Chemotherapy every two weeks for premenopausal breast cancer patients improves survival and does not increase risk of early menopause
Premenopausal women with breast cancer have a better chance of survival if they are given cycles of adjuvant chemotherapy closer together, every two weeks rather than every three weeks. Furthermore, this regimen, known as “dose-dense” adjuvant chemotherapy, does not seem to be associated with an increased risk of treatment-induced early menopause.
The findings will be presented today (Thursday) at the 10th European Breast Cancer Conference (EBCC-10) and the researchers say they are important for helping younger breast cancer patients and their doctors to make better-informed decisions about the choice of chemotherapy regimens that are given in addition to other treatments such as surgery, hormone therapy and radiotherapy.
Dr Matteo Lambertini, MD, a medical oncologist at IRCCS AOU San Martino-IST, National Institute for Cancer Research, Genoa, Italy, and at the Institut Jules Bordet, Brussels, Belgium, will tell the conference: “Our results confirm the superiority of dose-dense chemotherapy as compared to standard interval regimens in premenopausal patients at higher risk of relapse, and its use should be implemented in Europe, as it is in the United States.”
Currently, treatment guidelines vary between Europe (where there are no clear recommendations) and the USA (where dose-dense chemotherapy is now given more often than in Europe). Until now, there have been no good data on any increased risk of dose-dense chemotherapy triggering early menopause with its associated complications, including infertility.
Dr Lambertini and colleagues, led by Dr Lucia Del Mastro (also from IRCCS AOU San Martino-IST), carried out a meta-analysis of two large randomised phase III clinical trials that compared adjuvant chemotherapy given every two weeks (dose dense) or every three weeks (the standard interval); the MIG1 study looked at this in breast cancer patients whose disease had spread to their lymph nodes (node positive) or who were at high risk of relapse (high-risk, node-negative), while the GIM2 study investigated it in women with early stage, node positive disease. Treatment-induced amenorrhea (when the chemotherapy damages the ovaries, causing menstrual periods to stop and other menopausal symptoms) was defined as the absence of periods after the end of chemotherapy after three months in the MIG1 study and after 12 months in the GIM2 study.