Sachin Patil1*, Sean Senozan1,2, Boram Ji3 and Ronald S Chamberlain4
1Department of Surgery, Ascension Providence Hospital, Southfield, MI, Netherlands
2American University of the Caribbean School of Medicine, St. Maarten, Netherlands
3Saint George’s University School of Medicine, Grenada, West Indies
4Department of Surgery, Banner Health, Gilbert, AZ, USA
Introduction: Lipomatous neoplasms account for approximately 50% of soft tissue tumors with well-differentiated liposarcoma (WDL) being the most common histological subtype. WDL are lowgrade neoplasms with low propensity for local recurrence and metastasis. Surgery is the primary treatment and the role of radiation therapy is highly debated for this subtype. This study compares demographic, clinical characters, and the impact of radiation therapy on the long-term survival of extremity (EX) versus retroperitoneal (RP) WDL.
Materials and Methods: 1,358 patients with EX and RP WDL were identified in the Surveillance Epidemiology and End Results (SEER) database (1973-2008) and analyzed for age, gender, race, stage, surgical treatment, radiation therapy, and long-term survival. Chisquare test was used to compare categorical data and the Student’s t test was used for continuous data. Kaplan Meier survival analysis was performed to examine the impact of surgery and radiation therapy on longterm actuarial survival.Mantel-Cox log rank test was used to establish statistical significance. Data analysis was performed using SPSS version 20.0 (SPSS, Inc.).
Results: The mean age at WDL diagnosis was 61.4 ± 14.5 years for both groups. There was no Male: Female difference overall or between primary sites (p = 0.6). EX WDL were more common in non-whites compared to RP WDL (p< 0.001). The majority of patients in both primary sites had localized disease however, regional spread and distant metastasis was more common in RP WDL (p= 0.001). Surgery was performed in 95% of all WDL patients though slightly more commonly for EX WDL (p= 0.001).Radiation therapy was used in 19.1% of all patients, and substantially higher percentage of EX WDL (p = 0.02). Mean survival was higher and mortality rates were lower in EX WDL compared to RP WDL (p = 0.01). 5-year survival rates were 34% for both RP and EX WDL, while the10-year mortality rate was 8% for RP and 6% for EX WDL. Multivariate analysis identified age at diagnosis (Odds Ratio [OR] = 2.9), no surgery (OR = 5.4), and RP WDL (OR = 2.4) as associated with increased mortality.
Conclusion: RP WDL occurs more commonly in younger patients and whites, have a higher rate of metastasis, and are associated with a worse overall survival compared to EX WDL. Increased age at presentation, RP location, and failure to perform surgery are associated with increased mortality among all WDL patients. The addition of radiation therapy did not improve median survival in either the EX or RP WDL patient subgroups.
Well-differentiated liposarcoma; Radiation therapy; Outcomes
Patil S, xSenozan S, Ji B, Chamberlain RS. Well-Differentiated Extremity and Retroperitoneal Liposarcoma: A Population based Outcomes Study.Surg Oncol Clin Pract J. 2018;2(1):1007.