Human Papillomavirus
Vaginal Self-collection in Human Papillomavirus Testing Jerome L Belinson, MD1
and Robert G Pretorius, MD2
1. Professor of Surgery, Women’s Health Institute, Lerner School of Medicine, Cleveland Clinic, and President of Preventive Oncology International; 2. Section of Gynecologic Oncology, Department of Obstetrics and Gynecology, Kaiser Permanente
Abstract
The data are now overwhelming that the most cost-efficient primary screen for women over the age of 30–35 should be a test for high-risk types of human papillomavirus. A self-collected sample expands coverage by overcoming many of the known obstacles to participation in a screening program. In addition, self-sampling has the potential to be the most effective means to achieve high coverage rates in medically underserved regions of the world that lack the healthcare infrastructure to support traditional screening programs. Self-collection combined with high throughput, low cost-per-case, polymerase chain reaction-based technology has the sensitivity of a direct endocervical sample obtained by a physician. Therefore, we have the technology to reach millions of women around the world in a short period of time through large ‘event-type’ screening programs and centralized testing. Now we need to focus on developing the models that will enable us to efficiently place the technologies next to the women who need them the most.
Keywords Human papillomavirus (HPV), screening, cervical cancer, self-sampling, self-collection
Disclosure: The authors have no conflicts of interest to declare. Received: September 13, 2011 Accepted: October 21, 2011 Citation: US Obstetrics & Gynecology, 2011;6(2):113–5 Correspondence: Jerome L Belinson, MD, Offices of Preventive Oncology International, 2762 Fairmount Blvd, Cleveland Heights, OH 44118. E:
jlb@poiinc.org
Over the past 35 years, the human papillomavirus (HPV) and its causal relationship to cervical cancer has been documented and extensively studied.1
As a result, multiple assays have been developed to detect the presence of the critical high-risk types (HR-HPV).2–6
In addition, we now
have HPV vaccines that, when given to people previously unexposed to the HPV types in the vaccines, are virtually 100 % effective in preventing high-grade pre-cancers and cancers caused by those types.7,8
Even
though we have now opened the door of primary prevention, the need for worldwide distribution of the vaccine and the hundreds of millions of women already exposed to HPV will dictate a need for cervical cancer screening for decades to come.
There is strong evidence supporting the adoption of cervical cancer prevention strategies that focus on persistent infection with HR-HPV.9 First and foremost, the sensitivity of HPV testing has consistently been shown to be substantially higher than all other screening technologies. The HPV assays are true laboratory tests with minimal intra-test performance variability and therefore with predictable consistency.10 In addition, when compared with a negative cervical cytology, an endocervical specimen with a negative HR-HPV test has both a higher negative predictive value for cervical intraepithelial neoplasia (CIN) or cancer (CIN 3+)11
and a lower subsequent risk of CIN 3+.12–16 In the
long-term follow-up of the Kaiser Portland cohort by Schiffman et al., the reassurance against CIN 3+ after a single negative HPV test in women over the age of 30 was very long lasting, with a cumulative probability of 0.7 %.13
Shi et al.15 found that, in the Shanxi province cervical cancer © TOUCH BRIEFINGS 2011
screening study I (SPOCCS I) follow-up data, where all women were biopsied at baseline, a negative HPV with a biopsy of ≤CIN 1 was associated with a 0.15 % cumulative incidence of CIN 2+ at six years. A positive HPV and ≤CIN 1 at baseline were associated with a 7.56 % cumulative incidence of CIN 2+ over the same period of time. When compared with cervical cytology, the single disadvantage of endocervical HR-HPV tests is that they are less specific for CIN 3+.11
This lower
specificity of HR-HPV tests (more patients identified as positive) is because the HR-HPV assays detect both persistent and newly acquired HR-HPV infections. Persistent HR-HPV infections are more likely to be associated with CIN 2 or greater (CIN 2+) than are newly acquired infections.9
The data are now overwhelming that the most cost-efficient primary screen for women over the age of 30–35 (when a positive test is less likely to be a new infection) should be a test for HR-HPV.17,18
In areas of the world with
well-established and successful cytology-based screening programs (although inefficient), the paradigm shift required to move to primary HPV screening will be very slow. However, more than 85 % of the global burden of cervical cancer occurs in areas of the world with serious limits to their existing healthcare infrastructure.19
This dichotomy has provided both
a great challenge and an opportunity to implement effective and cost-efficient programs without push-back from existing programs and their proponents. During this process, it has become clear to many investigators that the infrastructure required for a clinic- or physician-based program is simply unattainable in many developing nations. It has become evident that, if a highly sensitive and specific self-collection method could be developed,
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