Definition
A.Sarcomas are divided into two broad categories.
1.Soft tissue sarcoma.
2.Bone sarcoma.
B.Soft tissues include adipose, muscle, tendinous, fibrous, and vascular tissues, and there are approximately 60 subtypes of soft tissue sarcoma. Examples include:
1.Osteosarcoma.
2.Ewing’s sarcoma.
3.Liposarcoma.
4.Rhabdomyosarcoma.
5.Leiomyosarcomas.
Incidence
A.In 2016, there was an estimated 12,310 new cases of soft tissue sarcomas and 4,990 patients died of the disease.
B.In 2016, there was an estimated 3,260 new cases of bone sarcomas and 1,550 patients died of the disease.
C.Although very rare in adults, sarcomas comprise ∼15% of all pediatric cancers.
D.Males are affected more frequently than females.
Pathogenesis
A.Sarcomas, as with many cancers, are often associated with cytogenetic abnormalities or molecular mutations.
B.Sarcomas have a wide range of clinical behaviors and outcomes depending on the subtype and extent of disease.
C.Expert pathological review is necessary to determine the specific subtype. Differentiation patterns can be difficult to ascertain, as there are approximately 60 different histologic subtypes.
D.Classification of sarcomas depends on tissue appearance, histologic grade, and cell of origin.
Predisposing Factors
A.Genetic factors.
B.Exposure to radiation.
C.Exposure to chemical carcinogens (e.g., Agent Orange or polyvinyl chloride).
Subjective Data
A.Common complaints/symptoms.
1.Sarcomas can occur in any anatomic area: About 46% occur in lower extremities, 18% occur in the torso, 13% occur in the upper extremities, 13% occur in the retroperitoneum, and 9% occur in the head and neck.
2.The clinical presentation depends on the tumor’s location.
3.Patients often present with:
a.Swelling.
b.Palpable soft tissue or bone mass.
c.Sometimes pain.
4.Patients may present with:
a.Constitutional symptoms such as fever, weight loss, and night sweats.
b.Neurological symptoms if there is involved nerve compression.
5.Patients with a mass increasing in size or a mass greater than 5 cm should undergo evaluation for possible sarcoma with imaging (x-rays, CT, and/or MRI).
Physical Examination
A.Vital signs.
B.Musculoskeletal: Evaluate location, size, and mobility of palpable mass.
C.Neurological: Assess for any sensory/motor deficits, gait abnormality, and strength.
D.Evaluate for metastatic disease.
1.Lymphatics: Assess for adenopathy.
2.Cough: Assess for metastatic spread to the lung.
3.Ascites: Retroperitoneal sarcomas can metastasize to the liver producing fluid wave.
Diagnostic Tests
A.General plan.
1.Imaging.
a.CT or MRI for suspected soft tissue sarcoma.
b.Conventional x-ray imaging should be performed for suspected bone sarcoma followed by CT and/or MRI.
c.Consider PET scan.
2.Biopsy.
a.Definitive diagnosis is based on biopsy of the mass. Core needle biopsy is typically sufficient to make an accurate diagnosis.
b.Fine needle aspiration (FNA) is not recommended.
3.Molecular/cytogenetic markers.
4.Metastatic evaluation.
a.May include MRI with gadolinium to evaluate for bone metastasis.
b.CT of the chest and/or abdomen to assess for lung or liver metastasis.
c.Consider whole body PET.
B.Staging.
1.Complete staging includes chest x-ray, CT scan of the chest, and bone scan to assess for metastatic disease.
2.For Ewing sarcoma, an MRI of the spine should be performed to assess for bone marrow metastases.
3.Soft tissue sarcomas (except retroperitoneal sarcomas): The tumor, node, metastasis (TNM) staging system is used.
4.Bone sarcomas: The Musculoskeletal Tumor Society (MSTS) staging system is used.
Differential Diagnosis
A.Lipoma.
B.Carcinoma.
C.Neuroma.
Evaluation and Management Plan
A.General plan.
1.Treatment and prognosis vary depending on the subtype, location, and extent of disease.
2.Therapy includes a combination of systemic therapy, radiation, surgery, and in some cases targeted therapy.
3.For localized sarcomas, surgical excision is the mainstay of treatment.
4.For metastatic disease, unresectable disease, large tumors (>5 cm), and tumors that are located in deeper tissues or have visceral involvement, systemic chemotherapy +/− radiation is often given followed by debulking surgery if indicated.
5.Chemosensitivity and choice of treatment differs based on histologic subtype.
B.Acute care issues in sarcoma.
1.Local surgical resections can be attempted as outpatient.
2.Patients are usually admitted for extensive debulking or cytoreductive surgery or chemotherapy.
3.Postoperative management usually focuses on pain control, wound care, pulmonary toileting, and early ambulation.
4.Complex aggressive chemotherapy usually requires inpatient admission.
a.High-dose chemotherapeutic combinations are employed depending on the type of sarcoma.
b.Two-dimensional echocardiography.
c.Routine blood work including electrolyte panel, blood urea nitrogen (BUN), and creatinine must be monitored for electrolyte imbalance/need for replacement and kidney function.
Follow-Up
A.Complete within first 6 weeks.
B.Surveillance in first year should occur at 3 months, 6 months, and then annually.
C.If patients have higher grade cancer, more frequent visits should be scheduled. An MRI of the primary site may be indicated.
Consultation/Referral
A.Referrals for patients with suspected sarcoma should be referred to a cancer center so they can be followed by a surgical oncologist, medical oncologist, and radiation oncologist.
B.Orthopedics should be consulted as well.
Special/Geriatric Considerations
A.Sarcomas are rare, but malignant tumors. Elderly patients are more often diagnosed with high stage sarcomas and have a higher mortality rate.
Bibliography
Lawrence, W., Jr., Donegan, W. L., Natarajan, N., Mettlin, C., Beart, R., & Winchester, D. (1987). Adult soft tissue sarcomas. A pattern of care survey of the American College of Surgeons. Annals of Surgery, 205(4), 349–359.
National Cancer Institute. (2016, September 12). Surveillance, epidemiology, and end results program. Retrieved from https://seer.cancer.gov/faststats/selections.php?series=cancer