Scottish adjuvant tamoxifen trial: a randomized study updated to 15 years

Area of Science:

• Oncology
• Clinical Trials
• Pharmacology

Background:

• The Scottish Adjuvant Tamoxifen Trial investigated tamoxifen's efficacy in breast cancer patients.
• Patients received tamoxifen either adjuvantly or after relapse.
• Initial results covered follow-up periods up to 8 years.

Purpose of the Study:

• To update results of the Scottish Adjuvant Tamoxifen Trial after a median follow-up of 15 years.
• To assess the long-term effects of adjuvant tamoxifen on survival, recurrence, and other malignancies.
• To evaluate the benefit of continuing tamoxifen beyond 5 years.

Main Methods:

• 1323 patients were randomized into adjuvant or control arms.
• A duration trial assessed stopping or continuing tamoxifen after 5 years in disease-free patients.
• Data on death, recurrence, and survival were analyzed for long-term outcomes.

Main Results:

• The 5-year adjuvant tamoxifen regimen maintained significant benefits in total survival, reduced systemic relapse, and decreased breast cancer mortality at 15 years.
• No additional survival or relapse benefit was observed for patients continuing tamoxifen beyond 5 years.
• P-values for survival (P=.006), relapse (P=.007), and breast cancer death (P=.002) indicate statistical significance.

Conclusions:

• Adjuvant tamoxifen therapy for operable breast cancer is effective for at least 15 years when administered for 5 years.
• Extended tamoxifen use beyond 5 years does not provide further advantages.
• A 5-year duration of adjuvant tamoxifen appears sufficient for women with operable breast cancer.