In a nutshell
Tamoxifen treatment is given to many breast cancer patients after surgery to prevent recurrences and improve survival. It is usually given for a maximum of 5 years. This study determined that longer treatments offer further survival benefit.
Some background
Tamoxifen is a drug used against breast cancers which produce estrogen receptors (ER). These are proteins that recognize estrogen (the female sex hormone) and promote tumor growth. Tamoxifen stops cancer progression by blocking the estrogen receptors. The treatment is given after surgery to destroy any remaining tumor cells.
Methods & findings
The present study involved 6846 women with ER positive breast cancer. 3418 women received standard treatment with Tamoxifen for a maximum of 5 years after surgery. The remaining 3428 women received treatment for 10 years. Results showed a significantly diminished risk of recurrence (return of the disease after a cancer-free period) and overall mortality in the 10-year Tamoxifen group. Ten years after the initial surgery, recurrences occurred in 711 (20.8%) patients in the 5-year Tamoxifen group versus 617 (17.9%) in the 10-year Tamoxifen group (overall risk reduction of 4% in 5-14 years). In terms of overall mortality after 10 years, there were 722 deaths in the 5-year Tamoxifen group (21.1%) versus 639 in the 10-year Tamoxifen group (18.6%).
The bottom line
These results prove that continuing Tamoxifen treatment for more than 5 years offers additional benefits by further reducing the risk of breast cancer recurrence and death.
The fine print
Despite the encouraging results, it is important to note that prolonged hormonal treatments, especially in postmenopausal women, increase the risk of endometrial cancer. The ER status of the tumor may also change and resistance to the drug may develop. Prolonged Tamoxifen treatment requires careful evaluation of the risk-benefit ratio for each patient.
Published By :
The Lancet
Date :
Dec 05, 2012
