Locoregional disease patterns in well-differentiated and dedifferentiated retroperitoneal liposarcoma: implications for the extent of resection?
BACKGROUND
Well-differentiated (WD)/dedifferentiated (DD) liposarcoma is the most common soft tissue sarcoma of the retroperitoneum. The frequency of distant metastasis is low and the major burden of disease is locoregional. We sought to define the patterns of locoregional disease to help guide surgical decision making.


METHODS
Data were collected from 247 patients with de novo or recurrent tumors treated at our institution from 1993 to early 2012. The number and location of tumors at both initial presentation and subsequent locoregional recurrence were determined by combined analysis of operative dictations and radiologic imaging.


RESULTS
Thirty-four percent of patients had multifocal locoregional disease (two or more tumors) at initial presentation to our institution, including 9 % who had tumors at synchronous remote retroperitoneal sites. The impact of multifocal disease on overall survival was dependent on histologic subtype (WD vs. DD) and disease presentation (de novo vs. recurrence) at the time of resection. Among patients with initial unifocal disease, 57 % progressed to multifocal locoregional disease with subsequent recurrence, including 11 % with new tumors outside of the original resection field. No clinicopathologic or treatment-related variable, including the type or extent of resection, was predictive of either multifocal or 'outside field' progression.


CONCLUSIONS
Multifocal disease is common in patients with WD/DD retroperitoneal liposarcoma, and tumors can also develop at remote, locoregional sites. Surgical resection remains the primary method of locoregional control in this disease; however, the aggressiveness of resection should be individualized, with consideration of both tumor and patient-related factors.
Department of Surgical Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA.
William W
WW
Tseng
John E
JE
Madewell
Wei
W
Wei
Neeta
N
Somaiah
Alexander J
AJ
Lazar
Markus P
MP
Ghadimi
Aviad
A
Hoffman
Peter W T
PW
Pisters
Dina C
DC
Lev
Raphael E
RE
Pollock
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002454:Cell Differentiation; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008080:Liposarcoma / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D012186:Retroperitoneal Neoplasms / Q000473:pathology* / Q000601:surgery; D055815:Young Adult