Incidence Of HPV-associated Cancers Research Articles

Human Papillomavirus-Attributable Cancers - United States, 2012-2016.

Human papillomavirus (HPV) causes nearly all cervical cancers and some cancers of the vagina, vulva, penis, anus, and oropharynx (1).* Most HPV infections are asymptomatic and clear spontaneously within 1 to 2 years; however, persistent infection with oncogenic HPV types can lead to development of precancer or cancer (2). In the United States, the 9-valent HPV vaccine (9vHPV) is available to protect against oncogenic HPV types 16, 18, 31, 33, 45, 52, and 58 as well as nononcogenic types 6 and 11 that cause genital warts. CDC analyzed data from the U.S. Cancer Statistics (USCS)† to assess the incidence of HPV-associated cancers and to estimate the annual number of cancers caused by HPV, overall and by state, during 2012-2016 (3,4). An average of 43,999 HPV-associated cancers were reported annually, and an estimated 34,800 (79%) of those cancers were attributable to HPV. Of these 34,800 cancers, an estimated 32,100 (92%) were attributable to the types targeted by 9vHPV, with 19,000 occurring among females and 13,100 among males. The most common were cervical (9,700) and oropharyngeal cancers (12,600). The number of cancers estimated to be attributable to the types targeted by 9vHPV ranged by state from 40 to 3,270 per year. HPV vaccination is an important strategy that could prevent these cancers, but during 2018, only half of adolescents were up to date on HPV vaccination (5). These surveillance data from population-based cancer registries can be used to inform the planning for, and monitor the long-term impact of, HPV vaccination and cancer screening efforts nationally and within states.

Increasing Incidence rates of Oropharyngeal Squamous Cell Carcinoma in Germany and Significance of Disease Burden Attributed to Human Papillomavirus.

Increasing incidences of head and neck cancers and rising proportions of these associated with human papillomavirus (HPV), especially in the oropharynx, have been reported in international studies. So far, the trends and contribution of HPV to the number of newly diagnosed cases of oropharyngeal squamous cell carcinomas (OPSCC) in Germany are uncertain. We investigated HPV association and incidence rates in a cohort of consecutively included patients with OPSCC in Giessen 2000-2017, and compared our results with regional (Giessen and the federal state of Hesse), national (Germany), and international (United States) databases. Regional data show a significant increase in the overall incidence rates of oropharyngeal cancers and in the incidence of HPV-associated cancers of the subsites tonsils and oropharynx, whereas other oropharyngeal subsites show no significant change. Analysis of national databases shows a significant incidence increase in Germany and in the United States. The rise in incidence is predominantly attributable to male patients in the US population, whereas in Germany rising OPSCC incidence is more associated with females. There is a significant elevation of OPSCC incidence rates in Germany, which corresponds to the recognized incidence increase of HPV-related oropharyngeal cancers based on experimental data from consecutively included patients of our cohort. Our investigation shows different patterns of this increase in Germany and in the United States, which demonstrates spatial heterogeneity and the need for population-based investigations regarding the role of HPV in oropharyngeal cancer.

Lack of clinician knowledge of human papillomavirus (HPV) vaccination to prevent HPV-related cancers in men: An interview study.

e18273 Background: Human papillomavirus (HPV) has a well-established link to cervical cancer and anogenital and oropharyngeal malignancies. Recognition of the HPV-caused cancer burden in males has led to expansions of female-only HPV vaccination programs to all genders. This study explored drivers of and barriers to gender-neutral HPV vaccination (GNV) program adoption, implementation, and potential impacts on the HPV-caused cancer burden. Methods: We conducted in-depth interviews with academic oncologists as well as advocacy, public health, infectious disease, and policy experts in six countries (Argentina, Australia, Austria, Brazil, Canada and Italy) from April-August 2018. Using a semi-structured discussion guide, we sought to elicit expert perceptions on factors affecting uptake of HPV vaccination in males and subsequent effects on the incidence of HPV-associated cancer. Data were analyzed for key themes. Results: Eighteen experts participated in the study, including three academic oncologists and two doctoral level oncology researchers. A key theme from the analysis was the critical need to promote education and awareness about GNV across all healthcare providers to facilitate vaccine uptake and high GNV coverage rates. Participants reported a lack of awareness among segments of practitioners about the effectiveness of the HPV vaccine in preventing HPV infection and associated cancers in all genders. They also described strategies to overcome knowledge gaps, such as partnerships with oncologists, cancer advocacy organizations, and professional medical societies, emphasizing the key role that all health care providers can play in raising awareness of the importance of HPV vaccination for all genders. Conclusions: Findings from this study suggest the need to enhance healthcare provider education about GNV, and the importance of a multi-specialty approach to promoting HPV vaccination to prevent infection and HPV associated morbidity and mortality in all genders.

