Background Squamous cell carcinoma of the anus (SCCA) incidence is rising in the United States. Study of incidence trends by stage at diagnosis, age-specific and birth cohort patterns, and trends in mortality could provide evidence for a true increase and etiological clues for the increase in incidence. Methods Using the US Cancer Statistics dataset, we examined trends in SCCA incidence (2001–2015) and mortality (2001–2016) rates. Join-point regression was used to compute annual and average annual percentage change (AAPC). Incidence patterns by 5-year age group and birth cohort were evaluated using incidence rate ratios (IRRs) and age-period-cohort modeling. Results SCCA incidence increased 2.7% per year (95% confidence interval [CI] = 2.1% to 3.3%), with pronounced increases in age groups 50 years and older. Distant-stage SCCA incidence tripled (AAPC = 8.6%, 95% CI = 5.4% to 12.0%, among men and AAPC = 7.5%, 95% CI = 4.8% to 10.2%, among women) and regional-stage SCCA incidence nearly doubled (AAPC = 4.7% for men and women) in both sexes; the AAPC for localized stage was 1.3% (95% CI = 0.6% to 2.0%) in men and 2.3% (95% CI = 1.8% to 2.8%) in women. Compared with adults born circa 1946, recently born black men (born circa 1986) had a nearly fivefold higher risk (IRR = 4.7, 95% CI = 2.1 to 10.2) of SCCA, and the risk doubled among white men (IRR = 2.0, 95% CI = 1.7 to 2.2) and white women (IRR = 2.1, 95% CI = 1.9 to 2.3) born after circa 1960. Anal cancer mortality rates increased 3.1% per year (95% CI = 2.6% to 3.5%) with statistically significant increases in age groups 50 years and older. SCCA incidence-based mortality increased 1.9% annually (95% CI = 0.5% to 3.4%), with a notable (4.9%, 95% CI = 2.4% to 7.3%, per year) rise in adults ages 60–69 years. Conclusion The increase in SCCA incidence, particularly advanced-stage disease, and a similar increase in mortality suggest a true increase in the occurrence of SCCA. Future research and improved prevention are urgently needed to mitigate the increasing disease burden.

Background: The burden of human papillomavirus (HPV) positive oropharyngeal squamous cell carcinoma (OPSCC) is disproportionately high among men, yet empirical evidence regarding the differential prevalence of oral HPV infection by gender is limited. Concordance of oral and genital HPV infection among men is unknown. Objective: To determine the prevalence of oral HPV infection, and concordance of oral and genital HPV infection among US men and women. Design: Nationally representative survey. Setting: Civilian noninstitutionalized population. Participants: Participants aged 18–69 years from the National Health and Nutritional Examination Survey (2011–2014). Measurements: Oral rinse, penile swab, and vaginal swab specimens were evaluated using polymerase chain reaction followed by type-specific hybridization. Results: The overall prevalence of oral HPV among men and women was 11.5% (equating to 11 million men nationwide) and 3.2% (3.2 million), respectively. High-risk oral HPV (HR-HPV) prevalence was higher among men (7.3%) than in women (1.4%). Oral HPV-16 was 6-times more common in men (1.8%) than in women (0.3%), i.e., 1.7 million men compared with 0.27 million women. Among men and women who reported having same gender sex partners, prevalence of HR-HPV infection was 12.7% and 3.6%, respectively. Particularly, among men who reported having ≥2 same gender oral sex partners, prevalence was 22.2%. Oral HPV prevalence among men with concurrent genital HPV infection was 4-fold greater (19.3%) compared to men without genital HPV infection (4.4%). Gender and lifetime number of oral sex partners were associated with overall HPV, HR-HPV, concordant overall HPV, and concordant HR-HPV infection. Limitations: Sexual behaviors were self-reported. Conclusion: Oral HPV infection is common among US men. Our findings provide several policy implications to guide future OPSCC prevention efforts to combat this disease.