Reducing HPV-associated cancer globally

Abstract

Human papillomavirus (HPV)-related cancers are a major worldwide public health concern. Virtually all cervical cancer is HPV related, with 70% caused by HPV16 and -18. Variable proportions of certain noncervical cancers (e.g., anal, vulvar, and oropharyngeal) are HPV related; more than 90% of the HPV-related ones are caused by HPV16, -18. The HPV-related cancers are dominated by cervical cancer in the developing world, where cervical cancer screening is limited. In this setting, widespread uptake of current HPV vaccines by adolescent girls could reduce this cancer's incidence and mortality by approximately two-thirds, with cost-effective screening programs of adult women having the potential to reduce mortality more rapidly. In the industrialized world, some noncervical HPV-related cancers, especially oropharyngeal, are rapidly increasing, and now rival the incidence of cervical cancer, whose rates continue to decline thanks to established cervical screening programs. Therefore, reducing HPV-associated noncervical cancers with HPV vaccination has greater importance in the industrialized world, especially because there are no approved screening programs for these cancers. Preventing the substantial number of noncervical HPV cancers in men will require either "herd" immunity through high-vaccination rates in females or male vaccination. Current HPV vaccination can complement cervical screening in protecting against cervical cancer and may permit the safe reduction of screening intensity in industrialized countries. Second-generation HPV vaccines (active against a broader array of cervical cancer-related HPV types) could prevent an even higher proportion of cervical precancer and cancer and might permit further reductions in screening intensity.

Figure 1

A, worldwide incidence and distribution of HPV-associated cancers (data from ref. 1). Red, HPV-positive cancer; white, HPV-negative cancer. B, incidence and distribution of HPV-associated cancers in the U.S. (data from refs. and 4). The approximate percentage of HPV-associated cancer attributable to HPV16 and -18 is also shown. Red, HPV-positive cancer; white, HPV-negative cancer.

Figure 1

A, worldwide incidence and distribution of HPV-associated cancers (data from ref. 1). Red, HPV-positive cancer; white, HPV-negative cancer. B, incidence and distribution of HPV-associated cancers in the U.S. (data from refs. and 4). The approximate percentage of HPV-associated cancer attributable to HPV16 and -18 is also shown. Red, HPV-positive cancer; white, HPV-negative cancer.