Protocol: A systematic review of the prevalence of Human Papillomavirus (HPV) infection, Cervical Intraepithelial Neoplasia (CIN) and Cervical Cancer in female prisoner population. Background Human papillomavirus (HPV) is a common infection among humans transmitted by sexual contact. There are more than a hundred types and among them, thirteen have been identified as causes of cancer. Cervical cancer is the second most common cancer in women worldwide and it is caused by HPV infection in almost every case. HPV types 16 and 18 cause 70% of the cases of cervical cancer and precancerous lesions. The burden of cervical cancer is not distributed evenly worldwide, since 85% of the annual deaths from cervical cancer occur in developing countries.(1) Types of screening for cervical cancer that are currently in use include Papanicolau (Pap) test and liquid-based cytology (LBC), visual inspection with Acetic Acid (VIA), and HPV testing.(1) Precancerous lesions, called Cervical Intraepithelial Neoplasia (CIN), can be detected with screening tests. They are classified under the Bethesda system in Low-grade Squamous Intraepithelial Lesions (LSIL) and High-grade Squamous Intraepithelial Lesion (HSIL).(2,3) Besides the causal role attributed to HPV, risk factors for cervical cancer include tobacco smoking, low socio-economic status, immunosuppression such as HIV/AIDS and transplant recipients, and occupational exposure to tetrachloroethylene.(4) Additionally, early age at first intercourse and multiple sexual partners are associated with higher risk of CIN and cervical cancer, through early and repeated acquisition of HPV infection. Many of these risk factors are likely to cluster in some vulnerable groups of the population, such as prisoners. Worldwide, there are more than ten million people in prison. The association of imprisonment and poor health outcomes is very well established both for physical and psychiatric diseases. Socio-economic and behavioural factors account for a large part of the burden.(5) However, lack of services and stigmatisation are likely to be playing an additional role. About 500,000 women are prisoners in criminal justice institutions worldwide, representing 2 9% of the total prison population. This proportion of female prisoners has been rising in many countries and is likely to continue growing. It has been observed that women in prison 1
have higher cancer rates than men, and in women cervical cancer is the most common.(5) The latter was confirmed in a study conducted in prisons in London, which assessed incidence of different types of cancer in prisoners. In this study, the most common diagnosis in women was intraepithelial carcinoma of the cervix, with the majority of them in the age group 20 to 30 years old.(6) Similarly, in a prison in Texas, cervical cancer was the most common cancer among women.(7) When performing screening tests to a prison population, a study in the UK found an abnormal-smear rate of 13%, which was double than the general population rate by that time.(8) In a prison in Brazil, 2937 women were tested for HPV, finding a prevalence of 16.3% of HPV infection by highly oncogenic viral types.(9) Awareness of the burden from HPV infection and its consequences in this marginalised group would help improve coverage and access to effective interventions, such as screening and reduction of risk factors. According to the World Health Organisation, screening for cervical cancer is only effective if a high proportion of women participate.(1) Control of infectious diseases is largely limited when stigmatised groups do not access public health interventions, generating pockets of disease that are hard to reach, and increasing the burden for society as a whole. Cervical cancer is completely preventable through risk factors control, specially HPV transmission, and screening programmes that detect the presence of HPV or intraepithelial neoplastic lesions before they progress into cancer. Therefore, public health efforts that are allocated in preventive interventions have the potential to reduce the burden from cervical cancer dramatically, and to have great impact in groups that are especially vulnerable to this disease, such as prisoners. Rationale Although poor health status of prisoner population compared to general population has been largely established, particularities of subgroups and how their health is affected by imprisonment are less clear. Women s health programmes advocate for prevention and early diagnosis of cervical dysplasia and cancer. However, female prisoners are frequently left behind in these efforts, being stigma a possible explanation. Higher rates of cervical cancer in prisoners compared to general population have been reported, but the magnitude of the difference as not been summarised, neither has the prevalence of HPV infection and precancerous lesions in this group. 2
Objectives The objective of this systematic review is to identify and evaluate the current evidence on the prevalence of HPV infection, cervical intraepithelial neoplasia and cervical cancer in female prisoners worldwide. Search strategy The search will be undertaken through the following online databases: Ovid Medline, Web of Science Core Collection, Embase, LILACS, Global Health, National Criminal Justice Reference Service Abstracts (NCJRS) and Proquest Dissertations & Theses. The search terms to be used are as follows and terms will be combined using the Boolean operators OR (within the columns) and AND (between the columns). Population Exposure Outcome women female woman prison* incarcerat* detainee* jail* convict* inmate* gaol* youth offend* deprived of freedom* deprived of liberty* criminal justice justice facilit* correctional penitentiary penal detention prison(mesh) HPV human papilloma virus human papillomavirus CIN cervical intraepithelial neoplasia* intraepithelial lesion* cervical cervix cervical cancer, uterine(mesh) cervical intraepithelial neoplasia (MeSH) papanicolaou smear(mesh) 3
The reference lists of relevant studies and review articles will be screened to identify any secondary references. The PRISMA guidelines for the presentation of systematic reviews will be followed. (10) Selection of studies After removal of duplicates all citations will be scanned for relevance. All relevant studies will be assessed for eligibility according to pre-specified inclusion and exclusion criteria. Data collection Data from included studies will be extracted from each study using a data collection proforma developed by the authors. Risk of bias analysis Each study will undergo quality assessment using a risk of bias tool developed by the authors and based on the Newcastle Ottawa Quality Assessment Scale. The tool will assess the quality of each study using a star allocation system. Synthesis of results Results from each study will be analysed by meta-analysis provided the data allows this. In the case of high heterogeneity, the evidence will be summarised narratively. Statistical analyses will be conducted using STATA. References (1) World Health Organisation. Human papillomavirus and cervical cancer. Fact sheet n 380. September 2013; Available at: http://www.who.int/mediacentre/factsheets/fs380/en/. Accessed May 1, 2014. (2) Public Health England. NHS Cervical Screening Programme. 2013; Available at: http://www.cancerscreening.nhs.uk/cervical/. Accessed May 1, 2014. 4
(3) Buckley CH, Butler EB, Fox H. Cervical intraepithelial neoplasia. Journal of Clinical Pathology 1982 January 01;35(1):1-13. (4) Cancer Research UK. Cervical cancer risk factors. Available at: http://www.cancerresearchuk.org/cancer-info/cancerstats/types/cervix/riskfactors/cervicalcancer-risk-factors. Accessed May 1, 2014. (5) Fazel S BJ. The health of prisoners. Lancet 2011;377:956-965. (6) Davies EA, Sehgal A, Linklater KM, Heaps K, Moren C, Walford C, et al. Cancer in the London prison population, 1986 2005. Journal of Public Health 2010 December 01;32(4):526-531. (7) Mathew P, Elting L, Cooksley C, Owen S, Lin J. Cancer in an incarcerated population. Cancer 2005;104(10):2197-2204. (8) Downey GP, Gabriel G, Deery AR, Crow J, Walker PG, Curtis P. Management of female prisoners with abnormal cervical cytology. BMJ 1994 BMJ Publishing Group Ltd;308(6941):1412-1414. (9) Lopes F, Latorre MRDO, Pignatari ACC, Buchalla CM. Prevalencia de HIV, papilomavirus humano e sifilis na Penitenciaria Feminina da Capital, Sao Paulo, 1997-1998. Cadernos de Saude Publica 2001;17:1473-1480. (10) Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. Annals of Internal Medicine 2009 August 18;151(4):264-269. 5