Beliefs about the risk factors for cervical cancer in a British population sample

Abstract

Background. The introduction of human papillomavirus (HPV) testing into cervical screening has the potential to alter public perceptions of cervical cancer by making explicit the role of a sexually transmitted virus in its etiology. HPV knowledge has been found to be poor, although there is evidence of public awareness of a link between sexual activity and cervical cancer risk. We explored beliefs about the risk factors for cervical cancer in a large population sample.

Methods. Face-to-face interviews were carried out with a representative sample of the British population. All participants were asked what they thought increased a women's chances of developing cervical cancer.

Results. The response rate was 71% (n = 1940). The most common single response was ‘don't know’ (38%). Forty-one percent of respondents mentioned factors relating to sex, but only 14% were aware of a link with sexual transmission and fewer than 1% named HPV. Women and more educated people had better knowledge of the established risk factors. The patterning of risk factor awareness by age varied across risk factors.

Conclusions. Awareness of the role of a sexually transmitted virus in the etiology of cervical cancer is very low in Britain. Provision of information associated with the introduction of HPV testing could change public perceptions of cervical cancer.

Introduction

High-risk types of human papillomavirus (HPV) are now accepted as a necessary though not sufficient etiological agent in the vast majority of cervical cancers [1]. For more than a century, the medical profession has known of a link between cervical cancer and sexual activity; Rigoni-Stern published his observations of the low incidence of cervical cancer in nuns as long ago as 1842. But only with the development of tests for HPV has the mechanism for the link been clearly established. HPV is widely acknowledged to be transmitted through sexual contact, which explains the epidemiological association between cervical cancer incidence and number of sexual partners. A range of co-factors is involved in the development of squamous intraepithelial lesions (SIL) and cancer, and current candidates include smoking, immunological factors, the contraceptive pill, having a high number of pregnancies, and other sexually transmitted infections (STIs) like chlamydia [2].

Testing for high-risk HPV has been recommended in the US for the management of women with borderline and mildly abnormal smear results (Atypical Squamous Cells of Undetermined Significance—ASC-US). Trials of HPV testing at triage are underway in the UK [3]. Using HPV testing as an adjunct to cytology in the primary screening of women over the age of 30 has been approved by the Food and Drug Administration (FDA) and has been advocated by some authors in the UK [4], [5].

Despite the long-established link between sexual activity and cervical cancer, the domains of cervical screening and sexual health have tended to remain quite separate, and the role of a sexually transmitted virus in causing cervical cancer has not been emphasized in public health messages. Authors in New Zealand have investigated the discourses surrounding cervical screening policy in that country, and have found evidence for deliberate suppression of information about the link between sexual activity and cervical cancer. Fears of stigmatizing cervical cancer and of deterring women from attending screening seem to have been the motivation for the lack of information about sexual risk factors in the patient literature on cervical screening [6], [7], [8]. In the UK, the current National Health Service (NHS) screening leaflet mentions behavioral risk factors (having sex at an early age; many sexual partners; not using condoms) but the involvement of a sexually transmitted virus is not made clear [9]. The previous NHS leaflet made no reference to any specific risk factors and merely stated that ‘cervical cancer is much less common in women who have never had sex’ [10].

The introduction of HPV testing into cervical screening and the management of cervical abnormalities has the potential to make this link explicit, and to change public perceptions of cervical cancer substantially, especially if awareness of HPV and the sexual behavioral risk factors for cervical cancer is currently low. A few studies have explicitly investigated HPV knowledge (see Ref. [11] for a full review). Three UK studies, one of female university employees, one of women attending a well-woman clinic, and one of female students, found that around 30% of women reported having heard of HPV [12], [13], [14]. Only about 10% of the employees and clinic attendees were aware of the link between HPV and cervical cancer, but 50% of the students endorsed HPV as a cause of cervical cancer. Given that only 30% had heard of the virus, the validity of this finding is questionable.

Low levels of HPV knowledge have been reported in several US studies of students and adolescents [15], [16], [17], [18], [19], and among adult women from low socioeconomic backgrounds [20]. Knowledge has predictably been found to be higher among those with an HPV diagnosis [21]. In one student sample, 72% had heard of HPV, and 44% knew about its link with cervical cancer [22], but the response rate was extremely low, so generalizability is limited. Most of these studies focused on HPV and genital warts, therefore providing limited insights into public awareness of the link between HPV and cervical cancer. In addition, none of the studies used representative population samples and very few included men.

While relatively few studies have assessed knowledge of the role of HPV, a greater number have investigated knowledge of cervical cancer risk factors more generally. A British population survey asked people to choose risk factors for cervical cancer from a list containing both correct and incorrect responses [23]. In the sample, 51% of men and 67% of women endorsed ‘many sexual partners’, 21% of men and 28% of women endorsed ‘smoking’, and 26% of men and 31% of women endorsed ‘viruses or infection’ as causes of cervical cancer. HPV per se was not one of the response options. In Australian women aged 50 to 75 years, 32% recognized having many partners as a risk factor, 6% recognized smoking, and 5% recognized both of these [24]. In a large American survey, 35% of women recognized having many sexual partners as a risk factor and 13% recognized smoking [25].

Overall, survey data from developed countries indicate that between a third and a half of women in these countries (or possibly more in the UK) recognize a link between sexual behavior and cervical cancer. Other investigations have used open-ended questions and qualitative methods to gain an understanding of women's beliefs about cervical cancer and its risk factors without imposing the constraints of fixed response options. UK studies of women from ethnic minority groups and working class backgrounds found that women associated cervical cancer with promiscuity [26], [27], [28]. Sexual activity was clearly regarded as a risk factor, and attending for screening was thought to convey messages about being sexually active. In the US, women from various ethnic backgrounds were found to know about a link between sexual activity and cervical cancer [29]. For women from Anglo-American backgrounds, this was associated with STIs, but for women from Latino backgrounds, risky sexual behavior had moral implications, with cancer sometimes seen as a ‘punishment from God’. Although this may point to a relatively high awareness of the link between cervical cancer and sex, it should be noted that women with abnormal smear results tend not to accept this explanation in their own case [30].

These studies indicate that although people may be aware of a link between cervical cancer and sexual activity, few know about the role of a sexually transmitted infection. Few of these studies have included men in their samples, which is consistent with a tendency to place the burden of responsibility for sexual health on women [31].

To understand the potential impact of the introduction of HPV testing on public perceptions of cervical cancer, we sought to quantify beliefs about the risk factors for cervical cancer, particularly those related to HPV and sexual activity, in a more detailed way than has previously been done in a population sample. We also examined associations between demographic characteristics and knowledge. Given the sexually transmitted nature of cervical cancer, men and women play an equal role in its etiology so it is important to establish men's knowledge as well as women's. It is plausible that knowledge might vary with age, particularly as discourses surrounding risk factors may have changed over time leading to cohort effects. Finally, social class differences in health-related knowledge are well established in other domains [32], [33], and we wanted to see whether they applied in this case. To gauge the extent to which the general population currently perceives a link between STIs, sexual activity, and cervical cancer, we conducted a large, representative population survey. Though eliciting beliefs about the causes and risk factors for cervical cancer, we can gain some insight into the current state of public knowledge into which information about HPV must be incorporated.