Rural-Urban Differences in Cancer Incidence and Trends in the United States.

Background: Cancer incidence and mortality rates in the United States are declining, but this decrease may not be observed in rural areas where residents are more likely to live in poverty, smoke, and forego cancer screening. However, there is limited research exploring national rural-urban differences in cancer incidence and trends.Methods: We analyzed data from the North American Association of Central Cancer Registries' public use dataset, which includes population-based cancer incidence data from 46 states. We calculated age-adjusted incidence rates, rate ratios, and annual percentage change (APC) for: all cancers combined, selected individual cancers, and cancers associated with tobacco use and human papillomavirus (HPV). Rural-urban comparisons were made by demographic, geographic, and socioeconomic characteristics for 2009 to 2013. Trends were analyzed for 1995 to 2013.Results: Combined cancers incidence rates were generally higher in urban populations, except for the South, although the urban decline in incidence rate was greater than in rural populations (10.2% vs. 4.8%, respectively). Rural cancer disparities included higher rates of tobacco-associated, HPV-associated, lung and bronchus, cervical, and colorectal cancers across most population groups. Furthermore, HPV-associated cancer incidence rates increased in rural areas (APC = 0.724, P < 0.05), while temporal trends remained stable in urban areas.Conclusions: Cancer rates associated with modifiable risks-tobacco, HPV, and some preventive screening modalities (e.g., colorectal and cervical cancers)-were higher in rural compared with urban populations.Impact: Population-based, clinical, and/or policy strategies and interventions that address these modifiable risk factors could help reduce cancer disparities experienced in rural populations. Cancer Epidemiol Biomarkers Prev; 27(11); 1265-74. ©2017 AACR.

Trends in Human Papillomavirus–Associated Cancers — United States, 1999–2015

Human papillomavirus (HPV) is a known cause of cervical cancer, as well as some oropharyngeal, vulvar, vaginal, penile, and anal cancers. To assess trends, characterized by average annual percent change (AAPC), in HPV-associated cancer incidence during 1999–2015, CDC analyzed data from cancer registries covering 97.8% of the U.S. population. A total of 30,115 new cases of HPV-associated cancers were reported in 1999 and 43,371 in 2015. During 1999–2015, cervical cancer rates decreased 1.6% per year; vaginal squamous cell carcinoma (SCC) rates decreased 0.6% per year; oropharyngeal SCC rates increased among both men (2.7%) and women (0.8%); anal SCC rates also increased among both men (2.1%) and women (2.9%); vulvar SCC rates increased (1.3%); and penile SCC rates remained stable. In 2015 oropharyngeal SCC (15,479 cases among men and 3,438 among women) was the most common HPV-associated cancer. Continued surveillance through high-quality cancer registries is important to monitor cancer incidence and trends in these potentially preventable cancers.

Baseline Incidence of HPV-Associated Invasive and in Situ Cancers in Germany Prior to Potential Vaccination Effects

Vaccines against human papillomaviruses are covered by statutory health insurances in Germany since March 2007. A reduction of cervical and other HPV-associated cancers is expected. Incidence rates of HPV-associated cancers preceding the introduction of vaccines are unknown. These, however, are important for assessing the effects of HPV vaccines. The aim of the present study was to bridge this knowledge gap. Based on cancer registry data from seven federal states, average yearly incidence rates for cervical, anogenital, oropharyngeal cancers and cancers of the oral cavity were calculated for the period 2003 to 2007. Additionally, estimated numbers of cases give an overview on the total burden of disease caused by HPV-associated cancers in Germany. Incidence trends from 2003 to 2013 are also presented. In Germany, 11,686 cases of invasive HPV-associated cancers occurred yearly before the introduction of HPV vaccines. The most common sites are cervical cancers for women (4,387 cases) and oropharyngeal cancers for men (2,770 cases) with age-standardized incidence rates of 8.8 and 5.9 cases per 100,000 persons, respectively. The age-standardized incidence rate for in situ cervical cancers amounts to 23.5 cases per 100 000 women. Incidence trends show significant increases of invasive vulvar, penile and anorectal cancers. This work presents robust incidence data of HPV-associated cancers in Germany prior to the introduction of the HPV vaccine. Effects of HPV vaccines on the incidence of HPV-associated cancers can be estimated for Germany earliest in 2019.

