Infectious pathogens are strong and modifiable causes of cancer. The aim of this study was to improve estimates of the global and regional burden of infection-attributable cancers to inform research ...priorities and facilitate prevention efforts.
We used the GLOBOCAN 2018 database of cancer incidence and mortality rates and estimated the attributable fractions and global incidence for specific anatomical cancer sites, subsites, or histological subtypes known to be associated with ten infectious pathogens classified as human carcinogens. We calculated absolute numbers and age-standardised incidence rates (ASIR) of infection-attributable cancers at the country level. Estimates were stratified for sex, age group, and country, and were aggregated according to geographical regions and World Bank income groups.
We found that, for 2018, an estimated 2·2 million infection-attributable cancer cases were diagnosed worldwide, corresponding to an infection-attributable ASIR of 25·0 cases per 100 000 person-years. Primary causes were Helicobacter pylori (810 000 cases, ASIR 8·7 cases per 100 000 person-years), human papillomavirus (690 000, 8·0), hepatitis B virus (360 000, 4·1) and hepatitis C virus (160 000, 1·7). Infection-attributable ASIR was highest in eastern Asia (37·9 cases per 100 000 person-years) and sub-Saharan Africa (33·1), and lowest in northern Europe (13·6) and western Asia (13·8). China accounted for a third of worldwide cancer cases attributable to infection, driven by high ASIR of H pylori (15·6) and hepatitis B virus (11·7) infection. The cancer burden attributed to human papillomavirus showed the clearest relationship with country income level (from ASIR of 6·9 cases per 100 000 person-years in high-income countries to 16·1 in low-income countries).
Infection-attributable cancer incidence, in addition to the absolute number of cases, allows for refined geographic analyses and identification of populations with a high infection-associated cancer burden. When cancer prevention is largely considered in a non-communicable disease context, there is a crucial need for resources directed towards cancer prevention programmes that target infection, particularly in high-risk populations. Such interventions can markedly reduce the increasing cancer burden and associated mortality.
International Agency for Research on Cancer.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Data on carcinogenicity of human papillomavirus (HPV) types in the anus are needed to inform anal cancer prevention through vaccination and screening. This is particularly the case for people ...infected with HIV, who are at an increased risk of anal cancer.
We did a systematic review of studies published from January, 1986, to July, 2017, in MEDLINE, Embase, and the Cochrane Library on anal HPV infection, without any language restrictions. Eligible studies reported type-specific HPV prevalence by strata of cytopathological or histopathological anal diagnosis, sex, and HIV status. Data requests were made to authors when necessary. We did a meta-analysis of type-specific HPV prevalence across the full spectrum of anal diagnoses, from normal cytology to anal cancer. We assessed the main outcome of type-specific HPV prevalence ratios PR, calculated across strata of anal diagnoses, gender, or HIV status, by use of generalised linear models.
95 studies were identified from the search, published between 1992–2017, from which 18 646 individuals fulfilled the criteria for inclusion in the analyses: 8534 people with normal cytology, 5730 with low-grade lesions, 2024 with high-grade lesions, and 2358 with anal cancer. HPV prevalence varied in normal cytology from 42% in HIV-negative women to 76% in HIV-positive men and, for each diagnosis, was higher in individuals who were HIV positive than those who were HIV negative. HPV16 positivity increased with diagnosis severity, being the only HPV type accounting for more HPV infection in anal cancer than normal cytology, both in individuals who were HIV negative (PR 5·0, 95% CI 3·8–6·6, p<0·0001) and those who were HIV positive (2·3, 1·9–2·7, p<0·0001). HPV16 positivity increased even between high-grade lesions and anal cancer, whereas other high-risk HPV types accounted for high proportions of low-grade or high-grade lesions but their prevalence decreased in anal cancer. However, HPV16 was less frequent in HIV-positive than HIV-negative anal cancer, both in men (PR 0·8, 95% CI 0·7–0·9, p<0·0001) and women (0·8, 0·6–1·0, p=0·063), and in HIV-positive versus HIV-negative high-grade lesions in women (0·6, 0·5–0·9, p=0·0077). Type-specific attribution of the non-HPV16 fraction of HIV-positive anal cancer is hindered by a high prevalence of multiple HPV infections.
HPV16 is by far the most carcinogenic HPV type in the anus, with enrichment of HPV16 even from high-grade lesions to anal cancer, both in individuals who are HIV negative and those who are HIV positive. Nevertheless, the fraction of anal cancer attributable to HPV16 is smaller in the HIV-positive population.
