Aspirin would prevent colorectal cancer

Patients at high genetic risk may benefit.

Hope for preventative treatment of cancer leads all researchers but also those at high risk. This applies to those with Lynch syndrome, a genetic disorder that increases the risk of cancer, including colorectal, but also other organs such as the endometrium. In this rare syndrome, but which remains the most common cause of hereditary colorectal cancer, patients should undergo colonoscopy including at least every two years from the age of 20 years. The goal is of course the early detection of colorectal cancer known to strike more than one in three of these patients.

The study published Friday in the international journal The Lancet, should give some hope to these patients for whom the average age of discovery of a colorectal cancer is 42 years (sometimes 25 years). This work demonstrates the preventive effect of aspirin. Over 850 people, half taking aspirin and the other half a placebo, it appears that patients who took daily aspirin 600 mg for 2 years had their risk of colorectal cancer reduced by third compared to those taking placebo (inactive product). And without adverse events. The authors found 18 cancers in 427 patients in the aspirin group as against 30 434 for placebo.

A solid foundation

In 2008, these same researchers had not demonstrated the efficacy of aspirin in this study. In extending the monitoring of patients taking aspirin for more than two years, they realized the preventive effect of aspirin. After two years, the difference between the two groups began to appear, but it was still statistically insufficient to draw conclusions.

Cautious optimism of Dr. David Malka, digestive cancer specialist at the Institut Gustave-Roussy (Villejuif): "This is a study that could add a new weapon next to the monitoring of patients for colonoscopy," said he. This time, Professor John Burn (Institute of Medical Genetics, Newcastle University) and colleagues are more categorical: "Our results, put in perspective with other recent research, provide a sound basis for recommending aspirin in preventing systematic in the Lynch syndrome, "they write in The Lancet. No more, they say, to define the correct dose and proper duration of treatment.

Specialists, however, surprised to get this result as the number of polyps detected by colonoscopy was similar for patients taking aspirin or placebo. The theory is, in fact, the polyps are the first step before a possible transformation into cancer. These results obtained in patients at high risk because of their genetic disease, can they be extrapolated to other classes? What is the risk / benefit of treatment in these cases, because of the risk of bleeding associated with aspirin? For now the results obtained with low doses of aspirin used in the prevention of recurrent cardiovascular events, generally less than 100 mg per day have shown no interest in reducing the risk of colorectal cancer -rectal. However, for patients with colorectal cancer treated, studies have shown a preventive effect of aspirin but moderate. It is too early to venture a general recommendation outside the Lynch syndrome.