The results come from an extended follow-up of 4175 women who participated in
the landmark tamoxifen study by the Swedish Breast Cancer Group. Those study
findings were originally reported in1996, showing that tamoxifen reduces the
recurrence rate of breast cancer.
Dr. Bo Nordenskjold, head of the Oncology Centre for Southeast Sweden, and
co-investigators found that among the women who took tamoxifen for two years,
381 women died from causes other than breast cancer over following years; that
compared with only 307 non-breast cancer deaths in the group that took tamoxifen
for five years.
At a press briefing Monday at the European Society of Medical Oncology
Congress, Nordenskjold said the major difference was in cardiovascular mortality
and specifically in deaths from coronary heart disease.
In the two-year group, 163 women died from cardiovascular disease, compared
with 136 women in the five-year group. In the 2-year arm, 78 women died from
coronary heart disease compared to 54 women in the 5-year arm.
The effect on coronary heart disease, however, is delayed.
"This difference in mortality in coronary heart disease is a late event,"
Nordenskjold said. "The first 7 or 8 years you see no difference. But the
difference emerges gradually."
