HPV Testing and Cervical Screening in the UK

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HPV Testing and Cervical Screening in the UK
Alex Sargent HPA Manchester
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Human Papillomaviruses

• Mainly infect the anogenital tract ( approx 40
  genotypes)
• Quite often asymptomatic
• LOW RISK (20 Types including types 6 and 11)
• Anogenital warts
• Very rarely found in cancers
• HIGH RISK (approx 14 types)
• Precursor lesions (CIN) cervical
  cancer
• Most malignancies of the anogenital tract

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99.7 of cervical cancers are directly linked to
previous infection with a High Risk HPV type

• Walboomers et al 1999

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High-risk HPV Prevalence (N24,510)
Percentage of HR HPV
Age Group
Kitchener et al 2006
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HR HPV Type by Cytology Grade
of Type Specific HPV Prevalence
Cytology Grade
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MRI Involvement in HPV

• Malignant progression of laryngeal papilloma
  associated with human papilloma virus type 6
  (HPV-6) DNA. A P Zarod, J D Rutherford, and G
  Corbitt. J Clin Pathol. 1988 41 280283
• Anal human papillomavirus and anal cancer.
  Tilston P. J Clin Pathol. 1997 50625-34
• A study of anal intraepithelial neoplasia in HIV
  positive homosexual men. Lacey HB, Wilson GE,
  Tilston P, Wilkins EG, Bailey AS, Corbitt G,
  Green PM. Sex Transm Infect. 1999 75172-7
• Natural history of cervical human papillomavirus
  infection in women during their first sexual
  relationship. Woodman CB, Collins S, Winter H,
  Bailey A, Ellis J, Prior P, Yates M, Rollason TP,
  Young LS. Lancet. 2001 3571831-6

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• More recent work has been our involvement in the
  ARTISTIC Trial
• Designed to investigate the value of
  incorporating HPV testing in to the English
  cervical cancer screening programme

Kitchener at al. Br J Cancer 2006 95(1)
56-61 Sargent et al. Br J Cancer 2008
98(10)1704-9 Kitchener et al Lancet Oncol.
200910(8)748. Kitchener at al Health
Technol Assess. 2009 13(51)1-150, iii-iv
Sargent et al. J Clin Microbiol. 2010 48(2),
554-8 Kitchener at al Eur J Cancer. 2011
47(6)864-71
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ARTISTIC Trial

• Main findings
• Primary cervical screening with combined LBC
  and HPV testing resulted in only a small
  reduction in the detection of high grade disease
  at the next screening round compared to LBC alone
• HPV testing, either for triage or as the
  initial screening test triaged by cytology, would
  be cost effective with no loss of sensitivity
• The screening interval could be increased
  from 3 to at least 6 years
• No significant adverse psychosocial effects
  were detected

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NHS HPV Triage Pilot Studies

• Studies showed
• A reduction of inadequate smears (from 9
  conventional cytology to 1-2 LBC)
• 46 (1680/3681) BNC 83 (1507/1825) mild
  dyskaryosis were HPV positive
• The rate of repeat smears fell by 74 (70
  for BNC 87 for mild)
• Rate of referral to colposcopy more than
  doubled (increased from 15-44 for BNC 37 -
  80 for mild)
• Direct referral of HPV positive women to
  colposcopy may lead to
  increased detection of CIN2

Legood. BMJ 2006 33279-83 Moss. BMJ 2006
33283-85
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Sentinel Sites project

• Funded by the NHS Cervical Screening Programme
• HPV Triage
• March 2008 -2011, 6 cytology centres (approx.
  10 screening population in England) acted as
  sentinel sites for HPV triage
• In the event of borderline or mild dyskaryosis
  cytology, residual material is tested for HR HPV
  using the Hybrid Capture 2 test (2RLU/Co)
• HPV Positive women are referred to colposcopy
• HPV Negative women are returned to routine recall
  (HPV testing has a high NPV)
• Virology testing centralised in Manchester
  Virology lab and Bristol Cytology lab

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Sentinel Sites project

• Test of cure
• In the event of an abnormal cytology report
  post-treatment, women are referred for colposcopy
  (standard practice)
• In the event of a normal cytology report,
  residual material is tested for high risk HPV by
  HC2 (2 RLU/Co)
• HPV negative women are referred for 3-year recall
  ( rather than annual recall for 10 years) and HPV
  positive women referred for colposcopy
• HPV-directed referral strategy is of considerable
  benefit to women in terms of reducing anxiety,
  uncertainty and the need for repeat smears, as
  well as reducing work load in cytology

