A recent report that 93 per cent of invasive cervical cancers worldwide contain human papillomavirus (HPV) may be an underestimate, due to sample inadequacy or integration events affecting the HPV L1 gene, which is the target of the polymerase chain reaction (PCR)-based test which was used. The formerly HPV-negative cases from this study have therefore been reanalyzed for HPV serum antibodies and HPV DNA. Serology for HPV 16 VLPs, E6, and E7 antibodies was performed on 49 of the 66 cases which were HPV-negative and a sample of 48 of the 866 cases which were HPV-positive in the original study. Moreover, 55 of the 66 formerly HPV-negative biopsies were also reanalyzed by a sandwich procedure in which the outer sections in a series of sections are used for histological review, while the inner sections are assayed by three different HPV PCR assays targeting different open reading frames (ORFs). No significant difference was found in serology for HPV 16 proteins between the cases that were originally HPV PCR-negative and -positive. Type-specific E7 PCR for 14 high-risk HPV types detected HPV DNA in 38 (69 per cent) of the 55 originally HPV-negative and amplifiable specimens. The HPV types detected were 16, 18, 31, 33, 39, 45, 52, and 58. Two (4 per cent) additional cases were only HPV DNA-positive by E1 and/or L1 consensus PCR. Histological analysis of the 55 specimens revealed that 21 were qualitatively inadequate. Only two of the 34 adequate samples were HPV-negative on all PCR tests, as against 13 of the 21 that were inadequate ( p< 0.001). Combining the data from this and the previous study and excluding inadequate specimens, the worldwide HPV prevalence in cervical carcinomas is 99.7 per cent. The presence of HPV in virtually all cervical cancers implies the highest worldwide attributable fraction so far reported for a specific cause of any major human cancer. The extreme rarity of HPV-negative cancers reinforces the rationale for HPV testing in addition to, or even instead of, cervical cytology in routine cervical screening.

Human papillomavirus is a necessary cause of invasive cervical cancer worldwide.

Estimates of the cancer incidence and mortality in Europe in 2006

Links between human papillomaviruses (HPVs) and cervical cancer were first suspected almost 30 years ago. DNA of specific HPV types has since been found in almost all cervical cancer biopsies. HPV oncogenes that are expressed in these cells are involved in their transformation and immortalization, and are required for the progression towards malignancy. Epidemiological studies have underlined that HPVs are the main aetiological factor for cervical cancer. But how has this knowledge been translated into the clinic to allow the prevention, screening and treatment of cervical cancer?

http://www.hu.ufsc.br/projeto_hpv/Papillomavirus%20and%20cancer.pdf

Papillomaviruses and cancer: from basic studies to clinical application

The causal role of human papillomavirus infections in cervical cancer has been documented beyond reasonable doubt. The association is present in virtually all cervical cancer cases worldwide. It is the right time for medical societies and public health regulators to consider this evidence and to define its preventive and clinical implications. A comprehensive review of key studies and results is presented.

https://jcp.bmj.com/content/jclinpath/55/4/244.full.pdf

The causal relation between human papillomavirus and cervical cancer

Classification of papillomaviruses

DNA from one biopsy sample of invasive cancer of the cervix contained sequences hybridizing with human papillomavirus (HPV) type 11 DNA only under nonstringent conditions. This DNA was molecularly cloned in lambda phage. Under stringent conditions of hybridization it cross-hybridized to a minor extent (less than 0.1%) with HPV types 10, 14, and 15 and showed no homology with DNA of other human HPV types. We therefore propose to designate it tentatively as HPV 16. HPV 16 DNA was used as a probe to test additional cancer biopsy samples from cervical, vulval, and penile cancer, as well as benign genital warts (condylomata acuminata) and cervical dysplasias for the presence of homologous sequences. In 61.1% (11/18) of cervical cancer samples from German patients sequences were found hybridizing with HPV 16 DNA under conditions of high stringency. In contrast, only 34.8% (8/23) of cancer biopsy samples from Kenya and Brazil revealed this DNA. Vulval and penile cancer biopsy samples hybridized to 28.6% (2/7) or 25% (1/4), respectively. Only 2 out of 33 condylomata acuminata contained HPV 16 DNA. Both positive tumors harbored in addition HPV 6 or HPV 11 DNA. The data thus indicate that HPV 16 DNA prevails in malignant tumors, rendering an accidental contamination with papillomavirus DNA from adjacent papillomas rather unlikely. The rare presence in benign genital papillomas in addition to common genital papillomaviruses suggests a dependence of HPV 16 replication on helper virus.

https://www.pnas.org/content/pnas/80/12/3812.full.pdf

A papillomavirus DNA from a cervical carcinoma and its prevalence in cancer biopsy samples from different geographic regions.