International Agency for Research on Cancer.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Background. Data on the relative carcinogenic potential of human papillomavirus (HPV) types among women infected with human immunodeficiency virus (HIV) (WHIV) are needed to inform prevention ...programs for this population. Methods. A systematic literature review and meta-analysis of high-risk HPV-type distribution in 19 883 HIV-positive women was performed. The women, from 86 studies worldwide, included 11 739 with normal cytological findings; 1784 with atypical squamous cells of undetermined significance (ASCUS); 2173 with low-grade and 1282 with high-grade squamous intraepithelial lesions (HSILs) diagnosed cytologically; 1198 with cervical intraepithelial neoplasia grade 1 (CIN1), 456 with CIN2, and 455 with CIN3 diagnosed histologically; and 796 with invasive cervical cancers (ICCs). A large proportion of WHIV, and almost all with ICCs, were from Africa. Results. In Africa, HPV 16 accounted for 13% of HPV-positive WHIV with normal cytological findings, but this proportion increased through ASCUS, low-grade squamous intraepithelial lesions, CIN1, and CIN2 (18%–25%), up to 41%–47% for CIN3 and ICCs. Only HPV 16, HPV 18, and HPV 45 accounted for a greater proportion of HPV infections in ICCs compared with normal cytological findings (ICC:normal ratios, 3.68, 2.47, and 2.55, respectively). Other high-risk types accounted for important proportions of low- and/or high-grade lesions, but their contribution dropped in ICCs, with ICC:normal ratios in Africa ranging from 0.79 for HPV 33 down to 0.38 for HPV 56. Findings for HPV 16 and HPV 18 in Europe/North America, Asia, and Latin America were compatible with those from Africa. Conclusions. HPV 16 and HPV 18 in particular, but also HPV 45, at least in Africa, warrant special attention in WHIV. Broad consistency of findings with those in HIV-uninfected population would suggest that the risk stratification offered by partial HPV genotyping tests also have relevance for HIV-positive women.
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BFBNIB, NUK, PNG, UL, UM, UPUK
A systematic literature review and meta-analysis on type-specific anal HPV prevalence identified sexual preference and HIV infection to be independent and similarly strong determinants of male anal ...HPV16 infection, confirming HIV-positive MSM as priorities for anal cancer prevention.
Abstract
Background
Anal human papillomavirus (HPV) infection, most notably HPV16, the central cause of anal cancer, is increased by anal sexual intercourse and worsened by human immunodeficiency virus (HIV)-positivity.
Methods
A systematic review and meta-analysis of type-specific anal HPV prevalence in men, compared according to sexual preference, HIV status, and, when available, anal cytopathology.
Results
Seventy-nine eligible studies included: 1805 HIV-negative men who have sex with women (MSW), 924 HIV-positive MSW, 8213 HIV-negative men who have sex with men (MSM), and 12758 HIV-positive MSM. Irrespective of anal cytopathology, HPV16 prevalence was significantly higher in MSM than MSW, both among HIV-negative (14% vs 3%; prevalence ratio (PR) 4.7; 95% confidence interval CI 2.5–8.9) and HIV-positive men (30% vs 11%; PR = 2.8; 95% CI, 1.9–4.1). Likewise, HPV16 was significantly higher in HIV-positive than HIV-negative men, both among MSW (PR = 3.5; 95% CI, 1.6–7.7) and MSM (PR = 2.1; 95% CI, 1.8–2.5). Anal HPV16 prevalence was similar between HIV-positive MSW and HIV-negative MSM. For MSM, anal HPV16 prevalence was significantly higher from studies with anal cytopathology, suggesting population sampling effects.
Conclusion
Sexual preference and HIV infection are independent strong determinants of male anal HPV16 infection, confirming HIV-positive MSM as priorities for anal cancer prevention.