Rural-urban differences in human papillomavirus knowledge and awareness among US adults

Rural residents of the United States have higher HPV-associated cancer incidence and mortality, and suboptimal HPV vaccine uptake compared to urban residents. This study aimed to assess differences in knowledge and awareness of HPV, the HPV vaccine, and HPV-associated cancers among rural and urban residents. We analyzed data from the Health Information National Trends Survey 2013–2017 on 10,147 respondents ages ≥18 years. Multivariable logistic regression analyses compared urban/rural differences in knowledge and awareness of HPV, associated cancers, and HPV vaccine. Models were adjusted for sex, age, race/ethnicity, education, household income, census region, health insurance, regular provider, internet use, and personal history of cancer. Overall, 67.2% and 65.8% of urban residents were aware of HPV and HPV vaccine, respectively, compared to only 55.8% and 58.6% of rural residents. Adjusted models illustrated that compared to urban residents, rural residents were less likely to be aware of HPV (OR = 0.68, 95% CI = 0.53–0.86) and HPV vaccine (OR = 0.78, 95% CI = 0.63–0.97). Among those who were aware of HPV, rural residents were less likely to know that HPV causes cervical cancer (OR = 0.62, 95% CI = 0.46–0.84) and that HPV can be transmitted through sexual contact (OR = 0.72, 95% CI = 0.56–0.94). No significant differences between rural and urban residents were noted for knowledge that HPV is transmitted sexually and that it causes oral, anal, and penile cancers. This study highlights significant rural health disparities in knowledge and awareness of HPV and the HPV vaccine compared to urban counterparts.

On the implications of desexualizing vaccines against sexually transmitted diseases: reflections from a practicing pediatrician

Human papillomavirus (HPV) vaccination holds great promise for drastically reducing the incidence of HPV-associated cancers of the genital tract, and possibly also certain head and neck cancers. Unfortunately, rates of HPV vaccine utilization among adolescents are low in many countries. Many research studies have identified the fact that HPV is a sexually transmitted infection as a barrier to higher vaccination rates. This is related to providers’ and parents’ reluctance to discuss or consider the burgeoning sexuality of their child. An approach suggested to overcome this barrier is to “desexualize” the vaccine. This entails focusing discussions and public messages on the cancer-preventing properties of the vaccine and ignoring or minimizing information about HPV’s sexual transmissibility. In an article by Velan and Yadgar, the authors argue that this approach does more harm than good. This associated commentary offers a slightly different viewpoint from one who has been “in the trenches” both clinically and from a research standpoint for many years.

Human papillomavirus in oropharyngeal cancer in Canada: analysis of 5 comprehensive cancer centres using multiple imputation.

The incidence of oropharyngeal cancer has risen over the past 2 decades. This rise has been attributed to human papillomavirus (HPV), but information on temporal trends in incidence of HPV-associated cancers across Canada is limited. We collected social, clinical and demographic characteristics and p16 protein status (p16-positive or p16-negative, using this immunohistochemistry variable as a surrogate marker of HPV status) for 3643 patients with oropharyngeal cancer diagnosed between 2000 and 2012 at comprehensive cancer centres in British Columbia (6 centres), Edmonton, Calgary, Toronto and Halifax. We used receiver operating characteristic curves and multiple imputation to estimate the p16 status for missing values. We chose a best-imputation probability cut point on the basis of accuracy in samples with known p16 status and through an independent relation between p16 status and overall survival. We used logistic and Cox proportional hazard regression. We found no temporal changes in p16-positive status initially, but there was significant selection bias, with p16 testing significantly more likely to be performed in males, lifetime never-smokers, patients with tonsillar or base-of-tongue tumours and those with nodal involvement (p < 0.05 for each variable). We used the following variables associated with p16-positive status for multiple imputation: male sex, tonsillar or base-of-tongue tumours, smaller tumours, nodal involvement, less smoking and lower alcohol consumption (p < 0.05 for each variable). Using sensitivity analyses, we showed that different imputation probability cut points for p16-positive status each identified a rise from 2000 to 2012, with the best-probability cut point identifying an increase from 47.3% in 2000 to 73.7% in 2012 (p < 0.001). Across multiple centres in Canada, there was a steady rise in the proportion of oropharyngeal cancers attributable to HPV from 2000 to 2012.

