Incidence of reversible amenorrhea in women with breast cancer undergoing adjuvant anthracycline-based chemotherapy with or without docetaxel

Background: To determine the incidence of reversible amenorrhea in women with breast cancer undergoing adjuvant anthracycline- based chemotherapy with or without docetaxel. Methods: We studied the incidence and duration of amenorrhea induced by two chemotherapy regimens: ( i) 6 cycles of 5- fluorouracil 500 mg/ m(2), epirubicin 100 mg/ m2 and cyclophosphamide 500 mg/ m2 on day 1 every 3 weeks ( 6FEC) and ( ii) 3 cycles of FEC 100 followed by 3 cycles of docetaxel 100 mg/ m2 on day 1 every 3 weeks ( 3FEC/ 3D). Reversible amenorrhea was defined as recovery of regular menses and, where available ( 101 patients), premenopausal hormone values ( luteinizing hormone ( LH), follicle-stimulating hormone ( FSH) and estradiol) in the year following the end of chemotherapy. Results: One hundred and fifty- four premenopausal patients were included: 84 treated with 6FEC and 70 with 3FEC/ 3D. The median age was 43.5 years ( range: 28 - 58) in the 6FEC arm and 44 years ( range: 29 53) in the 3FEC/ 3D arm. Seventy- eight percent of patients were treated in the context of the PACS 01 trial. The incidence of chemotherapy- induced amenorrhea at the end of chemotherapy was similar in the two groups: 93 % in the 6FEC arm and 92.8 % in the 3FEC/ 3D arm. However, in the year following the end of chemotherapy, more patients recovered menses in the 3FEC/ 3D arm than in the 6FEC arm: 35.5 % versus 23.7 % ( p = 0.019). Among the 101 patients for whom hormone values were available, 43 % in the 3FEC/ 3D arm and 29 % in the 6FEC arm showed premenopausal levels one year after the end of chemotherapy ( p < 0.01). In the 3FEC/ 3D group, there was a statistically significant advantage in disease-free survival ( DFS) for patients who were still amenorrheic after one year, compared to patients who had recovered regular menses ( p = 0.0017). Conclusion: Our study suggests that 3FEC/ 3D treatment induces more reversible amenorrhea than 6FEC. The clinical relevance of these findings needs to be investigated further.