This was a combination of 2 trials (SOFT/TEXT) for a total of 4690 premenopausal pts with hormone drive early breast ca (ER+)
All were treated with ovarian suppression (injections or ovarian surgery /radiation) for 5 yrs and either tamoxifen or exemestane. Exemestane is an aromatase inhibitor (AI)(like anastrozole and letrozole) which is superior to tamoxifen in the ppost menopausal setting. Thus, the SOFT/TEXT study aimed to emulate these results in premenopausal patients.
Overall 5yr DFS (prim endpt) was 91.1% for exe vs 87.3% tam. So there was a 4% improvement in freedom from breast cancer recurrence (helping an extra 1/25 patients). Some criticisms or concerns would include the lack of long term followup and assessment of implications for bone thinning (osteoporosis) and cardiovascular disease. The AIs can be challenging with higher rates of joint aches, mood disturbance and libido issues.
My sense is that this may suit the right premenopausal patient with higher risk disease who wants to maximise theie therapeutic gain and has maybe through chemotherapy not found the hormonal disruption troubling in the leadup to this discussion and consideration. A quirk of the PBS is that exemestane can only be used after prior TAM for 2-3 years but I don’ t regard its action as having a therapeutic advantage over the other AIs which are PBS listed ‘up front’. http://www.nejm.org/doi/full/10.1056/NEJMoa1404037
