2002 CTOS Annual Meeting Oral Presentations — Surgery

POSITIVE MARGINS AFTER ATTEMPTED WIDE EXCISION OF A SOFT TISSUE SARCOMA: IS FURTHER EXCISION NECESSARY?
[Abstract ID: 55]

Category: Surgery

Presentation: Oral

Authors: Edward Y. Cheng¹, Kathryn E. Dusenbery¹, Carlos M. Manivel¹, Denis R. Clohisy¹, Keith Skubitz¹, Roby C. Thompson¹

Author Institutions: ¹University of Minnesota Cancer Center, Minnesota, United States

Presenter: Edward Y. Cheng
cheng002@umn.edu

Correspondent: Edward Y. Cheng
cheng002@umn.edu
Minneapolis MN United States 55455
Ph: 612-625-4653
Fax: 612-626-6032

Objectives: When the surgical margin is positive after a planned wide excision, the aims of our study were to discern: 1)Is additional surgical excision or amputation warranted and, 2)If no additional surgery is done, is there a difference in overall survival (OS), continuous disease free survival (CDFS) or local recurrence (LRFS)?

Methods: We performed a review of all patients meeting the inclusion criteria: non-metastatic soft tissue sarcomas (excluding rhabdo), extremity, trunk, retroperitoneum,treatment period 1975 - 1997 @ Univ. Minnesota, age > 13 years. The treatment protocol was: attempted wide local excision, adjuvant radiation when closest margin is marginal, if positive margin identified on pathological analysis, further excision considered if technically possible depending upon size of surgical bed, anatomic location, patient’s desires. Independent pathologist evaluation was performed with surgical margins defined as: Negative (> 2 mm closest margin), Negative (< 2 mm closest margin), Positive-microscopic, Positive-macroscopic (gross tumor remaining), Inadvertent intraop contamination. Patients w/ a positive margin were then compared to those w/ a negative margin using standard survivorship analysis and Cox stepwise regression statistical methods.

Results: The study cohort consisted of 413 patients (180 female, 233 male), mean age 51 yrs, with diagnoses liposarcoma (104), MFH (142), synovial sarcoma (44), other sarcoma (123). Tumor grades were low (50), intermediate(53), & high (254). External beam radiation, mean dose 5688 cGy, was given preoperatively w/ postop boost to 112 (27%)patients & postoperatively only to 170 (41%) patients. No radiation was given to 131 (32%) patients. There was no difference in 5 yr OS between the positive vs. negative margin group, 76% vs. 61% (p=0.4), respectively. There was no difference in 5 yr CDFS between the positive vs. negative margin group, 61% vs. 68% (p=0.21), respectively. There was a statistical difference in 5 yr LRFS with the negative margin group being higher, 88% vs. 75% (p=0.02). The influence of grade and margin revealed that for LRFS, positive margin was a risk factor (p=0.02) but grade was not. For both CDFS and OS, grade was a risk factor (p=0.01 and 0.04, respectively) but margin status was not. Among only low grade tumors there was no diff in OS, CDFS or LRFS comparing the positive vs. negative margin groups. Among only high grade tumors, there was a diff in LRFS (p=0.002) and CDFS (p=0.049) but not OS.

Conclusions: We conclude a positive margin is associated with a higher risk of local relapse but not necessarily survival. When a positive surgical margin is sustained after a planned attempt at wide excision, additional surgery is not warranted for low grade tumors. For high grade tumors, CDFS but not OS is shorter when a positive margin occurs and therefore, it is uncertain if this is significant enough to warrant additional ablative surgery or amputation.