HPV and Lower Genital Tract Disease. Simon Herrington University of Edinburgh, UK Royal Infirmary of Edinburgh, UK

Transcription

1 HPV and Lower Genital Tract Disease Simon Herrington University of Edinburgh, UK Royal Infirmary of Edinburgh, UK

2 Conflict of interest/funding X None Company: Product royalties Paid consultant Research support

3 Human Papillomavirus Infection and Anogenital Disease High-risk HPV DNA is present in 99.7% of invasive cervical carcinomas Walboomers et al J Pathol 1999; 189: Mucosal HPV infection can also cause vulval and vaginal pre-cancerous lesions and genital warts

4 History 1976: Papillomavirus suggested as cause of cervical cancer (zur Hausen) : HPV 16/18 genome cloned from cervical cancers 1999: HPV DNA present in 99.7% of cervical cancers 2006: Vaccine introduced

5 Human Papillomavirus is Common Transmitted by intimate contact An estimated 80% of sexually active women will be exposed to the virus by age 50 Most infections will regress spontaneously after 6-12 months Over time, persistent infection can lead to progression of intraepithelial lesions to invasive disease

6 Human Papillomaviruses Non-enveloped, double-stranded DNA viruses 8 kb circular genome At least 200 genotypes pave.niaid.nih.gov Epitheliotropic Associated with warts and neoplasia

7 DPV EEFV BPV2 PCPV b 34 RhPV BPV1 CRPV 41 COPV 63 Phylogenetics a BPV4 22 MnPV a

8 Molecular Organisation Doorbar J Clin Sci 2006;110:525-41

9 The Papillomavirus Life Cycle Doorbar J Clin Sci 2006;110:525-41

10 _ prb E7 _ E7 E7 Checkpoints p16 p18 p15 p27 p21 p53 _ CDK4/ CDK6 _ High-Risk HPV E7 _ CDK2 CDK2 E6 p16 Cdc25 Cdc2 CycDs CycE CycA CycB E7 prb P prb P P DNA Replication (S phase) Mitosis (M phase)

11 Block-positive p16 continuous strong nuclear or nuclear plus cytoplasmic staining of the basal cell layer with extension upwards involving at least 1/3 of the epithelial thickness. The latter height restriction is somewhat arbitrary but adds specificity Darragh et al Int J Gynecol Pathol 2013; 32: 76-11

12 HPV and Neoplastic Progression

13 H&E Ki67 p16 INK4A Metaplasia Normal Inflammation CxCa CIN 3 CIN 1 / 2 p16 INK4A Immunohistochemistry H&E Ki67 p16 INK4A Klaes R et al Am J Surg Pathol 2002;11:

14 What Governs Progression? HPV type High-risk HPV types, particularly 16 and 18 Persistence of HPV infection Up-regulation of E6/E7 Loss of capacity to replicate viral DNA HPV integration Chromosome sites random Viral breakpoint consistent (E1/E2)

15 HPV-associated Neoplasia High vs low-risk HPV types Productive vs abortive/transforming infection Up-regulation of E6/E7 expression is key p16 protein expression is a surrogate marker of high-risk HPV E7 expression Lesion progression is associated with HPV integration Squamous disease predominates but most cervical glandular lesions are also HPV-driven

16 p16 as a Surrogate Marker of High-Risk HPV Infection p16 overexpression reflects prb pathway disruption and/or senescence, not just HPV infection In lower anogenital squamous intraepithelial lesions Discrimination between high-grade SIL and mimics Not for diagnosis of low-grade SIL Only block-type positivity should be considered positive In lower genital tract tumours Strong diffuse p16 positivity supports an HPV-associated aetiology Endometrioid endometrial adenocarcinomas can be diffusely positive Serous carcinomas are typically diffusely positive Context is important and p16 should be used as part of a panel

17 Issues p16 positive low-grade lesions p16 negative high-grade lesions Gene mutation/deletion Gene silencing Tendency to up-grade p16 does NOT grade lesion

18 p16 p16

19 Case History 64 year old female with a history of VIN New lesions on left and right side of vulva. Macroscopically the biopsies had an irregular skin surface The slides are from right (A) and left (B) vulval lesions

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23 p16

24 Ki67

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27 p16

28 Ki67

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30 p16

31 p16

32 p16

33 Ki67

34 Ki67

35 Diagnosis Combined HSIL and Squamous cell papillomata (LSIL) Mixed p16 staining pattern, with suprabasal Ki67 positivity in both areas, consistent with mixed high-risk and low-risk HPV infection

36 HPV-related Squamous Lesions Lesions associated with high-risk HPV infection are block positive for p16 with accompanying suprabasal Ki67 positivity This applies to both low-grade and high-grade SIL Lesions associated with low-risk HPV infection are p16 negative or patchily non- block positive, with basal keratinocyte sparing Ki67 is upregulated in areas of viral DNA replication providing a useful marker of low-risk HPV infection (low-grade SIL) in the absence of p16

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