Prognostic Impact of Pregnancy After Breast Cancer According to Estrogen Receptor Status: A Multicenter Retrospective Study

• Published in: Journal of clinical oncology Vol. 31; no. 1; pp. 73 - 79
• Main Authors: AZIM, Hatem A, KROMAN, Niels, CORDOBA, Octavi, DE AZAMBUJA, Evandro, GOLDHIRSCH, Aron, PICCART, Martine J, PECCATORI, Fedro A, PAESMANS, Marianne, GELBER, Shari, ROTMENSZ, Nicole, AMEYE, Lieveke, DE MATTOS-ARRUDA, Leticia, PISTILLI, Barbara, PINTO, Alvaro, JENSEN, Maj-Britt
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Society of Clinical Oncology 01-01-2013
• Subjects: Adult; Biological and medical sciences; Breast Neoplasms - metabolism; Breast Neoplasms - mortality; Breast Neoplasms - therapy; Case-Control Studies; Chemotherapy, Adjuvant; Combined Modality Therapy; Female; Follow-Up Studies; Gynecology. Andrology. Obstetrics; Humans; Mammary gland diseases; Mastectomy; Medical sciences; Middle Aged; Neoplasm Recurrence, Local - metabolism; Neoplasm Recurrence, Local - mortality; Neoplasm Recurrence, Local - therapy; Neoplasm Staging; Original Reports; Pregnancy; Pregnancy Complications, Neoplastic - metabolism; Pregnancy Complications, Neoplastic - mortality; Pregnancy Complications, Neoplastic - therapy; Pregnancy Outcome; Receptors, Estrogen - metabolism; Retrospective Studies; Survival Rate; Tumors; Young Adult; Estrogen receptor; Breast disease; Prognosis; Multicenter study; Breast cancer; Malignant tumor; Retrospective; Pregnancy; Mammary gland diseases; Cancerology; Female; Cancer; Hormonal receptor
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2012.44.2285

We questioned the impact of pregnancy on disease-free survival (DFS) in women with history of breast cancer (BC) according to estrogen receptor (ER) status.
A multicenter, retrospective cohort study in which patients who became pregnant any time after BC were matched (1:3) to patients with BC with similar ER, nodal status, adjuvant therapy, age, and year of diagnosis. To adjust for guaranteed time bias, each nonpregnant patient had to have a disease-free interval at least equal to the time elapsing between BC diagnosis and date of conception of the matched pregnant one. The primary objective was DFS in patients with ER-positive BC. DFS in the ER-negative cohort, whole population, and overall survival (OS) were secondary objectives. Subgroup analyses included DFS according to pregnancy outcome and BC-pregnancy interval. With a two-sided α = 5% and β = 20%, 645 ER-positive patients were required to detect a hazard ratio (HR) = 0.65.
A total of 333 pregnant patients and 874 matched nonpregnant patients were analyzed, of whom 686 patients had an ER-positive disease. No difference in DFS was observed between pregnant and nonpregnant patients in the ER-positive (HR = 0.91; 95% CI, 0.67 to 1.24, P = .55) or the ER-negative (HR = 0.75; 95% CI, 0.51 to 1.08, P = .12) cohorts. However, the pregnant group had better OS (HR = 0.72; 95% CI, 0.54 to 0.97, P = .03), with no interaction according to ER status (P = .11). Pregnancy outcome and BC-pregnancy interval did not seem to impact the risk of relapse.
Pregnancy after ER-positive BC does not seem to reduce the risk of BC recurrence.