Systemic Treatment in HPV-Induced Recurrent or Metastatic HNSCC.

Recurrent or metastatic head and neck cancer describes tumor deposits that arise locally, regionally, or at distant sites after treatment or distant metastases at the time of primary diagnosis. Prognosis for R/M squamous cell carcinomas of the head and neck (HNSCC) is poor and treatment options are limited in this situation. Human papillomavirus (HPV) is an important risk factor for HNSCC. About 40% of all HNSCC have been attributed to HPV in Europe. HPV positivity at initial diagnosis is the single best prognostic factor for survival. However, data for the prognostic and predictive value of HPV in the R/M situation are still scarce. Due to the rising incidence of HPV-associated cancers, the number of R/M HPV+ carcinomas is also expected to rise. This chapter therefore aims to give an overview of the current knowledge concerning the role of HPV as a prognostic and predictive marker in recurrent or metastatic HNSCC.

Using Social Marketing Theory as a Framework for Understanding and Increasing HPV Vaccine Series Completion Among Hispanic Adolescents: A Qualitative Study.

HPV vaccine series completion rates among adolescent Hispanic females and males (~39 and 21 %, respectively) are far below the Healthy People 80 % coverage goal. Completion of the 3-dose vaccine series is critical to reducing the incidence of HPV-associated cancers. This formative study applies social marketing theory to assess the needs and preferences of Hispanic mothers in order to guide the development of interventions to increase HPV vaccine completion. We conducted 51 in-depth interviews with Hispanic mothers of adolescents to identify the key concepts of social marketing theory (i.e., the four P's: product, price, place and promotion). Results suggest that a desire complete the vaccine series, vaccine reminders and preventing illnesses and protecting their children against illnesses and HPV all influence vaccination (product). The majority of Completed mothers did not experience barriers that prevented vaccine series completion and Initiated mothers perceived a lack of health insurance and the cost of the vaccine as potential barriers. Informational barriers were prevalent across both market segments (price). Clinics are important locations for deciding to complete the vaccine series (place). They are the preferred sources to obtain information about the HPV vaccine thus making them ideal locations to deliver intervention messages, followed by television, the child's school and brochures (promotion). Increasing HPV vaccine coverage among Hispanic adolescents will reduce the rates of HPV-associated cancers and the cervical cancer health disparity among Hispanic women. This research can inform the development of an intervention to increase HPV vaccine series completion in this population.

Human Papillomavirus–Associated Cancers — United States, 2008–2012

Human papillomavirus (HPV) is a known cause of cervical cancers, as well as some vulvar, vaginal, penile, oropharyngeal, anal, and rectal cancers (1,2). Although most HPV infections are asymptomatic and clear spontaneously, persistent infections with one of 13 oncogenic HPV types can progress to precancer or cancer. To assess the incidence of HPV-associated cancers, CDC analyzed 2008-2012 high-quality data from the CDC's National Program of Cancer Registries and the National Cancer Institute's Surveillance, Epidemiology, and End Results program. During 2008-2012, an average of 38,793 HPV-associated cancers were diagnosed annually, including 23,000 (59%) among females and 15,793 (41%) among males. By multiplying these counts by the percentages attributable to HPV (3), CDC estimated that approximately 30,700 new cancers were attributable to HPV, including 19,200 among females and 11,600 among males. Cervical precancers can be detected through screening, and treatment can prevent progression to cancer; HPV vaccination can prevent infection with HPV types that cause cancer at cervical and other sites (3). Vaccines are available for HPV types 16 and 18, which cause 63% of all HPV-associated cancers in the United States, and for HPV types 31, 33, 45, 52, and 58, which cause an additional 10% (3). Among the oncogenic HPV types, HPV 16 is the most likely to both persist and to progress to cancer (3). The impact of these primary and secondary prevention interventions can be monitored using surveillance data from population-based cancer registries.

