Effects of Colorectal Cancer Risk Factors on the Association Between Aspirin and Colorectal Cancer

Research Progress on the Relationship Between Inflammation and Colorectal Cancer

Colorectal cancer is one of the common malignant tumors. Relevant epidemiology and a large number of experimental studies have proved that chronic inflammation is highly correlated with the occurrence and development of colorectal cancer. And inflammatory bowel disease has been proven to be an independent risk factor for colorectal cancer. Various inflammatory cells participate in the establishment of the chronic inflammatory intestinal microenvironment required for the onset of colorectal cancer. The abnormal signal pathways mediated by various inflammatory factors and inflammatory mediators promote the occurrence of tumors, which are related to colorectal cancer and pathogenesis‐related inflammation mechanisms. At the gene level, miRNAs can also affect the pathogenesis of colorectal cancer by regulating mesenchymal epithelial transformation. This article reviews the relationship between inflammation and colorectal cancer as well as the related inflammatory mechanisms.

Aspirin Use and Risk of Colorectal Cancer Among Older Adults

Importance

Although aspirin is recommended for the prevention of colorectal cancer (CRC) among adults aged 50 to 59 years, recent data from a randomized clinical trial suggest a lack of benefit and even possible harm among older adults.

Objective

To examine the association between aspirin use and the risk of incident CRC among older adults.

Design, Setting, and Participants

A pooled analysis was conducted of 2 large US cohort studies, the Nurses' Health Study (June 1, 1980-June 30, 2014) and Health Professionals Follow-up Study (January 1, 1986-January 31, 2014). A total of 94 540 participants aged 70 years or older were included and followed up to June 30, 2014, for women or January 31, 2014, for men. Participants with a diagnosis of any cancer, except nonmelanoma skin cancer, or inflammatory bowel disease were excluded. Statistical analyses were conducted from December 2019 to October 2020.

Main Outcomes and Measures

Cox proportional hazards models were used to calculate multivariable adjusted hazard ratios (HRs) and 95% CIs for incident CRC.

Results

Among the 94 540 participants (mean [SD] age, 76.4 [4.9] years for women, 77.7 [5.6] years for men; 67 223 women [71.1%]; 65 259 White women [97.1%], 24 915 White men [96.0%]) aged 70 years or older, 1431 incident cases of CRC were documented over 996 463 person-years of follow-up. After adjustment for other risk factors, regular use of aspirin was associated with a significantly lower risk of CRC at or after age 70 years compared with nonregular use (HR, 0.80; 95% CI, 0.72-0.90). However, the inverse association was evident only among aspirin users who initiated aspirin use before age 70 years (HR, 0.80; 95% CI, 0.67-0.95). In contrast, initiating aspirin use at or after 70 years was not significantly associated with a lower risk of CRC (HR, 0.92; 95% CI, 0.76-1.11).

Conclusions and Relevance

Initiating aspirin at an older age was not associated with a lower risk of CRC in this pooled analysis of 2 cohort studies. In contrast, those who used aspirin before age 70 years and continued into their 70s or later had a reduced risk of CRC.

Chondroitin Sulphate and Glucosamine Use Depend on Nonsteroidal Anti-inflammatory Drug Use to Modify the Risk for Colorectal Cancer

BACKGROUND

A safe and effective colorectal cancer chemoprevention agent remains to be discovered. There is little evidence regarding the protective effect of chondroitin sulphate and glucosamine on colorectal cancer. We aimed to assess the association between colorectal cancer risk and the use of chondroitin sulphate and glucosamine using a large cohort with dispensed data.

METHODS

We performed a population-based case-control study in Catalonia using primary care reimbursed medication records (SIDIAP database). The study included 25,811 cases with an incident diagnosis of colorectal cancer and 129,117 matched controls between 2010 and 2015.

RESULTS

The prevalence of ever use was 9.0% (n = 13,878) for chondroitin sulphate, 7.3% (n = 11,374) for glucosamine, and 35% for regular use of nonsteroidal anti-inflammatory drugs (NSAID; n = 45,774). A decreased risk of colorectal cancer was observed among chondroitin sulphate use [OR: 0.96; 95% confidence interval (CI), 0.91-1.01], glucosamine use (OR: 0.92; 95% CI, 0.87-0.97), and concurrent use of chondroitin sulphate and glucosamine (OR: 0.83; 95% CI, 0.70-0.98). Especially for glucosamine, there was a dose-response association regarding duration and cumulative dose. The analysis stratified by simultaneous use with other NSAIDs showed that these drugs used without other NSAIDs do not reduce risk (OR: 1.06; 95% CI, 0.74-1.51). However, they may have a synergistic protective effect when used with other NSAIDs (OR: 0.80; 95% CI, 0.72-0.88).

CONCLUSIONS

This study does not provide strong support for an independent protective association of chondroitin sulphate or glucosamine on colorectal cancer risk in our population. However, these drugs may have a synergistic beneficial effect among NSAID users.

IMPACT

Chondroitin sulphate or glucosamine may contribute to the protective effect of NSAID use in colorectal cancer.