Asociación entre la historia reproductiva, el subtipo de cáncer de mama y la supervivencia de mujeres premenopáusicas / Association between reproductive history, breast cancer subtype, and survival in premenopausal women

Antecedentes y objetivo: La historia reproductiva influye en el riesgo de cáncer de mama. Hemos analizado su asociación con el subtipo tumoral y la supervivencia en mujeres premenopáusicas. Pacientes y métodos: Estudio observacional, retrospectivo, de mujeres premenopáusicas con carcinoma de mama, estadios I-III, en los últimos 20 años. Revisión de la historia reproductiva, de los datos clínicos y de los tratamientos en las historias de salud. Resultados: En 661 mujeres premenopáusicas (32,40% de 1.377 totales), la mediana de edad fue de 47 años (19-53), de la menarquia 12 (7-17), del primer parto 28 (16-41) y de número de partos 2 (0-9). Fueron nulíparas 111 (18,20%). Emplearon lactancia natural 359 (58,80%) con mediana de duración de 6 meses. Consumieron anovulatorios 271 (44,40%), con mediana de 36 meses. Se halló asociación entre menarquia <10 años y menos riesgo de subtipo luminal (OR: 0,52; IC 95%: 0,28-0,94; p=0,03), entre menarquia >11 años y menos riesgo de subtipo HER2 (OR: 0,50; IC 95%: 0,26-0,97; p=0,04) y entre primer parto >30 años y menos riesgo de subtipo triple negativo (OR: 0,40; IC 95%: 0,17-0,93; p=0,03). La probabilidad de supervivencia global y libre de enfermedad a 20 años fue de 0,80 (IC 95%: 0,71-0,90) y 0,72 (IC 95%: 0,64-0,79), respectivamente. Las pacientes con uno o más de un parto presentaron mejor supervivencia global que las nulíparas (HR: 0,51; IC 95%: 0,27-0,96, p=0,04). Conclusiones: Los hallazgos sugieren que existe asociación entre edad de la menarquia y del primer parto y subtipo de cáncer de mama. La nuliparidad está asociada con peor supervivencia.(AU)

Background and objective: Reproductive history influences breast cancer risk. We analysed its association with tumour subtype and survival in premenopausal women. Patients and methods: Retrospective, observational study of premenopausal women with stage I-III breast carcinoma in the last 20 years. Review of reproductive history, clinical data, and treatments in health records.Results: In 661 premenopausal women (32.40% of 1377 total cases), median age was 47 years (19-53), menarche 12 (7-17), first delivery 28 (16-41) and number of deliveries 2 (0-9). One hundred and eleven (18.20%) were nulliparous. Three hundred and fifty-nine (58.80%) used natural lactation, with a median duration of 6 months. Anovulatory drugs were used by 271 (44.40%), with a median duration of 36 months. Associations were found between menarche <10 years and lower risk of luminal subtype (OR: 0.52, 95% CI: 0.28-0.94; P=.03), between menarche >11 years and lower risk of HER2 subtype (OR: 0.50, 95% CI: 0.26-0.97; P=.04) and between first birth >30 years and lower risk of triple negative subtype (OR: 0.40, 95% CI: 0.17-0.93; P=.03). The 20-year overall and disease-free survival probabilities were 0.80 (95% CI: 0.71–0.90) and 0.72 (95% CI: 0.64-0.79) respectively. Patients with ≥1 delivery had better overall survival than nulliparous patients (HR: 0.51, 95% CI: 0.27-0.96, P=.04). Conclusions: The findings suggest an association between age at menarche and age at first delivery and breast cancer subtype. Nulliparity is associated with worse survival.(AU)

Association between reproductive history, breast cancer subtype, and survival in premenopausal women. / Asociación entre la historia reproductiva, el subtipo de cáncer de mama y la supervivencia de mujeres premenopáusicas.

BACKGROUND AND OBJECTIVE: Reproductive history influences breast cancer risk. We analysed its association with tumour subtype and survival in premenopausal women. PATIENTS AND METHODS: Retrospective, observational study of premenopausal women with stage I-III breast carcinoma in the last 20 years. Review of reproductive history, clinical data, and treatments in health records. RESULTS: In 661 premenopausal women (32.40% of 1377 total cases), median age was 47 years (19-53), menarche 12 (7-17), first delivery 28 (16-41) and number of deliveries 2 (0-9). One hundred and eleven (18.20%) were nulliparous. Three hundred and fifty-nine (58.80%) used natural lactation, with a median duration of 6 months. Anovulatory drugs were used by 271 (44.40%), with a median duration of 36 months. Associations were found between menarche <10 years and lower risk of luminal subtype (OR: 0.52, 95% CI: 0.28-0.94; P=.03), between menarche >11 years and lower risk of HER2 subtype (OR: 0.50, 95% CI: 0.26-0.97; P=.04) and between first birth >30 years and lower risk of triple negative subtype (OR: 0.40, 95% CI: 0.17-0.93; P=.03). The 20-year overall and disease-free survival probabilities were 0.80 (95% CI: 0.71-0.90) and 0.72 (95% CI: 0.64-0.79) respectively. Patients with ≥1 delivery had better overall survival than nulliparous patients (HR: 0.51, 95% CI: 0.27-0.96, P=.04). CONCLUSIONS: The findings suggest an association between age at menarche and age at first delivery and breast cancer subtype. Nulliparity is associated with worse survival.