Abstract 4048: HPV16 immunity induced by immune responses to mutations in E6 and E7 proteins

Abstract Human papillomavirus (HPV) causes 30% of cancers attributable to infectious pathogens. HPV16 causes most cervical, anal, vaginal, vulvar, and oropharyngeal cancers. Although preventive vaccines targeting HPV16 and 18 are available, rates of vaccination are uneven. The incidence of HPV-associated cancers for which no screening algorithms have been validated continues to increase. Development of squamous cervical cancer and its precursor, cervical intraepithelial neoplasia (CIN) 2/3 is associated with integration of HPV genome into the host genome, and expression of the HPV E6 and E7- gene products, which inactivate p53 and pRb respectively. Since E6 and E7 are constitutively expressed in cervical carcinomas and CIN, they present attractive immunotherapeutic targets. Development of immunotherapies has been limited, in part, by modest immunogenicity of vaccines tested to date. The purpose of this study is to augment the immunogenicity of the E6 and E7 antigens through mutational screening. A subset of CIN2/3 do undergo complete regression. Our lab has carried out a series of prospective clinical studies, including immunotherapeutic interventions, in subjects with CIN2/3. Peripheral blood T cell responses to E6 and E7 are marginal, and do not distinguish regressors in either vaccinated or unvaccinated subjects. However, in vaccinated subjects, the lesion microenvironment is comprised of new tertiary lymphoid structures, evidence of T cell proliferation elicited by cognate antigen, and clonally expanded TCRs. Tissue T cells in vaccinated subjects access dysplastic epithelium, in contrast to T cells in persistent lesions, which were confined to the stromal compartment. These findings suggest that T cells that could mediate regression can be elicited by vaccination. However, strategies to enhance immunogenicity would likely increase therapeutic effect. Here we present an approach designed to determine the effect of mutations in E6 and E7 on antigenicity. Mutations can enhance immune responses to antigens by several mechanisms, including altering antigen processing, trafficking, glycolsylation, and affinity to major histocompatibility complexes. Using error prone PCR, we generated libraries containing random mutations in the coding sequence of E6 and E7. Clones from each library are currently being screened in vitro to identify immunogenic mutants, which could be potentially used for multi-epitope vaccines. Citation Format: Maria Agarwal, Ashley Saint-Fleur, Jie Fu, Hyam Levitsky, Cornelia L. Trimble. HPV16 immunity induced by immune responses to mutations in E6 and E7 proteins. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4048. doi:10.1158/1538-7445.AM2015-4048

Trends in the incidence of human papillomavirus-related noncervical and cervical cancers in Alberta, Canada: apopulation-based study.

Recent epidemiologic studies have suggested that the incidence of noncervical cancers associated with human papillomavirus (HPV) is increasing. We assessed temporal, age-specific and sex-specific changes in the incidence of HPV-associated cancers in a population-based study. We used the Alberta Cancer Registry, a registry of all cancers diagnosed in the province of Alberta, Canada, to identify patients with cancers of the oropharynx, cervix, vulva, vagina, anus and penis (cancers associated with HPV) between Jan. 1, 1975, and Dec. 31, 2009. We estimated the age-standardized incidence of each cancer by sex- and age-specific group and assessed the annual percentage change using joinpoint regression. The age-standardized incidence of oropharyngeal cancers increased for each 5-year interval of the study period among men (annual percentage change 3.4, p<0.001) and women (annual percentage change 1.5, p=0.009). For anal cancers, the age-standardized rates increased among women (annual percentage change 2.2, p<0.001) and men (annual percentage change 1.8, p=0.008). The age-standardized incidence of cervical cancer increased with age, reaching an annual percentage change of -3.5 among women aged 75-84 years (p = 0.04). The rates of other HPV-associated cancers (vulvar, vaginal and penile) showed little change. Our findings showed increases in the incidence of the HPV-associated cancers of the oropharynx and anus among men and women, and increases in cervical cancer among younger women. The incidence of HPV-related cancers in younger age groups should continue to be monitored. Programs to prevent HPV infection, such as vaccination, should be considered for males as well as females.

HPV vaccination in HIV+ adolescents and young adults induces strong HPV-specific immune responses

Background HPV-associated ano-genital infections represent the most common sexually-transmitted disease in the general population. The incidence of HPV-associated cancers has been increasing in HIV-infected patients. HPV vaccination may be an approach to reduce the risk of HPVassociated cancers in HIV-infected patients and a combined strategy of screening and vaccination may guarantee an adequate prevention of HPV-associated lesions. Immunogenicity of HPV vaccines in HIVinfected patients is still not adequately evaluated. We analyzed immunogenicity of a quadrivalent HPV vaccine in HIV-infected patients without molecular evidence of vaccine-type HPV infection focusing on HPV-specific cell mediated immunity (CMI).