DNA of a new papillomavirus type was cloned from a cervical carcinoma biopsy. Two EcoRI clones of 7.8 and 6.9 kb in length were obtained, the latter contained a 900-bp deletion. The BamHI fragments of both clones were used to characterize the DNA. It represents a distinct type of papillomavirus as determined by its size, its cross-hybridization with DNA of other papillomavirus types under conditions of low stringency only, the co-linear alignment of its genome with HPV 6 and HPV 16 prototypes and its occasional occurrence as oligomeric episomes. We tentatively propose to designate it as HPV 18. DNA hybridizing with HPV 18 under stringent conditions was detected in 9/36 cervical carcinomas from Africa and Brazil, in 2/13 cervical tumors from Germany and 1/10 penile carcinomas. Benign tumors (17 cervical dysplasias, 29 genital warts), eight carcinomata in situ and 15 biopsies of normal cervical tissue were devoid of detectable HPV 18 DNA. HPV 18-related DNA was found, however, in cells of the HeLa, KB and C4-1 lines all derived from cervical cancer. The state of the viral DNA was investigated in four cervical cancer biopsies. The data reveal that the DNA might be integrated into the host cell genome. One tumor provided evidence for head to tail tandem repeats some of which persisted as circular episomes.

/pdf/a-new-type-of-papillomavirus-dna-its-presence-in-genital-36984ac3l8.pdf

A new type of papillomavirus DNA, its presence in genital cancer biopsies and in cell lines derived from cervical cancer.

Human genital tumors as well as recurrent laryngeal papillomas were analyzed for the presence of human papillomavirus (HPV) 6 and HPV 11 sequences. HPV 11 DNA was found in 7 of 14 laryngeal papillomas; in the 7 other tumors no HPV DNA was demonstrated. HPV 11 DNA was also found in all five atypical condylomata of the cervix included in this study. Condylomata acuminata mainly contained HPV 6 DNA. From 63 biopsy specimens, 41 clearly harbored HPV 6 DNA and 13 harbored HPV 11 DNA. In three tumors accurate typing was impossible, and in six additional ones neither HPV 6 nor HPV 11 DNA could be demonstrated. The data support a genital origin of laryngeal papillomavirus infections. In 4 of 24 malignant tumors, HPV 11 DNA or related sequences were demonstrated; 2 of the 4 were biopsy specimens from invasive cancer, and the other 2 originated from carcinomata in situ. A possible role of this or related papillomavirus types in the induction of malignant genital tumors remains to be elucidated.

https://www.pnas.org/content/pnas/80/2/560.full.pdf

Human papillomavirus types 6 and 11 DNA sequences in genital and laryngeal papillomas and in some cervical cancers

Human papillomaviruses in the pathogenesis of anogenital cancer.

The view that common warts (verrucae vulgares), juvenile warts (verrucae planae), and genital warts (condylomata acuminata) are caused by the same virus and that differences in appearance are the result of variations in location and host reactivity has been shared by dermatologists for several decades (Frey, 1924; Waelsch and Habermann, 1924; Young, 1964; Rowson and Mahy, 1967; Nasemann, 1974; Lever and Schaumburg-Lever, 1975). This has probably reduced the interest in specific types of human papillomas.

H. zur Hausen

Papers

A papillomavirus DNA from a cervical carcinoma and its prevalence in cancer biopsy samples from different geographic regions.

A new type of papillomavirus DNA, its presence in genital cancer biopsies and in cell lines derived from cervical cancer.

Human papillomavirus types 6 and 11 DNA sequences in genital and laryngeal papillomas and in some cervical cancers

Human papillomaviruses in the pathogenesis of anogenital cancer.

Human papillomaviruses and their possible role in squamous cell carcinomas.