{"product_id":"breast-cancer-and-pregnancy-why-special-considerations-before-treatment-are-essential","title":"Breast Cancer and Pregnancy: Why Special Considerations Before Treatment Are Essential","description":"\u003cp\u003e\u003cstrong\u003eSummary:\u003c\/strong\u003e Breast cancer diagnosed during pregnancy affects approximately 1 in every 1,000 pregnancies, and rates are rising. This review article explains why pregnant women with breast cancer need special medical consideration before treatment begins. The authors highlight that diagnosis is often delayed due to normal pregnancy-related breast changes, that pregnancy-associated breast cancer tends to be more aggressive, and that treatment decisions must carefully balance the health of the mother against the safety of the developing fetus. The key message for patients: a multidisciplinary team of specialists should work together to create an individualized treatment plan that optimizes outcomes for both mother and baby.\u003c\/p\u003e\n\n\u003ch1\u003eBreast Cancer and Pregnancy: Why Special Considerations Before Treatment Are Essential\u003c\/h1\u003e\n\n\u003ch2\u003eTable of Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"#ddn-key-points\"\u003eKey Points\u003c\/a\u003e\u003c\/li\u003e\n\n  \u003cli\u003e\u003ca href=\"#background\"\u003eWhy This Research Matters: Breast Cancer During Pregnancy\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#tumor-biology\"\u003eUnderstanding the Biology of Pregnancy-Related Breast Cancer\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#diagnosis-staging\"\u003eHow Breast Cancer Is Diagnosed and Staged During Pregnancy\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#pregnancy-monitoring\"\u003eMonitoring the Health of Both Mother and Baby\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#anesthesia\"\u003eUnderstanding the Risks of Anesthesia\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#treatment\"\u003eTreatment Options During Pregnancy: An Overview\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#surgery\"\u003eSurgery During Pregnancy\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#systemic-treatment\"\u003eSystemic Treatments: Chemotherapy, Targeted Therapy, and More\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#clinical-implications\"\u003eWhat This Means for Patients\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#limitations\"\u003eWhat This Review Could Not Answer\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#recommendations\"\u003eRecommendations for Patients and Families\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#ddn-faq\"\u003eFrequently Asked Questions\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#source\"\u003eSource Information\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ddn:keypoints:start --\u003e\n\u003ch2 id=\"ddn-key-points\"\u003eKey Points\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eBreast cancer affects about 1 in 1,000 pregnancies; any breast mass lasting over 2 weeks should be evaluated.\u003c\/li\u003e\n\u003cli\u003eSurgery for breast cancer is safe in all trimesters; reconstruction should wait until after birth.\u003c\/li\u003e\n\u003cli\u003eChemotherapy is avoided in the first trimester but can be given later; last dose at least 3 weeks before delivery.\u003c\/li\u003e\n\u003cli\u003eTamoxifen, trastuzumab, pertuzumab, and immunotherapy are not safe during pregnancy due to fetal risks.\u003c\/li\u003e\n\u003cli\u003eA multidisciplinary team should create an individualized plan; pregnancy termination is not automatically required.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ddn:keypoints:end --\u003e\n\n\n\u003ch2 id=\"background\"\u003eWhy This Research Matters: Breast Cancer During Pregnancy\u003c\/h2\u003e\n\n\u003cp\u003eBreast cancer (\u003cstrong\u003eBC\u003c\/strong\u003e) is the most common cancer in women worldwide, and approximately 7% of cases are diagnosed before the age of 40. While cancer diagnosed during pregnancy is rare — occurring in about 1 case per 1,000 deliveries — breast cancer is actually the most common cancer to affect pregnancy.\u003c\/p\u003e\n\n\u003cp\u003eThe incidence of breast cancer during pregnancy has been increasing in recent years. Among pregnant women under age 45, the rate of breast cancer ranges from \u003cstrong\u003e2.6% to 6.9%\u003c\/strong\u003e. For women under 35, breast cancer accounts for \u003cstrong\u003e15.6%\u003c\/strong\u003e of all breast cancer cases in that age group.\u003c\/p\u003e\n\n\u003cp\u003eBreast cancer diagnosed during pregnancy presents a complex challenge for both the patient and her clinicians. The expectation is that pregnant patients should be treated as effectively as non-pregnant patients, but standard therapies must be modified to balance the benefit to the mother against the risk to the fetus. The authors of this review stress that a \u003cstrong\u003emultidisciplinary team (MDT)\u003c\/strong\u003e approach at specialized centers is crucial. This team typically includes breast surgeons, obstetricians, radiologists, pathologists, and anesthesiologists who work together to make an early diagnosis and comprehensively evaluate patients at different stages of pregnancy and different stages of breast cancer.