Adjuvant tamoxifen versus tamoxifen plus CMF in the treatment of early breast cancer in Greece. Fifteen-year results of a randomised prospective trial and the potential risks of the antioestrogen.

Background: CMF and Tamoxifen are the most commonly administered drugs for the adjuvant treatment of early-stage breast cancer. We present the 15-year follow-up of our 250-patient series and evaluate the oestrogenic side-effect of Tamoxifen on the endometrium.

Patients And Methods: 250 women entered this prospective study from 1981-1986. They had all undergone modified radical mastectomyl and were randomly assigned to receive either Tamoxifen only for 4 years or combination of Tamoxifen with 6 cycles of standard CMF. Abdominal sonogram was used to determine endometrial thickness, with 6 mm as cut-off limit for endometrial biopsy.

Results: After 15.6 years of follow-up DFS and OS rates were better for the CMF + Tamoxifen, group (52.8% vs 39.2%--p = 0.043 and 57.6% vs 40.8%--p = 0.006 respectively). Only patients with more than 4 infiltrated nodes did not significantly benefit from adjuvant CMF. Postmenopausal women suffered more proliferative endometria compared to premenopausal ones (40.3% vs 15.6%), while life-threatening lesions (cancer and atypias) were found in 3.3% of the postmenopausal patients only.

Conclusion: CMF + Tamoxifen combination offers better long-term results for early-stage breast cancer patients. Dose reduction must be avoided if maximum results are to be achieved. More than 4 positive nodes seem to require additional chemotherapeutic manipulation. Tamoxifen's oestrogenic side-effect on the endometrium is quite common, but life-threatening lesions are rare, thus proving the drug's safety.