Does Pregnancy Worsen Breast Cancer Outcome?

An Interview With Frédéric Amant, MD, PhD

Frédéric Amant, MD, PhD; Linda Brookes, MSc


September 17, 2013

In This Article

Treat the Cancer, Maintain the Pregnancy

Current guidelines for the treatment of women diagnosed with breast cancer during pregnancy (BCP) state that chemotherapy -- similar to that recommended for non-pregnancy-associated breast cancer -- may be administered during the second and third trimesters of pregnancy without harm to the fetus.[1,2,3] However, until recently it has not been known whether pregnancy adversely affects the prognosis of these patients, although a recent meta-analysis indicated a poor prognosis with a higher risk for recurrence compared with controls.[4] This question now appears to have been answered by a large international collaborative study in women with primary BCP, which reported similar overall survival to nonpregnant patients. In the Journal of Clinical Oncology,[5] lead author Frédéric Amant, MD, PhD, Professor in the Department of Obstetrics and Gynecology at the Catholic University of Leuven, Belgium, described how BCP patients were identified from 2 registers maintained by the German Breast Group (GBG) and the international Cancer in Pregnancy (CIP) study. Survival in 311 of these patients was compared with survival in 865 breast cancer patients who did not have associated pregnancies. Median age was 33 years for the pregnant patients and 41 years for the nonpregnant patients. Over a median follow-up of 61 months, 42 (14%) pregnant patients and 103 nonpregnant patients (12%) died. For the whole group, after adjustment for age at diagnosis, stage, grading, histologic tumor type, ER/PR status, HER2, trastuzumab, and chemotherapy, the hazard ratio of pregnancy was 1.34 (95% CI, 0.93-1.91; P = .14) for disease-free survival (DFS). The investigators estimated that the 5-year DFS rate for pregnant patients would have increased from 65% to 71% if these patients had not been pregnant. The hazard ratio for pregnancy was 1.19 (95% CI, 0.73-1.93; P = .51) for overall survival (OS) with an estimated increase in 5-year OS rate from 78% to 81% if the pregnant patients had not been pregnant. Chemotherapy administered during the second or third trimesters was not associated with any negative effects on the fetus, although preterm delivery (before 37th week of gestation) was observed.

"Taken together, the available data confirm maternal and fetal safety when breast cancer is treated during pregnancy," Prof. Amant and coauthors concluded. "This information is important when patients are counseled and supports the option to start treatment with continuation of pregnancy," they added. In an editorial accompanying the report,[6] Richard L. Theriault, DO, and Jennifer K. Litton, MD (The University of Texas MD Anderson Cancer Center, Houston) commented that the findings provided "additional comfort for women and physicians who must care for the pregnant patient with breast cancer," and agreed that "the cancer can be treated, the pregnancy can be maintained, labor and delivery can be successful, and the outcome for mother and neonate can be expected to be favorable." Dr. Theriault, who is Chair of the NCCN Breast Cancer guidelines panel, and Dr. Litton described as "sound clinical advice" the recommendation to proceed with cancer treatment for the pregnant patient "in a carefully coordinated, multidisciplinary care approach." In their opinion, "The proscription of pregnancy after treatment of breast cancer because of concerns of cancer recurrence and death from breast cancer is not supported by these data, even for those who have had ER-positive disease."

Prof. Amant further discussed the findings of the study with Linda Brookes, MSc, for Medscape. Prof. Amant is principal investigator of the CIP study. He is also chair of the European Society of Gynaecological Oncology (ESGO)'s Task Force on Cancer in Pregnancy, a group that promotes research and aims to increase knowledge about cancer in pregnancy among healthcare workers and the public through national or regional initiatives involving oncologists, obstetricians, pediatricians, and other health professionals. Prof. Amant was lead author of an ESGO-endorsed consensus statement on diagnosis, staging methods, and treatment options of BCP.[7]


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