\u003c\/p\u003e\n\n\u003cp\u003eThe purpose of this article is to highlight the special considerations that must be addressed before treating pregnant women with breast cancer, and to review the existing evidence for managing these patients safely and effectively.\u003c\/p\u003e\n\n\u003ch2 id=\"tumor-biology\"\u003eUnderstanding the Biology of Pregnancy-Related Breast Cancer\u003c\/h2\u003e\n\n\u003cp\u003eAlthough the clinical features of breast cancer in pregnant women are similar to those in non-pregnant women, the diagnosis may be delayed. This happens because normal pregnancy-related changes — such as breast enlargement, colostrum secretion, and other physiological alterations — can mask or mimic the signs of cancer. It is important to understand that \u003cstrong\u003epregnancy does not cause breast cancer\u003c\/strong\u003e; rather, cancer can develop coincidentally during pregnancy.\u003c\/p\u003e\n\n\u003cp\u003eHowever, pregnancy can have a profound effect on the biology of breast cancer. Most breast cancers that develop during pregnancy are \u003cstrong\u003einvasive ductal carcinoma\u003c\/strong\u003e (cancer that begins in the milk ducts and spreads to surrounding breast tissue). \u003cstrong\u003eInvasive lobular carcinoma\u003c\/strong\u003e (cancer that begins in the milk-producing glands) develops far less frequently during pregnancy.\u003c\/p\u003e\n\n\u003cp\u003eStudies have reported that \u003cstrong\u003etriple-negative breast cancer (TNBC)\u003c\/strong\u003e — a more aggressive subtype that lacks estrogen receptors, progesterone receptors, and HER2 protein — is more prevalent during pregnancy. Compared to sporadic breast cancer (cancer that occurs outside of pregnancy), pregnancy-associated breast cancer tends to have:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eA higher histologic grade (more abnormal-looking cells)\u003c\/li\u003e\n  \u003cli\u003eA more aggressive profile\u003c\/li\u003e\n  \u003cli\u003eA more advanced stage at the time of diagnosis\u003c\/li\u003e\n  \u003cli\u003eA larger tumor size\u003c\/li\u003e\n  \u003cli\u003eA higher frequency of lymph node involvement\u003c\/li\u003e\n  \u003cli\u003eLess frequent expression of estrogen receptors (ERs) and progesterone receptors (PRs)\u003c\/li\u003e\n  \u003cli\u003eA greater likelihood of being inflammatory breast cancer\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe ultimate prognosis for breast cancer during pregnancy is a subject of debate. Some studies have found \u003cstrong\u003eno significant differences in prognosis\u003c\/strong\u003e between pregnant and non-pregnant women with breast cancer. However, a recent meta-analysis (a statistical analysis combining the results of multiple studies) noted a \u003cstrong\u003epoorer prognosis\u003c\/strong\u003e for breast cancer in pregnant women.\u003c\/p\u003e\n\n\u003cp\u003ePregnancy may also alter gene expression patterns in breast cancer cells. Researchers have observed abnormal expression of several genes involved in cancer development, including:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOncogenes\u003c\/strong\u003e (cancer-promoting genes): MYC, SRC, and FOS\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTumor suppressor genes\u003c\/strong\u003e (genes that normally prevent cancer): TP53, PTEN, and CAV1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApoptosis regulators\u003c\/strong\u003e (genes controlling programmed cell death): PDCD4, BCL2, and BIRC5\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTranscription regulators\u003c\/strong\u003e (genes controlling how other genes are turned on\/off): JUN, KLF1, and SP110\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDNA repair genes\u003c\/strong\u003e: Sig20, BRCA1, BRCA2, and FEN1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCell proliferation genes\u003c\/strong\u003e: AURKA and MKI67\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eImmune response genes\u003c\/strong\u003e: PD1 and PDL1\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThese genetic differences help explain why pregnancy-associated breast cancer can behave differently and may require a tailored treatment approach.\u003c\/p\u003e\n\n\u003ch2 id=\"diagnosis-staging\"\u003eHow Breast Cancer Is Diagnosed and Staged During Pregnancy\u003c\/h2\u003e\n\n\u003cp\u003eOne of the most critical issues is delayed diagnosis. During pregnancy, breast cancer diagnosis is often delayed by \u003cstrong\u003e1 to 13 months\u003c\/strong\u003e due to breast enlargement, colostrum secretion, and other pregnancy-related changes that can hide a suspicious mass. While \u003cstrong\u003e80% of palpable breast masses\u003c\/strong\u003e (masses that can be felt) found during pregnancy are benign, any mass that persists for more than \u003cstrong\u003e2 weeks\u003c\/strong\u003e should be taken seriously and evaluated.