Trends in incidence of anal cancer in Austria, 1983-2016.

BACKGROUND

Recent reports have noted increasing rates of anal cancer among high-income countries worldwide; however, little is known about these trends in Austria.

METHODS

Data on anal cancer from 1983 to 2016 were obtained from Statistics Austria. All tumors (n = 3567) were classified into anal squamous cell carcinomas (ASCC), anal adenocarcinomas (AADC), and others (unspecified carcinoma and other specific carcinoma). Anal cancer incidence rates were calculated in 5‑year cycles and incidence average annual percentage change (AAPC) to evaluate trends by sex, histology and age group.

RESULTS

The incidence rate of anal cancer was higher among females than males (relative risk, RR = 1.66, 95% confidence interval, CI: 1.55-1.79, p < 0.0001). From 1983 through 2016, incident anal cancer increased significantly (0.92 per 100,000 person-years to 1.85 per 100,000 person-years, AAPC = 1.93, 95% CI: 1.52 to 2.34, p < 0.0001), particularly among those 40-69 years old. From 1983 through 2016, the increasing anal cancer incidence was primarily driven by ASCC (0.47-1.20 per 100,000 person-years, AAPC = 2.23, 95% CI: 1.58 to 2.88, p < 0.0001) and others (other than ASCC and AADC, AAPC = 1.78, 95% CI: 1.01-2.55), yet stable in AADC (AAPC = 0.88, 95% CI: -0.48-2.25).

CONCLUSIONS

Despite being a rare cancer in Austria, the increase in anal cancer incidence rate from 1983 to 2016 was substantial, particularly in ASCC. The observed rising trends reflect the need to investigate associated risk factors that have increased over time to inform preventive measures.