One of the most awaited presentations in Chicago, at the annual congress of the American Society of Clinical Oncology, that of advanced or metastatic breast cancer in young and very young women. In fact, under the age of 39, cases of aggressive breast cancer are increasing. And, for the first time, one of the last drugs approved for this disease has been shown to be able to increase overall survival (and not just the one free from disease progression).

Let’s talk about ribociclib: after 42 months of follow-up, overall survival was 70% for women treated on the front line with the ribociclib combination plus standard hormone therapy, compared to 46% of those treated with hormone therapy alone standard (an aromatase inhibitor or tamoxifen). The risk of death is reduced by 29%. These are the final results of the MONALEESA-7 study, also published in the New England Journal of Medicine.

“Impacting results are those that we hope to observe in every clinical study and achieving it in an incurable disease like metastatic breast cancer is an incredible advancement for patients,” said Sara Hurvitz, Medical Director of the Jonsson Comprehensive Cancer Center Clinical Research Unit and Director of the Breast Cancer Clinical Trials Program at UCLA.

Ribociclib is a cyclin-dependent kinase inhibitor 4 and 6 (CDK4 / 6, two proteins that underlie tumor progression), approved in Europe at the end of last year for the first-line treatment of premenopausal women with breast cancer advanced or metastatic, hormonal receptor positive (HR + / HER2-). 

The increase in general survival is a difficult goal to achieve: it is a direct measure (as opposed to disease-free survival) to understand if the treatment is really able to increase the life expectancy of people affected by cancer. Demonstrating that a drug can increase overall survival is often difficult in clinical trials, both because it requires patients to be followed throughout their lives, and because they often receive many lines of treatment and the variability in the sequence in which they are taken can make it difficult measure this parameter correctly.


Metastatic breast cancer is the leading cause of cancer-related death in women, particularly in the younger age range, between 29 and 59 years. The risk of developing metastases after a first diagnosis of breast cancer is estimated at around 20-30%. In the case of tumors sensitive to female hormones, a risk seems to persist even more than 10 years after the first diagnosis.

“Young women with metastatic cancer live a very difficult condition,” concludes MJ DeCoteau, Executive Director of non-profit Canadian Rethink Breast Cancer: “They can be students, mothers or just beginning of their career. Knowing that an already approved treatment has proven to help them live longer is very important and gives hope ”.