\u003c\/p\u003e\n\n\u003cp\u003eThe evaluation of a suspicious breast mass proceeds similarly whether a woman is pregnant or not, but the standard staging workup must prioritize fetal safety. Here is what the review recommends at each step:\u003c\/p\u003e\n\n\u003ch3\u003eImaging: What Is Safe and What Should Be Avoided?\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eBreast ultrasonography (ultrasound)\u003c\/strong\u003e should be the first imaging test used to assess a breast mass during pregnancy because it is safe and highly sensitive. However, ultrasound may be less sensitive during pregnancy because breast tissue becomes denser.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eMammography with appropriate abdominal shielding\u003c\/strong\u003e can be useful to evaluate the extent of the disease. The abdominal shield protects the fetus from radiation exposure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eMagnetic resonance imaging (MRI) without gadolinium contrast\u003c\/strong\u003e can be used for further evaluation. Gadolinium (the contrast dye used in MRI) can cross the placental barrier and is considered potentially teratogenic (capable of causing birth defects), so it must be avoided during pregnancy.\u003c\/p\u003e\n\n\u003cp\u003eTests to avoid during pregnancy include:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBone scans and positron emission tomography (PET)\u003c\/strong\u003e — The ESMO (European Society for Medical Oncology) guidelines state these should be avoided during pregnancy\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eContrast-enhanced CT scans\u003c\/strong\u003e — should be avoided\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePET\/MRI\u003c\/strong\u003e — Although a few studies suggest 18F-FDG PET and PET\/MRI involve low fetal radiation exposure, there is not enough evidence to support their use for breast cancer staging during pregnancy\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eA radiologist must be a key member of the medical team to calculate the total radiation dose, review the indications for each test, and assess the risk-benefit ratio.\u003c\/p\u003e\n\n\u003ch3\u003eBiopsy: How Tissue Samples Are Taken\u003c\/h3\u003e\n\n\u003cp\u003eA \u003cstrong\u003ecore needle biopsy\u003c\/strong\u003e performed under local anesthesia is the preferred method for sampling any clinically suspicious breast mass during pregnancy. This involves using a hollow needle to remove a small cylinder of tissue for examination under a microscope.\u003c\/p\u003e\n\n\u003cp\u003eSuspected metastatic lymph nodes (lymph nodes that may have cancer spread to them) should be evaluated with ultrasound and \u003cstrong\u003efine needle aspiration biopsy\u003c\/strong\u003e for confirmation.\u003c\/p\u003e\n\n\u003cp\u003eAn important detail: \u003cstrong\u003epathologists should be informed that the patient is pregnant.\u003c\/strong\u003e This is because the presence of hyperplastic cells (cells that multiply excessively) during pregnancy can simulate atypia (abnormal cells), leading to an increase in false-positive results — meaning a biopsy might appear abnormal when it is actually benign.\u003c\/p\u003e\n\n\u003cp\u003eSystemic staging studies (tests to determine if cancer has spread) are recommended for advanced cancers, but only if the results would change treatment options. If necessary, staging tests should include chest radiography with abdominal shielding, liver ultrasound, and\/or non-contrast skeletal MRI.\u003c\/p\u003e\n\n\u003ch2 id=\"pregnancy-monitoring\"\u003eMonitoring the Health of Both Mother and Baby\u003c\/h2\u003e\n\n\u003cp\u003ePregnant women with breast cancer should always be considered a \u003cstrong\u003ehigh-risk group\u003c\/strong\u003e. This means they need more careful and continuous monitoring throughout their pregnancy, including:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMorphometric ultrasonography\u003c\/strong\u003e — detailed ultrasound measurements of the fetus's growth and development\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUmbilical artery Doppler assessment\u003c\/strong\u003e — a test that measures blood flow through the umbilical cord to check how well the placenta is delivering oxygen and nutrients to the baby\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eCalculating the \u003cstrong\u003egestational age\u003c\/strong\u003e (how far along the pregnancy is) and the \u003cstrong\u003eexpected date of delivery\u003c\/strong\u003e is critically important, as these factors directly impact breast cancer treatment planning. Allowing the pregnancy to reach \u003cstrong\u003efull term (37 weeks)\u003c\/strong\u003e is strongly recommended whenever possible.\u003c\/p\u003e\n\n\u003cp\u003eThe gynecologist\/obstetrician should be part of the multidisciplinary team and will determine the \u003cstrong\u003emode of delivery\u003c\/strong\u003e (vaginal delivery or cesarean section) based on obstetric indications — meaning decisions about how the baby is delivered are made for pregnancy-related reasons, not cancer-related reasons.\u003c\/p\u003e\n\n\u003cp\u003ePossible \u003cstrong\u003emicrometastases in the placenta\u003c\/strong\u003e (tiny clusters of cancer cells that may have traveled to the placenta) should be examined after delivery.