1. Extended Adjuvant Therapy With Aromatase Inhibitor Among Postmenopausal Breast Cancer

2. ABSTRACT
ABCSG 6a
MA17-1
MA.17R
NSABP B-33

3. Austrian Breast and Colorectal Cancer Study Group Trial(ABCSG) 6a
Raimund Jakesz, et al. J Natl Cancer Inst, 2007;99: 1845 – 53

4. Fig. 2 . Kaplan-Meier curves for recurrence-free survival in the anastrozole and no further treatment arms of ABCSG6a

5. Fig. 3 . Kaplan-Meier curves for distant metastatic recurrence free survival in the anastrozole and no further treatment arms of ABCSG6a

8. Table 4 . Incidence of predefined adverse events during ABCSG Trial 6a
The differences between the study arms were highly statistically significant ( P <.001) for hot flushes; asthenia, somnolence; allergy, cutaneous toxicity, skin rash; hair loss; and nausea (all grade 1 toxic effects).

9. CONCLUSION
Extended adjuvant endocrine therapy with anastrozole is a valid therapeutic option for breast cancer patients who have completed 5 years of adjuvant tamoxifen.

10. MA17-1
5187 postmenopausal women with primary breast cancer who had completed approximately 5 years of adjuvant tamoxifen therapy were randomly assigned to receive letrozole or placebo for five years
2593 were assigned to the letrozole group
2594 to the placebo group.
Paul E. Goss, et al. N Engl J Med, 2003,349,19:

11. Figure 1A: Kaplan-Meier Estimates of Disease-free Survival

12. Figure 1B: Kaplan-Meier Estimates of Overall Survival

14. CONCLUSION
As compared with placebo, letrozole therapy after the completion of standard tamoxifen treatment significantly improves disease-free survival.

15. MA.17R
1918 postmenopausal women with breast cancer who had received 4.5 to 6 years of adjuvant therapy with an aromatase inhibitor
Randomly assigned to receive letrozole (959 patients) or placebo (959 patients)for another 5 years.
P.E. Goss, et al. N Engl J Med,2016;375:

16. Figure 1A:The rate of 5-year disease-free survival was 95% in the letrozole group and 91% in the placebo group. The hazard ratio involving disease recurrence or the occurrence of contralateral breast cancer with letrozole versus placebo was 0.66 (P = 0.01).

17. Figure 1B: The rate of 5-year overall survival was 93% in the letrozole group and 94% in the placebo group, with a hazard ratio for death of 0.97 (P = 0.83).

18. Figure 2:The annual incidence rate of contralateral breast cancer was 0.21% in the letrozole group and 0.49% in the placebo group (P = 0.007), with a hazard ratio of 0.42

21. CONCLUSION
The extension of treatment with an adjuvant aromatase inhibitor (letrozole) to 10 years resulted in significantly higher rates of disease-free survival and a lower incidence of contralateral breast cancer than those with placebo
But the rate of overall survival was not higher with the aromatase inhibitor than with placebo.

22. NSABP B-33
Fig 1. CONSORT diagram of the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-33 trial.
Eleftherios P. Mamounas, et al. J Clin Oncol, 2008,26(12):

23. Fig 2. Kaplan-Meier estimates of disease-free survival with exemestane versus placebo (intent-to-treat) for eligible patients with follow-up.

24. Fig 3. Sites of first event with exemestane versus placebo
Fig 3. Sites of first event with exemestane versus placebo. P values are based on 4-year cumulative incidence rates. NED, no evidence of disease.

25. Fig 4. Kaplan-Meier estimates of relapse-free survival with exemestane versus placebo (intent-to-treat) for eligible patients with follow-up.

26. Fig 5. Reductions in disease-free survival event with exemestane versus placebo according to patient subgroups.

27. Conclusion
Despite early closure of accrual and considerable crossover to exemestane, original exemestane assignment in our trial resulted in reductions in DFS and RFS events of a magnitude similar to those seen with nonsteroidal aromatase inhibitors in the same setting.
Exemestane may provide another option for the extended adjuvant treatment of postmenopausal women with hormone-receptor–positive breast cancer who complete 5 years of adjuvant tamoxifen.

28. SUMMARY
ABCSG 6a
MA17-1
MA.17R
NSABP B-33