Chemoprevention for Colorectal Cancers: Are Chemopreventive Effects Different Between Left and Right Sided Colorectal Cancers?

Low-Dose Aspirin and Prevention of Colorectal Cancer: Evidence From a Nationwide Registry-Based Cohort in Norway

INTRODUCTION

To examine the association between low-dose aspirin use and risk of colorectal cancer (CRC).

METHODS

In this nationwide cohort study, we identified individuals aged 50 years or older residing for 6 months or more in Norway in 2004-2018 and obtained data from national registers on drug prescriptions, cancer occurrence, and sociodemographic factors. Multivariable Cox regression models were used to estimate the association between low-dose aspirin use and CRC risk. In addition, we calculated the number of CRC potentially averted by low-dose aspirin use.

RESULTS

We included 2,186,390 individuals. During the median follow-up of 10.9 years, 579,196 (26.5%) used low-dose aspirin, and 38,577 (1.8%) were diagnosed with CRC. Current use of aspirin vs never use was associated with lower CRC risk (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.84-0.90). The association was more pronounced for metastatic CRC (HR 0.79; 95% CI 0.74-0.84) than regionally advanced (HR 0.89; 95% CI 0.85-0.92) and localized CRC (HR 0.93; 95% CI 0.87-1.00; P heterogeneity = 0.001). A significant trend was found between duration of current use and CRC risk: HR 0.91 (95% CI 0.86-0.95) for <3 years, HR 0.85 (0.80-0.91) for ≥3 and <5 years, and HR 0.84 (0.80-0.88) for ≥5 years of use vs never use ( P trend < 0.001). For past use, HR were 0.89 (95% CI 0.84-0.94) for <3 years, 0.90 (0.83-0.99) for ≥3 and <5 years, and 0.98 (0.91-1.06) for ≥5 years since last use vs never use ( P -trend < 0.001). We estimated that aspirin use averted 1,073 cases of CRC (95% CI 818-1,338) in the study period.

DISCUSSION

In this nationwide cohort, use of low-dose aspirin was associated with a lower risk of CRC.

Risk and preventive factors of early-onset colorectal neoplasms: endoscopic and histological database analysis

BACKGROUND AND AIM

The incidence of early-onset colorectal neoplasms has been increasing in both Western and Eastern countries. However, the risks and preventive factors for these neoplasms in Eastern countries remain unclear.

METHODS

The data of 5580 patients who underwent colonoscopy between 2016 and 2021 were retrospectively evaluated. The primary outcome was advanced colorectal neoplasm (ACRN), defined as advanced adenomas (adenoma ≥10 mm, or with high-grade dysplasia or villous component) or adenocarcinoma. The clinical factors associated with ACRNs were determined for each age category (≤50 and >50 years), and the differences between the two categories were assessed. Odds ratios adjusted for age and sex were calculated.

RESULTS

Among 1001 patients (age ≤50 years), ACRN was found in 94 (9.4%). In this younger category, male sex (adjusted odds ratio [aOR]:2.34, 95% confidence interval [CI]:1.51-3.63) and a family history of colorectal cancer (aOR:2.14, 95% CI:1.17-3.89) were significantly associated with higher odds of developing ACRNs. ACRNs were detected in 726 (15.9%) of 4579 patients (age >50 years). In the older age category, smoking (aOR:1.32, 95% CI:1.08-1.63) was significantly associated with a higher risk of ACRNs. Exercise of >3.5 metabolic equivalent of task (METs) (aOR,0.80; 95% CI:0.67-0.96) was significantly associated with a lower risk of ACRNs.

CONCLUSION

The development of early-onset ACRNs was primarily associated with congenital factors, whereas that of late-onset ACRNs was associated with acquired ones. Colonoscopy is recommended for young male patients, particularly for those with a family history of colorectal cancer.