(Montreal) Most women who are diagnosed with breast cancer can now expect to survive the disease for several years, says a new study published by the medical journal The BMJ.
The data thus reveal that the average risk of death in the five years following diagnosis has fallen from 14% to 5% since the 1990s. This risk was 3% or less for more than 60% of women whose diagnosis is occurred between 2010 and 2015.
These figures, say the study authors, are very reassuring for women whose disease is detected early, since they can expect to survive it for a long time. The data will also help identify women whose risk of death remains higher, they add.
This improvement is attributable in particular to all the new weapons that modern medicine has acquired in recent years to fight breast cancer, commented Professor Alain Nepveu, who is a researcher at the Rosalind Cancer Institute and Morris Goodman of McGill University.
“All of this leads to progress. It’s not day and night, but in a number of cases it improves life expectancies, he said. What we can say, certainly, is that we lengthen the life expectancy of cancer patients, we give you time, and if you have cancer, time is precious. »
It is not only the life expectancy of patients that is extended, he adds, but also their quality of life that is improved, since new treatments often replace old ones, such as chemotherapy whose side effects unpleasant certainly need no further description.
While it has long been known that the survival rate of women with breast cancer is improving, this is the first time that this improvement has been measured and quantified. To achieve this, the study authors looked at more than 510,000 Britons affected by early breast cancer, for whom it was the first cancer, who were diagnosed between January 1993 and December 2015, and who had undergone surgery.
All women were followed until December 2020.
On average, the risk of mortality within five years of diagnosis was 14.4% for women diagnosed between 1993 and 1999, and 4.9% for those diagnosed between 2010 and 2015.
Considering only the approximately 155,000 women who were diagnosed between 2010 and 2015, mortality risk fluctuated widely depending on certain disease characteristics, patient age and time of detection. This risk was less than 3% for 62.8% of the women, but more than 20% for 4.6% of them.
Moreover, underlined Professor Nepveu, the authors of the study show that the larger the tumor is at the time of screening, the more mortality increases.
“That doesn’t mean a tumor that’s small won’t metastasize,” he said. But as the big tumor has more cells, then the frequency of metastases is increased, and it’s the metastases that kill you. »
That being said, he continues, when we look at the advances of the last few years, the 30-year survival rates show that we are on the way to transforming cancer “from fatal disease to chronic disease”.
“You end up living with your cancer and we can prolong your life so that you are at risk of dying from something other than cancer,” explained Professor Nepveu. And that is even in the worst cases. »
More than two million women are diagnosed with breast cancer each year worldwide.