Genotyping may improve risk stratification of high‐risk (HR) human papillomavirus (HPV)‐positive women in cervical screening programs; however, prospective data comparing the natural history and ...carcinogenic potential of individual HR types remain limited. A meta‐analysis of cross‐sectional HR HPV‐type distribution in 115,789 HPV‐positive women was performed, including 33,154 normal cytology, 6,810 atypical squamous cells of undetermined significance (ASCUS), 13,480 low‐grade squamous intraepithelial lesions (LSIL) and 6,616 high‐grade SIL (HSIL) diagnosed cytologically, 8,106 cervical intraepithelial neoplasia grade 1 (CIN1), 4,068 CIN2 and 10,753 CIN3 diagnosed histologically and 36,374 invasive cervical cancers (ICCs) from 423 PCR‐based studies worldwide. No strong differences in HPV‐type distribution were apparent between normal cytology, ASCUS, LSIL or CIN1. However, HPV16 positivity increased steeply from normal/ASCUS/LSIL/CIN1 (20–28%), through CIN2/HSIL (40/47%) to CIN3/ICC (58/63%). HPV16, 18 and 45 accounted for a greater or equal proportion of HPV infections in ICC compared to normal cytology (ICC:normal ratios = 3.07, 1.87 and 1.10, respectively) and to CIN3 (ICC:CIN3 ratios = 1.08, 2.11 and 1.47, respectively). Other HR types accounted for important proportions of HPV‐positive CIN2 and CIN3, but their contribution dropped in ICC, with ICC:normal ratios ranging from 0.94 for HPV33 down to 0.16 for HPV51. ICC:normal ratios were particularly high for HPV45 in Africa (1.85) and South/Central America (1.79) and for HPV58 in Eastern Asia (1.36). ASCUS and LSIL appear proxies of HPV infection rather than cancer precursors, and even CIN3 is not entirely representative of the types causing ICC. HPV16 in particular, but also HPV18 and 45, warrant special attention in HPV‐based screening programs.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Recent discoveries on the origins of modern humans from multiple archaic hominin populations and the diversity of human papillomaviruses (HPVs) suggest a complex scenario of virus-host evolution. To ...evaluate the origin of HPV pathogenesis, we estimated the phylogeny, timing, and dispersal of HPV16 variants using a Bayesian Markov Chain Monte Carlo framework. To increase precision, we identified and characterized non-human primate papillomaviruses from New and Old World monkeys to set molecular clock models. We demonstrate specific host niche adaptation of primate papillomaviruses with subsequent coevolution with their primate hosts for at least 40 million years. Analyses of 212 HPV16 complete genomes and 3582 partial sequences estimated ancient divergence of HPV16 variants (between A and BCD lineages) from their most recent common ancestors around half a million years ago, roughly coinciding with the timing of the split between archaic Neanderthals and modern Homo sapiens, and nearly three times longer than divergence times of modern Homo sapiens. HPV16 A lineage variants were significantly underrepresented in present African populations, whereas the A sublineages were highly prevalent in European (A1-3) and Asian (A4) populations, indicative of viral sexual transmission from Neanderthals to modern non-African humans through multiple interbreeding events in the past 80 thousand years. Remarkably, the human leukocyte antigen B*07:02 and C*07:02 alleles associated with increased risk in cervix cancer represent introgressed regions from Neanderthals in present-day Eurasians. The archaic hominin-host-switch model was also supported by other HPV variants. Niche adaptation and virus-host codivergence appear to influence the pathogenesis of papillomaviruses.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Pooled data on human papillomavirus (HPV) type distribution in invasive cervical cancer (ICC) can help to predict the potential impact of HPV type‐specific vaccines and screening tests, and to ...understand the carcinogenicity of HPV types. We performed a meta‐analysis of HPV type‐specific prevalence data published from 1990 to 2010, including a total of 243 studies and 30,848 ICC. The proportion of ICC associated with HPV16 and/or 18 (HPV16/18) was between 70 and 76% in all world regions except Asia. In Western/Central Asia, 82% of ICC was HPV16/18‐associated compared to only 68% in Eastern Asia. The 12 most common HPV types identified, in order of decreasing prevalence, were HPV16 (57%), 18 (16%), 58, 33, 45, 31, 52, 35, 59, 39, 51 and 56. The prevalence of other types, phylogenetically related to those above, ranged from <0.1% for HPV85 to 0.6% for HPV68. Overall HPV prevalence increased significantly from 85.9% in studies published from 1990 to 1999 to 92.9% in studies published from 2006 to 2010. Prevalence increases were large for multiple infections (from 4.0 to 15.7%) and for HPV16 (from 51.8 to 60.0%, including HPV16 alone or in multiple infections). Smaller but significant increases in prevalence were also seen for HPV39, 53 and 58. A large amount of recently published data has improved the understanding of the contribution of a broad range of HPV types to ICC in different world regions. However, estimating the fraction of ICC attributable to different types is increasingly complicated by the detection of multiple HPV infections in ICC.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK