While many other studies have reported similar findings with use of aspirin and other NSAIDs, the researchers of this latest study – including Dr. Andrew T. Chan of Massachusetts General Hospital in Boston – say the mechanisms behind this link are unclear.
“Routine use of aspirin, NSAIDs, or both for chemoprevention of cancer is not currently recommended because of uncertainty about risk-benefit profile,” the team notes.
As such, they believe gaining a better understanding of how aspirin and NSAIDs interact with certain gene variants may help identify which populations are most likely to see colorectal cancer prevention benefits with the use of these medications.
No reduced colorectal cancer risk found among people with variants in two SNPs
To reach their findings, the researchers conducted a genome-wide analysis of 10 studies initiated from 1976, involving 8,634 patients with colorectal cancer and 8,553 matched controls.
Information on participants’ use of aspirin, NSAIDs or both was collected in each study, and the researchers investigated how the medications interacted with single-nucleotide polymorphisms (SNPs) – DNA sequence variations – among participants and how this influenced their risk of colorectal cancer.
Fast facts about colorectal cancer
Approximately 1 in 20 people in the US will develop colorectal cancer at some point in their lifetime
Colorectal cancer is the second leading cause of cancer-related death in the US, though the death rate from the disease has fallen over the past 20 years
There are now more than 1 million survivors of colorectal cancer living in the US.
The results of the analysis revealed that, overall, participants who regularly used aspirin, NSAIDs or both were at lower risk of colorectal cancer, compared with those who were irregular users of these medications.
However, on assessing the results by participants’ genotypes, the team found regular use of aspirin and/or NSAIDs among participants who possessed two variants of the SNP rs16973225 – AC or CC – did not appear to affect the risk of colorectal cancer, while two rare variants of the SNP rs2965667 – TA or AA – was linked to an increased risk of colorectal cancer among regular aspirin and/or NSAID users.
The researchers point out that both of these SNPs are relatively rare; rs16973225 was only identified among 9% of participants, while rs2965667 was only found among 4% of participants.