\u003c\/p\u003e\n\n\u003cp\u003eTo avoid hematological toxicity (dangerously low blood cell counts) in the mother and fetus, the last round of chemotherapy should be administered \u003cstrong\u003e3 weeks prior to the planned date of delivery\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eThere is encouraging news for patients. Mounting evidence shows that breast cancer treatment during pregnancy has \u003cstrong\u003eno clear adverse effects on growth, cognitive function, or cardiac function in early childhood\u003c\/strong\u003e. This suggests that a diagnosis of cancer during pregnancy should \u003cstrong\u003enot be an automatic indication to abort the pregnancy\u003c\/strong\u003e. The only factor associated with a worse cognitive outcome in children was \u003cstrong\u003eprematurity\u003c\/strong\u003e — and this was independent of whether the mother received cancer treatment.\u003c\/p\u003e\n\n\u003ch2 id=\"anesthesia\"\u003eUnderstanding the Risks of Anesthesia\u003c\/h2\u003e\n\n\u003cp\u003eIf surgery is needed during pregnancy, anesthesia safety for both mother and fetus is a major consideration. Pregnancy causes significant changes in a woman's anatomy and physiology that increase the potential hazards of anesthesia. These maternal changes include:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIncreased cardiac output (the amount of blood the heart pumps)\u003c\/li\u003e\n  \u003cli\u003eReduced functional residual capacity (the amount of air remaining in the lungs after a normal breath out)\u003c\/li\u003e\n  \u003cli\u003eDilation of the pyelocaliceal system (widening of the drainage system of the kidneys)\u003c\/li\u003e\n  \u003cli\u003eDilutional anemia (a decrease in red blood cell concentration due to increased blood volume)\u003c\/li\u003e\n  \u003cli\u003eGastroesophageal reflux (stomach acid flowing backward into the esophagus)\u003c\/li\u003e\n  \u003cli\u003eChanges in glucose and adrenal metabolism\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe main anesthesia-related risks during pregnancy involve \u003cstrong\u003eairway edema\u003c\/strong\u003e (swelling of the airway tissues), \u003cstrong\u003erestrictive lung physiology\u003c\/strong\u003e (reduced ability of the lungs to expand fully), and \u003cstrong\u003easpiration\u003c\/strong\u003e (inhaling stomach contents into the lungs).\u003c\/p\u003e\n\n\u003cp\u003eA previous study suggested that adverse fetal outcomes after surgery during pregnancy may be related to the mother's underlying medical condition rather than the effects of anesthesia itself — a reassuring finding.\u003c\/p\u003e\n\n\u003cp\u003eFor patient safety, the review notes that the patient should be positioned with a \u003cstrong\u003e15–30° left lateral tilt\u003c\/strong\u003e during surgery. This position reduces aortocaval compression (pressure on the major blood vessels) and decreases the incidence of supine hypotensive syndrome (a dangerous drop in blood pressure when lying flat on the back).\u003c\/p\u003e\n\n\u003ch2 id=\"treatment\"\u003eTreatment Options During Pregnancy: An Overview\u003c\/h2\u003e\n\n\u003cp\u003eGuidelines state that breast cancer during pregnancy should be treated in accordance with the management of breast tumors in non-pregnant women, including local control of the disease and prevention of systemic (whole-body) metastases. However, several important factors must be considered before treatment begins:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eClinicopathological characteristics (the specific features of the tumor)\u003c\/li\u003e\n  \u003cli\u003eGestational age at the time of breast cancer diagnosis\u003c\/li\u003e\n  \u003cli\u003eExpected date of delivery\u003c\/li\u003e\n  \u003cli\u003eThe patient's own wishes\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe goals of the multidisciplinary team are three-fold: to \u003cstrong\u003ecure the pregnant patient\u003c\/strong\u003e of breast cancer, to \u003cstrong\u003esupport the pregnancy\u003c\/strong\u003e, and to \u003cstrong\u003enot harm the fetus\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"surgery\"\u003eSurgery During Pregnancy\u003c\/h2\u003e\n\n\u003cp\u003eSurgery can be considered \u003cstrong\u003esafe in all trimesters\u003c\/strong\u003e of pregnancy. The gestational age at diagnosis is an important factor in devising the surgical plan. Two main surgical options are available:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRadical modified mastectomy (RMM)\u003c\/strong\u003e — removal of the entire breast along with some of the underarm lymph nodes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBreast-conserving surgery\u003c\/strong\u003e (also called lumpectomy) — removal of only the tumor and a small margin of surrounding healthy tissue\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eBoth are reasonable options for a pregnant woman with breast cancer, with some important caveats:\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eIn the first trimester:\u003c\/strong\u003e If breast-conserving surgery is chosen, the radiation therapy that normally follows it may need to be delayed for the sake of fetal safety. Therefore, \u003cstrong\u003emastectomy should be recommended for patients who wish to continue the pregnancy\u003c\/strong\u003e — removing the whole breast eliminates the need for follow-up radiation.