0.09) but HPV45 was marginally more likely to be detected in treated than untreated aliquots (P=0.07), suggesting that these differences represented chance (intra-test variability). It can be concluded that residual Hybrid Capture-positive specimens can be genotyped by PCR after Hybrid Capture 2 processing.
    Journal of Virological Methods 01/2008; 146(1-2):80-5. DOI:10.1016/j.jviromet.2007.06.001 · 1.78 Impact Factor
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    ABSTRACT: The usefulness of mouthwash as a transport medium for cervical specimens for carcinogenic human papillomavirus (HPV) DNA testing has not been evaluated. Two cervical specimens were collected from each of 34 patients, with one placed in mouthwash (Scope, Proctor and Gamble, Inc.) and the other in a liquid cytology medium commonly used for HPV DNA testing in alternating order. Paired specimens were tested by a PCR assay for carcinogenic HPV and a PCR HPV genotyping assay for 37 HPV types at 0, 3, and 6 weeks after collection; the results of the HPV genotyping assay were categorized into HPV risk groups according to cancer risk (HPV-16 > HPV-18 > other carcinogenic HPV types > noncarcinogenic HPV types > negative). After 4 months of storage, specimens were tested using a second, non-PCR test for carcinogenic HPV. We observed a >or=94% total agreement and kappa values of >or=0.88 between media at each time point for PCR-detected carcinogenic HPV. We observed a >or=74% total agreement, >or=0.62 unweighted kappa, and >or=0.75 linearly weighted kappa between media at each time point for PCR-detected HPV cancer risk category. Finally, we observed an 88% total agreement and kappa of 0.77 between media for carcinogenic HPV detection using a second test after 4 months of storage. We suggest that mouthwash might be used as a low-cost, safe, nonflammable storage and transport medium for cervical specimens for HPV DNA testing in cervical cancer screening programs.
    Cancer Epidemiology Biomarkers & Prevention 04/2007; 16(4):840-3. DOI:10.1158/1055-9965.EPI-06-0909 · 4.13 Impact Factor
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    ABSTRACT: We evaluated a commercialized PCR assay, Linear Array, that detects 37 human papillomavirus (HPV) genotypes, using a sample of liquid cytology specimens (n = 534). We found a strong association of an increasing level of HPV risk (HPV type 16 [HPV16] > HPV18 > other carcinogenic types > noncarcinogenic types > negative specimens) with increasing severities of cytologic interpretations (PTrend < 0.0005) and histologic diagnoses (PTrend < 0.0005).
    Journal of Clinical Microbiology 12/2006; 44(11):3915-7. DOI:10.1128/JCM.01305-06 · 3.99 Impact Factor

Publication Stats

114 Citations
27.88 Total Impact Points


  • 2012
    • National Cancer Institute (USA)
      • Division of Cancer Epidemiology and Genetics
      베서스다, Maryland, United States
  • 2011
    • Kaiser Permanente
      • Section for Infectious Diseases
      Oakland, California, United States