Health.-Breast cancer survivors are less likely to get pregnant but tend to have healthy babies

MADRID, 10 (EUROPA PRESS)

A large meta-analysis of breast cancer survivors of childbearing age has shown that they are less likely than the general public to become pregnant and are at increased risk of certain complications, such as preterm birth. However, the majority of those who become pregnant deliver healthy babies and have no adverse effects on their long-term survival, according to data presented at the 2020 San Antonio Breast Cancer Symposium in the United States.

“With the availability of more effective anticancer treatments, survival has gained substantial attention. Today, returning to a normal life after cancer diagnosis and treatment must be seen as a crucial ambition in cancer care. patients diagnosed during their reproductive years, this includes the possibility of completing their family planning “, explains the corresponding author of the study, Matteo Lambertini, associate professor of medical oncology at the University of Genoa – IRCCS Polyclinic San Martino Hospital in Genoa (Italy) .

As the average age for pregnancy has increased over time, it has become more common for women to be diagnosed with breast cancer before having a child. Additionally, Lambertini explains that many of the cancer therapies that have successfully reduced mortality from breast cancer have potential long-term toxic effects on the body, including potentially harmful fertility and future family planning.

For example, adjuvant endocrine therapy that is prescribed for women diagnosed with hormone receptor positive breast cancer is given for five to 10 years after diagnosis and during this treatment, pregnancy is contraindicated.

In this study, the researchers conducted a systematic review of the literature of 39 studies that identified women who had been pregnant after a breast cancer diagnosis. They evaluated studies to assess the frequency of post-treatment pregnancies in these women, fetal and obstetric outcomes, disease-free survival, and overall survival. In total, they collected data on 114,573 breast cancer patients.

Compared with women in the general population, patients who had had breast cancer were 60 percent less likely to have a pregnancy. Lambertini points out that this study did not specifically collect the total number of women who tried to conceive, so it is possible that some women did not attempt pregnancy after completing treatment.

Some studies included in the analysis reported such data, and Lambertini estimates that more than half of the young women who tried to conceive did so. Also, some women who did not intend to conceive became pregnant. Lambertini highlights that this finding suggests that cancer patients of childbearing age should also receive accurate information about contraception.

The study has shown that, compared to women in the general population, breast cancer survivors had a 50 percent higher risk of having a low-birth-weight baby; 16 percent increased risk of having a small-for-gestational age baby; 45 percent increased risk of preterm labor and 14 percent increased risk of having a C-section.

However, more importantly, there was no significantly increased risk of birth defects or other complications of pregnancy or delivery. The increased risk of low birth weight and small gestational age appeared to be restricted mainly to women who had received prior chemotherapy.

Pregnancy after breast cancer was not associated with poor patient outcomes. Compared with breast cancer patients who did not have a subsequent pregnancy, those who did become pregnant had a 44 percent lower risk of death and a 27 percent lower risk of disease recurrence.

When the “healthy mother effect” is controlled for, which suggests that women who feel well and have a good prognosis are the most likely to try to conceive, women who became pregnant had a 48% lower risk of death and a 26 % risk of disease recurrence.

The analysis further indicated that pregnancy appeared safe in all BRCA states, node status, prior chemotherapy exposure, pregnancy interval (the amount of time between breast cancer diagnosis and pregnancy), and pregnancy outcomes.

Overall, Lambertini says, the analysis showed that pregnancy after breast cancer was confirmed to be safe without negatively affecting the prognosis of patients.

“These findings are critically important in raising awareness of the need for a deeper consideration of patients’ desire for pregnancy as a crucial component of their survival care plan. This begins by offering oncofertility counseling to all young patients with newly diagnosed breast cancer, “he says.

The study’s first author, Eva Blondeaux, a medical oncology fellow at the IRCCS San Martino Polyclinic Hospital, explains that the increased risk of birth and fetal complications indicates that clinicians should more closely monitor pregnant breast cancer survivors in compared to healthy pregnant women. However, the overall findings and the lack of negative effects on survival indicate that many women can successfully go through pregnancy after breast cancer.

The authors note that the main limitation of the study was that it did not allow examination of individual patient data, and most of the included studies were retrospective analyzes.

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