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eIn the second and third trimesters:\u003c\/strong\u003e Breast-conserving surgery might be an option for early-stage breast cancer.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eReconstructive surgery\u003c\/strong\u003e (surgery to rebuild the breast shape) should be postponed until after birth. This is because normal pregnancy-related breast changes could affect the cosmetic results in unexpected ways.\u003c\/p\u003e\n\n\u003cp\u003eRegarding \u003cstrong\u003esentinel lymph node biopsy\u003c\/strong\u003e (a procedure to remove and examine the first lymph node that cancer would likely spread to): breast cancer during pregnancy has a high incidence of axillary lymph node metastases (cancer spread to underarm lymph nodes). However, there is \u003cstrong\u003eno level 1 evidence\u003c\/strong\u003e (the highest grade of evidence from randomized controlled trials) to support the routine use of sentinel lymph node biopsy in pregnant breast cancer patients. The American Society of Clinical Oncology (ASCO) guidelines do not support this procedure during pregnancy, while the National Comprehensive Cancer Network (NCCN) guidelines endorse its safety according to the patient's wishes. Other guidelines advise sentinel lymph node biopsy when axillary ultrasound and a suspicious lymph node biopsy are negative.\u003c\/p\u003e\n\n\u003cp\u003eWhen sentinel lymph node biopsy is performed, it should be done using \u003cstrong\u003e99mTc-albumin nanocolloids\u003c\/strong\u003e (a radioactive tracer that is considered safe). The following dyes should be avoided:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBlue dye and isosulfan blue\u003c\/strong\u003e — avoided due to the risk of an allergic or anaphylactic (severe allergic) reaction in the mother\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMethylene blue\u003c\/strong\u003e — contraindicated during the first trimester because it is teratogenic (can cause birth defects)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"systemic-treatment\"\u003eSystemic Treatments: Chemotherapy, Targeted Therapy, and More\u003c\/h2\u003e\n\n\u003cp\u003eSystemic treatments — including chemotherapy, hormone therapy, targeted therapies, and immunotherapy — are generally \u003cstrong\u003eavoided in the first trimester\u003c\/strong\u003e because of the high risk of teratogenicity (birth defects) and abortion. Available data on the risks of these drugs during pregnancy are limited to case reports, animal studies, and studies with small sample sizes.\u003c\/p\u003e\n\n\u003cp\u003eBefore any oncological (cancer) treatment is given, a \u003cstrong\u003efetal ultrasound must be performed\u003c\/strong\u003e to rule out pre-existing abnormalities. Major factors that must be evaluated before starting systemic therapy include:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePhysiologic changes during pregnancy\u003c\/li\u003e\n  \u003cli\u003eGestational age\u003c\/li\u003e\n  \u003cli\u003ePlacental passage (how easily the drug crosses the placenta to reach the fetus)\u003c\/li\u003e\n  \u003cli\u003ePharmacokinetic characteristics of the drug (how the body absorbs, distributes, metabolizes, and eliminates it)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eChemotherapy: The Safest Options\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eAnthracyclines\u003c\/strong\u003e are considered the treatment of choice during pregnancy because of their very low placental transfer. One study reported that \u003cstrong\u003edoxorubicin and epirubicin\u003c\/strong\u003e are not teratogenic (do not cause birth defects), while another study found they may increase the risk of prematurity and low birth weight.\u003c\/p\u003e\n\n\u003cp\u003eMultiple chemotherapy regimens have been studied in pregnancy, including:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFAC\u003c\/strong\u003e — 5-fluorouracil, doxorubicin (Adriamycin), and cyclophosphamide, given in 3-week cycles\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFEC\u003c\/strong\u003e — 5-fluorouracil, epirubicin, and cyclophosphamide\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAC\u003c\/strong\u003e — doxorubicin (Adriamycin) and cyclophosphamide\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEC\u003c\/strong\u003e — epirubicin and cyclophosphamide\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeekly epirubicin\u003c\/strong\u003e as a single drug\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eAC and EC regimens\u003c\/strong\u003e are the ones most often used to treat breast cancer during pregnancy. A retrospective cohort study (a study that looks back at existing patient data) indicated that \u003cstrong\u003edose-dense chemotherapy\u003c\/strong\u003e — giving chemotherapy more frequently than standard schedules — was safe in 10 pregnant women with breast cancer. However, the review notes that a dose-dense schedule may generally not be recommended during pregnancy.