Many physicians prescribe aspirin to patients with a family history of colorectal cancer to mitigate the risk of developing cancer at a later age. Researchers wanted to test the efficacy of both low and high dose aspirin based treatment against non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs), calcium, vitamin D, folic acid, alone or in combination, for advanced metachronous neoplasia prevention.
The researchers used data based on several randomized controlled trials where the participants suffered from colorectal neoplasia who had been treated with chemoprevention agents and compared with placebo or other treatment agents. The study was published in BMJ.
They looked at the risk of advanced metachronous neoplasia as primary efficacy outcome while major adverse health outcomes were also considered for safety. Different ranking systems and probability measures were used along with quality of evidence grading system.
15 randomized controlled trials were selected, which involved a cumulative total of 12,234 patients. These selected trials compared a total of 10 different treatment strategies. Non-aspirin NSAIDs were ranked best in terms of advanced metachronous neoplasia prevention, compared with placebo.
Following non-aspirin NSAIDS, low dose treatment was the ideal treatment for advanced metachronous neoplasia prevention. Not only is low dose aspirin the second best prevention drug, it was also the safest among chemoprevention agents, whereas non-aspirin NSAIDS were deemed low in terms of safety.
High dose aspirin was deemed effective in preventing advanced metachronous neoplasia but was considered less safe, compared to low dose aspirin. One important fact the researchers mentioned was that efficacy of agents for metachronous colorectal cancer reduction could not be estimated in the meta-nalysis.
According to the researchers, for individuals who had previously suffered from colorectal neoplasia, non-aspirin NSAIDs were the most efficacious option for the prevention of advanced metachronous neoplasia, while low dose aspirin was the safest after going through the meta-analysis results.
In conclusion, non-aspirin NSAIDS were quite effective in preventing advanced metachronous neoplasia in the long term, over a three to five-year period, but given the safety risk it is better to be used only in patients who have a history of high risk neoplasia.
The researchers also added that low dose aspirin could be a more viable option due to its safety. Shared decision making would be even more beneficial, given patients have a thorough understanding of risk and benefits of each agent and physicians are informed about patients’ requirements and preferences.
Additionally, given the low confidence in several calculations, researching genetic expressions at the molecular level and precision chemoprevention trials are needed. Both will enable to precisely figure out how each individual can potentially respond to neoplasia treatment agents, thereby highlighting possible risks and likelihood of treatment response. With the availability of these precise metrics, more accurate and safer treatment strategies can be developed.
Colorectal cancer is the third most common cancer globally and costs the US healthcare sector $14 billion annually.
Over 85% of non-genetic colorectal cancers arise from benign tumors. Colon screenings have been shown to prevent non-genetic colorectal cancer, but can be expensive and are not readily available, especially in developing countries.
Despite getting screened, many individuals still develop cancerous tumors, either due to missed tumors or rapidly growing tumors. Due to all these facts, physicians are instead looking to extensively research chemo preventive techniques to offer better prognosis and health outcomes in this fairly common cancer.
Previous research has shown that aspirin prevents colorectal cancer, but the evidence was at best mixed. The exact mechanism by how aspirin functions is unknown, but scientists think that aspirin’s anti-inflammatory properties might be involved somehow.
This study was quite thorough as it involved a massive subject size, combined direct and indirect clinical evidence and compared them across all the various agents, focusing on dosage, treatment duration, co-interventions and outcome assessment, so as to offer a precise and accurate solution.
Scientists believe that aspirin blocks the activity of COX-1 and COX-2 enzymes. These enzymes are massively involved in causing inflammation and give rise to many inflammatory symptoms. Inflammation is a natural reaction of the body’s immune system in response to an infection or physical injury, as it allows the body to fight and heal the damaged tissues.
In the case of chronic inflammation, the inflammatory process does not end when the injury is healed and can continue for a prolonged time. Over time inflammation can cause many biological changes including growth of new tissues. When this tissue growth becomes too rapid, DNA mutation can occur which can give rise to tumors known as neoplasia
Most of these tumors are benign but some go on to become malignant and cause cancer, known as malignant neoplasia. When tumors disappear on their own and reappear after some interval of time, or appear at different intervals throughout a person’s life, it is known as metachronous neoplasia.