Future patterns in burden and incidence of squamous cell carcinoma of the anus in the United States, 2001-2035.

Squamous cell carcinoma of the anus (SCCA) incidence has been rising in the United States, particularly among older adults (≥65 years). We estimated the impact of this rise on future burden (through 2035) using age-period-cohort modeling. The SCCA burden (cases/year) is expected to rise, reaching approximately 2700 among men and approximately 7000 among women in 2031-2035 (burden during 2016-2020 among men and women was approximately 2150 and approximately 4600), with most cases 65 years of age or older (61% in men and 70% in women in 2031-2035; from 40% and 46% in 2016-2020). SCCA incidence (per 100 000) is projected to rise among older men aged 65-74, 75-84, and 85 years or older (5.0, 4.9, and 4.3 in 2031-2035 vs 3.7, 3.8, and 3.4 in 2016-2020, respectively) and women (11.2, 12.6, and 8.0 in 2031-2035 vs 8.2, 6.8, and 5.2 in 2016-2020, respectively). The projected rise in SCCA burden among older adults is troubling and highlights the importance of improving early detection and clinical care.