\u003c\/p\u003e\n\n\u003cp\u003eAlthough chemotherapy is considered safe and well-tolerated during the second and third trimesters, the multidisciplinary team must closely monitor fetal safety and maternal blood pressure throughout treatment. Importantly, \u003cstrong\u003echemotherapy should not be administered after 35 weeks of gestation\u003c\/strong\u003e to prevent hematological complications (blood-related complications) during delivery.\u003c\/p\u003e\n\n\u003ch3\u003eTargeted Therapies: What Is Contraindicated\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eTrastuzumab\u003c\/strong\u003e (Herceptin) is strictly \u003cstrong\u003econtraindicated\u003c\/strong\u003e throughout pregnancy due to the high risk of \u003cstrong\u003eoligohydramnios\u003c\/strong\u003e (low amniotic fluid) and\/or \u003cstrong\u003eanhydramnios\u003c\/strong\u003e (no amniotic fluid). The erbB2\/neu gene, which this drug targets, is related to fetal organogenesis (the development of fetal organs). A systematic review and meta-analysis concluded that more adverse events occur when trastuzumab is used in the second\/third trimester than in the first trimester.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePertuzumab\u003c\/strong\u003e and \u003cstrong\u003eT-DM1\u003c\/strong\u003e (ado-trastuzumab emtansine) are also contraindicated because no data are available on their use in pregnant women.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eLapatinib\u003c\/strong\u003e (a small-molecule tyrosine kinase inhibitor) is presumed to cross the placenta during all phases of pregnancy. The limited data available do not support its use in pregnant patients.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCDK4 and CDK6 inhibitors\u003c\/strong\u003e (a class of targeted drugs used in breast cancer) have no available data on use during pregnancy.\u003c\/p\u003e\n\n\u003ch3\u003eHormone (Endocrine) Therapy: Not Safe During Pregnancy\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eEndocrine therapy\u003c\/strong\u003e — including tamoxifen and luteinizing hormone-releasing hormone (LHRH) analogues — is \u003cstrong\u003econtraindicated\u003c\/strong\u003e for treating breast cancer during pregnancy due to the high risk of birth defects, which can be up to \u003cstrong\u003e17.6%\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eTamoxifen\u003c\/strong\u003e is teratogenic and increases the risk of breast cancer in offspring, as verified in animal experiments. A systematic review identified major malformations associated with tamoxifen exposure during pregnancy, including:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eAmbiguous genitalia (genitals that are not clearly male or female)\u003c\/li\u003e\n  \u003cli\u003ePierre Robin sequence (a condition marked by an underdeveloped jaw, a cleft palate, and a tongue that falls backward)\u003c\/li\u003e\n  \u003cli\u003eOculoauriculovertebral dysplasia (also called Goldenhar syndrome, affecting the face, ears, and spine)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eMinor malformations include preauricular skin tags (small skin growths in front of the ear) and severe hypermetropia (severe farsightedness).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAromatase inhibitors\u003c\/strong\u003e — another class of hormone therapy — have no available data on human exposure during pregnancy, though data from animal models exist.\u003c\/p\u003e\n\n\u003ch3\u003eRadiation Therapy: Timing Is Everything\u003c\/h3\u003e\n\n\u003cp\u003eRadiation has \u003cstrong\u003edose- and gestational-week-dependent effects\u003c\/strong\u003e on the fetus. Due to its teratogenic effects, radiation therapy is generally \u003cstrong\u003enot considered a safe treatment option\u003c\/strong\u003e during pregnancy. However, radiotherapy could be performed in the first trimester and at the beginning of the second trimester with careful dose adjustment — an exposure of 0.01 mGy (milligray, a unit of radiation absorption) is below the threshold dose — and with proper abdominal shielding. The multidisciplinary team must carefully balance the risks and benefits of radiation therapy for both the mother and the fetus.\u003c\/p\u003e\n\n\u003ch3\u003eImmunotherapy: Not Recommended\u003c\/h3\u003e\n\n\u003cp\u003eThe PD-1\/PD-L1 pathway — the target of many modern immunotherapy drugs — is involved in immune tolerance during pregnancy (the process that prevents the mother's immune system from rejecting the fetus). In studies involving pregnant animals, \u003cstrong\u003eanti-PD-1\/PD-L1 treatment increased the risk of miscarriages, premature delivery, and birth mortality\u003c\/strong\u003e. Therefore, \u003cstrong\u003eimmunotherapy during pregnancy is contraindicated\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"clinical-implications\"\u003eWhat This Means for Patients\u003c\/h2\u003e\n\n\u003cp\u003eFor a woman diagnosed with breast cancer during pregnancy, the review offers several important takeaways:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eA cancer diagnosis should not automatically mean termination of pregnancy.