HPV Associated Cancer Incidence Rates Point to Needed Efforts to Increase HPV Vaccination Coverage

HPV Associated Cancer Incidence Rates Point to Needed Efforts to Increase HPV Vaccination Coverage

Abstract IA23: Cervical tissue T cells in HPV disease.

Abstract Despite the availability of preventative vaccines, human papillomaviruses (HPVs) cause more cancers than any other virus. Like other viral pathogens that cause human cancers, most HPV infections do not cause overt harm, let alone symptoms. Indeed, in immune-competent persons, most genital infections are eventually cleared. Nonetheless, the incidence of HPV-associated cancers in anatomic sites for which no screening algorithms have been validated is rising steadily. Preinvasive, intraepithelial lesions are associated with integration of the HPV genome into the host genome, and subsequent expression of the viral oncoproteins, E6 and E7, which are required for disease initiation and persistence. These true tumor-specific antigens provide non-“self” targets for immune therapies. The relatively indolent clinical course of preinvasive lesions, and tissue tropism of HPV infections provide opportunities to identify and treat early stage disease. In cervical HPV disease, a subset of high grade dysplastic lesions, cervical intraepithelial neoplasia grade 3 (CIN3), do in fact undergo complete regression, which is presumably immunologically mediated. However, T cell responses to viral antigens, measured in the blood, have not been informative with respect to immune responses in the cervical mucosa. Our team has been studying strategies to enhance the quality and magnitude of immune responses to HPV antigens. Ongoing clinical trials testing therapeutic vaccination and strategies to manipulate the lesion microenvironment to enhance homing and access of immune effector cells will be discussed. The design of these trials has been informed by studies of tissue-resident T cells in normal cervical mucosa, and by changes identified in dysplastic mucosa, both in lesions that regress, and in those that do not, in the course of a defined, prospective study window. Changes in the composition and distribution of tissue T cells postvaccination will be presented. Strategies to modify the stromal compartment of HPV lesions to promote lesion clearance will also be discussed. Citation Format: C.L. Trimble, J. Teague, T.C. Wu, R.A. Clark. Cervical tissue T cells in HPV disease. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr IA23.

Preventing Human Papillomavirus Disease

Preventing Human Papillomavirus Disease

Human papillomavirus-related disease in people with HIV.

The incidence of human papillomavirus (HPV)-related cancers has increased among people with HIV infection compared with the general population. This review will describe recent findings in HPV-associated cancer incidence since the introduction of antiretroviral therapy, HPV/disease prevalence at sites other than cervix and anus, and recent data on screening and treatment of anal intraepithelial neoplasia. Consistent with high prevalence of anogenital HPV infection, new data on cervical intraepithelial neoplasia and anal intraepithelial neoplasia in HIV-positive men and women show that the incidence of cervical cancer has not declined since the introduction of antiretroviral therapy and that the incidence of anal cancer is rising. Several studies also highlight high rates of HPV infection and HPV-associated disease at sites other than the cervix and anus, including the penis and the mouth. Treatment methods for anal intraepithelial neoplasia have been described and show reasonable efficacy. New data imply that the problem of HPV-related cancers will not decline among HIV-positive men and women in the antiretroviral therapy era, highlighting the need to perform studies to determine if screening and treatment of anal intraepithelial neoplasia will prevent development of anal cancer. Recent data show progress in both these areas.

Prevalence of sleep apnoea in patients over 40 years of age with spinal cord lesions.

Twenty two patients over the age of 40 with stable spinal cord damage underwent overnight sleep studies to investigate the prevalence of sleep apnoea. Ten patients had some evidence of obstructive sleep apnoea (OSA). Hypoxic events were scored as number of dips of SaO2 more than 4% below the preceding 10 minute average (> 4% SaO2 dip rate). All the patients had more than five such dips per hour and six had clearly abnormal dip rates of more than 15 per hour. Two other patients had dip rates above 10 per hour without apnoeas but periods of central hypoventilation mainly during rapid eye movement (REM) sleep. OSA appears to be more common in older patients with spinal cord injury than in the general population. Possible relevant factors include patient selection, reduced ventilatory function secondary to spinal cord damage, sleep posture and medication.