Aspirin, a new hope against cancer, Should we all take aspirin to prevent cancer? The question arises again after the release, Wednesday, March 21, the site of the British medical weekly The Lancet, three new studies, conducted by the team of Professor Peter Rothwell. They show that a daily aspirin reduces mortality and the risk of metastases.
Founder of the Research Unit on the prevention of stroke at the University of Oxford, Peter Rothwell calls for caution, however: it is too early to conclude that everyone would clearly benefit of such prophylaxis. Who joined the notice, unanimous, and other specialists.
British researchers have collected data from tests originally designed to assess the benefits on the cardiovascular system, a continuous shooting aspirin. This method, if it has the advantage of allowing easy access to data of tens of thousands of individuals, does not have the same guarantees that a study specifically designed to assess the benefits of a drug vis- -vis the cancer.
75 ES MILLIGRAMM
In a previous study, published in December 2010, Mr. Rothwell and colleagues had shown a reduction of about 20% lower risk of cancer deaths among 25,000 participants treated daily for four years with a low dose (75 mg) aspirin. It reached 30% to 40% after five years of this treatment.
The three new studies confirm the reduction of deaths and the risk of malignancies. They also show a decreased risk of metastatic cancer. The benefits are particularly evident in adenocarcinomas, the most common tumors.
The first study includes the results of 51 trials where participants were divided, randomly, in a group with a group without aspirin or aspirin. Cancer risk decreased by 15% on aspirin. The reduction reached 37% with once daily for five years or more. The benefit is already evident after three years of treatment: the effect is reduced by about one quarter. “It’s huge,” admits Anne-Odile Hueber, National Institute of Health and Medical Research (University of Nice), colorectal cancer specialist.
PREVENTION OF METASTASIS
The second study showed a 31% reduction in risk of adenocarcinoma metastases already at diagnosis and 55% of subsequent development of metastases. In the case of colorectal cancer, the risk of subsequent metastasis is even reduced by 74%.
The daily aspirin is also associated with a decrease in cancer deaths among people who developed adenocarcinoma, particularly in the absence of metastases at diagnosis (50% reduction). “These results provide the first evidence in humans that aspirin prevents distant metastases of cancers,” rejoice authors of three studies.
The third study is the reduced risk of colorectal cancer around 40%.
In a commentary accompanying the Lancet three studies, two Harvard doctors welcome these results “compelling”, but stressed the problem of the inherent risk of bleeding effects of aspirin, which thins the blood.
A disadvantage which tempers the benefits of this medication. The team of Peter Rothwell has been found that the risk of bleeding increases in the early trials, although it decreases with time and disappear after three years of treatment.
“No one will venture to recommend solely on the basis of these studies the daily aspirin in cancer prevention,” say in chorus Anne-Odile Hueber, Fabio Calvo, director of research at the National Cancer Institute (INCA ), and Dominique Maranichi, former president of INCA.
“To know who and what age to give aspirin or by preventing the occurrence of cancer, either to prevent a recurrence or metastases, it is essential to mount a specific clinical trial of great magnitude. It is for public agencies such as the INCA and its counterparts in other countries to develop, “said Calvo.
“Elucidate the molecular mechanisms”
Researchers must work in two directions, according to Ms. Hueber: “The first is to elucidate the molecular mechanisms explaining the effect of aspirin on tumor cells and the initial stages of cancer development. The second is to developing hybrid aspirin, which would retain the benefits in cancer prevention, without side effects. ”
Another point remains unclear. “We do not know why it does not work with an aspirin every other day,” says Calvo. Peter Rothwell would not be surprised that “the effects of treatment taken on alternate days, absent in the short term, will reveal if followed over the long term.” His team is awaiting publication next year, results of a large trial of aspirin in cardiovascular prevention, the Women’s Health Study, in determining that question.