Longer tamoxifen therapy cuts heart disease deaths

NEW YORK (Reuters Health) – Women with breast cancer who
take tamoxifen for 5 rather than 2 years apparently lower their
risk of dying from coronary heart disease, according to a
report in the Journal of the National Cancer Institute.

When compared with other forms of add-on or adjuvant
therapy, tamoxifen “tends to decrease mortality from coronary
heart disease,” Dr. Bo Nordenskjold, from Linkoping University
Hospital in Sweden, and colleagues write. “Our results strongly
support the use of tamoxifen in the adjuvant treatment of
breast cancer patients,” they add.

The findings come from a study of 4175 women with breast
cancer who were free of any recurrence of the disease after
taking tamoxifen for 2 years. Half the group was then assigned
to continue this therapy for 3 more years, while the other half
discontinued its use.

Compared with 2 years of tamoxifen therapy, 5 years of
therapy was tied to a reduction in deaths from all causes,
deaths specifically due to breast cancer, and with a decreased
risk of developing cancer in the other breast.

However, the longer duration therapy was associated with an
increased risk of endometrial cancer.

Use of tamoxifen for 5 years cut heart disease mortality by
33 percent compared with that seen with 2 years of therapy, the
investigators found. After 10 years, the death rate due
specifically to coronary heart disease was 2.1 percent and 3.5
percent in the 5- and 2-year tamoxifen groups, respectively.

The findings indicate that in addition to cutting breast
cancer deaths, 5 years of tamoxifen therapy reduces the risk of
death from coronary heart disease, the team concludes.

SOURCE: Journal of the National Cancer Institute, November
2, 2005.