Cyclophosphamide-free chemo may promote menses resumption

Breast cancer patients receiving treatment with a cyclophosphamide-free chemotherapy regimen are likely to resume their menses, according to a phase III trial.

Premature menopause associated with chemotherapy has been shown to have serious consequences, including infertility. The current trial was initiated to establish whether a chemotherapy regimen that did not contain cyclophosphamide would increase the likelihood of menses resumption and improve survival outcomes.

A total of 521 young women (median age 34 years, interquartile range 1–38 years) with ER-positive HER2-negative breast cancer were randomized to receive adjuvant epirubicin/cyclophosphamide followed by weekly paclitaxel (EC-wP; n=261) or epirubicin/paclitaxel followed by weekly paclitaxel (EP-wP; n=260). Treatment was given following definitive surgery, and all patients received adjuvant endocrine therapy for at least 5 years following chemotherapy.

The rate of menstrual resumption at 12 months after chemotherapy was higher with EP-wP (63.1 percent, 95 percent confidence interval [CI], 57.2–68.9) than with EC-wP (48.3 percent, 95 percent CI, 42.2–54.3), with an absolute difference of 14.8 percent (95 percent CI, 6.37–23.2; p<0.001).

Of note, a posthoc exploratory analysis conducted using patient-reported outcome questionnaires revealed that more women in the EP-wP than the EC-wP group were able to get pregnant.

At a median follow-up of 62 months, the 5-year disease-free survival (DFS) was comparable at 78.3 percent (95 percent CI, 72.2–83.3) with EC-wP and 84.7 percent (95 percent CI, 79.3–88.8) with EP-wP (p=0.07).

Safety data were consistent with the known safety profiles of relevant drugs.