Invited commentary: Human papillomavirus infection and risk of cervical precancer--using the right methods to answer the right questions

The road ahead for cervical cancer prevention and control

Since the early 1950s, Papanicolaou ("Pap") cytology screening has dramatically reduced cervical cancer mortality in most high-income settings. Currently, human papillomavirus (hpv) vaccination has the greatest potential to reduce the global burden of cervical cancer and precancerous lesions. However, as the prevalence of precancerous lesions declines, maintaining cytology as the primary screening test in settings with established programs might become less efficient. A reduction in test performance (sensitivity, specificity, and positive predictive value) would lead to an increase in unnecessary colposcopy referrals. Fortunately, hpv dna testing has emerged as a suitable candidate to replace cytology. Compared with the Pap test, hpv testing is less specific but much more sensitive in detecting high-grade precancerous lesions, less prone to human error, and more reproducible across settings. Linkage of hpv vaccination and screening registries could serve the added role of monitoring vaccine efficacy. As a triage test, cytology is expected to perform with sufficient accuracy because most hpv-positive smears would contain relevant abnormalities. This approach and others-for example, hpv testing followed by genotyping-are being evaluated in large population studies and have already been recommended in some settings. Other specific biomarkers that might perform well for screening and triage include hpv E6/E7 messenger rna testing, methylation of host or viral genes, and p16(INK4a) staining. Considering the rapid pace of major discoveries and the anticipated arrival of a nonavalent hpv vaccine (currently in phase iii trials), the evidence base in this field has become an elusive target and will continue to be an obstacle for policymakers.

Turning disciplinary knowledge into solutions

Turning disciplinary knowledge about preadolescents' and adolescents' exposure to risk factors for cancer as adults into solutions for preventing such an outcome requires that investigators from a variety of backgrounds and disciplines come together to share knowledge. Optimally, these collaborations would occur across two dimensions: (1) transdisciplinary, from the molecular or cellular level (e.g., animal studies of endocrine disruption) to the societal level (e.g., economic studies related to state tobacco policies); and (2) translational, using basic research findings in clinical and other sciences to implement prevention programs and public policy. Only when collaboration is commonplace can the disparate groups of investigators working on cancer prevention during preadolescence and adolescence gain a holistic picture of the risk factors, inform one another's work, and learn what we need to know to devise successful interventions for preventing cancer. Working transdisciplinarily also helps to ensure that messages to health professionals, policymakers, the news media, and the public are consistent and coordinated. At present, those investigating preadolescent and adolescent risk for adult cancer disseminate their knowledge individually, thus missing the opportunity to synthesize knowledge, coordinate dissemination, and implement prevention programs. In this article, we distinguish multidisciplinary, interdisciplinary, and transdisciplinary approaches; argue for the benefits of a transdisciplinary approach to devising successful solutions; and explore how to achieve transdisciplinary functioning.