SAN ANTONIOA European metaanalysis suggests that breast cancer
patients over age 73 may live just as long if treated with tamoxifen
(Nolvadex) instead of surgery.
Speaking at the 21st Annual San Antonio Breast Cancer Symposium, Dr.
Giorgio Mustacchi, director of the University of Trieste Cancer
Center, Italy, reported long-term results from a combined analysis of
data from Italys Group for Research on Endocrine Therapy in the
Elderly (GRETA) and the United Kingdoms Cancer Research Centre
Since in these studies tamoxifen alone and tamoxifen plus
surgery yielded the same overall survival rates, minimal surgery plus
tamoxifen for very frail, elderly women should be sufficient,
Dr. Mustacchi said.
Between 1984 and 1992, 913 operable patients over age 70 with mostly
T2 tumors (2 to 5 cm) were randomized to either tamoxifen alone or
tamoxifen plus surgery. Although the GRETA study encompassed more T1
tumors (42% vs 24% in the CRC), mastectomy was more common (84% vs
30% in the CRC).
Dosing schedules were also markedly different: GRETA used a 1-day 160
mg tamoxifen loading dose with 20 mg daily thereafter in the
nonsurgical arm and 20 mg daily without the loading dose in the
surgical arm. The CRC used a 40 mg daily dose in both arms.
Merged data, first presented at the 1998 American Society of Clinical
Oncology (ASCO) annual meeting, showed that patients randomized to
primary surgery did not have a significant advantage in terms of
overall survival (RR = 0.86, P = .09). However, the risk of death
from breast cancer was significantly reduced by surgery, with a
hazard ratio of 0.70 (95% CI, 0.51 to 0.95).
These data translate to a a highly significant 30% less
probability of death from breast cancer with surgeryalong with
a 95% probability that the difference is related to treatment, and
not chance, Dr. Mustacchi said.
Further analysis of 13-year survival data showed that surgery did
significantly improve overall survival in patients aged 70 through
73. However, it had no significant effect on overall survival in the
three age groups over 73 years of age (74 to 76, 77 to 79, and over 80).
Real or an Artifact?
Professor Mustacchi told Oncology News International that the
apparent benefit for younger women could be real or could be a
statistical artifact (less than 25% of the whole study
population was under the age of 73).
Another intriguing idea, he said, is that the time to relapse
could be longer than the given time (lifespan), and that
patients may have died for other reasons prior to relapse.
Also, in terms of overall survival, it may be that tamoxifen is
reducing deaths from causes other than breast cancer, such as heart
disease and fractures resulting from osteoporosis.