Management of Soft Tissue Sarcoma in Pregnancy
For pregnant women diagnosed with soft tissue sarcoma, surgery can be safely performed during pregnancy for localized disease, while chemotherapy with single-agent doxorubicin (60-75 mg/m²) should be reserved for the second trimester if metastatic disease requires urgent treatment, and radiation therapy must be deferred until after delivery. 1
Timing of Diagnosis and Initial Assessment
The gestational age at diagnosis fundamentally determines the management strategy:
First trimester diagnosis: If the tumor is localized and does not require immediate intervention, observation until the second trimester is recommended 1. For aggressive disease requiring urgent treatment, pregnancy termination should be discussed 1.
Second trimester diagnosis: This is the optimal window for intervention if treatment cannot be delayed until delivery 1. Surgery can be performed safely, and if systemic therapy is absolutely necessary for metastatic disease, single-agent doxorubicin at 60-75 mg/m² is the recommended regimen 1.
Third trimester diagnosis: If diagnosed late in the third trimester, consider pre-term delivery followed by initiation of full oncologic therapy 1.
Surgical Management During Pregnancy
Surgery remains the primary treatment for localized soft tissue sarcoma and can be performed during pregnancy without significant maternal or fetal risk 2, 3:
Wide excision with tumor-free margins is the standard surgical approach, even during pregnancy 1.
The surgical goal is to remove the tumor with a rim of normal tissue; 1 cm margins are acceptable, though minimal margins at resistant anatomic barriers (muscular fasciae, periosteum, perineurium) are permissible 1.
Two patients in a large cohort were successfully treated with wide excision during pregnancy without adverse outcomes 2.
Most surgical interventions can be safely performed during the second trimester, with nine of 17 cases in one series treated surgically during pregnancy 3.
MRI and ultrasound are safe imaging modalities during pregnancy for surgical planning 4.
Radiation Therapy Considerations
Radiation therapy must be deferred until after delivery due to fetal toxicity concerns 1:
Standard postoperative radiation (50-60 Gy in 1.8-2 Gy fractions) cannot be administered during pregnancy 1.
For high-grade, deep tumors >5 cm that would typically require adjuvant radiation, this component of treatment is postponed until the postpartum period 1.
The delay in radiation therapy does not appear to significantly impact maternal prognosis when surgery achieves adequate margins 2, 3.
Chemotherapy in Pregnancy
Chemotherapy should be avoided in the first trimester and used only when absolutely necessary for metastatic disease in the second trimester 1:
Single-agent doxorubicin (60-75 mg/m²) is the recommended regimen if chemotherapy cannot be deferred 1. This recommendation is based on the overall safety profile of doxorubicin in pregnancy across multiple cancer types.
Avoid combination regimens: While doxorubicin plus ifosfamide has been reported in nine pregnant patients, the limited safety data on ifosfamide and lack of survival advantage over single-agent doxorubicin favor monotherapy 1.
One case report documented successful administration of adriamycin, ifosfamide, and granisetron during the third trimester without remarkable toxicity 4.
Adjuvant chemotherapy should be deferred to the postpartum period whenever possible 3. In the largest cohort study, chemotherapy was consistently deferred until after delivery 3.
Delivery Planning
The mode and timing of delivery should be determined by obstetric indications, not oncologic factors 2, 3:
Vaginal delivery is possible in most cases (9 of 16 deliveries in one series) 2.
Cesarean section should be performed for standard obstetric indications (7 of 16 cases) 2.
Most patients can be delivered at term 3. Early delivery (before 37 weeks) should be considered only when maternal treatment cannot be safely delayed 3.
Three patients in one series required delivery before 37 weeks to proceed with therapy; one neonate at 34 weeks developed respiratory distress syndrome requiring intubation 3.
Prognosis and Outcomes
Soft tissue sarcomas diagnosed during pregnancy do not appear to have worse prognosis compared to non-pregnant patients 2, 3:
Median disease-free survival was 15.1 months and median overall survival was 25.4 months in one cohort, comparable to non-pregnant populations 2.
There were no perinatal or infant deaths in the largest reported series 3.
Three newborns were premature but demonstrated normal growth and development 2.
Maternal deaths occurred only in patients with metastatic disease, not as a consequence of pregnancy itself 3.
Critical Pitfalls to Avoid
Delayed diagnosis is the most common error in managing sarcomas during pregnancy 4:
Any deep soft tissue mass or superficial lesion >5 cm warrants immediate referral to a sarcoma center, even during pregnancy 1.
Clinical misdiagnosis, attribution of symptoms to pregnancy, and patient refusal have all contributed to treatment delays 4.
Core needle biopsy (>16G) under imaging guidance is safe during pregnancy and should not be delayed 4.
Do not automatically defer all treatment until delivery: For localized disease, surgery during the second trimester is safe and may prevent disease progression 2, 3.
Avoid combination chemotherapy regimens: The toxicity profile and lack of survival benefit over single-agent doxorubicin make combination therapy inappropriate during pregnancy 1.
Multidisciplinary Team Requirements
Management requires coordination between sarcoma specialists, maternal-fetal medicine, and neonatology 2, 4:
All cases should be managed at a sarcoma reference center with expertise in pregnancy-associated malignancies 1.
The team must include pathologists, radiologists, surgeons, radiation oncologists, medical oncologists, obstetricians, and neonatologists 1, 2.
Treatment decisions should be tailored individually based on tumor biology, gestational age, and maternal-fetal risk assessment 2.