\u003c\/strong\u003e Evidence shows that treatment can be safe for the baby, especially when chemotherapy is given in the second and third trimesters.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIt takes a village.\u003c\/strong\u003e The multidisciplinary team approach is not optional — it is essential. Patients should expect to see multiple specialists who work together to plan their care.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTiming matters.\u003c\/strong\u003e The gestational age at diagnosis drives many treatment decisions. Knowing the expected date of delivery is as important as knowing the cancer stage.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNot all treatments are equal in pregnancy.\u003c\/strong\u003e Some chemotherapy drugs (like anthracyclines) have decades of safety data in pregnancy, while other treatments (like trastuzumab, tamoxifen, and immunotherapy) are strictly contraindicated.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEarly diagnosis saves lives and reduces complications.\u003c\/strong\u003e Because pregnancy can mask breast symptoms, patients should not ignore a persistent breast mass. A mass lasting more than 2 weeks should be evaluated with ultrasound.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"limitations\"\u003eWhat This Review Could Not Answer\u003c\/h2\u003e\n\n\u003cp\u003eThe authors acknowledge significant gaps in evidence. Clinical trials for breast cancer treatments routinely \u003cstrong\u003eexclude pregnant women\u003c\/strong\u003e, which means much of the available data comes from case reports, animal studies, and small retrospective reviews rather than large randomized controlled trials.\u003c\/p\u003e\n\n\u003cp\u003eSpecific unanswered questions include:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eThe safety of dose-dense chemotherapy during pregnancy (only one small study of 10 women exists)\u003c\/li\u003e\n  \u003cli\u003eThe safety of newer targeted therapies such as pertuzumab, T-DM1, lapatinib, and CDK4\/6 inhibitors\u003c\/li\u003e\n  \u003cli\u003eThe effects of aromatase inhibitors during pregnancy (no human data available)\u003c\/li\u003e\n  \u003cli\u003eWhether the poorer prognosis seen in pregnancy-associated breast cancer is due to the cancer biology itself or the inevitable delays in diagnosis\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe long-term outcomes for children exposed to cancer treatment in the womb — particularly cardiac function, fertility, and cancer risk later in life — require more research, though current evidence on growth, cognition, and cardiac health in early childhood is reassuring.\u003c\/p\u003e\n\n\u003ch2 id=\"recommendations\"\u003eRecommendations for Patients and Families\u003c\/h2\u003e\n\n\u003cp\u003eBased on this review, here is what patients should know and consider:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSeek care at a specialized center.\u003c\/strong\u003e Management of breast cancer during pregnancy should be handled by a multidisciplinary team with experience in this complex situation. Ask if your hospital has a team that includes breast surgeons, obstetricians, radiologists, pathologists, and anesthesiologists who work together regularly.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReport any persistent breast mass immediately.\u003c\/strong\u003e Do not assume a lump is just a normal pregnancy change. While 80% of breast masses during pregnancy are benign, a mass lasting more than 2 weeks deserves proper evaluation.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDiscuss all treatment options with your team before deciding.\u003c\/strong\u003e Ask about the specific chemotherapy regimens recommended, the gestational age windows for safe treatment, and why certain medications (like hormonal therapy or HER2-targeted drugs) are not recommended during pregnancy.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePlan the delivery timeline carefully.\u003c\/strong\u003e Your team should help you coordinate the timing of chemotherapy so that the last dose is given at least 3 weeks before the planned delivery date, and chemotherapy should not be given after 35 weeks of gestation.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAllow the pregnancy to reach full term if possible.\u003c\/strong\u003e Full term (37 weeks) is strongly recommended. The only factor linked to worse cognitive outcomes in children was prematurity, not cancer treatment itself.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAsk about fetal monitoring.\u003c\/strong\u003e Your pregnancy should be monitored as a high-risk pregnancy, with regular ultrasounds and umbilical artery Doppler assessments.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eKnow that abortion is not the only option.\u003c\/strong\u003e The evidence does not support automatic termination of pregnancy. Many women can successfully complete cancer treatment while continuing their pregnancy, giving birth to healthy babies.