The results of a recent study find that women who become pregnant Debate about Safety of Pregnancy After Breast Cancer (dateline February 24, 2004) | Breast Health News | Imaginis - The Women's Health & Wellness Resource Network

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Debate about Safety of Pregnancy After Breast Cancer (dateline February 24, 2004)


The results of a recent study find that women who become pregnant after breast cancer treatment do not appear to be at greater risk of dying from breast cancer than women who do not have children after their breast cancer experience. However, experts warn that the design of the study could be flawed and that pregnancy after breast cancer may pose risks for women. The issue of pregnancy after breast cancer should be discussed carefully with a physician familiar with the woman’s diagnosis and treatment, often after a waiting period of two or more years.

Pregnancy after breast cancer is often a concern for women who are diagnosed with the disease at a young age. Young women are more likely to be diagnosed with aggressive-type breast cancers compared to older women. In fact, many cases of breast cancer among women under 40 years of age have been shown to be attributed to mutations of the BRCA1 (breast cancer gene 1) or BRCA2 (breast cancer gene 2) genes, which also increase the risk for ovarian cancer. 

In the current study, Beth Mueller, PhD of the Fred Hutchinson Cancer Research Center, and colleagues studied 438 women who had given birth after a diagnosis of breast cancer from a pool of more than 15,000 women under age 45 with a history of breast cancer. These women were then compared to 12 women under age 45 who had not given birth after their breast cancer diagnosis.

The results of the study showed that women who gave birth 10 months or more after their breast cancer diagnosis had a significantly decreased risk of dying compared to women who did not have children after their diagnosis. Thus, the researchers conclude that pregnancy after breast cancer does not increase the risk of death.

Though the study is promising, experts warn that it may be flawed. According to Jeanne Petrek, MD, Director of the Evelyn H. Lauder Breast Center at Memorial Sloan-Kettering Cancer Center, this study may suffer from the healthy mother effect. That is, women who feel healthier after their breast cancer diagnosis may be more likely to have children than other women who have been diagnosed with the disease, tainting the objectivity of the study findings.

Furthermore, the researchers did not gather data on breast cancer recurrence and therefore do not know whether the women who did not have children had already experienced a return of the disease, which would increase their chances of death. In light of these issues, long-term studies are needed that follow women from breast cancer diagnosis, through treatment, through pregnancy.

A waiting period may be advised for women who have been treated for breast cancer and are able to have children. For women diagnosed with early-stage breast cancer, pregnancy is usually reasonable two or more years after diagnosis and treatment. Several details such as cancer type, degree of metastasis (spread), and amount of radiation and/or chemotherapy received should be considered before advising a woman whether it is safe to become pregnant after breast cancer. For example, those at higher risk for an early recurrence may be advised to wait and be closely observed prior to attempting a pregnancy.

Women with advanced breast cancer or recurrent tumors may not be good candidates for future pregnancies. Chemotherapy may also have an adverse effect on the ovaries and lead to fertility problems or a higher rate of spontaneous miscarriages. However, each individual is different, and all pre-menopausal women should discuss the issue of future pregnancies with their physicians before their initial breast cancer treatment if they are interested in having children after treatment. In some cases, women may wish to consider banking eggs prior to treatment (particularly chemotherapy) if they wish to have children in the future.

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