Juicio TACT2 en el cáncer de mama precoz (EBC): Las tasas diferenciales de amenorrea en las mujeres premenopáusicas siguientes epirubicina adyuvante (E) o epirubicina acelerada (AE), seguido de capecitabina (X) o CMF

BACKGROUND:

TACT2, a multicentre randomised phase III trial with E-CMF as control (Poole NEJM 2006), tests 2 hypotheses in a 2x2 factorial design: A) accelerated chemotherapy (CT) improves outcomes: (B) capecitabine (X) gives similar efficacy but preferential side-effect profile to CMF. Here we focus on impact of treatment on menstruation in premenopausal women (≤50 years old).

METHOD:

Between Dec 2005-08, 4391 patients (4371 women, 20 men) with node positive or high risk node negative invasive EBC were randomised to receive either E (100mg/m2 x 4) q3wk or aE (100mg/m2 x 4 plus pegfilgrastim, 6mg d2) q2wk followed by classical CMF q4wk x 4 or X (2500mg/m2/day x 14) q3wk x 4. Impact on menstruation was assessed 18 months post-randomisation for premenopausal women ≤50 years old (n=1626). Use of elective ovarian ablation was taken as evidence of continuing menses, and data analysed by multiple logistic regression.

RESULTS:

Data describing menstruation at 18 months were received for 1361 premenopausal patients. 711/1361 (52%) patients had continuing periods or elective ablation by 18 months (CMF 219/667 (33%), X 492/694 (71%), p<0.001). aE rather than E resulted in fewer patients menstruating at the end of chemotherapy but this effect was lost by 18 months. In adjusted analyses, independent predictors of the continuation of periods included treatment with X over CMF and lower age (continuous) (both p<0.001). Epirubicin schedule and ER status were not significant. A significant interaction was seen between age and X (p=0.02), with a protective effect of X on continuation of menses greatest in older patients.

CONCLUSION:

E followed by X has much lower risk of permanent loss of menstrual function in pre-menopausal EBC women than CMF after E, particularly for those >40 years old. Whilst comparable efficacy data on these regimens are awaited, these data could be important when interpreting future analyses in TACT2.