Autoimmune disease and the risk of anal cancer in the US population aged 66 years and over.

BACKGROUND: In the United States, anal squamous cell carcinoma rates have increased rapidly, particularly among women 50 or older than 66 years of age. As immunosuppression is associated with increased risk, autoimmune conditions may be associated with greater risk of anal squamous cell carcinoma. METHODS: We conducted a population-based, case-control study using Surveillance, Epidemiology, and End Results-Medicare data (2000-2017). Anal squamous cell carcinoma cases (n = 4505) were matched to 200 000 cancer-free controls. Using multivariable logistic regression, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between 47 autoimmune conditions diagnosed before selection, identified using Medicare claims, and anal squamous cell carcinoma. The Bonferroni threshold was used to correct for multiple comparisons. Population attributable fractions were calculated for conditions nominally associated with anal squamous cell carcinoma. RESULTS: In total, 18% of anal squamous cell carcinoma cases and 15% of cancer-free controls had a diagnosed autoimmune condition. Any autoimmune condition was associated with an increased risk of anal squamous cell carcinoma (OR = 1.11, 95% CI = 1.02 to 1.21; population attributable fraction = 1.8%). Anal squamous cell carcinoma was associated with systemic lupus erythematosus (OR = 1.79, 95% CI = 1.32 to 2.42; population attributable fraction = 0.4%) and nominally associated (P < .05) with sarcoidosis (OR = 2.09, 95% CI = 1.30 to 3.37; population-attributable fraction = 0.2%) and psoriasis (OR = 1.28, 95% CI = 1.06 to 1.56; population attributable fraction = 0.5%). Stratified by sex, only women showed statistically significant associations for systemic lupus erythematosus (OR = 1.97, 95% CI = 1.46 to 2.68). Statistically significant interaction was observed by sex for psoriasis (men vs women: OR = 1.68 [95% CI = 1.03 to 4.28] vs OR = 1.12 [95% CI = 0.88 to 1.43]) and polymyalgia rheumatica (OR = 0.33 [95% CI = 0.12 to 0.89] vs OR = 0.99 [95% CI = 0.75 to 1.30]). CONCLUSION: Systemic lupus erythematosus, sarcoidosis, and psoriasis were associated with a moderately increased risk of anal squamous cell carcinoma. Given these conditions' rarity and moderate associations with anal squamous cell carcinoma, autoimmune diseases cannot explain the rising trend in this disease.

The potential application of personalized preventive research.

With increases in life expectancy, the focus has shifted to living a healthier, longer life. By concentrating on preventing diseases before occurrence, researchers aim to diminish the increasing gap in medical costs and health inequalities prevalent across many nations. Although we have entered an era of post-genomics, we are still in infancy in terms of personalized preventive research. Personalized preventive research has and will continue to improve with advancements in the use of biomarkers and risk assessment. More evidence based on well-designed epidemiologic studies is required to provide comprehensive preventive medical care based on genetic and non-genetic profile data. The realization of personalized preventive research requires building of evidence through appropriate methodology, verification of results through translational studies as well as development and application of prediction models.