Risk of second primary cancer after a first potentially-human papillomavirus-related cancer: A population-based study.

Human papillomaviruses (HPV) are involved in the development of anogenital and head and neck cancers. The purpose of this study was to assess the risk of developing a second primary cancer (SPC) after a first potentially-HPV-related cancer, and to analyze the sites where SPCs most frequently occurred in these patients. All patients with a first cancer diagnosed between 1989 and 2004, as recorded by 10 French cancer registries, were followed up until December 31, 2007. Only invasive potentially-HPV-related cancers (namely, cervical, vagina, vulva, anal canal, penile, oropharynx, tongue and tonsil) were included. Standardized Incidence Ratios (SIRs) were calculated to assess the risk of SPC. A multivariate Poisson regression model was used to model SIRs separately by gender, adjusted for the characteristics of the first cancer. 10,127 patients presented a first potentially-HPV-related cancer. The overall SIR was 2.48 (95% CI, 2.34-2.63). The SIR was 3.59 (95% CI, 3.33-3.86) and 1.61 (95% CI, 1.46-1.78) in men and women respectively. The relative risk of potentially-HPV-related SPC was high among these patients (SIR=13.74; 95% CI, 8.80-20.45 and 6.78; 95% CI, 4.61-9.63 for men and women, respectively). Women diagnosed in the most recent period (2000-2004) showed a 40% increase of their relative risk of SPC as compared with women diagnosed between 1989 and 1994 (ratio of SIRs=1.40; 95% CI, 1.06-1.85). HPV cancer survivors face an increased risk of SPC, especially second cancer. Clinicians may consider this increased risk of developing HPV-related SPC during follow-up to improve subsequent cancer prevention in these patients.