Trends in epidemiology and primary treatment of anal squamous cell carcinoma in the Netherlands (1990–2021)

• Published in: International journal of cancer Vol. 154; no. 9; pp. 1569 - 1578
• Main Authors: Ho, Vincent K. Y., Deijen, Charlotte L., Hemmes, Birgit, Erning, Felice N., Snaebjornsson, Petur, Triest, Baukelien, Grotenhuis, Brechtje A.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.05.2024; Wiley Subscription Services, Inc
• Subjects: Adenomatous polyposis coli; Age composition; Anal cancer; anal carcinoma; Anus; Cancer therapies; Colorectal cancer; Disease management; Epidemiology; Females; Genital cancers; incidence; Males; Medical prognosis; Medical technology; Medical treatment; Population studies; Primary care; Squamous cell carcinoma; survival; Survival analysis; Trends; Netherlands; epidemiology; incidence; anal carcinoma; survival; squamous cell carcinoma
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.34811

A rapid increase in the incidence of anal squamous cell carcinoma (SCC) was reported in several countries over the past decades. This study assessed trends in epidemiology and primary treatment over a 32‐year period (1990–2021) using the Netherlands Cancer Registry. The study population included 4273 patients, 44.2% male and 55.8% female (median age 63 years). The age‐standardised incidence rate (European Standardised Rate, ESR) increased from 0.5 to 1.6 per 100,000, which entailed an average annual percentage change (AAPC) of 5.0% (95% confidence interval [CI]: 4.5%–5.8%). While incidence among females increased continuously over the total period (AAPC 4.9%; 95%CI: 4.4%–5.6%), to 1.8 per 100,000 ESR in 2021, incidence among males increased until 2016 (annual percentage change [APC] of 6.3%; 95%CI: 5.6%–10.7%), after which it seemed to stabilise (APC −2.1%; 95%CI: −16.8%–4.5%). Significant trends were also observed in distribution of age, tumour stage and primary treatment modalities. Five‐year relative survival (RS) was estimated using the Pohar–Perme estimator, and this improved from 56.1% in 1990–1997 (95%CI: 49.3%–62.4%) to 67.9% in 2014–2021 (95%CI: 64.7%–70.9%), but remained poor for stage IV disease. Evaluation through a multivariable Poisson regression model demonstrated diagnosis in the most recent period to be independently associated with better RS, in addition to female sex, younger age, early disease stage and any treatment. In conclusion, the rising incidence of anal SCC seems to decline in males, but not in females, and advances in diagnostics and therapeutic management have likely contributed to improved prognosis. What's new? Recent reports indicate that the incidence of anal squamous cell carcinoma (SCC) is increasing, particularly in high‐income countries. In this study, trends in anal SCC incidence were analyzed specifically in the Netherlands and were further assessed to determine their impact on patient prognosis over time. From 1990–2021, anal SCC incidence was found to have increased steadily among Dutch women and among both men and women over age 65. For men younger than 54, incidence increased until 2016, then stabilized, survival rates improved across all disease stages, excluding stage IV, possibly owing to diagnostic and therapeutic advances.