10 years of treatment vs 5 years of treatment with hormone therapy in patients with early stage breast cancer.

This study wanted to find out if continuing hormone therapy for 10 years was more effective than doing it for 5 years in patients with early stage breast cancer. The study found that the patients who continued treatment for 10 years survived for longer without the disease coming back compared to those who were only treated for 5 years.

Some types of breast cancer have receptors on the surface of the cells which respond to hormones, such as estrogen and progesterone. This knowledge has been used to develop treatments for breast cancer called hormone therapy, or endocrine therapy. It is well known that in patients with hormone-positive early stage breast cancer, treating for 5 years is more effective and results in longer survival than only treating for 1-2 years. It is not known how treatment longer than 5 years will affect survival in early stage breast cancer patients.

This study consisted of 30,848 patients over 12 different trials. Each trial was slightly different. Overall, the patients in each of the trials were randomly assigned to received hormone therapy for either 5 or 10 years. After the treatment was finished, the patients were followed to see how long it took them to get the disease again, or how long they survived.

It was found that the patients who were treated for 5 years developed the disease again sooner than those who were treated for 10 years. The treatment that worked the best was when the patients received tamoxifen (Nolvadex) for 5 years, followed by an aromatase inhibitor for the next 5 years. The most suitable groups to receive 10 years of treatment are those with estrogen receptor positive breast cancer and progesterone receptor positive breast cancer. The treatment also works well in patients who are post-menopausal, and who have cancer in their lymph nodes. There was no benefit to overall survival seen.

The authors concluded that 10 years of hormone therapy is more effective at preventing the cancer coming back, compared to only 5 years of therapy in patients with early stage breast cancer.

This is a very large study, because it combined the results of a number of other studies performed across the world. While there is more room for error in this kind of study, because it is so large, the results are most likely correct.

Discuss with your oncologist if prolonging your treatment is right for you.