New: NCI-funded clinical trial search
Mednet Logo

Abstract

Background

Suppression of ovarian estrogen production reduces the recurrence of hormone-receptor-positive early breast cancer in premenopausal women, but its value when added to tamoxifen is uncertain.

Methods

We randomly assigned 3066 premenopausal women, stratified according to prior receipt or nonreceipt of chemotherapy, to receive 5 years of tamoxifen, tamoxifen plus ovarian suppression, or exemestane plus ovarian suppression. The primary analysis tested the hypothesis that tamoxifen plus ovarian suppression would improve disease-free survival, as compared with tamoxifen alone. In the primary analysis, 46.7% of the patients had not received chemotherapy previously, and 53.3% had received chemotherapy and remained premenopausal.

Results

After a median follow-up of 67 months, the estimated disease-free survival rate at 5 years was 86.6% in the tamoxifen-ovarian suppression group and 84.7% in the tamoxifen group (hazard ratio for disease recurrence, second invasive cancer, or death, 0.83; 95% confidence interval [CI], 0.66 to 1.04; P=0.10). Multivariable allowance for prognostic factors suggested a greater treatment effect with tamoxifen plus ovarian suppression than with tamoxifen alone (hazard ratio, 0.78; 95% CI, 0.62 to 0.98). Most recurrences occurred in patients who had received prior chemotherapy, among whom the rate of freedom from breast cancer at 5 years was 82.5% in the tamoxifen-ovarian suppression group and 78.0% in the tamoxifen group (hazard ratio for recurrence, 0.78; 95% CI, 0.60 to 1.02). At 5 years, the rate of freedom from breast cancer was 85.7% in the exemestane-ovarian suppression group (hazard ratio for recurrence vs. tamoxifen, 0.65; 95% CI, 0.49 to 0.87).

Conclusions

Adding ovarian suppression to tamoxifen did not provide a significant benefit in the overall study population. However, for women who were at sufficient risk for recurrence to warrant adjuvant chemotherapy and who remained premenopausal, the addition of ovarian suppression improved disease outcomes. Further improvement was seen with the use of exemestane plus ovarian suppression. (Funded by Pfizer and others; SOFT ClinicalTrials.gov number, NCT00066690.).

Related Questions

How do you approach adjuvant endocrine therapy in a pre-menopausal patient with node negative HR+HER2- breast cancer with a high Oncotype RS who received adjuvant chemotherapy?

1
1 Answers

Mednet Member
Mednet Member
Medical Oncology · Mayo Clinic Rochester

The SOFT/TEXT study can be used to answer this question. SOFT was a phase III study in premenopausal women with ER+ disease comparing ovarian function suppression (OFS)+ an aromatase inhibitor (AI) to OFS + tamoxifen vs tamoxifen alone; TEXT compared OFS+AI vs OFS+tamoxifen. The vast majority of wom...

In women in whom you suspect chemotherapy-induced amenorrhea and are required to start an AI, what is your strategy with regard to ovarian suppression?

1 Answers

Mednet Member
Mednet Member
Medical Oncology · University of Texas MD Anderson Cancer Center

For patients who were premenopausal at the time of breast cancer diagnosis (or shortly before) and who cease menses either spontaneously or due to chemotherapy, many will continue to have ovarian production of estrogen without periods, or resume periods for up to 2 years (and sometimes after even lo...

Would you recommend the SOFT/TEXT adjuvant approach of ovarian suppression/AI in a premenopausal woman with high-risk disease who still desires to have a pregnancy?

1 Answers

Mednet Member
Mednet Member
Medical Oncology · University of Texas MD Anderson Cancer Center

In the SOFT trial, the disease-free survival impact of adding ovarian suppression to hormonal therapy was not statistically significant in the overall population, but was superior in higher risk patients, including those who received chemotherapy. While we typically do not guide treatment based on s...

Should ovarian suppression be recommended to premenopausal ER/PR positive patients?

1 Answers

Mednet Member
Mednet Member
Medical Oncology · Indiana University School of Medicine

The SOFT trial (https://www.ncbi.nlm.nih.gov/pubmed/25495490) found an improvement in DFS for combined ovarian suppression + AI compared to tamoxifen alone (the OA + Tam group was intermediate). While the overall results were positive, I think putting the results in practice requires looking at the ...