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Study: Pregnancy around the time of a breast cancer diagnosis does not negatively affect survival

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Contents

At a glance                  Questions for your doctor
Findings               In-depth                
Clinical trials Limitations
Guidelines Resources


STUDY AT A GLANCE

This study is about:

Whether or not a pregnancy before, during, or after a breast cancer diagnosis impacts survival. 

Why is this study important?

More women are becoming pregnant before, during, or after they are diagnosed with breast cancer. Although previous studies suggested that pregnancy occurring a year or more after breast cancer treatment did not affect survival, that research did not provide definitive proof.

The researchers classified study participants into 4 groups:

  • No pregnancy: These women did not conceive from 5 years before to 5 years after their breast cancer diagnosis.
  • Pregnancy before breast cancer: These women were pregnant from 1 to 5 years before their breast cancer diagnosis.
  • Pregnancy-associated breast cancer: These women were pregnant from 11 months before to 21 months after a breast cancer diagnosis. 
  • Pregnancy following breast cancer: These women were pregnant from 22 to 60 months after a breast cancer diagnosis.

Study findings: 

  1. The 5-year survival rates for breast cancer patients with no pregnancy right before, during or after breast was 88%.
  2. For women who were pregnant before, during, or right after breast cancer they found the following 5 year survival rates: 
    • About 85% for women in the pregnancy before breast cancer group
    • About 82% for women in the pregnancy-associated group
    • About 97%, for women in the pregnancy following breast cancer group

What does this mean for me?

These findings show that the timing of pregnancy does not negatively affect breast cancer survival. This study also showed that younger pregnant women have a lower rate of survival than older women. However, other studies have shown similar findings in women who are not pregnant. Therefore, it is likely that in this study, the worse outcome of younger pregnant women is related to age at diagnosis rather than to pregnancy.

Posted 5/23/17

References

Iqbal J, Amir E, Rochon PA, et al. “Association of the timing of pregnancy with survival in women with breast cancer.” JAMA Oncology. 2017; 3(5): 659-665.

Disclosure

FORCE receives funding from industry sponsors, including companies that manufacture cancer drugs, tests and devices. All XRAYS articles are written independently of any sponsor and are reviewed by members of our Scientific Advisory Board prior to publication to assure scientific integrity.

This article is relevant for:

Young women diagnosed during or right after pregnancy and young survivors considering pregnancy after breast cancer

This article is also relevant for:

people with triple negative breast cancer

people with ER/PR + cancer

people with Her2-positive cancer

people with a genetic mutation linked to cancer risk

people with breast cancer

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IN-DEPTH REVIEW OF RESEARCH

Study background:

The number of women who become pregnant around the time of or after a breast cancer diagnosis is increasing. When treating women with breast cancer, doctors must consider the best approach for treatment as well as the health of both the mother and baby. Pregnant women do not typically receive chemotherapy during the first trimester, and radiotherapy and hormonal therapies are not recommended during pregnancy.

Previous research showed that women who were diagnosed with breast cancer during pregnancy or one year after pregnancy tend to have higher-grade breast cancers, but whether the survival rates of these women are affected is unknown. Additionally, it is not known how long women should wait after breast cancer treatment to try to conceive—some health care providers advise waiting at least 2 years because of a concern that hormones such as that are released during pregnancy may worsen survival.

Javaid Iqbal and colleagues from the University of Toronto and other institutes published their study results in JAMA Oncology in May 2017, comparing overall survival of breast cancer patients who were pregnant before, during, or after diagnosis. 

Researchers of this study wanted to know:

Does pregnancy affect survival in women with breast cancer?

Population(s) looked at in the study:

The 7,553 women involved in this study were from Ontario, Canada and had a diagnosis of breast cancer in the Ontario Cancer Registry. Only women with invasive cancer were studied (women who were younger than 20 or older than 45 at the time of diagnosis, women with a personal history of a previous cancer, and women with 0 breast cancer () were excluded.)

  • No pregnancy: These women did not conceive from 5 years before to 5 years after their diagnosis. At the beginning of the study, this group included 5,832 women.
  • Pregnancy before breast cancer: Baby was conceived 1 to 5 years before diagnosis. At the beginning of the study, this group included 1,108 women.
  • Pregnancy-associated breast cancer: Baby was conceived between the 11 months before a breast cancer diagnosis to 21 months after diagnosis. At the beginning of the study, this group included 501 women.
  • Pregnancy following breast cancer: Baby was conceived 22 to 60 months after diagnosis. At the beginning of the study, this group included 112 women.

