www.hpboardreview.com Hematology-Oncology Volume 12, Part 1 37
Soft Tissue Sarcoma: Diagnosis and Treatment
mining the TNM staging for 117 patients. They
found that conventional imaging correctly classified 77% of patients, PET alone correctly classified 70%, PET/CT correctly classified 83%,
and PET/CT combined with conventional imaging correctly staged 87%. 22
•;Which;subtypes;are;most;likely;to;metastasize?
Although the vast majority of sarcomas spread
hematogenously, 3 have a propensity to spread
lymphogenously: epithelioid sarcoma, rhabdomyosarcoma, and clear-cell sarcoma. Additionally,
certain subtypes are more likely to metastasize:
leiomyosarcomas, synovial sarcomas, neurogenic
sarcomas, rhabdomyosarcomas, and epithelioid
sarcomas. 23 Sarcomas metastasize to the lungs
more frequently than to the liver. The metastatic
pattern is defined primarily by sarcoma subtype
and site of primary tumor. Sarcomas rarely metastasize to the brain (~1%).
MANAGEMENT
CASE CONTINUED
The patient undergoes an ultrasound to better visualize the mass. Given the heterogeneous
character of the mass, he is referred for an MRI
to evaluate the mass and a CT scan of the chest,
abdomen, and pelvis to evaluate for distant
metastases. MRI reveals a 5. 1 cm × 4. 6 cm heterogeneous mass invading the superficial fascia
of the rectus femoris muscle. No suspicious
lymph nodes or other masses are identified on
imaging. The patient next undergoes an image-guided core needle biopsy. Pathology from that
procedure is consistent with a stage III, T2b-
NxMx, grade 3, dedifferentiated liposarcoma.
•;What;is;the;best;management;approach;for
this patient?
SURGERY
Surgery is the mainstay of treatment for STS.
Patients with the best prognosis are those who
undergo complete resection with negative sur-
gical margins. 24, 25 Goal tumor-free margin is 1
to 3 cm. 26 Complete resection confers the best
long-term survival. Both local and metastatic
recurrence is higher in patients with incomplete
resection and positive margins. 24, 25 In a study that
analyzed 2084 localized primary STSs, patients
with negative margins had a local recurrence
rate of 15% versus a rate of 28% in patients with
positive margins. This translated into higher
5-year local recurrence-free survival for patients
with negative surgical margins (82%) com-
pared to patients with positive margins (65%). 27
Another study similarly found that patients with
negative margins at referral to their institution
who underwent postoperative radiation had
high local control rates of 93% (95% confi-
dence interval [CI] 87% to 97%) at 5, 10, and
15 years. 26 Although radiation improves local
control, neither preoperative or postoperative
radiation has been shown to improve progres-
sion-free or overall survival. 28 Other factors that
are associated with risk of recurrence are tumor
location, history of previous recurrence, age of
patient, histopathology, tumor grade, and tumor
size. Approximately 40% to 50% of patients with
high-grade tumors (defined as size > 5 cm, deep
location, and high grade) will develop distant
metastases. 29
Zagars et al found that positive or uncertain
resection margin had a relative risk of local recurrence of 2.0 (95% CI 1. 3 to 3. 1; P = 0.002),
and presentation with locally recurrent disease
(vs new tumor) had a relative risk of local recurrence of 2.0 (95% CI 1. 2 to 3. 4; P = 0.013). 26
Patients with STS of head and neck and deep
trunk have higher recurrence rates than those
with superficial trunk and extremity STS. A
single-institution retrospective review demonstrated that patients with completely resectable
retroperitoneal sarcomas have longer median
survival (103 months) compared to patients
with incompletely resected abdominal sarcomas
( 18 months). 25
Rosenberg and colleagues compared ampu-
tation to limb-sparing surgery and radiation. 24