Long-Term Follow-up of Adjuvant Tamoxifen in Women With Breast Cancer
Posted: Monday, April 15, 2019
According to Maria Ekholm, MD, and colleagues, of Lund University in Sweden, 2 years of adjuvant tamoxifen therapy can impart long-term advantages in women with estrogen receptor–positive breast cancer—including reduced rates of breast cancer recurrence and metastasis. In fact, the authors highlighted that the benefits of adjuvant tamoxifen “seem to extend beyond 15 years.” The results of this Swedish study were published in the European Journal of Cancer.
“The carryover effect associated with tamoxifen remains for a long period and is not restricted to [contralateral breast cancer] but applies to all breast cancer–related events, including distant recurrence,” concluded the authors.
In this long-term survival analysis of the Swedish SBII:2pre trial, 560 patient records spanning 30 years from 23 hospitals were reviewed. The records focused on patients who were enrolled as premenopausal women with breast cancer, irrespective of hormone receptor status. These patients were randomly assigned to receive adjuvant tamoxifen therapy or no systemic treatment (276 and 284 women, respectively).
At 30 years of follow-up, adjuvant tamoxifen prolonged breast cancer recurrence–free survival compared with no treatment (P = .011), but it did not significantly affect the rate of distal recurrence. In women with estrogen receptor–positive breast cancer, both breast cancer and distal recurrence rates were reduced with adjuvant therapy (P = .001 and P = .043, respectively). Furthermore, the rate of contralateral breast cancer in the tamoxifen group was lower than in the control group (P = .035). However, for 165 women in the tamoxifen group who were later diagnosed with metastasis, the median survival was 29 months, versus 43 months in the control group.
“Our results may encourage patients experiencing difficulties in tolerating endocrine therapy to adhere to tamoxifen treatment for at least 2 years.”
Disclosure: The study authors reported no conflicts of interest.