Study findings: 

  1. The 5-year survival rates for breast cancer patients were:
    • About 88% for those who did not become pregnant.
    • About 85% for those who were pregnant before diagnosis (baby was conceived 1 to 5 years before diagnosis).
    • About 82% for those who were pregnant at the time of their diagnosis (baby was conceived between the 11 months before diagnosis to 21 months after diagnosis).
    • About 97%, the lowest risk of death found, for women who were pregnant 6 months or more after their diagnosis.
  2. For women with pregnancy-associated breast cancer, younger women (under 35 years old) tended to have poorer overall survival.
  3. Women with pregnancy-associated breast cancers were more likely to have ER-negative tumors compared to non-pregnant women (about 37% compared to about 23%).

Limitations:

The Ontario Cancer Registry does not provide some of the data that the researchers collected (tumor size, ER/PR status, etc.) for breast cancer cases that were diagnosed before 2010. Additionally, the researchers had to estimate the time of conception for women who had abortions because their data was unavailable. Finally, the researchers were unable to obtain any information on the use of hormonal treatment.

Conclusions:

This study suggests that pregnancy before, during or after a breast cancer diagnosis does not negatively affect survival, confirming other study results showing that other factors, such as age at diagnosis can impact survival for women who become pregnant around the time of a breast cancer diagnosis. More work should be done to understand the relationship between breast cancer and pregnancy. Meanwhile, this study is hopeful for women who want to have children following a diagnosis of breast cancer as well as women who were pregnant prior to, or at the time of, a breast cancer diagnosis.

Posted 5/23/17

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Expert Guidelines
Expert Guidelines

The National Comprehensive Cancer Network (NCCN) provides guidelines for fertility in people diagnosed with cancer. 

The NCCN recommends doctors discuss the following with adolescents and adults with cancer before treatment begins:

  • fertility plans and preferences
  • fertility preservation options, including:
    • whether therapy can be delayed long enough for a cycle of egg stimulation
    • cryopreservation
    • medications like GnRH agonist therapy during to preserve ovarian function in premenopausal women with breast cancer
  • the importance of follow-up with a gynecologist or fertility specialist to monitor ovarian function over time
  • the risks of infertility due to cancer and related treatment
  • the effects of treatment on breastfeeding
  • the importance of avoiding pregnancy and options for safe and effective birth control while in treatment
  • safe timing for considering pregnancy after treatment 
  • the emotional impact of discussions about fertility preservation
  • financial resources for fertility preservation
  • the effects of treatment on sexual function during and after treatment

Doctors should refer patients as indicated for the following services:

  • All patients who are interested in preserving their fertility should be referred to a fertility preservation clinic before starting treatment.
  • Patients who need assistance with complex medical decision-making should be referred to a mental health professional.
  • Patients who are experiencing sexual dysfunction should be referred to a sexual health specialist. 

Updated: 02/06/2022

Questions To Ask Your Doctor
Questions To Ask Your Doctor

  • I was previously treated for breast cancer; when can I safely conceive?
  • Can I interrupt hormonal therapy to become pregnant?
  • How can I preserve my fertility before breast cancer treatment?
  • What treatments are safe for my baby?
  • Is my cancer diagnosis going to affect my baby?
  • Should I delay treatment until after I have the baby?
  • Are there precautions I can take if I have to receive treatment during my pregnancy?
  • Are there signs I should look for that would indicate my child was affected by my cancer diagnosis during pregnancy? 

Open Clinical Trials
Open Clinical Trials

The following research studies related to fertility preservation are enrolling patients.

Fertility preservation studies for women

Fertility preservation for men

  • NCT02972801: Testicular Tissue Cryopreservation for Fertility Preservation. Testicular tissue cryopreservation is an experimental procedure involving testicular tissue that is retrieved and frozen. This technique is reserved for young male patients, with the ultimate goal that their tissue may be used in the future to restore fertility when experimental techniques emerge from the research pipeline.

Updated: 09/29/2023

Peer Support
Peer Support

The following organizations offer peer support services for people with, or at high risk for breast cancer:

Updated: 11/29/2022

Find Experts
Find Experts

The following resources can help you locate an expert near you or via telehealth. 

Finding fertility experts

  • The Oncofertility Consortium maintains a national database of healthcare providers with expertise in fertility preservation and treatment of people who are diagnosed with cancer or at high risk for cancer due to an .  
  • Livestrong has a listing of 450 sites that offer fertility preservation options for people diagnosed with cancer. Financial assistance may be available to make the cost of fertility preservation affordable for more patients.


Other ways to find experts

Updated: 04/07/2023

Who covered this study?

Oncology Nurse Advisor

Does pregnancy increase risk of death in women with breast cancer? This article rates 2.5 out of 5 stars

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