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePlan for breast reconstruction after delivery.\u003c\/strong\u003e Reconstructive surgery should wait until after birth for the best cosmetic outcomes.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003c!-- ddn:faq:start --\u003e\n\u003ch2 id=\"ddn-faq\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhy is breast cancer diagnosis often delayed during pregnancy?\u003c\/h3\u003e\n\u003cp\u003eNormal pregnancy changes like breast enlargement, colostrum secretion, and denser tissue can hide a suspicious lump. This can delay diagnosis by 1 to 13 months. While 80% of breast masses during pregnancy are benign, any lump lasting more than 2 weeks should be evaluated with ultrasound.\u003c\/p\u003e\n\u003ch3\u003eIs surgery safe during pregnancy for breast cancer?\u003c\/h3\u003e\n\u003cp\u003eYes, surgery for breast cancer is considered safe in all trimesters of pregnancy. Mastectomy or breast-conserving surgery may be options depending on your stage and gestational age. Reconstructive surgery should be postponed until after birth to allow breast changes from pregnancy to settle.\u003c\/p\u003e\n\u003ch3\u003eWhich breast cancer treatments are not safe during pregnancy?\u003c\/h3\u003e\n\u003cp\u003eHormone therapy like tamoxifen is contraindicated because it risks birth defects. HER2-targeted drugs such as trastuzumab, pertuzumab, and T-DM1 are also unsafe. Immunotherapy is not recommended. Radiation therapy is generally avoided. Your medical team will help choose safe options for your situation.\u003c\/p\u003e\n\u003ch3\u003eWhen can chemotherapy be given during breast cancer treatment in pregnancy?\u003c\/h3\u003e\n\u003cp\u003eChemotherapy is generally avoided in the first trimester due to birth defect risk. It can be given in the second and third trimesters. Anthracycline-based regimens like AC or EC are often used. The last dose should be at least 3 weeks before delivery, and not after 35 weeks of gestation.\u003c\/p\u003e\n\u003ch3\u003eDo I have to terminate my pregnancy if I have breast cancer?\u003c\/h3\u003e\n\u003cp\u003eNo. Evidence shows that treatment can be safe for the baby, especially when chemotherapy is given in the second and third trimesters. The review states that cancer during pregnancy should not be an automatic reason for abortion. Many women continue pregnancy and deliver healthy babies.\u003c\/p\u003e\n\u003ch3\u003eHow is the baby monitored during breast cancer treatment?\u003c\/h3\u003e\n\u003cp\u003eYour pregnancy is considered high-risk. Monitoring includes detailed ultrasound measurements of fetal growth, umbilical artery Doppler assessment to check blood flow, and careful tracking of gestational age. The team aims for delivery at full term, 37 weeks, whenever possible. The last chemotherapy is timed to protect the baby.\u003c\/p\u003e\n\u003c!-- ddn:faq:end --\u003e\n\n\u003ch2 id=\"source\"\u003eSource Information\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eOriginal article title:\u003c\/strong\u003e Breast cancer and pregnancy- Why special considerations prior to treatment are needed in multidisciplinary care\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors:\u003c\/strong\u003e Mingdi Zhang, Jing Zhou, Ling Wang\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAffiliations:\u003c\/strong\u003e Department of Breast Surgery, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China; Laboratory for Reproductive Immunology, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China; The Academy of Integrative Medicine of Fudan University, Shanghai, China; Shanghai Key Laboratory of Female Reproductive Endocrine-related Diseases, Shanghai, China\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eJournal:\u003c\/strong\u003e BioScience Trends, 2021; 15(5):276-282. DOI: 10.5582\/bst.2021.01187\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eArticle type:\u003c\/strong\u003e Review\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c\/strong\u003e The original research was supported by grants from the Shanghai Municipal Commission of Health, the Obstetrics and Gynecology Hospital of Fudan University, the Shanghai Municipal Commission for Science and Technology, the Shanghai Natural Science Fund, and the Chinese Association of Integration of Traditional and Western Medicine.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest:\u003c\/strong\u003e The authors declared no conflicts of interest.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eNote: This patient-friendly article is based on peer-reviewed research published in BioScience Trends. It is intended for educational purposes and should not replace individualized medical advice from your healthcare team. Always discuss your specific situation with your doctors.\u003c\/em\u003e\u003c\/p\u003e","brand":"DiagnosticDetectives.Com","offers":[{"title":"Default Title","offer_id":47427812819100,"sku":null,"price":0.0,"currency_code":"EUR","in_stock":true}],"url":"https:\/\/diagnosticdetectives.de\/products\/breast-cancer-and-pregnancy-why-special-considerations-before-treatment-are-essential","provider":"DiagnosticDetectives.Com","version":"1.0","type":"link"}