Kitchener et al. BJOG 2008 1151001-1007
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HR HPV Positivity Rate by Referral Site
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Improvements to the NHS CSP

• Increased identification of high grade CIN and
  increased specificity in women undergoing HPV
  triage
• HPV triage offers immediate referral to
  colposcopy for those who may have significant
  disease rapid return to routine recall for
  women unlikely to have significant disease due to
  high NPV of HPV testing
• HPV ToC offers rapid return to routine recall for
  treated women (approx. 80)
• Reduced repeat testing will give rise to savings
  in primary care and laboratories

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HPV TESTINGNEW TECHNOLOGIES STUDY
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Qiagen HC2 assay

• Clinically regarded as the Gold Standard
• Approved cervical specimens include Cytyc
  ThinPrep PreservCyt solution SurePath
  preservative fluid
• Signal amplification DNA screening assay
• Targets 13 HR types
• Semi-automated system available
• No internal control for sample integrity
• Known issues regarding cross-reactivity

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Qiagen Hybrid Capture 2 (HC2) Test
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The Rapid Capture System

Courtesy of Digene
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• ALTERNATIVE HPV TESTS

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Basic Methodologies

• HPV Detection performed by molecular assays
• - Signal Amplification (HC2 Cervista)
• - Nucleic Acid Amplification (PCR TMA NASBA)

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• Screening assays
• Designed to detect the group of High Risk HPV
  Genotypes
• Some assays also have limited genotyping capacity
  for types 16 and 18
• Genotyping assays
• Designed to Genotype the majority of the HPV
  types infecting the Genital Tract-particularly
  the High Risk Genotypes
• Usually based on either a line blot assay format
  or micro-array system
• As yet of questionable value in the cervical
  screening programme

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Some Commercial Screening Assays

• Qiagen HC2
• GenProbe APTIMA
• Roche AMPLICOR
• Roche Real Time
• Abbott Real Time
• Hologic Cervista
• Norchip
• Bio-Tools
• Gen ID
• Genomica

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Clinical Validation

• In the case of HPV infections there is a big
  difference between analytical sensitivity and
  clinical sensitivity /specificity
• Meijer CJ et al have recently developed
  guidelines for high-risk HPV test requirements
  for primary cervical screening and validation
  guidelines for candidate HPV assays
• Int J Cancer 2009 Feb 1 124 (3) 516-20

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Guidelines for HPV Testing

• The sensitivity of the candidate test for CIN2
  should be at least 90 of the sensitivity of
  the HC2 assay to Detect Clinical Disease
• The specificity of the candidate test for CIN2
  should be at least 98 of the specificity of the
  HC2 assay
• For our study the minimum sensitivity has been
  raised to 95

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New Technologies Study

• Aim
• To demonstrate non-inferiority of any new test
  relative to Qiagen Hybrid Capture 2, in terms of
  both sensitivity and specificity for detection of
  high grade disease (CIN2)
• To assess the clinical utility of the test for
  triage of low grade cytology
• New tests were assessed at Bristol HPA and
  Manchester HPA - 2500 SurePath LBC and 2500
  ThinPrep LBC

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Commercial Assays Under Evaluation
New Test Surepath Thinprep
Roche Cobas 4800 ? ?
Abbott rt HPV ? ?
Gen-probe HPV APTIMA ?
Hologic Cervista HPV ?
non-CE marked
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Conclusions

• All assays so far have proved non-inferior to the
  HC2 assay
• Genprobe (SurePath) and Hologic are still under
  evaluation
• New tests are highly automated
• All assays have internal controls
• Abbott and Roche tests can simultaneously detect
  and identify types 16 and 18

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Possible Future

• Setting up of sentinel sites to pilot primary HPV
  testing in cervical screening
• Use of self sampling to improve coverage of the
  cervical screening programme

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Acknowledgements

• Prof Henry Kitchener and the ARTISTIC Team
• Prof Julietta Patnick and members of the NHSCSP
• Members of the Primary Screening Group
• Andrew Bailey and Staff in Virology, Manchester
  Royal Infirmary