NSAS-BC02 substudy of chemotherapy-induced amenorrhea (CIA) in premenopausal patients who received either taxane alone or doxorubicin(A) cyclophosphamide(C) followed by taxane as postoperative chemotherapy

Background
Chemotherapy-induced amenorrhea (CIA) is one of the critical side effects from the chemotherapy in premenopausal patients with breast cancer. The goals of our study are the following: (1) to investigate the factors affecting the incidence of CIA; and (2) to evaluate the prognostic role of CIA in premenopausal patients with breast cancer.
Methods
We conducted a post hoc retrospective substudy to examine the incidence of the CIA and the relationship between CIA and prognosis in NSAS-BC02 that compared taxane alone to Doxorubicin(A) Cyclophosphamide(C) followed by taxane in postoperative patients with node-positive breast cancer
Results
Of 395 premenopausal women, 287 (72.7%) had CIA due to protocol treatment. Regarding type of protocol regimen, proportion of CIA was 76.9% in AC Paclitaxel(P), 75.2% in AC Docetaxel(D), 62.8% in PTX, and 75.2% in DTX. Predictive factors of CIA were age increase by 5 years (OR 1.50), ER positivity (OR 2.08), and HER2 3 + ( OR 0.40) according to logistic regression analysis. According to the log rank test and the Cox proportional hazards model, CIA group had significantly better disease-free survival than non-CIA group (P < .0001). However, according to time-dependent Cox model that was used to reduce guarantee-time bias, CIA was not a statistically significant prognostic factor in both ER-positive and ER-negative patients.
Conclusion
Treatment with taxane alone caused high frequency of CIA in premenopausal women with breast cancer. CIA did not turn out to be an independent prognostic factor, taking guarantee-time bias into consideration. Further clinical studies are needed to validate these findings.